Four Point Contact B. SKF QJ330 N2MA

The SKF QJ330 N2MA four-point bearing (150x320x65 mm) accommodates axial loads in both directions and features a split inner ring and retaining grooves.

The QJ330 N2MA four-point bearing is a single-row radial angular contact ball bearing in the SKF Explorer design, with raceways designed to accommodate high axial forces in both directions. With a bore of 150 mm, an outside diameter of 320 mm and a width of 65 mm, this rolling bearing requires less axial installation space than double-row bearing arrangements. The two-piece inner ring allows for a large number of balls, which enhances the load-carrying capacity during operation.

For which operating conditions is the QJ330 N2MA four-point bearing designed?

It is primarily used in bearing locations where predominantly axial forces occur within limited axial installation space, or as a pure axial bearing in combination with a separate radial bearing. The two retaining grooves in the outer ring, offset by 180 degrees, allow the bearing to be secured against rotation within the housing. The brass cage guides the rolling elements even under demanding thermal and dynamic operating conditions.

What is the significance of tolerances and design for the QJ330 N2MA?

This design combines dimensional accuracy to tolerance class P6 with higher running accuracy to P5, which promotes smooth concentricity. Thanks to the split inner ring, the bearing can be fitted in separate stages: the outer ring with ball cage and the inner ring halves can be fitted onto the shaft and housing one after the other. Designed for a temperature range of –30 to +200 degrees, the open bearing requires a suitable external housing seal as well as a tailored lubrication system.