Ball bearing screw is widely used in the dull top secret , but the difference between dull acceptance Ball is certainly not identical , Ka Machinery Co., Ltd. Nantong finishing difference in this ball of application areas :
Rotating Nut (R1) Series Ball : Semiconductor dull, dull industrial people , woodworking machines , laser processing machines, conveying devices.
Precision ground ball screws : CNC dull, Nanjing intermediate precision air conditioning vent thing machines, industrial dull , electronic dull, dull transportation , aerospace industry , the use of other antenna actuator , the valve switching devices.
Ball cap style : Fast handling system, as usual dull industrial automation dull.
Heavy Ball : All-electric injection molding machines, stamping machines, semiconductor manufacturing equipment , heavy-duty brakes, industrial dull , forging dull.
High DN value Ball : High-speed stuff , high-speed integrated processing center machine .
Rolled Ball Screws Level : low friction , smooth operation of the benefits and costs low while agile supply .
High-speed ball screw : CNC rigid , precision stuff machines, industrial dull, dull electronics , high-speed rigid.
2013年8月29日星期四
Ball bearing under way force status classification
Single push thrust bearings are mounted on the ends and ball screw preload . Can improve the axial stiffness of the ball bearing screw ; pre-stretching resettlement , preload large, so screw things only suffer tension. But the essentials of the screw placement is more sensitive to thermal deformation , while bearing life than double push - push-push low . Push- push-push one pair of ends mounted thrust bearing and radial ball bearings portfolio, the screw has a maximum stiffness , which can be used at both ends of the double bearing , thrust bearing and last radial ball bearings, and impose tight top force . The essentials appropriate for high rigidity , high speed, high precision , precision ball screw drive system . However, this arrangement can essentials thermal deformation of the screw into the thrust bearing preload , so plan requires increase the thrust bearing stiffness of the bearing ability and bracket . Double push a simply supported at one end mounted type thrust bearing , a second end attached to the ball bearings , axial stiffness is not too high ; ball out of the use of thermal deformation should be too small and the impact of resettlement should be too small to make heat and screw things when away from the common section at one end mounted thrust bearing , thrust bearing due to restrained thermal elongation and bred gap . pushing a freestyle thrust bearing mounted at one end and the other end unconnected. Its end is the free state, so carrying ability of small , low axial stiffness
2013年8月27日星期二
How to check the appearance of bearing
In the use of cross bearing, we first check the appearance of imported bearings, to determine whether it conforms to the standard we require. Here to share with everyone one that we should check that those parts. Bearings should be checked for astigmatism lamp, the appearance of the bearings, cracks and other parts of careful observation.
1, various mechanical injuries, such as rubs, scratches, bruised, bumps, etc., can cause adverse bearing installation, causing partial load and stress concentration, resulting in a decline in rotation accuracy and service life.
2, rust, black and pits, the latter two are easy to store moisture and dirt defects, the most likely to develop into rust. The corrosion is the cause poor installation, the sources of early wear and fatigue, severe corrosion cause bearing scrap.
3, various cracks, such as raw materials, crack, crack forging, heat treatment and grinding cracks, cracks, these cracks in the future during the operation of the bearing, will be a source of stress concentration and rapid expansion, resulting in rupture of the bearing of the bearing life and safety at work of great impact. In fact, for the important purpose bearings, bearing factory has 100% of its constituent parts or ray magnetic particle inspection.
4, peeling and folding, these two defective part and base metal binding is not strong, and its surroundings often exist to varying degrees, or depleted carbon decarburization phenomenon, materials easy caving, debossing or wear of the bearing life and accuracy are negative.
5, riveted or welded cage quality rivet head is mainly observed deviation, skew, relaxation, lack of meat or 'eyelid', the correct position of the welding, solder joint is too large or too small, whether strong or welding welding caused by excessive stuck rolling phenomenon more than a few that we focus on checking SKF bearings in part inspection, in addition to other than the part of the inspection, in addition to poor quality such as typing, such as illegible, damaged, shall be considered as defective, In severe cases, can not be accepted.
1, various mechanical injuries, such as rubs, scratches, bruised, bumps, etc., can cause adverse bearing installation, causing partial load and stress concentration, resulting in a decline in rotation accuracy and service life.
2, rust, black and pits, the latter two are easy to store moisture and dirt defects, the most likely to develop into rust. The corrosion is the cause poor installation, the sources of early wear and fatigue, severe corrosion cause bearing scrap.
3, various cracks, such as raw materials, crack, crack forging, heat treatment and grinding cracks, cracks, these cracks in the future during the operation of the bearing, will be a source of stress concentration and rapid expansion, resulting in rupture of the bearing of the bearing life and safety at work of great impact. In fact, for the important purpose bearings, bearing factory has 100% of its constituent parts or ray magnetic particle inspection.
4, peeling and folding, these two defective part and base metal binding is not strong, and its surroundings often exist to varying degrees, or depleted carbon decarburization phenomenon, materials easy caving, debossing or wear of the bearing life and accuracy are negative.
5, riveted or welded cage quality rivet head is mainly observed deviation, skew, relaxation, lack of meat or 'eyelid', the correct position of the welding, solder joint is too large or too small, whether strong or welding welding caused by excessive stuck rolling phenomenon more than a few that we focus on checking SKF bearings in part inspection, in addition to other than the part of the inspection, in addition to poor quality such as typing, such as illegible, damaged, shall be considered as defective, In severe cases, can not be accepted.
Requirements for machine tool spindle bearings
In the machine tool bearings, bearings is widely used. Spindle bearing with certain technical requirements. Introduce to you the following analysis
1 speed and temperature
With the development of science and technology, more and more high spindle speed, speed range and thus the greater the deep groove ball bearing high speed stability requirements are also increasing. Machine tool spindle bearing temperature is an important factor in limiting speed of the bearing. Under normal circumstances, the right choice bearing type, tolerance levels, configuration, clearance (preload) size, lubricants and lubrication, etc., to a certain extent, improve the speed performance of rolling bearings.
(2) carrying capacity and life
The general machine tool, the life of the main spindle assembly to maintain accuracy of the spindle is its period of use, therefore, required to maintain the accuracy bearing spindle assembly performance to meet life requirements. For heavy-duty machine tools or powerful cutting machine, you should first consider the bearing capacity.
3 stiffness and vibration resistance
To ensure the quality of the machining, the spindle system must have sufficient rigidity, otherwise it will have a greater re-mapping error even flutter. Vibration resistance refers to the forced vibration and self-excited vibration capability. Spindle assembly vibration resistance depends on the spindle and bearing stiffness and damping. Using the preload bearing can effectively increase the stiffness of the spindle system.
4 Noise
In high-speed grinder, the grinding noise and bearing noise is the main ingredient should be used in low-noise rolling bearings.
1 speed and temperature
With the development of science and technology, more and more high spindle speed, speed range and thus the greater the deep groove ball bearing high speed stability requirements are also increasing. Machine tool spindle bearing temperature is an important factor in limiting speed of the bearing. Under normal circumstances, the right choice bearing type, tolerance levels, configuration, clearance (preload) size, lubricants and lubrication, etc., to a certain extent, improve the speed performance of rolling bearings.
(2) carrying capacity and life
The general machine tool, the life of the main spindle assembly to maintain accuracy of the spindle is its period of use, therefore, required to maintain the accuracy bearing spindle assembly performance to meet life requirements. For heavy-duty machine tools or powerful cutting machine, you should first consider the bearing capacity.
3 stiffness and vibration resistance
To ensure the quality of the machining, the spindle system must have sufficient rigidity, otherwise it will have a greater re-mapping error even flutter. Vibration resistance refers to the forced vibration and self-excited vibration capability. Spindle assembly vibration resistance depends on the spindle and bearing stiffness and damping. Using the preload bearing can effectively increase the stiffness of the spindle system.
4 Noise
In high-speed grinder, the grinding noise and bearing noise is the main ingredient should be used in low-noise rolling bearings.
2013年8月24日星期六
Vibration bearing vibration group selection
Vibration bearings and plain bearings of the different characteristics
1, Appearance Features
Vibration bearings:
A. rolling diameter increased, the rolling body length increased.
B. outer rib cage guided by the roller, the roller to reduce the force.
C. Use of the inner wall to guide roller, roller improve functioning.
D. cylindrical roller bearing cage with the overall structure, strength greatly increased.
E. aligning bearing hole diameter tank design, lubrication effect.
Plain bearings:
A. roller bearing diameter and length of the rolling elements are small.
B. cage with rollers or inner guidance.
C. Cylindrical roller bearing cage using rivet structure, easy to loose, out cover.
D. aligning bearing no sump hole diameter, lubrication poor results.
2, the choice of materials
Vibration bearings:
A. inner and outer rings and rolling bearing steel vacuum degassing, good fatigue resistance.
B. cage aluminum manganese bronze material, high strength, good elasticity, abrasion resistance better.
Plain bearings:
A. inner and outer rings and rolling with common bearing steel.
B. cage made of zinc brass, low strength, poor flexibility.
3, heat treatment
Vibration bearings:
A. inner and outer rings using shell - Ma Ma mixed hardening or quenching and tempering, uniform hardness, internal stress; toughness, shock and vibration.
B. In the temperature less than 150C when working stability.
Plain bearings:
Inner and outer rings using ordinary quenching method, poor toughness, shock and vibration performance is poor, poor thermal stability.
4, tolerances and manufacturing process
Vibration bearings:
A. strict accordance with the P6 class precision manufacturing standards, especially in inner diameter tolerance is very small.
B. ball size ≤ 0.002 Difference
C. Cylindrical roller diameter of a convexity practice, to avoid stress concentration.
D. rolling surface ultra-precision processing, smooth finish.
Plain bearings:
A. General PO level precision tolerances (part P6 class standard) manufacturing.
B. rolling grouping ≤ 0.005.
C. Cylindrical Roller without convexity practice.
D. Part raceway only for polished finish low.
5, the internal clearance
Vibration bearings:
Clearance by mechanical vibration requirements of production, range control in a small range, and good consistency.
Plain bearings:
Clearance generally based on the standard group or group C3 production, clearance, or small, or range, discreteness.
6, using the results
Vibration bearings:
Low noise, low temperature rise, good stability, long life, no early fatigue.
Plain bearings:
Noise, temperature rise, stability is not good, life is short, there is the phenomenon of early fatigue.
Bearing vibration group selection
With the bearing manufacturing technology has improved continuously, reflecting the dynamic performance of the bearing vibration and noise are increasingly valued by the people. Users of the bearing vibration and noise awareness of the technical characteristics are also increasingly sensitive requirements are also increasing.
Bearing vibration refers to the geometric center of the bearing part is the instantaneous deviation from an ideal position moves, bearing parts with time-varying elastic deformation, and other rotary motion bearing all the movements necessary, known bearing vibration.
For a single bearing vibration testing, currently using two units of measurement. One for Acceleration, which is measured in decibels (dB), category code Z1, Z2, Z3; another type of speed, which is measured in microns / second (um / s), group codenamed ZV1 , ZV2, ZV3. These flags bearing vibration group bearing the supplementary code into basic code on the right.
Bearing vibration and noise are closely related, because the vibration source of the noise, the noise is vibration characterization, so in bearing manufacturing and testing process, through strict control of the bearing vibration value targets, to achieve the purpose of bearing noise control.
In the choice of bearing vibration constituencies, must be based on the specific use of the bearing conditions. If the host for smooth operation have special requirements, you should choose more appropriate bearing vibration group to meet and achieve the smooth operation of its provisions, such as machine tool spindles. Of the bearing vibration and noise are a requirement, such as cars and aircraft, the same should be used in the corresponding bearing vibration groups in order to achieve the requirements. The noise of the bearing with special requirements, such as electric fans and some other appliances should be used with low noise bearings, in order to meet the requirements.
The main factors affecting bearing vibration
By the bearing structural design parameters determined by stiffness, flexibility, quality, and damping vibration system constituted under the operating conditions will produce adapt to its mechanical vibrations.
Manufacturing process of the deviation caused by vibration, the smaller the deviation, vibration is smaller. Surface of the ball roundness, waviness, surface roughness of the bearing part of the most influential factor of vibration, followed by the inner and outer shape of the channel error and surface roughness, cleanliness and again is the bearing lubricant quality.
Operating conditions, such as installation conditions, speed, direction of the axial load borne by, for money.
1, Appearance Features
Vibration bearings:
A. rolling diameter increased, the rolling body length increased.
B. outer rib cage guided by the roller, the roller to reduce the force.
C. Use of the inner wall to guide roller, roller improve functioning.
D. cylindrical roller bearing cage with the overall structure, strength greatly increased.
E. aligning bearing hole diameter tank design, lubrication effect.
Plain bearings:
A. roller bearing diameter and length of the rolling elements are small.
B. cage with rollers or inner guidance.
C. Cylindrical roller bearing cage using rivet structure, easy to loose, out cover.
D. aligning bearing no sump hole diameter, lubrication poor results.
2, the choice of materials
Vibration bearings:
A. inner and outer rings and rolling bearing steel vacuum degassing, good fatigue resistance.
B. cage aluminum manganese bronze material, high strength, good elasticity, abrasion resistance better.
Plain bearings:
A. inner and outer rings and rolling with common bearing steel.
B. cage made of zinc brass, low strength, poor flexibility.
3, heat treatment
Vibration bearings:
A. inner and outer rings using shell - Ma Ma mixed hardening or quenching and tempering, uniform hardness, internal stress; toughness, shock and vibration.
B. In the temperature less than 150C when working stability.
Plain bearings:
Inner and outer rings using ordinary quenching method, poor toughness, shock and vibration performance is poor, poor thermal stability.
4, tolerances and manufacturing process
Vibration bearings:
A. strict accordance with the P6 class precision manufacturing standards, especially in inner diameter tolerance is very small.
B. ball size ≤ 0.002 Difference
C. Cylindrical roller diameter of a convexity practice, to avoid stress concentration.
D. rolling surface ultra-precision processing, smooth finish.
Plain bearings:
A. General PO level precision tolerances (part P6 class standard) manufacturing.
B. rolling grouping ≤ 0.005.
C. Cylindrical Roller without convexity practice.
D. Part raceway only for polished finish low.
5, the internal clearance
Vibration bearings:
Clearance by mechanical vibration requirements of production, range control in a small range, and good consistency.
Plain bearings:
Clearance generally based on the standard group or group C3 production, clearance, or small, or range, discreteness.
6, using the results
Vibration bearings:
Low noise, low temperature rise, good stability, long life, no early fatigue.
Plain bearings:
Noise, temperature rise, stability is not good, life is short, there is the phenomenon of early fatigue.
Bearing vibration group selection
With the bearing manufacturing technology has improved continuously, reflecting the dynamic performance of the bearing vibration and noise are increasingly valued by the people. Users of the bearing vibration and noise awareness of the technical characteristics are also increasingly sensitive requirements are also increasing.
Bearing vibration refers to the geometric center of the bearing part is the instantaneous deviation from an ideal position moves, bearing parts with time-varying elastic deformation, and other rotary motion bearing all the movements necessary, known bearing vibration.
For a single bearing vibration testing, currently using two units of measurement. One for Acceleration, which is measured in decibels (dB), category code Z1, Z2, Z3; another type of speed, which is measured in microns / second (um / s), group codenamed ZV1 , ZV2, ZV3. These flags bearing vibration group bearing the supplementary code into basic code on the right.
Bearing vibration and noise are closely related, because the vibration source of the noise, the noise is vibration characterization, so in bearing manufacturing and testing process, through strict control of the bearing vibration value targets, to achieve the purpose of bearing noise control.
In the choice of bearing vibration constituencies, must be based on the specific use of the bearing conditions. If the host for smooth operation have special requirements, you should choose more appropriate bearing vibration group to meet and achieve the smooth operation of its provisions, such as machine tool spindles. Of the bearing vibration and noise are a requirement, such as cars and aircraft, the same should be used in the corresponding bearing vibration groups in order to achieve the requirements. The noise of the bearing with special requirements, such as electric fans and some other appliances should be used with low noise bearings, in order to meet the requirements.
The main factors affecting bearing vibration
By the bearing structural design parameters determined by stiffness, flexibility, quality, and damping vibration system constituted under the operating conditions will produce adapt to its mechanical vibrations.
Manufacturing process of the deviation caused by vibration, the smaller the deviation, vibration is smaller. Surface of the ball roundness, waviness, surface roughness of the bearing part of the most influential factor of vibration, followed by the inner and outer shape of the channel error and surface roughness, cleanliness and again is the bearing lubricant quality.
Operating conditions, such as installation conditions, speed, direction of the axial load borne by, for money.
High-speed bearings during installation and fit issues to consider when
A high speed bearings fit and clearance according to both the high-speed bearing requirements, but also according to temperature bearing requirements, so consider the coordination and clearance to take account of the following points:
(1) when the temperature rose to high temperature dimensional change and hardness;
(2) high speed, the centrifugal force caused by the force system change and shape change.
In short, high-speed, high-temperature conditions, coordination and clearance from the choice of motor bearings should strive to maintain the accuracy and performance.
In order to ensure the bearing raceway after installation of small deformation, interference fit amount of interference can not get too big, and high speed centrifugal force and high temperature thermal expansion, or offset with the surface normal pressure. Or so with the surface relaxation, so the amount of interference must be considered under the premise of these two factors to be carefully calculated, at room temperature under constant speed and effective amount of interference for high-speed bearings may be invalid.
In considering the high speed motor bearing clearance only to consider the above factors, but also to consider the axis thermal expansion effects on the bearing clearance, bearing in working condition requires that there is at operating temperature optimum clearance, and this clearance is taken into account, the outer ring ball groove center precise alignment of state formation. As high-speed bearings for lower relative sliding and internal friction, it is best not to use the inner and outer rings relative axial displacement method to adjust the ball bearing clearance.
In considering the amount of interference with the bearing and clearance, to note that materials at high temperatures becomes soft and easily deformed features, as well as many from the room temperature to high temperature changes cause some permanent deformation possibilities.
(2) the requirement for host-related parts
Where high-speed rotary motor bearings bearing system requires precision dynamic balancing shaft and the bearing seat hole installation site should have a higher than normal requirements of dimensional accuracy and geometrical precision, especially for concentricity and retaining shoulder seat hole or journal the vertical, and in consideration of these issues, it must also be noted that the high-speed operation of the bearing elements and high-temperature factor.
(1) when the temperature rose to high temperature dimensional change and hardness;
(2) high speed, the centrifugal force caused by the force system change and shape change.
In short, high-speed, high-temperature conditions, coordination and clearance from the choice of motor bearings should strive to maintain the accuracy and performance.
In order to ensure the bearing raceway after installation of small deformation, interference fit amount of interference can not get too big, and high speed centrifugal force and high temperature thermal expansion, or offset with the surface normal pressure. Or so with the surface relaxation, so the amount of interference must be considered under the premise of these two factors to be carefully calculated, at room temperature under constant speed and effective amount of interference for high-speed bearings may be invalid.
In considering the high speed motor bearing clearance only to consider the above factors, but also to consider the axis thermal expansion effects on the bearing clearance, bearing in working condition requires that there is at operating temperature optimum clearance, and this clearance is taken into account, the outer ring ball groove center precise alignment of state formation. As high-speed bearings for lower relative sliding and internal friction, it is best not to use the inner and outer rings relative axial displacement method to adjust the ball bearing clearance.
In considering the amount of interference with the bearing and clearance, to note that materials at high temperatures becomes soft and easily deformed features, as well as many from the room temperature to high temperature changes cause some permanent deformation possibilities.
(2) the requirement for host-related parts
Where high-speed rotary motor bearings bearing system requires precision dynamic balancing shaft and the bearing seat hole installation site should have a higher than normal requirements of dimensional accuracy and geometrical precision, especially for concentricity and retaining shoulder seat hole or journal the vertical, and in consideration of these issues, it must also be noted that the high-speed operation of the bearing elements and high-temperature factor.
2013年8月23日星期五
Crossed roller bearings isolation block design defects and improvement
Crossed roller bearings known as cross roller bearings, cylindrical roller generally use roller or tapered roller in a single raceway cross mutually arranged between the roller and the roller cage or through isolation block interval, with high rotational accuracy, the larger the capacity, the smaller dimensions and a higher rotational speed and rigidity, with a very wide range of uses.
cross roller bearing design flaws and improve it.
1 inside the bearing arrangement of the roller, two adjacent rollers arranged in cross, all arranged in the same direction roller intersects the centerline axis of the rotary bearing, two rollers arranged in a direction opposite to the axis of intersection of the center line of the bearing slewing relative to the plane of the center roller symmetrical.
2 Isolation of existing designs of the defect blocks according to the current design, two cylindrical grooves spacers axis the axis perpendicular to the radial plane spacers are parallel, and in that the projection plane perpendicular to each other. Manufactured using current design method has the advantage of an isolation block with good versatility. As long as the selection of different roller bearing the same specifications, generally can use the same kind of isolation blocks. Spacers is cylindrical, its axis center line tangent to the circle of rollers. However, two adjacent roller axes A and B blocks are not isolated from the axis perpendicular to the radial plane are parallel.
Prime line roller work surface and isolation block cylindrical groove surface pixel lines are not parallel, but inclined at an angle, causing the contact state is not good, affect the bearing rotation flexibility and precision rotation speed is higher, the effect is also more obvious. Therefore, it is necessary to improve the design of the separators, the separators of the roller axis of the cylindrical grooves parallel to the axis, thereby improving the isolation block the cylindrical roller groove surface. The higher the speed, the more obvious the effect.
cross roller bearing design flaws and improve it.
1 inside the bearing arrangement of the roller, two adjacent rollers arranged in cross, all arranged in the same direction roller intersects the centerline axis of the rotary bearing, two rollers arranged in a direction opposite to the axis of intersection of the center line of the bearing slewing relative to the plane of the center roller symmetrical.
2 Isolation of existing designs of the defect blocks according to the current design, two cylindrical grooves spacers axis the axis perpendicular to the radial plane spacers are parallel, and in that the projection plane perpendicular to each other. Manufactured using current design method has the advantage of an isolation block with good versatility. As long as the selection of different roller bearing the same specifications, generally can use the same kind of isolation blocks. Spacers is cylindrical, its axis center line tangent to the circle of rollers. However, two adjacent roller axes A and B blocks are not isolated from the axis perpendicular to the radial plane are parallel.
Prime line roller work surface and isolation block cylindrical groove surface pixel lines are not parallel, but inclined at an angle, causing the contact state is not good, affect the bearing rotation flexibility and precision rotation speed is higher, the effect is also more obvious. Therefore, it is necessary to improve the design of the separators, the separators of the roller axis of the cylindrical grooves parallel to the axis, thereby improving the isolation block the cylindrical roller groove surface. The higher the speed, the more obvious the effect.
Cross roller bearing raceway gears and repair
Commonly used in the manufacture of gears with steel quenched and tempered steel, hardened steel, case hardening steel and nitriding steel. Slightly lower than the strength of forged steel, commonly used in sizes larger gear; poor mechanical properties of gray cast iron can be used for light load of open gear drive; ductile iron can partially replace the steel gears; multi-purpose plastic gear at light load and low noise requirements of the place, with its paired gear generally good thermal conductivity of steel gears. Once the gear wear, how to fix next described in detail.
Crossed roller bearing Gear Repair:
The best way to go is to measure the wear of the ring gear worst damage teeth, the gear module to ensure the same case, by calculating, re-hobbing, negative change of the gear position, the same, the gear unit associated with it The output pinion positive displacement, in order to ensure that the two gears meshing center distance constant, a pair of gears to high displacement. Followed by the corrupted repair worn teeth first with liquid plastic or surfacing and leave allowance, then hobbing to its original size. To ensure that the original transmission parts and spare parts (such as the output pinions, etc.) can be used again, the need to ensure the same gear center distance of tooth repair, using the method of surfacing reprocessing.
Raceway Repair:
Four raceway formed by the diameter of the square cross-section, the diagonal perpendicular to the ground, that is, each raceway by both the overall cross-sectional diameter of the center line of a 45 ° angle, the raceway surface damage is more serious, oval-shaped, with a flange ring and the annular surface dents to the front indicated baselines grinding raceway surface (due to high surface hardness), by measuring the roundness deviation of 3mm, after grinding, measuring hardness, were HRC30 ~ 40, in order to ensure a 45 ° angle, special production model (see figure II) is used to measure angles. Raceway surface-hardening, quenching hardness HRC55 ~ 60. Then again grinding.
Crossed roller bearing Gear Repair:
The best way to go is to measure the wear of the ring gear worst damage teeth, the gear module to ensure the same case, by calculating, re-hobbing, negative change of the gear position, the same, the gear unit associated with it The output pinion positive displacement, in order to ensure that the two gears meshing center distance constant, a pair of gears to high displacement. Followed by the corrupted repair worn teeth first with liquid plastic or surfacing and leave allowance, then hobbing to its original size. To ensure that the original transmission parts and spare parts (such as the output pinions, etc.) can be used again, the need to ensure the same gear center distance of tooth repair, using the method of surfacing reprocessing.
Raceway Repair:
Four raceway formed by the diameter of the square cross-section, the diagonal perpendicular to the ground, that is, each raceway by both the overall cross-sectional diameter of the center line of a 45 ° angle, the raceway surface damage is more serious, oval-shaped, with a flange ring and the annular surface dents to the front indicated baselines grinding raceway surface (due to high surface hardness), by measuring the roundness deviation of 3mm, after grinding, measuring hardness, were HRC30 ~ 40, in order to ensure a 45 ° angle, special production model (see figure II) is used to measure angles. Raceway surface-hardening, quenching hardness HRC55 ~ 60. Then again grinding.
2013年8月22日星期四
Double row deep groove ball bearing wear prevention
Due to wear caused by the amount of material loss referred to wear. This can be by measuring the length, volume, or mass to obtain the change, and accordingly they are called wire wear
Volume, the volume and quality of wear wear.
Double row deep groove ball bearing mainly refers to installation and adjustment factors, use and maintenance, repair and other maintenance meets the technical requirements. According bearing installation, use, maintenance
Care and maintenance of the technical requirements for the operation of the bearings to withstand load, speed, temperature, vibration, noise and lubrication condition monitoring and inspection, hair
Are abnormal immediately find reasons to adjust it back to normal. Installation conditions are the primary factors that one of the factors bearing is often caused by improper installation
Resulting package bearing between the various parts of the stress state changes, bearing in abnormal state of operation and early life of the inner end of the main factors is the knot
Structural design, manufacturing processes and materials quality double row deep groove ball bearings determine the quality of three major factors.
1 improper use bearings.
Cause: The installation, operation, or improper removal may cause deformation or defect in the cage
Recommendation: Use the appropriate operating, installation and removal tool
(2) inadequate lubrication
Reasons: inadequate or improper lubrication may cause abrasions or serious element of the double row deep groove ball bearing deformation
Recommendation: Improved lubrication system, aptly timed to supplement or replace the lubricant
3 rust and corrosion
Cause: Contact with water may cause water pump bearing element pitting and rusting. Rust after injury double row deep groove ball bearings at work may cause spalling
Recommendation: regularly check seals to ensure good sealing effect, correct storage of imported bearings
4 Current
Cause: The rotation is powered may cause grooves or nicks. Double row deep groove ball bearing is stationary, electrically operated Improper grounding can cause minor burns
Recommendation: In the outside of the bearing parts before welding through proper ground connection to reduce or avoid the current through the bearing
5 External materials
Cause: The abrasive particle contamination and debris intrusion may lead bearings face wear, abrasions and depression
Recommendation: Clear intrusive particles and debris, replace the lubricant, check the sealing system
6. Eccentric
Reason: eccentric, inclined or excessive load may result in geometric stress concentration or flaking
Recommendation: precision machining imported bearing and retaining shoulder
Double row deep groove ball bearings after installation, in order to check for proper installation, operation should be checked. Small machines can be rotated by hand to confirm whether the rotation along
Cheong. Check the project due to nick, indentation caused by dysfunctional, because poor installation, mount the torque generated by poor processing unstable, due Tour
Gap is too small, the installation error, caused by seal friction torque is too large and so on. Without exception, you can begin powering.
Volume, the volume and quality of wear wear.
Double row deep groove ball bearing mainly refers to installation and adjustment factors, use and maintenance, repair and other maintenance meets the technical requirements. According bearing installation, use, maintenance
Care and maintenance of the technical requirements for the operation of the bearings to withstand load, speed, temperature, vibration, noise and lubrication condition monitoring and inspection, hair
Are abnormal immediately find reasons to adjust it back to normal. Installation conditions are the primary factors that one of the factors bearing is often caused by improper installation
Resulting package bearing between the various parts of the stress state changes, bearing in abnormal state of operation and early life of the inner end of the main factors is the knot
Structural design, manufacturing processes and materials quality double row deep groove ball bearings determine the quality of three major factors.
1 improper use bearings.
Cause: The installation, operation, or improper removal may cause deformation or defect in the cage
Recommendation: Use the appropriate operating, installation and removal tool
(2) inadequate lubrication
Reasons: inadequate or improper lubrication may cause abrasions or serious element of the double row deep groove ball bearing deformation
Recommendation: Improved lubrication system, aptly timed to supplement or replace the lubricant
3 rust and corrosion
Cause: Contact with water may cause water pump bearing element pitting and rusting. Rust after injury double row deep groove ball bearings at work may cause spalling
Recommendation: regularly check seals to ensure good sealing effect, correct storage of imported bearings
4 Current
Cause: The rotation is powered may cause grooves or nicks. Double row deep groove ball bearing is stationary, electrically operated Improper grounding can cause minor burns
Recommendation: In the outside of the bearing parts before welding through proper ground connection to reduce or avoid the current through the bearing
5 External materials
Cause: The abrasive particle contamination and debris intrusion may lead bearings face wear, abrasions and depression
Recommendation: Clear intrusive particles and debris, replace the lubricant, check the sealing system
6. Eccentric
Reason: eccentric, inclined or excessive load may result in geometric stress concentration or flaking
Recommendation: precision machining imported bearing and retaining shoulder
Double row deep groove ball bearings after installation, in order to check for proper installation, operation should be checked. Small machines can be rotated by hand to confirm whether the rotation along
Cheong. Check the project due to nick, indentation caused by dysfunctional, because poor installation, mount the torque generated by poor processing unstable, due Tour
Gap is too small, the installation error, caused by seal friction torque is too large and so on. Without exception, you can begin powering.
For bearing clearance and rolling material issues
Effective clearance or clearance work is called rolling installed in the host after a certain load, up to a certain temperature stable operation mode, scroll
The actual presence of the bearing clearance. Obviously, the effective clearance smaller than the clearance work. The original rolling bearing clearance is complete after installation in front of the machine,
Located in a free state clearance. In fact the original clearance by measuring it is difficult not learned. So that the original clearance clearance inspection is often used instead.
roll bearings and rolling elements typically use high carbon chromium bearing steel. Most of the bearing steel in the JIS SUJ2. Large bearings SUJ3. SUJ2 of
Chemical composition, in the world, as the imported bearings material has been normalized. For example: With AISL52100 (United States), DIN100Cr6 (Germany),
BS535A99 (UK), etc. are the same kinds of steel.
Rolling bearing rings and rolling elements, side repeatedly withstand high contact pressure, sliding along one side of the rolling contact. Retainer rings and roll with one side
Moving body on both sides, or one side sliding contact side under tension and compression forces. Therefore, the bearing rings, rolling elements and cage materials, performance,
Main requirements imports bearing rings, rolling material required performance: rolling fatigue strength, high hardness, high wear resistance.
The actual presence of the bearing clearance. Obviously, the effective clearance smaller than the clearance work. The original rolling bearing clearance is complete after installation in front of the machine,
Located in a free state clearance. In fact the original clearance by measuring it is difficult not learned. So that the original clearance clearance inspection is often used instead.
roll bearings and rolling elements typically use high carbon chromium bearing steel. Most of the bearing steel in the JIS SUJ2. Large bearings SUJ3. SUJ2 of
Chemical composition, in the world, as the imported bearings material has been normalized. For example: With AISL52100 (United States), DIN100Cr6 (Germany),
BS535A99 (UK), etc. are the same kinds of steel.
Rolling bearing rings and rolling elements, side repeatedly withstand high contact pressure, sliding along one side of the rolling contact. Retainer rings and roll with one side
Moving body on both sides, or one side sliding contact side under tension and compression forces. Therefore, the bearing rings, rolling elements and cage materials, performance,
Main requirements imports bearing rings, rolling material required performance: rolling fatigue strength, high hardness, high wear resistance.
2013年8月21日星期三
Reasonable installation location slewing soft zone
Manufacturing process due to slewing bearing inevitably produce a soft zone, which requires the use and selection of slewing device user to install its software with a reasonable position to improve bearing life. The general principle is to try to be flexible with position mounted slewing small changes in load and carry the force minimum position.
Usually turn on the device with mounting ring soft pitching rotation perpendicular to the surface projection line location, such as loading, or stacker-reclaimer slewing ring soft tape on the device to be installed perpendicular to the centerline of the cantilever cutting through the center of the rotation , which stands on the center of rotation of the left or right side face of the cantilever 90 degree position.
The mechanical design is usually soft belt at this position does not exist slewing roller bearing device maximum force state. The next ring of soft rotary device with the device according to the installation location of the center of gravity of the situation and to determine the rotation angle range. If the rotation angle is about 100 degrees, the maximum rotation center of gravity of the portion above the front, it is recommended to lower ring mounted on the rear of the soft belt, or 180 degree position. If the rotation center of gravity of the section above the front and rear position change position are equal, you can optionally install the next soft belt loop angular position.
Usually turn on the device with mounting ring soft pitching rotation perpendicular to the surface projection line location, such as loading, or stacker-reclaimer slewing ring soft tape on the device to be installed perpendicular to the centerline of the cantilever cutting through the center of the rotation , which stands on the center of rotation of the left or right side face of the cantilever 90 degree position.
The mechanical design is usually soft belt at this position does not exist slewing roller bearing device maximum force state. The next ring of soft rotary device with the device according to the installation location of the center of gravity of the situation and to determine the rotation angle range. If the rotation angle is about 100 degrees, the maximum rotation center of gravity of the portion above the front, it is recommended to lower ring mounted on the rear of the soft belt, or 180 degree position. If the rotation center of gravity of the section above the front and rear position change position are equal, you can optionally install the next soft belt loop angular position.
Slewing loss and storage
slewing bearing loss factor mainly refers to the use of installation and adjustment, use and maintenance, repair and other maintenance meets the technical requirements. Installation conditions are the primary factors that one of the factors, slewing ring often due to improper installation of the parts of the entire slewing between the force status changes, slewing ring in the abnormal state of operation and losses. According slewing installation, use, maintenance, maintenance of the technical requirements for operation of the rotary bearing to withstand load, speed, temperature, vibration, noise and lubrication condition monitoring and inspection, abnormal should immediately find reasons to be adjusted to normal. Moreover, the quality of the grease and the surrounding medium, and the atmosphere is also very important for analytical testing.
Slewing oiled at the factory and used film wrapped, the packaging rust generally valid 3-6 months. Their storage temperature should be 20 ± 10 ℃, with relative humidity less than 60%, more than valid, it should be timely maintenance. Slewing inventory should be greased after one year, and check its rotation flexibility.
Slewing bearing factory generally fixed on pallets or containers, with a single piece packaging and packaging into groups of two forms. Transport and storage should be kept level, not collision and extrusion, not rain, storage should be smooth. Slewing ring should be stacked flat between isolation.
Slewing lifting holes generally can be screwed into safe lifting eyebolts.
Slewing oiled at the factory and used film wrapped, the packaging rust generally valid 3-6 months. Their storage temperature should be 20 ± 10 ℃, with relative humidity less than 60%, more than valid, it should be timely maintenance. Slewing inventory should be greased after one year, and check its rotation flexibility.
Slewing bearing factory generally fixed on pallets or containers, with a single piece packaging and packaging into groups of two forms. Transport and storage should be kept level, not collision and extrusion, not rain, storage should be smooth. Slewing ring should be stacked flat between isolation.
Slewing lifting holes generally can be screwed into safe lifting eyebolts.
2013年8月20日星期二
Bearing parts heat treatment Common Pitfalls
Heat treatment of common defects bearing parts Abstract: tightening machinery industry continued decline in corporate profits high speed machining is the development trend of automobile mold manufacturing heavy ball screw recently successfully developed the basis for programming CNC milling machinery industry: technological advances driving the industry's sustained prosperity first imported CNC hobbing machine in Hangzhou high-speed rolling oils selected row angular contact ball bearing and double row angular contact ball bearings in Japan to open up China Machine Tool & Mold strengthen efforts to efficiently market the discussion thread turning what is grinding? laser control breaker developed in Japan new linear drive unit grease terminology heat treatment of steel Talking surfacing welding materials research environmental problems self-lubricating bearings new applications differential transmission Displacement Sensor structure optimization and its digital interface circuit design valve selection, function and The main factors piping system virtual manufacturing technology in manufacturing applications processed tissue surface defects common parts bearing overheating cause stress bearing parts heat quenched microstructure common quality defects overheating quenching cracks stiff enough heat deformable surface decarburization 1. overheated bearing parts coarse quenched microstructure was observed overheating overheating degree must determine exactly GCr quenched microstructures observed tissue acicular martensite microstructure formation may be due to thermal quenching quenching.
Bearing parts after heat treatment of the common quality defects are: hardened microstructure overheating, lack of heat, quenching cracks, hardness is not enough, heat deformation, surface decarburization, soft points.
1 overheat
Port from the bearing part can be observed on the rough microstructure after hardening overheating. But to determine the exact extent of overheating must observe the microstructure. If GCr15 steel hardened tissues appear coarse acicular martensite, was quenched overheating tissue. Formation may be due to the quenching temperature is too high or too long causing heat insulation comprehensive overheating; also may be due to the original organization carbon ribbon severe in the two areas with the formation of carbon between the local martensite needles thick, caused by local overheating. Overheating tissues residual austenite increases, dimension stability decreased. As quenching overheated steel coarse crystals, may cause parts of the decrease in toughness, impact resistance decreased, the bearing life is reduced. Even cause serious overheating quenching cracks.
(2) less heat
Quenching temperature is low or poor cooling in the microstructure produced more than the standard prescribed troostite organization called due to heat tissue, which decrease in hardness, wear resistance drastically reduced, affecting bearing life.
3 quenching cracks
Bearing parts in the quenching process due to the formation of stress cracks called quenching cracks. Cause such cracks reasons: because the quenching temperature is too high or too fast cooling, thermal stress and metal mass volume change when the stress fracture resistance than steel; work surface defects original (such as surface micro-cracks or draw marks) or steel internal defects (such as slag, severe non-metallic inclusions, white point, residual shrinkage, etc.) at a stress concentration quenching; severe surface decarburization and carbide segregation; parts after quenching and tempering insufficient or timely tempering; previous process caused by too much stress cold punching, forging folding, turning deep marks, oil, sharp edges, etc. ditch. In short, resulting in quenching cracks may be due to one or more of these factors, the existence of internal stress cracks forming the main hardening. Quenching cracks deep and slender, straight fracture, fracture surface without oxidation colors. It is often in the bearing rings on the straight longitudinal cracks or ring cracking; ball bearing on the shape of the S-shaped, T-shaped or ring. The organization is characterized by quenching cracks no cracks on both sides of decarburization phenomenon, the obvious difference with forging cracks and material cracks.
4 heat deformation
Bearing parts during heat treatment, the presence of thermal stress and stress, this stress can be superimposed on each other, or partially offset, is complex, because it along with the heating temperature, heating rate, cooling, cooling rate, part shape and the size of the change, so the heat distortion is inevitable. Understand and grasp its variation can make the bearing part of the deformation (such as elliptical rings, rose and large size) placed controllable range, is conducive to the production of conduct. Of course, during the heat treatment the mechanical collision of parts also cause deformation, but this deformation can be used to reduce and improve operations avoided.
5 surface decarburization
Bearing parts in the heat treatment process, if it is heated in an oxidizing medium, the surface oxidation occurs to parts of the surface carbon content reduced, resulting in surface decarburization. Surface decarburization depth over the last machining allowance will make parts scrapped. Determination of surface decarburization depth available in metallographic examination and microhardness metallographic method. In the surface layer microhardness distribution curve measurement prevail, do arbitration criterion.
6 soft spots
Because insufficient heating and cooling is bad, improper operation and other causes hardening of the bearing surface of the part of the phenomenon known locally insufficient hardness quenching soft spots. It is the same as the surface decarburization can cause surface wear resistance and fatigue strength in serious decline.
Bearing parts after heat treatment of the common quality defects are: hardened microstructure overheating, lack of heat, quenching cracks, hardness is not enough, heat deformation, surface decarburization, soft points.
1 overheat
Port from the bearing part can be observed on the rough microstructure after hardening overheating. But to determine the exact extent of overheating must observe the microstructure. If GCr15 steel hardened tissues appear coarse acicular martensite, was quenched overheating tissue. Formation may be due to the quenching temperature is too high or too long causing heat insulation comprehensive overheating; also may be due to the original organization carbon ribbon severe in the two areas with the formation of carbon between the local martensite needles thick, caused by local overheating. Overheating tissues residual austenite increases, dimension stability decreased. As quenching overheated steel coarse crystals, may cause parts of the decrease in toughness, impact resistance decreased, the bearing life is reduced. Even cause serious overheating quenching cracks.
(2) less heat
Quenching temperature is low or poor cooling in the microstructure produced more than the standard prescribed troostite organization called due to heat tissue, which decrease in hardness, wear resistance drastically reduced, affecting bearing life.
3 quenching cracks
Bearing parts in the quenching process due to the formation of stress cracks called quenching cracks. Cause such cracks reasons: because the quenching temperature is too high or too fast cooling, thermal stress and metal mass volume change when the stress fracture resistance than steel; work surface defects original (such as surface micro-cracks or draw marks) or steel internal defects (such as slag, severe non-metallic inclusions, white point, residual shrinkage, etc.) at a stress concentration quenching; severe surface decarburization and carbide segregation; parts after quenching and tempering insufficient or timely tempering; previous process caused by too much stress cold punching, forging folding, turning deep marks, oil, sharp edges, etc. ditch. In short, resulting in quenching cracks may be due to one or more of these factors, the existence of internal stress cracks forming the main hardening. Quenching cracks deep and slender, straight fracture, fracture surface without oxidation colors. It is often in the bearing rings on the straight longitudinal cracks or ring cracking; ball bearing on the shape of the S-shaped, T-shaped or ring. The organization is characterized by quenching cracks no cracks on both sides of decarburization phenomenon, the obvious difference with forging cracks and material cracks.
4 heat deformation
Bearing parts during heat treatment, the presence of thermal stress and stress, this stress can be superimposed on each other, or partially offset, is complex, because it along with the heating temperature, heating rate, cooling, cooling rate, part shape and the size of the change, so the heat distortion is inevitable. Understand and grasp its variation can make the bearing part of the deformation (such as elliptical rings, rose and large size) placed controllable range, is conducive to the production of conduct. Of course, during the heat treatment the mechanical collision of parts also cause deformation, but this deformation can be used to reduce and improve operations avoided.
5 surface decarburization
Bearing parts in the heat treatment process, if it is heated in an oxidizing medium, the surface oxidation occurs to parts of the surface carbon content reduced, resulting in surface decarburization. Surface decarburization depth over the last machining allowance will make parts scrapped. Determination of surface decarburization depth available in metallographic examination and microhardness metallographic method. In the surface layer microhardness distribution curve measurement prevail, do arbitration criterion.
6 soft spots
Because insufficient heating and cooling is bad, improper operation and other causes hardening of the bearing surface of the part of the phenomenon known locally insufficient hardness quenching soft spots. It is the same as the surface decarburization can cause surface wear resistance and fatigue strength in serious decline.
Raw material roller press bearing damage cause analysis and maintenance recommendations
In the dry process cement production line process, the raw material has been widely used roller press, and has made considerable economic and social benefits, a significant increase of its energy-saving effect is also recognized by the majority of manufacturers to use. But in the course of its use, the bearing life is short, damage and replacement process cycle is long, costly, labor-intensive, but it restricts the normal operation of the rotary kiln.
My company put into operation by the end of 2012 the two 4500t / d clinker production line, run until June 2003, four sets of Chengdu Lijun Industrial Co., Ltd. manufactured CLF180-120 there have been varying degrees of roller presses the problem of high bearing temperatures, 7 mid-May the 2nd roll maneuver near the gear side roller bearing damage. Total running time of 2041 hours, the service life of less than three months.
First, the device pre-operational status
Roller press run early bearing temperature between 50-60 degrees, there is no abnormal noise, bearing grease used by the U.S. Castrol brand Molub-Alloy 777-2 ES model roller presses grease, the amount of fuel in strict accordance with equipment manufacturers Requests the Executive. Five to six months, there have been several cycles of water blockage, resulting in bearing temperature up to 70 degrees. In mid-June, found that the lower part of the inner bearing oil outlet circulating water discharge phenomenon occurs suspected side of the bearing end cap rupture caused by cooling water, then turn off the inside of the circulating water, the new grease replenishing the oil discharged into the roller press production. In early July, roller presses the bearing temperature has been hovering around 55 degrees to 75 degrees, for various reasons during the roller press is always open to open the stop, there have been more than 24 hours continuously feeding situation. July 10 start, roller press repeatedly appear continuous feeding more than four hours on account of the temperature exceeds 75 degrees to stop jumping. July 12 greaser checking the oil discharge roller press discovered the bearing fragments. Determine the bearing roller press has been damaged. Since the roller press has been put into the roll gap deviation, pressure instability. Deviation due to the roll gap gauge, pressure gauge, the width of the roll gap and other factors frequently exceeds the limit mediation, there have been almost no more than 48 hours continuously feeding situation.
Second, the disintegration of the investigation bearing damage
After the demolition of the roller press gearbox bearing cap open and found that there is a rift bearing outside diameter, a broken ball bearings, inner and outer diameter with five out of crack, the bearing inner and outer raceway badly worn bearing retainer wear . Bearing cap surrounded by circulating water cooling on both sides have two brass compression fracture phenomena, round copper tubes are flattened, leading to fracture, width of about 100mm. Check the other side of the roll maneuver roller bearings, intact, the bearing clearance of 0.75mm, within the normal range.
Third, bearing damage cause analysis and improvement
1 First, bearing life is too short not to troubleshoot and manufacturer of quality bearing assembly itself, but should also work with bearing operating conditions in harsh environments and have a great relationship.
2. Bearing thermal design flaws. Such a large bearing operating process will produce a lot of frictional heat, so that both sides of the bearing cap manufacturer designed circulating path, the heat generated by the bearing grease and the case conduction through the cooling copper tube absorbs heat water circulating outflow apparatus body, lower bearing temperatures. But it cooled copper mounting position is unreasonable, bearing swing too easy to squeeze into the brass, brass deformation caused by blockage, fracture, loss of cooling effect. To avoid copper tube is extruded, only increase the gap between the copper and the bearing, to ensure a greater swing bearing free space, which requires manufacturers to redesign, production bearing cap or another design a cooling device.
3 brass water lead to rupture of the rear bearing lubrication failure, it could be this short bearing life is an important factor. Equipment inspection work found during the inspections bearing lower discharge port has water leakage, immediately made a report, but this is not possible in the cooling copper pipe break after the first time discovered. Since the bearing inner brass cap by squeezing fracture, circulating water entering the bearing, destroyed the environment lubrication, the bearing balls and the raceway serious friction generates a lot of heat, bearing balls and the diameter of each component such damage.
4 brass frequent clogging cooling and design too small, poor cooling effect also affect bearing life. Cooled copper diameter is too small, the circulating water and debris clog adhesion brass scale deposition in the roller press often occurs during operation bearing high temperature, inlet and outlet brass examination revealed multiple blockage, affecting the cooling effect, the final installed at the inlet Y-strainer before easing clogging.
5 roller presses the material into the inadequate control of particle size, diameter 200mm super chunk too, long nip large deviations, corrective frequently lead to bearing overload and shorten the service life. Initial production mining crushing, crushing machine safety door is not well controlled, resulting in more than 150mm above the individual particle size of limestone blocks into the next process, clogging the feed opening roller press, leading to uneven feeding, causing the roll gap large deviations, and even lead roll sewing too large equipment mediation. Granularity than 100mm rigid material frequently enters roller presses, roller presses squeeze in an instant when all the large reaction force bearing on the bearing itself, the life of the bearing caused a fundamental impact. Improved granularity of limestone, sandstone and clay crusher materials and faulty phase continued up to more than two months, no broken, large water through the bypass feed materials into the roller press feeding system, more than 250mm above the chunk size is almost Each class appears stuck roll gap, resulting in the roll gap width gauge mediation. This is the roller press operation there have been no more than six months more than 48 hours continuously feeding the root cause.
6 There is no steady flow positions periodically removed materials, excluding enrichment metal, so that the device frequently overloaded mediation affect bearing life. Material into the roller press is impossible to avoid the presence of metal objects and accumulation roller presses the original width of the roll gap of about 20mm, 70mm roll gap will exceed the overload relief, less than 50mm metal objects will only increase the roll surface wear, greater than 50mm size metal objects or materials into the roller press is too large, it will cause the rollers instantly generate excessive impact force, resulting in the roll gap than 70mm, the pressure exceeds 15MPa, exceeds the bearing load limits, the control system will suddenly roller press release pressure or mediation. Especially metal roller presses will cycle loop in the roller press greatest harm. So they requested that must be periodically clearing, clearing accumulated in the roller press metal objects within the system, reduce or avoid damage to equipment, particularly bearing.
7 hidden when the hydraulic system is now hidden, long-term bias is serious roll gap. As the hydraulic system problems, often lower than the pressure roller presses the side of the working pressure, both sides of the roll gap large deviation hydraulic pump long-term frequent correction, resulting in roller presses the bearing operating conditions poor, heavy load, the service life is reduced.
Fourth, the late running Precautions
Roller press bearing life is short, equipment failure rate is the current cement industry a common problem, through analysis of the above reasons, the production process management is a top priority, as long as control the granularity of the material into the roller press, regularly scheduled clearance, reducing metal roller presses against the probability of overload damage to the bearings, excluding hydraulic system problems, eliminating the long-term bias roll gap phenomenon, problem solving partial cutting, take care of the bearing uniform force. As long as the above points, improving the operating environment of the equipment, the equipment can operate normally, to extend the life of each part, in order to improve the operation rate.
2013年8月19日星期一
Bearing removal attention to four basic questions
Bearing removal and installation should be equally careful. Careful not to damage Koyo bearings and various parts, especially the interference fit bearing removal difficult operation. Therefore, at the design stage to take into account in advance for easy removal, according to the need to design the removal tool is also very important. In the demolition, according to the drawings of demolition methods, in order to investigate the bearing with the conditions to obtain the demolition job foolproof.
Removing the interference fit of the outer ring, the circumference of the housing in advance several outer extrusion screw is provided with a screw, the screw tightened equally side, while the removal. These usually cover the screw holes blind plugs, tapered roller bearings, etc. separable bearings, the housing block set shoulders several incisions, the use of pads, with press dismantling, demolition, or gently pounding.
Removal of the inner ring can be used to pull the latest simple mechanical pressure. At this time, pay attention to your inner bear its pullout.
Big ball bearing inner ring removal by hydraulic method. By setting the hydraulic pressure to the shaft hole, to make easy to pull. Large width of the bearing is oil law and drawing fixtures and use, disassembly operations.
NU, NJ type cylindrical roller bearing inner ring disassembly can take advantage of induction heating method. Local heating in a short time, after drawing the inner ring expansion method.
Removal more compact adapter sleeve bearings, fastening the shaft stopper supporting inner ring, the nut back several times, using the pads with a hammer and beat demolished.
Large bearings, the use of hydraulic demolition easier, in the cone axis pressurized oil feed hole, so that the inner expansion, demolition bearing approach. Operation, there is the possibility of bearing sudden prolapse, the best use of the nut block as well as files.
A shaft and bearing selection and control room tolerance bearings pressed into the direction of rotation should be no block flexible. If significant rotation is not flexible, then the shaft size is too large, and forbearance decline. As obvious after entering the "imperfections" in a sense of hand rotation shaft tolerance axial bearings or shaft may be too poor roundness. Therefore, a good shaft and bearing in the control room should be controlled at roundness tolerance, tolerance control only for many domestic manufacturers, no roundness control.
2, the bearing assembly method of the bearing is a precision products, such as improper assembly of the channel, it is easy to damage the bearings, bearing damage. In assembling the bearing should have a dedicated mold, can not hit, into the shaft when the pressure forces can only be a small circle, circle, only by the force loop. Congress requested the pneumatic or hydraulic pressure when using the upper and lower outer mold mounted on a horizontal state, if inclined bearing channel will lead to damage of power, leaving the bearing guide ring bearings.
3, the assembly to prevent foreign bodies mounted on the rotor balancing is done, it is prone to iron homeostasis bearing into the bearing, so it is best to do before loading bearing balance. Some manufacturers in order to facilitate assembly, with some oil or lubricating grease internal coating, carriers bearing assembly is often difficult to control the amount, if the oil or fat in a large indoor bearing, bearing accumulate along the axis, easily enter the bearing rotation. Japan is not the best room bearings coated with oil or grease, such as non-coated bearings, without the accumulation of the control room.
4, anti-rust paint paint rust is characterized in that a sealed multi-motor assembly motor sounds good, but put in the warehouse for some time, the motor becomes a very unusual sound, remove the bearing severe rust. Many manufacturers will be considered before the bearing problem, through our continuous publicity, has now been realized that the main electrical insulating paint factory is the question. The main problem is, insulating paint volatile acid at a certain temperature, humidity, corrosive substances, bearing passage leading to the formation of corrosion damage. The only problem now is to choose a good varnish, after a period of drying air assembly.
Removing the interference fit of the outer ring, the circumference of the housing in advance several outer extrusion screw is provided with a screw, the screw tightened equally side, while the removal. These usually cover the screw holes blind plugs, tapered roller bearings, etc. separable bearings, the housing block set shoulders several incisions, the use of pads, with press dismantling, demolition, or gently pounding.
Removal of the inner ring can be used to pull the latest simple mechanical pressure. At this time, pay attention to your inner bear its pullout.
Big ball bearing inner ring removal by hydraulic method. By setting the hydraulic pressure to the shaft hole, to make easy to pull. Large width of the bearing is oil law and drawing fixtures and use, disassembly operations.
NU, NJ type cylindrical roller bearing inner ring disassembly can take advantage of induction heating method. Local heating in a short time, after drawing the inner ring expansion method.
Removal more compact adapter sleeve bearings, fastening the shaft stopper supporting inner ring, the nut back several times, using the pads with a hammer and beat demolished.
Large bearings, the use of hydraulic demolition easier, in the cone axis pressurized oil feed hole, so that the inner expansion, demolition bearing approach. Operation, there is the possibility of bearing sudden prolapse, the best use of the nut block as well as files.
A shaft and bearing selection and control room tolerance bearings pressed into the direction of rotation should be no block flexible. If significant rotation is not flexible, then the shaft size is too large, and forbearance decline. As obvious after entering the "imperfections" in a sense of hand rotation shaft tolerance axial bearings or shaft may be too poor roundness. Therefore, a good shaft and bearing in the control room should be controlled at roundness tolerance, tolerance control only for many domestic manufacturers, no roundness control.
2, the bearing assembly method of the bearing is a precision products, such as improper assembly of the channel, it is easy to damage the bearings, bearing damage. In assembling the bearing should have a dedicated mold, can not hit, into the shaft when the pressure forces can only be a small circle, circle, only by the force loop. Congress requested the pneumatic or hydraulic pressure when using the upper and lower outer mold mounted on a horizontal state, if inclined bearing channel will lead to damage of power, leaving the bearing guide ring bearings.
3, the assembly to prevent foreign bodies mounted on the rotor balancing is done, it is prone to iron homeostasis bearing into the bearing, so it is best to do before loading bearing balance. Some manufacturers in order to facilitate assembly, with some oil or lubricating grease internal coating, carriers bearing assembly is often difficult to control the amount, if the oil or fat in a large indoor bearing, bearing accumulate along the axis, easily enter the bearing rotation. Japan is not the best room bearings coated with oil or grease, such as non-coated bearings, without the accumulation of the control room.
4, anti-rust paint paint rust is characterized in that a sealed multi-motor assembly motor sounds good, but put in the warehouse for some time, the motor becomes a very unusual sound, remove the bearing severe rust. Many manufacturers will be considered before the bearing problem, through our continuous publicity, has now been realized that the main electrical insulating paint factory is the question. The main problem is, insulating paint volatile acid at a certain temperature, humidity, corrosive substances, bearing passage leading to the formation of corrosion damage. The only problem now is to choose a good varnish, after a period of drying air assembly.
Methods to improve the accuracy of precision bearings
In order to improve precision roller bearing with precision the actual installation, you must not make use of the bearing deformation measurement methods and measuring tools, precision bearings and cylindrical bore size of the mating surfaces of the actual precision measurement can be related inner and outer diameters All measurement items to be measured, and the measured data to make a comprehensive analysis of this as far and precision worthy of shaft and housing bore bearing mounting portion size. In actual measurements made with the respective shaft and housing bore size and geometry should be the same with the measuring bearing temperature conditions.
To ensure the effect of a higher actual mating shaft and the bearing bore to match the surface, the roughness should be as small as possible.
In making these measurements, should be cylindrical and the bearing bore, the housing bore and the shaft, and a corresponding surface of the chamfered sides near the assembly, respectively, showing the maximum deviation to make the direction of two marks, so that In actual assembly, the mating alignment of both the maximum deviation of the same position, so that after assembly, the two sides can be partially offset by the deviation.
Directional signs made two aims can compensate for deviations into account, even if both sides supporting each rotation accuracy improved, but also between the two bearing seat hole and both ends of the journal concentricity error partially eliminated. Surface hardening on the mating surfaces to implement measures, such as sandblasting, with a diameter slightly larger than the precision plunger plug holes, once inside, there is help to improve the fitting accuracy.
To ensure the effect of a higher actual mating shaft and the bearing bore to match the surface, the roughness should be as small as possible.
In making these measurements, should be cylindrical and the bearing bore, the housing bore and the shaft, and a corresponding surface of the chamfered sides near the assembly, respectively, showing the maximum deviation to make the direction of two marks, so that In actual assembly, the mating alignment of both the maximum deviation of the same position, so that after assembly, the two sides can be partially offset by the deviation.
Directional signs made two aims can compensate for deviations into account, even if both sides supporting each rotation accuracy improved, but also between the two bearing seat hole and both ends of the journal concentricity error partially eliminated. Surface hardening on the mating surfaces to implement measures, such as sandblasting, with a diameter slightly larger than the precision plunger plug holes, once inside, there is help to improve the fitting accuracy.
2013年8月10日星期六
High-speed precision angular contact ball bearing installation
High-speed precision angular contact ball bearing, mainly used for high-speed rotating occasions lighter loads, requiring high precision bearings, high speed, low vibration and low temperature rise a certain life. Often high-speed spindle support member installed in pairs, is the inner surface grinding spindle speed key component parts.
High-speed precision angular contact ball bearing service life of a great relationship with the installation, you should note the following:
1 bearing installation should be clean, clean room for the bearing to be carefully matching, bearing spacers to go through the grind of maintaining high inner and outer ring spacers under the premise of the spacer should be controlled in parallel 1um the following;
(2) Before installing the bearings should be cleaned, cleaning the inner slope upward, feel should be flexible, no sense of stagnation, dried, placed in a predetermined amount grease, oil mist lubrication should be placed in the case of a small amount of oil mist;
3 bearing installation tool should be used exclusively, even by force, is strictly prohibited beat;
4 bearing deposit should be clean and ventilated, non-corrosive gases, relative humidity less than 65%, long-term storage should be periodically rust.
High-speed precision angular contact ball bearing service life of a great relationship with the installation, you should note the following:
1 bearing installation should be clean, clean room for the bearing to be carefully matching, bearing spacers to go through the grind of maintaining high inner and outer ring spacers under the premise of the spacer should be controlled in parallel 1um the following;
(2) Before installing the bearings should be cleaned, cleaning the inner slope upward, feel should be flexible, no sense of stagnation, dried, placed in a predetermined amount grease, oil mist lubrication should be placed in the case of a small amount of oil mist;
3 bearing installation tool should be used exclusively, even by force, is strictly prohibited beat;
4 bearing deposit should be clean and ventilated, non-corrosive gases, relative humidity less than 65%, long-term storage should be periodically rust.
Angular contact ball bearings operating instructions
1, the operating instructions for the preparation of: according to equipment for the preparation of items that can be processed, which includes operations job preparation and job steps, process characteristics control requirements (processing device parameters, such as grinding diameter, the workpiece and wheel speed , sand turn trimming frequency, slim bearing, eccentricity, etc.; channel coarse and fine, overtime, workpiece speed, beat frequency and angle Whetstone, Whetstone pressure and ultra-precision time and other parameters; tooling adjustment norms, etc.), product characteristics control requirements (process control projects, testing tools, etc.), the main products project failed rework operations guidance.
2, the product process control plan preparation: There are general and specific product model two kinds. Sequential arrangement by a process flow diagram of the process carried out, work number is consistent, some processes can be combined, but the need for notes, such as demagnetization cleaning. Characteristics projects and processes should be the same size cards, it is important also need to specify the process characteristics, such as grinding channel, the wheel speed, workpiece speed, light grinding time, dresser, etc., generally have the book provides guidance on the job, you can indicate references . There are specific types of product specification shall control the planning process and grind super size card processing agreement. Also the measurement technology, measurement sampling samples, control methods and error proofing, response plans and corrective measures, according to the actual production can do and control and to ensure quality content preparation, because of the part of the production control plan requirements must be process control.
3, the product of the preparation process failure modes: first by a process flow diagram and the process of risk assessment, was named high-risk failure analysis to be done.
There are general and specific product model two kinds. Sequential arrangement by a process flow diagram of the process carried out, work number consistent. Included were rated high risk of failure processes may require the presence of all, the possible consequences, which may be the reason of being a means of control methods, and the possibility of them out, and whether measures need to be taken and so on.
Such as grinding end faces potential failure modes and failure reasons: ① width size is too large or too small, mainly related to the grinding time
And stress-related; ② parallelism tolerance, when using the vertical shaft surface grinding machine, its failure causes the wheel spindle is not perpendicular to the magnetic table, magnetic units surface wear, magnetic units magnetic enough, grinding work, "slip", magnetic units surface dirty, dirty work or face burr, magnetic rotary precision is not high, when using double end grinder, the two parallel grinding wheel face is not good, two wheel face serious wear and tear, improper installation exit guide plate, grinding I such as excessive; ③ flatness tolerance, when using the vertical shaft surface grinding machine, its failure causes a workpiece is too thin, heat deformation, wheel too hard, cutting fluid supply, etc., when using the double end grinder, the main export at the guide plate is not properly installed and so on.
Grinding diameter when the potential failure modes and failure reasons: ① aperture is too large, the bearing surface size tolerance, was grinding the workpiece aperture to remain excessive, over automatic feed stroke, etc.; ② tolerance ellipse, oval workpiece support surface too large, reflected in the mill complex on the surface of the workpiece support surface with card injury; ③ cylindricity tolerance, the workpiece spindle axis and the wheel axis is not parallel to the centerline, wheel dressing well, wheel width too wide, vertical reciprocating distance is too short, rough cylinder through the large, rough diameter stay excessive infeed is too fast, too short a time without feeding, wheel too soft; ④ holes face is not perpendicular magnetic clamps enough support position not equal.
2, the product process control plan preparation: There are general and specific product model two kinds. Sequential arrangement by a process flow diagram of the process carried out, work number is consistent, some processes can be combined, but the need for notes, such as demagnetization cleaning. Characteristics projects and processes should be the same size cards, it is important also need to specify the process characteristics, such as grinding channel, the wheel speed, workpiece speed, light grinding time, dresser, etc., generally have the book provides guidance on the job, you can indicate references . There are specific types of product specification shall control the planning process and grind super size card processing agreement. Also the measurement technology, measurement sampling samples, control methods and error proofing, response plans and corrective measures, according to the actual production can do and control and to ensure quality content preparation, because of the part of the production control plan requirements must be process control.
3, the product of the preparation process failure modes: first by a process flow diagram and the process of risk assessment, was named high-risk failure analysis to be done.
There are general and specific product model two kinds. Sequential arrangement by a process flow diagram of the process carried out, work number consistent. Included were rated high risk of failure processes may require the presence of all, the possible consequences, which may be the reason of being a means of control methods, and the possibility of them out, and whether measures need to be taken and so on.
Such as grinding end faces potential failure modes and failure reasons: ① width size is too large or too small, mainly related to the grinding time
And stress-related; ② parallelism tolerance, when using the vertical shaft surface grinding machine, its failure causes the wheel spindle is not perpendicular to the magnetic table, magnetic units surface wear, magnetic units magnetic enough, grinding work, "slip", magnetic units surface dirty, dirty work or face burr, magnetic rotary precision is not high, when using double end grinder, the two parallel grinding wheel face is not good, two wheel face serious wear and tear, improper installation exit guide plate, grinding I such as excessive; ③ flatness tolerance, when using the vertical shaft surface grinding machine, its failure causes a workpiece is too thin, heat deformation, wheel too hard, cutting fluid supply, etc., when using the double end grinder, the main export at the guide plate is not properly installed and so on.
Grinding diameter when the potential failure modes and failure reasons: ① aperture is too large, the bearing surface size tolerance, was grinding the workpiece aperture to remain excessive, over automatic feed stroke, etc.; ② tolerance ellipse, oval workpiece support surface too large, reflected in the mill complex on the surface of the workpiece support surface with card injury; ③ cylindricity tolerance, the workpiece spindle axis and the wheel axis is not parallel to the centerline, wheel dressing well, wheel width too wide, vertical reciprocating distance is too short, rough cylinder through the large, rough diameter stay excessive infeed is too fast, too short a time without feeding, wheel too soft; ④ holes face is not perpendicular magnetic clamps enough support position not equal.
2013年8月9日星期五
Deep groove ball bearings rust knowledge
Deep groove ball bearing division between the rust and rust usually finished rust.
Workers between the rust belongs antirust processing, usually in 3-30 days. Will generally water-based rust inhibitor can be. The advantage of water-based rust inhibitor is a simple operation and low cost. And rust after degreasing cleaning is not required.
Finished rust generally refers to the deep groove ball bearing assembly before storage or rust after delivery, usually within a month to 2 years or so. General use apply anti-rust oil or rust VCI paper packaging. VCI antirust paper packaging has the advantage of good rust, free cleaning before assembly, easy to operate, environmentally friendly energy.
VCI antirust paper will always release a small amount of rust inhibitor (VCI Definition: volatile corrosion inhibitor). In this paper, the package, the package is formed in a protective layer of gas can be reliably suppressed corrosion of deep groove ball bearings. VCI rust-proof paper in direct contact with the bearing and have anti-rust within a certain distance; bearing VCI antirust paper packaging rust, rust-proof up to 3 years; bearing VCI antirust film packaging rust, rust up a years. This is the most used product Harbin HRB, now commonly used in plastic barrels rust processes.
Workers between the rust belongs antirust processing, usually in 3-30 days. Will generally water-based rust inhibitor can be. The advantage of water-based rust inhibitor is a simple operation and low cost. And rust after degreasing cleaning is not required.
Finished rust generally refers to the deep groove ball bearing assembly before storage or rust after delivery, usually within a month to 2 years or so. General use apply anti-rust oil or rust VCI paper packaging. VCI antirust paper packaging has the advantage of good rust, free cleaning before assembly, easy to operate, environmentally friendly energy.
VCI antirust paper will always release a small amount of rust inhibitor (VCI Definition: volatile corrosion inhibitor). In this paper, the package, the package is formed in a protective layer of gas can be reliably suppressed corrosion of deep groove ball bearings. VCI rust-proof paper in direct contact with the bearing and have anti-rust within a certain distance; bearing VCI antirust paper packaging rust, rust-proof up to 3 years; bearing VCI antirust film packaging rust, rust up a years. This is the most used product Harbin HRB, now commonly used in plastic barrels rust processes.
Affect the life of deep groove ball bearing analysis of the factors
Deep groove ball bearing material largely determines the bearing life, once the metallurgical quality bearing steel GCr15 early bearing failure is caused by the most important reason. Technically increased dramatically in the metallurgical, bearing steel and other materials have appeared, has been greatly improved.
In bearing failure analysis, from raw material bearing failure caused the proportion has also been greatly improved, but is still manufacturing materials main bearing failure, but also with deep groove ball bearing service life considerably relations.
Bearing complex manufacturing process, to go through several processes before they can get the finished product, including forging, heat treatment, turning and grinding and other processes to complete the technical ability and quality, will affect the bearing life and apply effects, especially heat treatment and grinding process, it is the direct cause of many bearing failures, manufacturers need to be highly valued.
deep groove ball bearing after installation, in order to check the installation is not correct, you want to run checks. Small machines can be rotated by hand to make sure is not rotate smoothly. Check items mainly due to foreign bodies, indentation caused by dysfunctional, because poor installation, mount poor processing and the emergence of torque instability, because clearance is too small, the installation error, caused by seal friction torque is too large, and so . If no exception, you can begin powering.
On the shaft and bearing, the bearing requirements in the radial, axial and tangential direction in three directions fix its position. Radial and tangential positioning through the tight fit of the bearing rings mining achieve axial positioning only in a few cases, a tight fit; generally use limit axial parts, such as end caps and rings etc. is limited to the axial position In the clearance range.
Select match should focus on the following four points:
(A) the bearing rings and the circumferential surface should be well supported even by force, in order to reduce distortion, and give full play to the bearing capacity.
(2) In its mating surface of the ferrule can not slide along the tangential direction, otherwise it will damage the mating surfaces.
(3) the free end of the shaft and the bearing must be capable of bearing adapt to changes in length of the hole, which must have to adapt to the axial position in a range of swimming ability.
(4) must pay attention to the deep groove ball bearing mounting and dismounting is simple, saving time and labor costs.
In bearing failure analysis, from raw material bearing failure caused the proportion has also been greatly improved, but is still manufacturing materials main bearing failure, but also with deep groove ball bearing service life considerably relations.
Bearing complex manufacturing process, to go through several processes before they can get the finished product, including forging, heat treatment, turning and grinding and other processes to complete the technical ability and quality, will affect the bearing life and apply effects, especially heat treatment and grinding process, it is the direct cause of many bearing failures, manufacturers need to be highly valued.
deep groove ball bearing after installation, in order to check the installation is not correct, you want to run checks. Small machines can be rotated by hand to make sure is not rotate smoothly. Check items mainly due to foreign bodies, indentation caused by dysfunctional, because poor installation, mount poor processing and the emergence of torque instability, because clearance is too small, the installation error, caused by seal friction torque is too large, and so . If no exception, you can begin powering.
On the shaft and bearing, the bearing requirements in the radial, axial and tangential direction in three directions fix its position. Radial and tangential positioning through the tight fit of the bearing rings mining achieve axial positioning only in a few cases, a tight fit; generally use limit axial parts, such as end caps and rings etc. is limited to the axial position In the clearance range.
Select match should focus on the following four points:
(A) the bearing rings and the circumferential surface should be well supported even by force, in order to reduce distortion, and give full play to the bearing capacity.
(2) In its mating surface of the ferrule can not slide along the tangential direction, otherwise it will damage the mating surfaces.
(3) the free end of the shaft and the bearing must be capable of bearing adapt to changes in length of the hole, which must have to adapt to the axial position in a range of swimming ability.
(4) must pay attention to the deep groove ball bearing mounting and dismounting is simple, saving time and labor costs.
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