Four Point Contact B. SKF QJ220 N2MA

The SKF QJ220 N2MA four-point bearing, measuring 100 × 180 × 34 mm, accommodates high, fluctuating axial loads whilst maintaining a compact axial design.

The QJ220 N2MA four-point bearing is a single-row radial ball bearing from the QJ series with a 100 mm bore, 180 mm outer diameter and 34 mm width. SKF’s Explorer design is specifically engineered to accommodate high axial loads in both directions. The two-piece inner ring provides space for a large number of rolling elements, which enhances the axial load-carrying capacity. The design transmits axial forces in a dimensionally stable and controlled manner within a confined installation space.

For which load requirements is the QJ220 N2MA four-point bearing used?

The four-point bearing is primarily used where alternating axial forces need to be supported within a limited axial installation space. This design is often used as a pure axial bearing in combination with a separate radial bearing. The increased dimensional accuracy to tolerance class P6 and the running accuracy to P5 ensure smooth running characteristics under demanding operating conditions. However, this design is not intended for bearing arrangements subject to purely radial main loads.

What is the function of the brass cage and retaining grooves in the QJ220 N2MA?

The solid brass cage guides the balls at operating temperatures ranging from –30 to +150 degrees. The bearing can be secured in the housing using dowel pins via the two retaining grooves in the outer ring, which are offset by 180 degrees. This prevents the outer ring from rotating unintentionally. As this is an open bearing without a seal, users must select the lubricant and housing seal to suit the specific environmental conditions. The component has a standard radial bearing clearance.