摘要 |
A piston pump having structure to maintain substantially parallel alignment of a piston rod and a crosshead extension as a crosshead slide undergoes wear. The structure includes a slot defined by the end of the piston rod for receiving a male pilot of the crossband extension. In a further embodiment, the piston rod has a male pilot and the end of the crosshead extension defines a slot for receiving the male pilot of the pisto n rod. The slot may be oblong in a direction transverse to the longitudinal axis of the piston rod. The structure may additionally or alternatively include a centering sleeve attached to the outer surface of the piston rod adjacent to and coaxial with the piston. A backflushing system may be used with the sleeve to keep the piston, piston sleeve, and pump cylinder cool. One such system has a conduit connected to the sleeve and in liquid communication with an annular cavity between the sleeve and the pump cylinder to circulate coolant therethrough.
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