What factors can affect the preload of the main shaft bearing

The core factors influencing the preload of the main shaft bearing mainly fall into the following categories:

The inherent properties of the bearing ‌

Different types of bearings (such as angular contact bearings and thrust ball bearings), as well as parameters like the inner diameter, outer diameter and width of the bearings, will directly determine the setting range of the preload force. The requirements for preload force adaptation of different models of bearings vary significantly.

Spindle speed ‌

When the bearing speed exceeds the critical value, the gyroscopic torque will become the core factor affecting the preload force. The higher the speed, the greater the required preload force. Under high-speed working conditions, the change in preload force will directly affect the rigidity and temperature rise performance of the main shaft.

Working conditions ‌

The actual load that the bearing bears and the temperature changes during operation will alter the thermal expansion of the internal components of the bearing, thereby changing the initially set preload. Under heavy-load and large temperature difference conditions, the fluctuation of the preload will be more significant.

Pre-tightening method: ‌

Under high-speed working conditions, the preload force will increase or decrease significantly due to the temperature difference and centrifugal force of the parts. Constant pressure preloading relies on springs to maintain pressure, and the stability of the preloading force under dynamic working conditions is far superior to that of positioning preloading.

Bearing structural parameters ‌

Structural parameters such as the curvature radius of the inner and outer raceways, the number of balls, the ball diameter, and the initial contact Angle will change the contact state under the same preload, indirectly affecting the actual effective preload force.