Hydraulic pump with torque limiting drive - has spring-operated torque coupling between pump drive shaft and drive pulley flange

摘要

The belt driven pulley (50) is mounted on the pump drive shaft (27) via a sleeve (57) and a corresponding hub flange (53) of the pulley. A coil spring (59) is wound over the flange and the sleeve to provide a torque coupling between the pulley and the shaft, with limited torque transfer. The coil is wound in the same direction as the rotation. The pump output is controlled by a swashplate (30) displaced against return spring pressure (40) by a servo piston (43). The coil spring of the torque limiter is secured with one end in either the sleeve or the flange. ADVANTAGE - Minimises damage to pump; simple torque limiter.