How to cool the hot lathe spindle bearings?

The shaft parts of the machine tool, especially the main shaft, are generally assembled with rolling or plain bearings and rotate at a high speed, sometimes generating high heat. If this phenomenon is not eliminated in time, it will cause the bearing to overheat and cause the temperature of the corresponding part of the machine tool to rise and cause thermal deformation. In severe cases, the spindle and the tailstock will not be equal, which not only affects the precision and machining accuracy of the machine itself, but also The machine tool bearings will burn out.

On a lathe, the main shaft is generally assembled with a rolling bearing or a plain bearing and rotates at a high rotational speed, thereby generating a large amount of heat.

The main shaft bearing is the main heat source in the headstock. If the heat generated by it is not discharged in time, the bearing will overheat and the temperature of the corresponding part of the lathe will rise, resulting in thermal deformation. In severe cases, the main shaft and the tailstock will not be equal. This not only affects the accuracy and machining accuracy of the lathe itself, but also burns the bearings and even the main shaft.

The reason for the overheating of the main shaft can be summarized as follows: the friction of the main shaft bearing is too small to increase the friction and frictional heat; in the long-term full-load turning, the rigidity of the main shaft is reduced, bending occurs, and the transmission is not stable and generates heat. When troubleshooting this problem, it should be noted that it is necessary to adjust the clearance of the main shaft bearing; the supply of lubricating oil should be controlled to clear the oil passage; try to avoid the long-term load on the lathe.

According to years of practical experience, the main measures to reduce the heat generation of bearings are:

(1) Appropriately reduce the diameter of the rolling elements. Reducing the diameter of the rolling element reduces the centrifugal force and the gyro moment, thereby reducing friction and reducing heat generation.

(2) Adopt new materials. For example, ceramic materials are used as rolling elements. Compared with steel ball angular contact ball bearings, ceramic ball bearings have reduced rolling and sliding friction between the balls and the raceways at high speeds, and the heat generation is reduced.

(3) Use a reasonable lubrication method. Lubricating methods such as oil and gas and oil mist not only have lubrication effect on the bearing, but also have a certain cooling effect.

Reprinted from the network