Angular contact bearings better support "combined loads" (loading in both the
radial and axial directions) and the contact angle of the bearing should be
matched to the relative proportions of each. The larger the contact angle
(typically in the range 10 to 45 degrees), the higher the axial load supported,
but the lower the radial load. In high speed applications, such as turbines, jet
engines, dentistry equipment, the centrifugal forces generated by the balls will
change the contact angle at the inner and outer race.
The contact angle is defined as the angle between the line joining the points of contact of the ball and the raceways in the radial plane, along which the load is transmitted from one raceway to another, and a line perpendicular to the bearing axis.
The main types of angular contact ball bearings,
Single row angular contact ball bearings
Double row angular contact ball bearings
Four-point contact ball bearings