There are contact angles among races and balls.the standard contact angles are 15°,25°and40° Bearings with a larger contact angle can accommodate much larger axial load.those with a smaller are much suitable for high-speed rotation.
Double-row Angular Contact Ball Bearings
Two Single-row Angular Contact Ball Bearings can be mounted in pair.they can be mounted with back face to back fave(DB),front face to front face(DF)or back face to front face(DT).
Four-point contact ball bearings
There are two typical types.one is QJ000(176000) type, which has split inner rings and contact angles of 35°
The other one is QJF000(16000)type,which has two split outher rings and contact angles of35°.
They can accommodate radial loads and axial loads and axial loads in both directions.
They are mainly applied in wire and bar mill, and roll neck of narrow strip mill to p; a y a role of thrust
One this kind of bearing can replace two angular contact ball bearings matched pair in fact to face or back to back.
Each rolling element is in contact with each of the inner and outer rings at a single point, and both contact points lie on the contact angle line.the line runs to either the right or the left depending on the direction of the axial load.