摘要 |
A control system for a motor through which a specific rotary output is obtained from a given input signal by controlling an operational supply of fluidic energy. The control system includes a direct mechanical servo which receives the input signal to control a rotary plate directional valve through which the operational supply of fluid is communicated to the motor. The direct mechanical servo includes a compound epicyclic gear train and an intermittent motion gear mechanism which compares the input position with the output position of the motor to establish a feedback signal which repositions the rotary valve plate directional valve to a null position when the rotary output equals that requested by the input signal. The control system further includes a regulator assembly which receives a variable reference signal to control the fluid pressure of the supply fluid. The variable reference signal which represents the work performed by the motor also passes through a relief valve. When the output torque of the motor reaches a predetermined value, the relief valve opens and a portion of the fluid supplied to the motor is vented to an exhaust conduit to protect any mechanism operated by the motor from receiving excessive torque. |