When the bearing is rotating, the free vibration of the cage and its impact with the rolling element or the ring will cause noise.
This noise may appear in various bearings, but the sound pressure level is low and it is low frequency. Its characteristics are:
A. Whether it is a stamped cage or a plastic cage, this noise may be generated.
b. Whether it is thin oil or grease lubrication, this noise will occur.
c. This noise is most likely to occur when the outer ring is under pressure.
d. When the radial clearance is large, this noise is easy to appear.
Due to the gap between cage window holes, cage and ring, which inevitably exist in the finished bearing, it is very difficult to completely eliminate the cage noise. However, it can be improved by reducing assembly errors and optimizing reasonable gaps.
Another type of cage noise is caused by self-excited vibration of the cage caused by friction between the cage and other bearing guide surfaces. The stamping cage of the bearing is thin, the rigidity in the radial and axial plane is low, and the overall stability is poor. When the bearing is rotating at high speed, it will produce self-excited vibration due to bending deformation, causing noise.
When the bearing is subjected to radial load and the grease performance is poor, the rolling element suddenly accelerates after leaving the load zone and collides with the cage, resulting in noise. This pounding sound is inevitable, but with the increase of operating time, its sound will gradually disappear.
