Bearing arrangement for a tracker ball

摘要

In a tracker-ball bearing arrangement, a tracker ball formed by a rotatable sphere 10, for example of phenolic resin, is supported by three bearing projections 11, for example of ruby, providing sliding contact with the sphere 10. As shown in Fig. 1, the arrangement may include additional bearing projections 15 on an upper bearing plate 14 to ensure equal support of the sphere in any orientation.