The raceway between the inner and outer ring of an angular contact ball bearing has certain offset angle in the direction of the bearing axis. It attributes that it is designed to carry combined loads. The combined loads are the simultaneously acting radial and axial loads. The offset angle between the raceway of inner and outer rings creates a contact angle, the greater contact angle creates greater axial loads carrying capacity. The contact angle (α) is defined as the angle between the ball and the raceways at the radial plane. The contact angle between a ball and raceways draws a line which perpendicular to the bearing axis, where the load is transmitted from one raceway to another.
Angular contact ball bearings are available in different configurations, i.e. single row, double row, and four point contact ball bearings.
Single Row Angular Contact Ball Bearing
Single row angular contact ball bearings are designed to accommodate acting axial loads in one direction only. An acting force in axial direction will be produced when the bearing is under radial loads, and this axial acting force must be balanced by a counter force. Due to this, single row angular contact ball bearings are normally fitted or paired against another bearing. The most common contact angle is 40°, also available 25° and 30°.
Double Row Angular Contact Ball Bearings
Double row angular contact ball bearings are basically a combination or back to back mounting of 2 pieces of single row angular contact ball bearings. This combination of bearings, double row angular contact ball bearings can accommodate radial loads, and axial loads acting in both directions.
Four Point Contact Ball Bearings
Four point contact ball bearings have their inner rings split in to 2 pieces with a contact angle of normally 35°. Its split inner rings enable a large number of balls to be integrated in the bearing and creating higher load carrying capacity. This design has overcome the shortage of single row angular contact bearings; they support axial loads acting in both directions. Another advantage of four point contact ball bearings is it takes up considerably less axial space than double row angular contact ball bearings.