Reasons for cage fracture during rolling bearing operation

The cage in the rolling bearing plays a role in equidistant isolation of the rolling element and preventing it from falling, guiding and driving the rolling element to rotate. Generally speaking, the bearing cage will not be damaged under reasonable working conditions, but incorrect operations in daily production can reduce the service life of the bearing cage. Common failure phenomena of retaining frames include: damaged retaining frames, loose or broken rivets, broken retaining frames, and scattered rolling elements. So, what are the reasons for the fracture of the bearing cage?

1. Insufficient lubrication

During the operation of bearings, if the lubrication work is not done properly, it will affect normal operation. Therefore, it is necessary to ensure that the lubricating oil is sufficient and sufficient for the use of the bearings. If the lubricating oil is insufficient, the bearings will be in a state of poor oil, which will make it easier to form bite wear. This will worsen the condition of the working surface, and the torn materials from bite wear will enter the cage, causing abnormal loads on the cage, which may cause cage fracture.

2. Abnormal load on the cage

When the cage encounters problems during installation, such as inadequate installation, tilting, excessive interference, etc. It is relatively easy to cause a decrease in clearance, which intensifies friction and heat generation during use, softens the surface, and causes abnormal peeling prematurely. As the peeling expands, foreign objects enter the pocket holes of the cage, causing the cage to operate slowly and generate additional loads, exacerbating the wear of the cage. Such a deteriorating cyclic effect may cause the cage to fracture and be scrapped.

3. Foreign objects have invaded the bearing cage

In fact, the intuitive reason for the fracture of the cage is because foreign objects enter the cage. Once foreign objects enter, they will affect the operation of the cage, especially some hard foreign objects, which will intensify the wear of the cage and generate abnormal additional loads, which may cause the cage to fracture.

4. Creep phenomenon

Creep phenomenon is also one of the reasons for cage fracture. The so-called creep refers to the sliding phenomenon of the ring. In the case of insufficient interference on the mating surface, the sliding causes the load point to move in the surrounding direction, resulting in the deviation of the ring from the axis or the outer shell in the circumferential direction. Once creep occurs, significant wear occurs on the mating surface, and the worn powder may enter the interior of the bearing, resulting in abnormal wear, raceway peeling, cage wear, and additional loads, which may even cause cage fracture.

5. The quality of the cage is too poor

The quality issues of the cage also affect its use. If the quality is poor, it is possible to fracture when encountering wear and tear during use, especially when the cage is defective. Common defects include cracks, large foreign metal inclusions, shrinkage holes, bubbles, or riveting defects such as missing nails, cushion nails, or gaps in the joint surface of the two halves of the cage, and serious riveting injuries. These situations are all likely to cause the cage to fracture.

The above is an introduction to the analysis of the causes of bearing cage fracture. In fact, there are many other reasons that can cause fracture, such as when the bearing vibrates, the inertia force can be large enough to cause fatigue cracks, and these cracks can also lead to cage fracture over time. If the bearing exceeds the design speed of the cage, the inertia experienced in the cage may also cause the cage to fracture.