| 摘要 |
<p>A hydraulically actuated multi-cylinder reciprocating piston pump includes two double acting cylinder and piston type hydraulic actuators each connected to a working fluid piston and hydraulically interconnected by a control circuit to provide alternate delivery and suction strokes to the respective working fluid pistons. The piston rod chambers of the hydraulic power actuators are interconnected to transfer operating fluid therebetween to drive the actuating pistons on their return strokes. Each cylinder actuator is provided with a sleeve type pilot valve interposed in a hydraulic circuit including a main spool type control or distributing valve for operating the cylinder actuators in timed relation to each other. The hydraulic circuit includes a main high pressure source of actuator operating fluid and a lower pressure source of pilot actuator and leakage make up fluid for the actuator piston transfer circuit. The main power fluid control valve is configured to prevent stalling of the hydraulic actuators and to prevent premature shifting of the actuators so that a substantially uniform delivery of working fluid is provided by the pump.</p> |
