Lubrication is a necessary condition for the normal operation of motor bearings. Rolling bearings are grease-lubricated and are the most widely used bearings in motor products. Rolling bearings are classified into open and sealed bearings. Sealed bearings are filled with grease when leaving the factory and do not need to be filled again when assembling the motor. The maintenance of the bearings can be replaced according to the service life of the motor or bearing. For most motors, open bearings are used, that is, the motor manufacturer fills the bearings with appropriate grease according to different operating conditions.
In the actual operation process of the motor, it is found that some motors have stable bearing operation when they are just started, but after running for a period of time, obvious bearing noise due to poor lubrication occurs. This problem occurs from time to time during the test stage of the motor and the operation stage of the motor.
The fundamental reason for the poor lubrication of the motor bearing is that the original grease cannot be circulated after being thrown out. To solve this problem, it is necessary to start with the design of the motor bearing system, and through the necessary physical space constraints, reduce the range of grease movement, and force the thrown grease to enter the bearing cavity again.
Through the comparative analysis of motor bearing structures of different motor manufacturers, it can be found that some motor manufacturers improve the bearing lubrication system by adjusting the cavity size of the bearing cover, while some motor manufacturers restrict the flow space of grease by adding the idea of bearing oil-slinging pan.
In addition to the constraints and limitations of the lubrication space of the bearing system, the matching relationship between the bearing and the bearing seat, and the bearing and the bearing chamber is very critical to prevent the degradation and failure of the grease after the bearing heats up due to improper matching; the axial position control of the motor rotor, that is, what we call axial movement control, should also be used to reduce the problem of grease being forced to be thrown out of the shaft cavity.