Causes of bearing cage damage include:
Insufficient bearing lubrication: The lubricant or grease may have dried out and not been replenished in time (maintenance); the wrong grade of lubricant or grease may have been used.
Impact loads on the bearing: Intense vibrations under impact loads cause the rolling elements to strike the cage.
Bearing cleanliness: Poor sealing within the bearing housing allows dust to enter, increasing friction between the rolling elements and the cage, thus damaging the cage.
Incorrect installation: Incorrect bearing installation can damage the cage during installation.
Bearing creep: Creep refers to the sliding of the bearing rings. When the interference fit is insufficient, slippage causes the load point to shift circumferentially, resulting in a circumferential misalignment of the rings relative to the shaft or housing.
Abnormal Loading of Bearing Cages
Improper installation, tilting, excessive interference fit, etc., can easily reduce clearance, increase friction and heat generation, soften the surface, and cause premature abnormal spalling. As spalling expands, foreign objects enter the cage pockets, causing cage operation to be hindered and generating additional loads, accelerating cage wear. This vicious cycle can lead to cage breakage.
Bearing Cage Material Defects
Cracks, large foreign metal inclusions, shrinkage cavities, bubbles, and riveting defects such as missing pins, shims, or gaps at the mating surfaces of the two cage halves, as well as severe riveting damage, can all cause cage breakage.
Intrusion of Hard Foreign Objects
The intrusion of hard foreign objects or other impurities accelerates cage wear. Addressing these causes will significantly extend bearing life. Many bearing failures are not due to the bearing's inherent lifespan, but rather to external environmental factors such as insufficient lubrication, dust ingress, incorrect installation, excessive load, excessive temperature, and misaligned couplings.
Other reasons, such as misalignment of the coupling causing bearing misalignment and uneven force, excessively tight belt installation, and environmental issues, can all damage the bearing or cage.