| 摘要 |
<p>A reciprocating actuator is axially connected to drive a reciprocating pump. An exhaust tube (52), open to the outside, passes through a piston (21) of the reciprocating actuator and into an inner hole (62) axially disposed in a working rod that connects an actuator piston (21) of the reciprocating actuator to the reciprocating pump. A valve mechanism (31) communicates a chamber (26) above the actuator piston (21) with the inner hole (62) during upward motion of the piston (21), whereby actuator fluid above the piston (21) is exhausted to the outside through the exhaust tube (52). The resulting axial exhausting of the actuating fluid permits inserting a large portion of the device into a drum for pumping of liquid. The invention permits use of a two-stage rod system, which is capable of obtaining high pumping pressure. The inner hole (62) is communicated with a space whose volume changes when the working rod makes a vertical movement. Different piston sizes can be used in the reciprocating actuator and the reciprocating pump, whereby higher or lower pump pressure is attainable. <IMAGE></p> |
