SURFACE FINISHES FOR USE IN OIL PUMPS AND METHODS OF PROVIDING SURFACE FINISHES IN OIL PUMPS

摘要

A pump wherein at least a first engaging surface is formed on the housing adjacent to the pumping chamber. At least a second engaging surface formed on the pumping mechanism that frictionally engages the first engaging surface during movement of the pumping mechanism with respect to the housing. A surface finish is provided on at least one of the first engaging surface or the second engaging surface to create a plurality of recesses therein to reduce the surface area of the first and second engaging surfaces that is in frictional engagement.