Installation of Needle Bushes

In the case of needle bushes, it should be noted that their thin-walled outer ring is located in the housing bore with very large compression. A housing with thickness variations and localised imperfections may cause deformation of the bush, which is meant to guarantee a smooth operation. With a geometrically uniform shape and good load distribution the best results can be obtained.

Axial fixation of the needle bushes is not neccessary due to the large pressure in the housing bore.The unmarked side of the bush must remain moved away from any shoulder, seal, cover, spacer or edge of another bush. If it is required for machining, there is a housing with shoulders, the latter must be moved away sufficiently from the bush to avoid deforming at the edge during mounting. The force required to insert the needle bush must be applied without shock to the side marked with the bearing part number. Therefore, it is advised to use a small press fitted with a suitable mandrel to apply uniform force to the bush centred in the housing (fig. 1).

The axial movement of the mandrel should be limited by a shoulder coming against the face of the housing. Needle bushes with one closed end should preferably have the open end presented to the housing bore (fig. 2).

In case this is not possible, the force may be applied to the inside face of the closed end in the case of bushes type DLF (fig. 3) (this should not be done in the case of bushes type BK).

Download our Nadella Needle Bearings catalogue  to get more information.