Four-point contact ball bearings QJ3 series are single row, non-self-retaining radial angular contact ball bearings having raceways which are designed to enable axial loads to be accommodated in both directions. They need less axial space than double row bearings. The centre points of curvature of the arc-shaped raceways on the inner and outer ring are offset relative to each other in such a way that the balls are in contact with the bearing rings at four points under radial load.

These bearings QJ3 series have solid outer rings, split inner rings and ball and cage assemblies with brass or polyamide cages. The two-piece inner ring allows a large complement of balls to be accommodated in the bearing. The inner ring halves are matched to the particular bearing and must not be interchanged with those of other bearings of the same size. In an axial direction, four point contact bearings are considerably narrower than, for example, double row angular contact ball bearings. Four point contact bearings are often combined with a radial bearing and used as an axial bearing with radial clearance in a housing.

For the cages, four point bearings have machined brass cages (letter codes MPA for QJ bearings, MPB for Q bearings). Single row, double-sided angular contact ball bearings, type Q.

Application

The angular contact ball bearings are widely used in industrial drive, automotive chassis and gearboxes, compressors, agricultural vehicles and equipment, motors and generators, construction, industrial fan, industrial transmission and other fields.