About the purpose of bearing preload
The main purpose and representative examples of the preload are as follows:
(1) Improve the guiding precision of the bearing. Spindle bearings and measuring instrument bearings for machine tools.
(2) Improve rigidity. The main shaft bearing of the machine tool and the pinion bearing of the car differential mechanism.
(3) Reduce vibration and noise during operation. Bearings for small motors.
(4) Prevent the sliding of the rolling elements relative to the inner and outer ring raceways due to the moment of inertia. High-speed rotating angular contact ball bearings and thrust ball bearings.
(5) Compensate for wear and pressure during operation and extend working life.
(6) Keep the rolling element and bearing ring in the correct position. Thrust ball bearings and thrust spherical roller bearings mounted on a horizontal shaft.
Shaft guidance accuracy
A shaft supported by a preload bearing has a high guiding accuracy because the flexing ability of the shaft under load is limited by the preload. The pre-pressure differential bearing has high guiding precision and high rigidity, and can maintain accurate and constant meshing, and the additional dynamic force is small, so the running noise is low, and the meshing gear has a long life.
The stiffness of a bearing is defined as the ratio of the force acting on the bearing to the amount of elastic deformation of the bearing. In a certain load range, the elastic deformation of the preloaded bearing is smaller than that of the preloaded bearing.
Low noise operation
The smaller the running clearance of the bearing, the better the guidance of the rolling element in the unloaded area, and the lower the noise during the running of the bearing.
Compensation for wear and pressure
During operation, the wear and pressure of the bearing increase the clearance, but can be compensated by the preload.
Long working life
In some cases, bearing pairs and preloads can increase operational reliability and extend service life. Because the proper amount of preload can improve the bearing load distribution, it can increase its working life.
Reprinted from the network