Short stack bearing assembly

摘要

A mud motor bearing assembly is disclosed for an oil-lubricated downhole drill mud motor. A number of parallel sets of angular contact ball bearings are located between the mandrel and the bearing housing in a sealed, oil-filled chamber to provide all compressive thrust load bearing, extension thrust load bearing and radial load bearing capacity. Oil filled pistons at each end retard the progress of mud contamination into the inside of the chamber containing the ball bearings.