Card injury
Damage state: A so-called card injury is a surface damage caused by a summation of a minor burn caused by a sliding surface injury. Linear scratches in the circumferential direction of the slide surface and rolling surface. The trochoidal flaw on the end of the roller is caught near the collar surface of the roller end.
Reason: excessive load, excessive preload. Poor lubrication. Foreign body bites into. Inner ring outer ring inclination, shaft deflection. The accuracy of the shaft and FAG bearing housing is poor.
Measures: Check the size of the load. Preloading should be appropriate. Improve lubricants and lubrication methods. Check the accuracy of the shaft and FAG bearing housing.
2. Stripping
Damage state: When FAG bearing is subject to load rotation, rolling surface or rolling body surface of inner ring and outer ring shows scaly peeling due to rolling fatigue.
Reason: The load is too large. Poor installation (non-linear) Torque Load Foreign material intrusion and ingress of water. Poor lubrication, inappropriate lubricant FAG bearing clearance is not appropriate. The accuracy of FAG bearing housings is not good, and the rigidity of FAG bearing housings is not uniform. The deflection of large shafts is caused by rust, erosion, abrasion, and indentation (surface deformation phenomena).
Measures: Check the size of the load and revisit the FAG bearing used in the study to improve the installation method. Improve the sealing device and prevent rust when shutting down. Use an appropriate viscosity lubricant to improve the lubrication method. Check the accuracy of the shaft and FAG bearing housing. Check clearance.
3, cracks, cracks
Damage state: The so-called crack means that the raceway wheel or rolling element generates crack damage. If you continue to use it, it will also include cracks in the development of cracks.
Reason: too much interference. Excessive load, impact load. Peeling has developed. Thermal and fretting wear due to contact of the raceway wheel with the mounting member. Creep caused by heat. The cone shaft has a bad cone angle. The cylindricity of the shaft is poor. The corner radius of the shaft step is larger than that of the FAG bearing and causes interference with the FAG bearing chamfer.
Measures: Appropriate amount of interference. Check the load conditions. Improve the installation method. The shape of the shaft should be appropriate.
4, peeling
Damage state: The appearance of a dark surface with slight wear. There are many micro cracks in the dark surface from the surface to depths of 5-10m, and micro-disintegration occurs in a large area (micro-stripping).
Cause: The lubricant is not suitable. Foreign matter enters the lubricant. Bad lubricant causes rough surfaces. The surface finish of paired rolling parts is not good.
Action: Select a lubricant to improve the seal to improve the surface finish of the mating rolling part.
5, fracture
Damage state: The so-called fracture refers to a small fraction of breakage due to the application of musical shock or excessive load on the ribs of the raceway wheel or a local part of the roller angle.
Cause: The installation was hit. Excessive load. Poor use such as falling.
Measure: Improve the installation method (hot install, use appropriate tool holders). Correct load conditions. FAG bearings are installed in place so that the ribs are supported.
6. Pseudo Brinell indentation
Damage state: During the micro-vibration, wear is developed due to vibration and shaking at the contact portion between the rolling element and the raceway wheel, resulting in an imprint of tired Brinell indentation.
Reason: Vibration and oscillation of the FAG bearing during stalling during transit. Small amplitude swing motion. Poor lubrication.
Action: Secure the shaft and FAG bearing housing during transportation. The inner and outer rings must be packaged separately when transporting. Add preload to reduce vibration. Use the appropriate lubricant.
7. Indentation damage: When a small metal powder, foreign matter, etc. is caught, dents are generated on the raceway surface or the rolling surface. Due to impacts during installation and the like, a concave surface (Brinell hardness indentation) is formed at the pitch intervals of the rolling elements.
Cause: Foreign materials such as metal powders bite in. The impact load is too large during assembly or during transportation.
Measures: impact sleeve. Improve the sealing device. Filter oil. Improve assembly and use.
8, rust, corrosion
Damage status: FAG bearing rust and corrosion have raceway wheels, pit-like rust on the surface of rolling elements, overall rust and corrosion.
Cause: Intrusion of water and corrosive substances (paint, gas, etc.). The lubricant is not suitable. Water droplets are attached due to the condensation of water vapor. Stop at high temperatures and humidity. Heavy rust prevention during transportation. The storage state is not suitable. Not suitable for use.
Measures: Improve the sealing device. Study lubrication methods. Anti-rust measures when stopped. Improve your storage methods. Use caution when using it.
9, pear skin pitting
Damage state: A weakly shiny, dark pear-like pitting produced on the raceway surface.
Cause: Foreign material bites in during lubrication. Dew condensation due to moisture in the air. Poor lubrication.
Measures: Improve the sealing device. Filter oil thoroughly. Use a suitable lubricant.
10, burns
Damage state: The raceway wheels, rolling elements, and cages rapidly heat up during rotation until they discolor, soften, weld, and break.
Cause: Bad lubrication. Excessive load (pre-pressurized). Excessive speed. The clearance is too small. Intrusion of water and foreign matter. Shaft and FAG bearing housings have poor accuracy and large shaft deflection.
Measures: Research lubricants and lubrication methods. Correct FAG bearing selection. Study fit, FAG bearing clearance and preload. Improve the sealing device. Check the accuracy of the shaft and FAG bearing housing. Improve the installation method.
11, fretting wear
Damage state: Wear due to relatively small sliding between the two contact surfaces occurs at the contact portion between the raceway surface and the rolling elements. Due to the occurrence of red-brown and black wear powder, it is also called fretting wear.
Cause: Bad lubrication. Small amplitude rocking motion. Insufficient amount of interference.
Measure: Use proper lubricant. Add preload. Check the amount of interference. Apply lubricant to the mating surface
12, color change
Damage state: Due to temperature rise, lubricant reaction, etc., raceway wheels, rolling elements and cages are discolored.
Cause: Bad lubrication. The reflection with the lubricant causes a hot oil immersion. The temperature rises greatly. [1]
Measures: Improve the lubrication method.
13, creep
Damage state: The so-called creepage refers to the case where a gap occurs in the mating surface of the FAG bearing. In the case where the mating surface slides relative to each other, the mating surface that exhibits creep exhibits a mirror light or dark surface, and sometimes the sheet has a scratch. Wear occurs.
Reason: Insufficient amount of interference or clearance fit. The tightening sleeve is not tight enough.
Measures: Check the amount of interference and implement stop-over measures. Tighten the adapter sleeve properly. Study the accuracy of the shaft and FAG bearing housings. Axial preloading. Raceway wheel side fastening. Bonding mating surface. Apply slip agent to the mating surface.
14. Electro-Erosion Damage: Electro-Erosion refers to the phenomenon that current flows through the thin lubricating film during the flow of the FAG bearing raceway wheel and rolling element contact parts of the circulating weight, and the surface appears local melting and irregularities. phenomenon.
Reason: The difference in ground potential between the outer ring and the inner ring.
Measure: When setting the circuit, the current does not flow through the FAG bearing section. Insulate FAG bearings.
15, wear and tear
Damage state: The so-called wear is due to friction caused by the raceway or rolling surface, roller end surface, the surface of the collar and the cage concave and other wear.
Cause: Foreign material intrusion, rust corrosion caused by the development. Poor lubrication. Slippage due to irregular movement of the rolling elements.
Measures: Improve the sealing device. Clean FAG bearing box. Filter oil thoroughly. Check the lubricant and lubrication method. Prevent non-linearity.
16, install the scar
Damage status: Axial linear scratches on the raceway surface and rolling surface when used during installation and disassembly.
Cause: Impact load at the time of mounting and dismounting of the inner ring and outer ring during installation and disassembly.
Measure: Use a suitable tool to use the press and prevent the impact load. Centering between installations.
Damage state: A so-called card injury is a surface damage caused by a summation of a minor burn caused by a sliding surface injury. Linear scratches in the circumferential direction of the slide surface and rolling surface. The trochoidal flaw on the end of the roller is caught near the collar surface of the roller end.
Reason: excessive load, excessive preload. Poor lubrication. Foreign body bites into. Inner ring outer ring inclination, shaft deflection. The accuracy of the shaft and FAG bearing housing is poor.
Measures: Check the size of the load. Preloading should be appropriate. Improve lubricants and lubrication methods. Check the accuracy of the shaft and FAG bearing housing.
2. Stripping
Damage state: When FAG bearing is subject to load rotation, rolling surface or rolling body surface of inner ring and outer ring shows scaly peeling due to rolling fatigue.
Reason: The load is too large. Poor installation (non-linear) Torque Load Foreign material intrusion and ingress of water. Poor lubrication, inappropriate lubricant FAG bearing clearance is not appropriate. The accuracy of FAG bearing housings is not good, and the rigidity of FAG bearing housings is not uniform. The deflection of large shafts is caused by rust, erosion, abrasion, and indentation (surface deformation phenomena).
Measures: Check the size of the load and revisit the FAG bearing used in the study to improve the installation method. Improve the sealing device and prevent rust when shutting down. Use an appropriate viscosity lubricant to improve the lubrication method. Check the accuracy of the shaft and FAG bearing housing. Check clearance.
3, cracks, cracks
Damage state: The so-called crack means that the raceway wheel or rolling element generates crack damage. If you continue to use it, it will also include cracks in the development of cracks.
Reason: too much interference. Excessive load, impact load. Peeling has developed. Thermal and fretting wear due to contact of the raceway wheel with the mounting member. Creep caused by heat. The cone shaft has a bad cone angle. The cylindricity of the shaft is poor. The corner radius of the shaft step is larger than that of the FAG bearing and causes interference with the FAG bearing chamfer.
Measures: Appropriate amount of interference. Check the load conditions. Improve the installation method. The shape of the shaft should be appropriate.
4, peeling
Damage state: The appearance of a dark surface with slight wear. There are many micro cracks in the dark surface from the surface to depths of 5-10m, and micro-disintegration occurs in a large area (micro-stripping).
Cause: The lubricant is not suitable. Foreign matter enters the lubricant. Bad lubricant causes rough surfaces. The surface finish of paired rolling parts is not good.
Action: Select a lubricant to improve the seal to improve the surface finish of the mating rolling part.
5, fracture
Damage state: The so-called fracture refers to a small fraction of breakage due to the application of musical shock or excessive load on the ribs of the raceway wheel or a local part of the roller angle.
Cause: The installation was hit. Excessive load. Poor use such as falling.
Measure: Improve the installation method (hot install, use appropriate tool holders). Correct load conditions. FAG bearings are installed in place so that the ribs are supported.
6. Pseudo Brinell indentation
Damage state: During the micro-vibration, wear is developed due to vibration and shaking at the contact portion between the rolling element and the raceway wheel, resulting in an imprint of tired Brinell indentation.
Reason: Vibration and oscillation of the FAG bearing during stalling during transit. Small amplitude swing motion. Poor lubrication.
Action: Secure the shaft and FAG bearing housing during transportation. The inner and outer rings must be packaged separately when transporting. Add preload to reduce vibration. Use the appropriate lubricant.
7. Indentation damage: When a small metal powder, foreign matter, etc. is caught, dents are generated on the raceway surface or the rolling surface. Due to impacts during installation and the like, a concave surface (Brinell hardness indentation) is formed at the pitch intervals of the rolling elements.
Cause: Foreign materials such as metal powders bite in. The impact load is too large during assembly or during transportation.
Measures: impact sleeve. Improve the sealing device. Filter oil. Improve assembly and use.
8, rust, corrosion
Damage status: FAG bearing rust and corrosion have raceway wheels, pit-like rust on the surface of rolling elements, overall rust and corrosion.
Cause: Intrusion of water and corrosive substances (paint, gas, etc.). The lubricant is not suitable. Water droplets are attached due to the condensation of water vapor. Stop at high temperatures and humidity. Heavy rust prevention during transportation. The storage state is not suitable. Not suitable for use.
Measures: Improve the sealing device. Study lubrication methods. Anti-rust measures when stopped. Improve your storage methods. Use caution when using it.
9, pear skin pitting
Damage state: A weakly shiny, dark pear-like pitting produced on the raceway surface.
Cause: Foreign material bites in during lubrication. Dew condensation due to moisture in the air. Poor lubrication.
Measures: Improve the sealing device. Filter oil thoroughly. Use a suitable lubricant.
10, burns
Damage state: The raceway wheels, rolling elements, and cages rapidly heat up during rotation until they discolor, soften, weld, and break.
Cause: Bad lubrication. Excessive load (pre-pressurized). Excessive speed. The clearance is too small. Intrusion of water and foreign matter. Shaft and FAG bearing housings have poor accuracy and large shaft deflection.
Measures: Research lubricants and lubrication methods. Correct FAG bearing selection. Study fit, FAG bearing clearance and preload. Improve the sealing device. Check the accuracy of the shaft and FAG bearing housing. Improve the installation method.
11, fretting wear
Damage state: Wear due to relatively small sliding between the two contact surfaces occurs at the contact portion between the raceway surface and the rolling elements. Due to the occurrence of red-brown and black wear powder, it is also called fretting wear.
Cause: Bad lubrication. Small amplitude rocking motion. Insufficient amount of interference.
Measure: Use proper lubricant. Add preload. Check the amount of interference. Apply lubricant to the mating surface
12, color change
Damage state: Due to temperature rise, lubricant reaction, etc., raceway wheels, rolling elements and cages are discolored.
Cause: Bad lubrication. The reflection with the lubricant causes a hot oil immersion. The temperature rises greatly. [1]
Measures: Improve the lubrication method.
13, creep
Damage state: The so-called creepage refers to the case where a gap occurs in the mating surface of the FAG bearing. In the case where the mating surface slides relative to each other, the mating surface that exhibits creep exhibits a mirror light or dark surface, and sometimes the sheet has a scratch. Wear occurs.
Reason: Insufficient amount of interference or clearance fit. The tightening sleeve is not tight enough.
Measures: Check the amount of interference and implement stop-over measures. Tighten the adapter sleeve properly. Study the accuracy of the shaft and FAG bearing housings. Axial preloading. Raceway wheel side fastening. Bonding mating surface. Apply slip agent to the mating surface.
14. Electro-Erosion Damage: Electro-Erosion refers to the phenomenon that current flows through the thin lubricating film during the flow of the FAG bearing raceway wheel and rolling element contact parts of the circulating weight, and the surface appears local melting and irregularities. phenomenon.
Reason: The difference in ground potential between the outer ring and the inner ring.
Measure: When setting the circuit, the current does not flow through the FAG bearing section. Insulate FAG bearings.
15, wear and tear
Damage state: The so-called wear is due to friction caused by the raceway or rolling surface, roller end surface, the surface of the collar and the cage concave and other wear.
Cause: Foreign material intrusion, rust corrosion caused by the development. Poor lubrication. Slippage due to irregular movement of the rolling elements.
Measures: Improve the sealing device. Clean FAG bearing box. Filter oil thoroughly. Check the lubricant and lubrication method. Prevent non-linearity.
16, install the scar
Damage status: Axial linear scratches on the raceway surface and rolling surface when used during installation and disassembly.
Cause: Impact load at the time of mounting and dismounting of the inner ring and outer ring during installation and disassembly.
Measure: Use a suitable tool to use the press and prevent the impact load. Centering between installations.
Although there are many types of tapping screws, they all have the following similarities:
(1) are generally made of carbonized carbon steel (accounting for 99% of total production). It can also be made of stainless steel or non-ferrous metals.
(2) The product must be heat treated. Carbon steel tapping screws must be carbonized and stainless steel tapping screws must be solution hardened. In order to make tapping screws to meet the requirements of the standard of mechanical properties and performance.
(3) The product surface hardness is high, the core toughness is good. That is, "soft inside strong outside". This is a major feature of tapping Screw performance requirements. If the surface hardness is low, it can not be screwed into the matrix; If the core toughness is poor, a twist will break, can not be used. So "inside soft outside steel" is self-tapping screw to meet the use of performance, very important requirements.
(4) The surface of the product needs surface protection treatment, generally electroplating treatment. Some product surface must be treated by phosphate (photostatting), such as wall panel self - tapping screws for photostatting.
(5) Production by cold heading process. It is recommended to use high-speed cold heading machine and high-speed wire rolling machine or high-speed planetary wire rolling machine. High speed is emphasized here to ensure product quality. Only the head of tapping screw produced by high-speed machine is well formed and the thread quality is high.
Round head Tapping screw,hex tapping screw,flat head tapping screw,pan head tapping screw,truss head tapping screw
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