Needle Roller/Axial Ball BearingsNeedle roller/axial deep groove ball bearings can support axial forces in one direction as well as high radial forces.
Needle roller/axial deep groove ball bearings are available with a full complement ball set or with a cage-guided rolling element set. They do not have an inner ring and are therefore particularly compact in a radial direction. However, they require a shaft raceway that is hardened and ground. If the shaft cannot be used as a rolling bearing raceway, inner rings IR can be used instead.
With type NX, bearing arrangements can be achieved with very small shaft centre distances, such as those that may be present in multi-spindle drilling machines, due to the compact radial dimensions. A sheet steel end cap secured to the radial bearing component grips the shaft locating washing of the axial bearing and holds the axial bearing component together.
Type NKX is not self-retaining. The radial needle roller bearing, axial ball and cage assembly and the shaft locating washer can thus be fitted independently of each other.
Type NKX..-Z is self-retaining, as this has a sheet steel end cap which holds the axial bearing component together. The end cap is designed without lubrication holes and is rigidly connected to the housing locating washer of the radial bearing component.
In order to support axial forces, the axial bearing component must be preloaded to 1% of the basic static axial load rating. Skewing between the shaft and housing is not possible.
If the bearing design capable of supporting axial loads in one direction is to support axial forces from alternating directions, two bearings must be adjusted against each other.