Four point contact ball bearings

A four-point contact ball bearing makes it easy to simplify machine designs that have a combination of radial, thrust and moment loads because it can handle all three simultaneously. They are primarily used for slow to moderate-speed applications, or where oscillatory movement is predominant.Thanks to a unique ball path geometry that produces twice as many contact points, a four-point contact bearing can resist radial, thrust and moment loads individually or in any combination. It has one row of balls with an inner race and an outer race. The ball grooves are generated from two centers, with each radius slightly larger than the ball radius. Contact angles are typically 35° off the radial centerline, but can be varied to suit the application.Four-point contact bearings are especially effective in applications in which the rotating element has a high ratio of diameter to axial length. Most have a large ratio of bore to section size: the larger this ratio, the thinner and more flexible are the individual races. Thin section bearing sizes range from 1" to 40" and slewing ring bearings range from 4" to 178" O.D.