Working principle and usage method of motor bearing grease

Working principle and usage method of motor bearing grease

The lubrication of the motor bearing relies on the lubricating oil that is precipitated when the three-dimensional fiber network structure in the grease is broken under the action of shear, forming a layer of lubricating film on the rotating elements of the bearing, the bearing seat and the bearing race for lubrication Effective.

When the newly installed grease bearing starts to rotate, the grease is first thrown out from the rotating element, and quickly circulates and cools in the cavity of the bearing cover. Then the grease is cut into the rotating element from the outside of the rotating bearing race. The part of the grease close to the surface of the rotating element breaks the fiber network structure by the shearing action, so that a small amount of precipitated lubricant is in the rotating element and the seat. A lubricating film is formed on the surface of the ring. The rest of the grease still maintains an intact fiber network structure, which plays a role of cooling and sealing.

When the bearing just starts to rotate, the turbulence of the grease generates frictional heat, which causes the bearing temperature to rise to a maximum. Then, with the continuous shearing action, the lubricating oil is precipitated, and after a layer of lubricating film is formed on the rotating elements of the bearing, the bearing seat and the bearing race, this frictional heat is gradually reduced, and at the same time, it is continuously thrown out from the rotating elements. The lubricating grease in the cavity of the bearing cap has a good cooling effect, so that the temperature of the bearing gradually decreases and approaches an equilibrium value, as shown in the figure below.

From the working principle of the above motor bearing grease, it can be seen that the grease in the motor bearing does not rely on the grease to adhere to the metal surface for lubrication, but like a liquid to circulate continuously in the cavity of the bearing cover. That is, it is continuously thrown out from the rotating element into the cavity of the bearing cover, and continuously returned from the cavity of the bearing cover to the rotating element, thereby repeated shearing and cooling, which ensures that the bearing does not generate abnormal temperature rise. The modern high-grade electromechanical department bearing grease must be able to ensure that it runs in the bearing according to this working principle.

The amount of grease filled in the motor bearing should be kept in 1/3 of the total cavity in the bearing cover, leaving 2/3 of the space, so as to ensure that there is enough space for the grease thrown from the rotating elements to fully cool down Return to the rotating element to achieve the purpose of controlling the temperature rise. At the same time, pay attention to the amount of filled grease not to be too small. Because the amount of grease is too small, the grease thrown from the rotating element cannot return from the bearing cap to the rotating element, resulting in insufficient lubrication.