loading

Knowledge

Home  > Knowledge  > 

Common failure modes and countermeasures of rolling bearings

Common failure modes and countermeasures of rolling bearings

2021-06-25

1.Unilateral limit position of channel spalling off

The spalling at the limit position of the single side of the channel is mainly manifested in the serious spalling belt at the junction of the channel and the retaining edge. The reason is that the bearing is not installed in place or sudden axial overload in the process of operation. The countermeasures are to ensure that the bearing is installed in place or the outer ring fit of the free side bearing is changed to a clearance fit, in order to compensate the bearing when the bearing is overloaded. If it is impossible to ensure that the installation is in place, the oil film thickness of the lubricant can be increased (to improve the viscosity of the lubricant), or the load of the bearing can be reduced to reduce the direct contact of the bearing.

2.The channel peels off symmetrically in the circumferential direction

Symmetric peeling shows that the inner ring is peeling off the surrounding ring, while the outer ring is peeling off in a circumferential symmetrical position (that is, the short axis direction of the ellipse), which is mainly caused by the excessive ellipse of the bearing box hole. When the bearing is pressed into the bearing box hole with a larger ellipse, the outer ring of the bearing will produce an ellipse, and the clearance in the short axis direction will be significantly reduced or even negative. Bearing under the action of load, the inner ring rotation produces circumferential spalling marks, the outer ring only produces spalling marks in the symmetric position of the short axis direction, which is the main reason for the early trial sale of the bearing. The countermeasure is to improve the machining precision of the bearing box hole.

3.The raceway is slanting off

The inclined peeling ring belt on the bearing working surface indicates that the bearing is working in an inclined state when the inclination Angle reaches

Precision, improve the use of conditions, and strengthen the quality control in the bearing manufacturing process.5.Cage fracture is an occasional abnormal failure mode. The reasons are mainly as follows: A.Abnormal load of the cage.Such as the installation does not reach the designated position, slope, etc of a large amount of interference of the clearance is reduced, increasing frictional heating, soften surface, the early abnormal spalling, along with the expansion of peeling, flaking, foreign body into the cage pocket hole lead to keep running block and generate additional load, aggravated the wear and tear in the cage, so with deterioration of the cycle, it may cause maintains a fracture.

B.Poor lubrication mainly refers to the bearing running in a state of poor oil, easy to form adhesive wear, so that the working surface of the state of evil, adhesive wear produced tears easy to enter the cage, so that the cage produces abnormal load, may cause the cage fracture.

C.The intrusion of foreign matter is a common mode of cage fracture failure. Due to the invasion of hard foreign bodies, the wear of the cage is aggravated and the abnormal additional load is produced, which may lead to the cage fracture.

D.Creep phenomenon is also one of the causes of cage fracture. The so-called creep multi-finger ring sliding phenomenon, in the match

In the case of insufficient interference of the joint plane, the load point moves to the surrounding direction due to sliding, resulting in the phenomenon that the position of the ring deviates from the relative axis or the outer shell to the circumferential direction. Once the creep occurs, the mating surface is significantly worn, and the wear powder may enter the bearing interior, forming the process of abnormal wear, raceway spalling, cage wear and additional load, and even may cause the rupture of the support.

E.Cage fracture may be caused by cage material defects (such as cracks, large different metal inclusions, shrinkage holes, bubbles) and riveting defects (lack of nails, padded nails, or the gap between the two parts of the cage and serious riveting). Take measures to strictly control the manufacturing process.

6.Card injury

The so-called sticking injury is the surface damage caused by the summary of minor burns on the part of the sliding surface injury. Linear scars in the circumferential direction of the slide surface and rolling surface.The roller end face of the pendulum line scar, close to the roller end face of the axial torus wound. The main reasons for jamming are: excessive load, excessive preloading, poor lubrication, foreign body bite, the tilt of inner and outer rings, shaft deflection, shaft, bearing box accuracy is poor, etc. This can be solved by proper preloading, improved lubricants and lubrication methods, and improved accuracy of shafts and bearing boxes.

7.Wear and tear

Wear failure refers to the relative sliding friction between the surfaces, resulting in continuous wear of metal on the working surface of the loss of efficiency. The main factors that cause wear failure are lubricant failure or lack of lubricant, the wrong lubrication mode, the grinding force into the bearing, and the load is too large. The solution can be improved by improving the lubricant or lubrication method, enhance the performance of the sealing mechanism, etc.

8.scratch

The so-called abrasion is in the raceway surface and rolling surface, with the rolling body skid and oil film heat crack produced by the small burn of the summary and surface damage. Produces surface roughness with adhesion. The main causes of abrasion are high-speed light load, rapid acceleration and deceleration, improper lubricant, water intrusion, and so on. Solution: improve preloading, improve bearing clearance, use good oil film lubricant, improve lubrication method, improve the sealing device, etc.

9.indentation

Bite into small metal powder and foreign bodies, etc. in the raceway surface or the rotary surface of the dent or due to the impact of installation, etc., in the rolling body spacing interval formed a concave surface (Brinell hardness indentation). Causing the main factors of indentation method and other methods to solve.

11.Current corrosion (electric corrosion)

The so-called electric erosion refers to the current in the rotating bearing ring and the contact part of the rolling body flow, through the thin lubricating oil film sparks, the surface of the local melting and concave-convex phenomenon. The main causes of current corrosion are the potential difference between the outer ring and the inner ring and the effect of static electricity. Solution: When setting the circuit, the current does not pass through the bearing to insulate the bearing, and the electrostatic grounding device is connected.

12.The rust and corrosion of bearings include raceway, pit rust, comprehensive rust, and corrosion on the surface of the rolling body.

The rust and corrosion of bearings will cause pit rust on the surface of the ring and rolling body, pear skin rust and pit rust with the same spacing of rolling body, and comprehensive rust and corrosion. There are many reasons for the rust and corrosion failure of rolling bearings. The main reasons are: the invasion of water or corrosive substances (paint, coal gas, etc.), improper lubricant; Due to the condensation of water vapor with water droplets, high temperature and wet stop, transportation over the course of poor rust prevention, storage state are not appropriate, use is not appropriate.

The solutions are as follows: improve the sealing device, study the lubrication method, use effective anti-rust measures when to stop, improve the storage method, and pay attention to the use.

3. In addition to the above common failure forms, there are many failure forms of rolling bearings in actual operation, which need to be further analyzed and studied.

To sum up, from the common failure mechanism and failure mode of bearings, it can be seen that although rolling bearings are precise and reliable mechanical foundation parts, improper use will also cause early failure.

Under normal circumstances, if the bearing can be used correctly, it can be used until the fatigue life. The early failure of bearings is mainly caused by the manufacturing accuracy, installation quality, use of strip, lubrication effect, invasion of external foreign matter, thermal influence and sudden failure of the main engine. Therefore, the correct and reasonable use of bearings is system engineering. In the application design, manufacturing, and installation process of bearings, corresponding measures can be taken to improve the service life of bearings and main engines effectively, which is the common responsibility of bearing manufacturing enterprises and customers.

Radial clearance adjustment method for cylindrical roller bearings

The composite radial load on the fixed load is exposed from the local ring raceway fixed ring and transmitted to the corresponding shaft or bearing local. This load is characterized by the fact that the radial load vector is relatively static in the composite and loop. Load bearing rings can be used relatively loosely.

Rotating load is applied to the cylinder rotating along the circumferential direction of the synthetic radial load on the full cylindrical roller bearing ring, the rotation of various parts, such as a load of rotation, which is borne by the synthetic vector phase ring radial load rotation. The rotating load ring is closely matched, in special cases, the load, such as elected, is light or heavy at low speed under the load, only occasionally the ring, the bearing is made of hard material and the surface roughness is high, the rotating load bearing medium finger can also be used to be looser.

Third load oscillation, the load or no load direction of synthetic direction uncertain load ring radial load, its characteristic is the synthetic ring radial load vector circle, in a certain region within the impact load, the vibration of the load, its direction is swinging, roll to bear a certain area, or acting on the bearing load, the load value change constantly. To bear the load swing, the outer ring, and shaft, bearing, the hole should be closely used.

The commonly used methods for adjusting the radial clearance of full cylindrical roller bearings are as follows:

1. The side clearance of cylindrical and elliptical bearing bushing can be adjusted by manual scraping or repairing and scraping after padded turning in the middle of the bearing.

2. The top clearance of cylindrical and elliptical bearing bush can be adjusted by manual scraping or by adding a pad to the face of the bearing when the situation permits.

3. In principle, scraping and adjusting the clearance of the bearing bush are not allowed for the multi-wedge fixed bearing bush. When the clearance is not suitable, a new tile should be replaced.

4. Tilting bearing for the multi-oil wedge is not allowed to repair and scrape tile. When the gap is not suitable, the tile should be replaced. The thickness of the adjustable tile can be adjusted by adding stainless steel pad under the tile behind the adjusting block or thinning the adjusting block thickness method to adjust the amount of tile. Pay attention to the multi-wedge tilting bearing bush, the thickness error between the same group of tiles should be less than 0.01mm.

rolling bearings

Chat Online 编辑模式下无法使用
Leave Your Message inputting...
Thanks for your message, we will reply you soon in our working time!