Patent ID: 6290475
Filing Date: 2001-09-18
Classification: F04B

Abstract:
In a sucker rod pump of a type having a plunger that reciprocates within a pump barrel in a sliding fit, an improvement for reducing harm to the pump caused by sand intermixed with the fluid being pumped, the improvement comprising:a lower wiper body connected to a lower end of the plunger and including a hollow cylinder having an axial bore extending completely through it, having an outwardly facing surface, and having a helical groove in said outwardly facing surface;wiper material seated in said helical groove and protruding radially outward beyond said outwardly facing surface of said hollow cylinder; and,a passage extending through said hollow cylinder from the axial bore to a location on said outwardly facing surface outside said helical groove;whereby, on a downstroke of the plunger, the wiper material precedes the plunger to wipe sand from the pump barrel, and simultaneously, some of the fluid being pumped flows under pressure between said hollow cylinder and the pump barrel, carrying the wiped sand through said passage into the bore of said hollow cylinder and imparting a torque to said lower wiper body which causes the plunger to rotate so as to distribute wear on the plunger and the pump barrel more uniformly.