Detailed technical content
Designed primarily for axial function
Four-point contact ball bearings commonly have an inner ring split into two halves, allowing more balls to be arranged in a compact cross-section. The raceway design creates contact points through which axial loads can be transmitted in both directions. One bearing can therefore perform a function that, in some arrangements, would require two single-row angular contact ball bearings.
However, this is not a bearing intended to prioritize high radial loads. SKF notes that axial load should be the dominant component in typical arrangements. In many gearboxes, a four-point contact bearing is paired with a separate radial-load bearing, such as a cylindrical roller bearing.
Mounting and locating the outer ring
Because the inner ring is separable, the two inner-ring halves must be clamped axially in the machine assembly correctly. In arrangements where the four-point bearing carries axial load only, the outer ring must have suitable conditions so that it is not forced to carry an unintended radial load. Some designations have a locating groove on the outer ring to prevent the outer ring from rotating.
When replacing a designation, check the QJ product series, axial clearance, cage, locating groove and the manufacturer’s mounting requirements.
