As to why high-speed bearings choose the four-point contact ball structure, this article analyzes the reasons one by one, and provides some theoretical and practical basis for selection.

First of all, select the slewing bearing, which is positioned at a high speed, at least above 30rpm, generally more than 10rpm, and the four-point contact ball bearing structure is preferred.

Secondly, because the ball bearing and the raceway are in four-point contact, which is a point contact, during the movement of the contact point, when the two circles are theoretically absolutely parallel up and down, the flexibility is far more than that of the crossed roller and the three-row ball structure. The latter is usually a line contact motion process and can be understood as a surface contact.

Again, ball bearings can use PTFE cage and copper cage to increase the speed, 60-120rpm.

Due to the structure, noise and vibration will occur at extreme high speeds, usually by grinding the grooves and improving the accuracy to the greatest extent possible to reduce the index. 

The four-point contact ball bearing adopts integral steel cage or PTFE cage, which can improve the reliability and stability of the bearing.