Gear pumps with low pressure shaft lubrication

摘要

An improved gear pump includes seal plates having lubrication channels communicating between the low pressure side of the zone where the gear teeth intermesh and the shaft bearings. Lubricant flow is directed first through one bearing on one side of the pump and then back through the other bearing on that side to the pump inlet chamber. Placement of the lubrication channels on the low pressure side of the pump where the volume between intermeshing teeth is increasing ensures that flow reversals in the bearings and lubricant aeration are avoided; and renders bearing flow rate less sensitive to pressure so that relatively large flow channels may be used in the wear plate.