Variable preload ball drive

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings for the purposes of illustrating the preferred embodiment of the invention only, and not for the purpose of limiting the same, FIG.
1 shows a variable preload ball drive 10 for transmitting power from an input drive 12 to an output drive 14.
The input drive device 12 may have a variable speed device such as a motor vehicle engine.
The output drive device 14 may be coupled to a variable speed, variable power demand device such as an air conditioner, alternator or power assist device.
The ball drive 10 generally comprises an outer race 15, an inner race assembly 16, a circumferential series of torque balls 18, a spider 20 and a preload assembly 22, all of which are concentrically disposed with respect to a rotational axis 24.
The input spider 20 is drivingly connected to the input drive device 12.
The inner race assembly 16 and the preload assembly 22 are drivingly connected to an output shaft 26 coupled to the output drive device 14.
The spider 20 drives the torque balls 18 in planetary movement with respect to the outer race 15, fixed to a frame member 28.
to thereby drive the inner race assembly 16 at a constant ratio increase in speed.
The variable preload assembly 22 cooperates with inner race assembly 16 as hereinafter noted to provide for variable loading of the torque balls 18.
The outer race 15 is generally cylindrical and has an outer cylindrical surface fixedly received within a corresponding bore in the frame member 28 by any suitable means not shown here in detail.
An annular raceway 30 is formed in the inner cylindrical surface of the outer race 15.
The radius of the raceway 30 is slightly larger than the radius of the torque balls 18.
The inner race assembly 16 is a torque dividing two-piece construction having a fixed race 32 fixedly connected to the outer end of the drive shaft 26 and a loading race 34 rotatably supported by the outer surface of the drive shaft 26 and axially movable with respect to fixed race 32 under the action of the variable preload assembly 22