Multiple speed drive system

Abstract

An oil shear clutch-brake unit includes a housing rotatably supporting an input shaft and an output shaft in axial alignment, and the housing encloses a set of interfitting clutch plates and discs for coupling the input shaft to the output shaft and a set of interfitting brake plates and discs for braking the output shaft. A non-rotating actuating member or piston is also enclosed within the housing and is actuated from a neutral position by springs and/or fluid for either clamping the clutch plates and discs or clamping the brake plates and discs. A cooling and lubricating oil is circulated within the housing and between the plates and discs, and the pressure of the fluid for actuating the piston is adjustable for selecting the torque transmitted through the clutch and brake. The output shaft of the clutch-brake unit drives the shaft of a high speed electric motor, and the input shaft is coupled to the output shaft of a gear reducer which mounts on the housing of the clutch-brake unit and is driven by a second electric motor. The assembly of the clutch-brake unit may be arranged in-line with the high speed motor with a direct coupling of the shafts, or the assembly may be located above the high speed motor with a belt drive coupling of the shafts. In one embodiment, a second annular piston is located within the housing and actuates stop pins which hold the first piston in the neutral position.