Abstract: Disc brakes have heretofore not received wide utilization on fork lift trucks because of the problems of space and lubrication. A lift truck has a very small, central hub area which greatly limits the size and type of brake and the ways of lubricating the brake. The disc brake actuator (7) of the present invention meets the problem of incorporating disc brakes (10) into the limited space of the wheel drive assembly (22) of a fork lift truck by mechanically applying the disc brakes (10) through axial rotation of the actuator (37,50) about the jack shafts (18). The difficulty of lubricating the disc brakes (10) is overcome either by utilizing the brake actuator (37) as a conduit for lube oil from the differential (11) or sealing off the lube oil from the differential (11) with a seal (58) in the brake actuator (50) so that the disc brakes (10) can be independently lubricated.

Abstract: A wheel drive assembly (10) for a vehicle has a spindle (14) with a bore (24). A shaft (30) is positioned within the bore (24) and defines a cavity (44) between the shaft (30) and spindle (14). A brake (46) is positioned within the cavity (34). A planetary gear assembly (74) is positioned about the shaft (30) and contained within the spindle bore (24). With the brake (36) and planetary gear assembly (40) positioned within the spindle (14), the spindle (14) constitutes a reaction ring gear. Bearings (94,96) riding on the spindle (14) can be spaced apart substantially the entire length of the spindle (14) to reduce disproportionate or excessive loading on the bearings (94,96). Serviceability of the drive assembly (10) is simplified owing to the arrangement of its components and the overall width of the vehicle is not increased while accommodating the widely spaced bearings and spindle support for the planetary gear assembly ( 74).