The worm shaft bearings are primarily axially loaded, the load direction changing with the direction of rotation of the worm. The radial loads acting on the bearings are relatively small. A locating-flating bearing arrangement is selected. The locating bearing comprises two universal angular contact ball bearings FAG 7310B.TVP.UA. Suffix UA indicates that the bearings can be mounted in any tandem, O or X arrangement. When the bearings are paired in O or X arrangement and the shaft is machined to j5 and the housing to J6, the bearings feature a small clearance. The two angular contact ball bearings are mounted in X arrangement. Depending on the direction of rotation of the worm shaft, either one or the other bearing accommodates the axial load. A cylindrical roller bearing FAG NU309E.TVP2 is mounted as the floating bearing.
Worm gear shaft
The bearings of the worm gear shaft are mainly radially loaded; the axial loads are relatively low in comparison. A deep groove ball bearing FAG 6218 is therefore provided at the locating bearing end and a cylindrical roller bearing FAG NU218E.TVP2 at the floating bearing end.
The worm gear and the bearings are oil lubricated. The oil level should coincide with the lowest point of the worm teeth pitch circle diameter. The sealing rings at the shaft openings prevent oil from escaping and offer adequate protection against contamination.