SHOCK ABSORBER FOR OIL WELL PUMPING UNIT

摘要

A shock absorber for use between the reciprocating member of an oil well pumping mechanism and a polish rod connected to the rod spring and movable along a vertical pumping axis. The shock absorber comprises an upper and lower end plate having a peripheral surface around the plumping axis and defining a polish rod clearance opening. A coil spring is located between the plates and is concentric with and surrounding the pumping axis. A friction reducing centering head secured to at least one of the plates (preferably the lower plates) centers polish rod in the clearance opening and holds the polish rod away from the peripheral wall of the plate.