Positive hydraulic direct drive for vehicles

摘要

A vehicle has a primary drive pump in communication with driven pumps associated with each wheel for driving the vehicle as hydraulic fluid is ported to the wheel pumps through a by-pass valve. The pumps are similarly designed with each including a rotor co-axially mounted within a fixed stator defining an annular pump chamber when fluid entering an intake opening moves against gradually extending vanes provided on the rotor. The fluid exits through a discharge opening in the stator, and the vanes are designed to be fully retracted at a position between the openings and gradually extended so as to fully extend after moving beyond the intake opening. Also, the vanes gradually retract as they approach the discharge opening. Such a vane movement is effected by means of eccentric grooves provided on opposing side walls of the stator with which portions of the vanes cooperate, thereby avoiding the need for the vane tips constantly contacting a cam surface and being urged in such position by means of springs as in the prior art.