How to detect the quality of bearings?

This is according to the vibration standard of bearing quality inspection.

There are the following two standards: national standard of vibration acceleration (commonly known as Z standard) and vibration speed standard (commonly known as V standard).

Yangzhou Fuenqi said: Bearings can generally show obvious acceleration increase in operation. With the development of fatigue, the vibration speed and displacement increase gradually, indicating that the bearing has been damaged by fatigue. Especially when testing bearings, pay close attention to whether the vibration value is unstable (it is recommended to use analog pointer instrument, which can be observed very clearly). If it swings, it indicates that there is an unstable vibration signal and the acceleration is also very large, especially when the speed increases at the same time, it is likely that there is a bearing "slip" fault.

For the new equipment, although the vibration is very small, which meets the national standard, there is a small amplitude vibration and swing phenomenon in the bearing part. After eliminating the problem of bearing matching, it is likely that there is something wrong with the geometric size of the bearing, such as the ellipse of the bearing steel ring. When the roller passes through the long axis of the ellipse, it may be blocked instantly due to the reduction of the gap, and the subsequent rollers will continue to squeeze, resulting in sliding friction, and each roller will have sliding friction here, resulting in unstable signals. Special attention: when checking rolling bearings, you must not ignore the change of bearing acceleration value. Acceleration can predict the failure of rolling bearings earlier.