Remote constant hydraulic pressure control - has motor servo controlled by valve actuated by motor inlet-outlet pressure differential

摘要

The hydraulic constant pressure control is intended for automatic remote control of an hydraulic motor (7). It comprises a control valve (1) with two outlets (2, 3) connected to the two ends of a servo-cylinder (6) of the motor. The valve (1) is a sliding valve whose sliding member is rigidly or resiliently coupled to the piston (8) of an actuating cylinder (9). The cylinder (9) is connected to a control pressure inlet line (10) and an outlet line (11) and the piston (8) is spring-loaded (12) and pressure-loaded on the same side by a plunger (13). The plunger is actuated by the pressure in a pressure line (14) which is connected to the inlet (15) and outlet (16) of the motor (7) via a double-acting non-return valve (27).