Stripping

Damage state: When the FAG bearing is subjected to load rotation, the raceway surface or the rolling surface of the inner ring and the outer ring exhibits fish scale-like peeling due to rolling fatigue.

Cause: The load is too large. Poor installation (non-linear) torque load foreign matter intrusion, water ingress. Poor lubrication, improper lubricant, FAG bearing clearance is not appropriate. The accuracy of the FAG bearing housing is not good, and the deflection of the rigid uneven shaft of the FAG bearing housing is caused by large rust, erosion points, scratches and indentations (surface deformation phenomena).

Measures: Check the size of the load and the FAG bearing used in the re-inspection to improve the installation method to improve the sealing device and prevent rust during shutdown. Use a lubricant of appropriate viscosity to improve the lubrication method. Check the accuracy of the shaft and FAG bearing housing. Check the clearance.

2. Peeling

Damage state: It shows a dark surface with slight abrasion. There are many tiny cracks on the dark surface from the surface to 5-10m deep, and tiny shedding (small peeling) occurs in a wide range.

Cause: The lubricant is not suitable. Foreign matter enters the lubricant. Poor lubricant causes a rough surface. The surface finish of the paired rolling parts is not good.

Action: Select a lubricant to improve the seal to improve the surface finish of the paired rolling parts.

3. Card injury

Damage state: The so-called card injury is a surface damage caused by a combination of minute burns generated in a sliding surface injury. Linear flaws in the circumferential direction of the slide surface and the rolling surface. The tangential flaw of the roller end face is close to the jamming of the collar surface of the roller end face.

Cause: Excessive load, excessive preload. Poor lubrication. Foreign body bites into it. The inclination of the outer ring of the inner ring and the deflection of the shaft. The accuracy of the shaft and FAG bearing housing is poor.

Action: Check the size of the load. Preload should be appropriate. Improve lubricants and lubrication methods. Check the accuracy of the shaft and FAG bearing housing.

4. Break

Damage state: The so-called fracture refers to a small break due to the application of a musical impact or an excessive load to a part of the rim or the roller angle of the race wheel.

Cause: The installation was hit. The load is too large. Poor use, such as dropping.

Action: Improve the installation method (hot pack, use the appropriate tool holder). Correct the load conditions. The FAG bearing is mounted in place to support the rib.

5. Cracks, cracks

Damage state: The so-called crack refers to the crack damage caused by the race wheel or the rolling element. If it continues to be used, it will also include cracks that develop cracks.

Reason: Too much excess. Excessive load, impact load. Stripping has developed. Heat and fretting wear due to contact of the race wheel with the mounting member. The fever caused by creep. The cone angle of the cone shaft is poor. The cylindricity of the shaft is poor. The corner radius of the shaft step is larger than the FAG bearing chamfer, which causes interference with the FAG bearing chamfer.

Measures: The amount of interference is appropriate. Check the load conditions. Improve the installation method. The shape of the shaft should be appropriate.

6. Indentation

Damage state: A dent formed on the raceway surface or the rotating surface when biting into a small metal powder, foreign matter, or the like. A concave surface (Brinell hardness indentation) is formed at intervals of the rolling elements due to impact during installation or the like.

Cause: Foreign matter such as metal powder is bitten. The impact load during assembly or during transportation is too large.

Action: Impact bushing. Improve the sealing device. Filter the oil. Improve assembly and use.

Pear-like pitting

Damage state: weakly glossy dark pear-like pitting on the raceway surface.

Cause: Foreign matter bites in the lubrication process. Condensation due to moisture in the air. Poor lubrication.

Action: Improve the sealing device. Fully filter the lubricant. Use a suitable lubricant.

8. Wear

Damage state: The so-called wear is caused by friction, such as the raceway surface or the rolling surface, the roller end surface, the collar surface and the concave surface of the cage.

Cause: Foreign matter intrusion, development caused by rust and electric erosion. Poor lubrication. Slip due to irregular movement of the rolling elements.

Action: Improve the sealing device. Clean the FAG bearing housing. Fully filter the lubricant. Check lubricant and lubrication methods. Prevent non-linearity.

9. Fret wear

Damage state: Wear due to relatively repeated slight sliding between the two contact faces occurs on the contact portion of the raceway surface and the rolling elements. Due to the occurrence of reddish brown and black abrasion powder, it is also called fretting wear corrosion.

Cause: Poor lubrication. Small amplitude rocking motion. Insufficient interference.

Action: Use a suitable lubricant. Add preload. Check the excess. Apply lubricant to the mating surface

10. False Brinell indentation

Damage state: During the vibration period, the contact between the rolling element and the race wheel is developed due to vibration and shaking, resulting in an impression that is similar to the Brinell indentation.

Reason: During the transportation process, the vibration and oscillation of the FAG bearing during the stoppage. A small amplitude swing motion. Poor lubrication.

Measure: The bite is fixed to the shaft and the FAG bearing housing during transportation. The inner and outer rings should be packaged separately during transportation. Plus preload to reduce vibration. Use a suitable lubricant.

11. Creep

Damage state: The so-called creep refers to the fact that when a gap is formed on the mating surface of the FAG bearing, the mating surface where the creep occurs is a mirror-like bright or dark surface, sometimes with a card jam. Wear occurs.

Cause: Insufficient interference or clearance fit. The adapter sleeve is not fast enough.

Measures: Check the excess amount and implement the stop-loss measures. Tighten the adapter sleeve properly. Study the accuracy of the shaft and FAG bearing housing. Axial preloading. The side of the raceway wheel is fastened. Bond the mating surface. Apply a slip agent to the mating surface.

12. Burns

Damage state: The race wheel, rolling element and cage are heated rapidly during rotation until discoloration, softening, welding and breakage.

Cause: Poor lubrication. Excessive load (preload is too large). The speed is too high. The play is too small. Intrusion of water and foreign matter. The accuracy of the shaft and FAG bearing housing is poor and the deflection of the shaft is large.

Action: Study lubricants and lubrication methods. Correct the choice of FAG bearings. Research fit, FAG bearing clearance and preload. Improve the sealing device. Check the accuracy of the shaft and FAG bearing housing. Improve the installation method.

13. Electro-erosion

Damage state: The so-called electric erosion refers to a phenomenon in which a current flows through a thin lubricating oil film when a circulating weight-weighted FAG bearing race wheel and a contact portion of a rolling element flow, and local melting and unevenness appear on the surface thereof.

Cause: The ground potential difference between the outer ring and the inner ring.

Action: When setting the circuit, the current will not flow through the FAG bearing part. Insulate the FAG bearing.

14. Rusty, corrosion

Damage state: The rust and corrosion of FAG bearings include raceway wheels, pit rust on the surface of rolling elements, total rust and corrosion.

Cause: Intrusion of water, corrosive substances (paint, gas, etc.). The lubricant is not suitable. Water droplets are attached due to condensation of water vapor. Stop when the temperature is high and wet. Heavy rust prevention during transportation. The storage status is not suitable. Not suitable for use.

Action: Improve the sealing device. Study lubrication methods. Anti-rust measures when stopped. Improve storage methods. Pay attention when using it.

15.Installation scars

Damage state: axial linear damage caused to the raceway surface and rolling surface during installation and disassembly.

Cause: Impact load during installation and disassembly of the inner ring and outer ring at an inclined installation or disassembly.

Action: Use a punching machine with the right tool to prevent shock loads. Centering between each other during installation.

16. Discoloration

Damage state: The raceway wheel and the rolling elements and the cage are discolored due to temperature rise and lubricant reaction.

Cause: Poor lubrication. The reflection with the lubricant causes a hot immersion. The temperature rises greatly. [1]

Action: Improve the lubrication method.

Source: Luoyang Zhongyue Precision Bearing Co., Ltd.

Concerned about surprises

Tags: FAG interference amount mating surface clearance electric erosion

Previous: China Nonferrous Metals Industry Technology Introduction Next: Detailed Process and Process of Cold Plating

Putty Knife

Putty Knife,Solid Plastic Handle Putty Knife,Soft Grip Handle Putty Knife,Wood Handle Scraper

PRO-CHARGER CO., LTD. (VICTOR HERO HOLDINGS LTD, TIME VALUE LTD.) , https://www.pro-chargerco.com