Variable displacement hydraulic pressure intensifier

Abstract

A hydraulic pressure intensifier for boosting normal system pressure in a hydraulic system to a higher level in order to increase the force provided by a pressure-operated actuator. The hydraulic pressure intensifier has a motor-pump unit with a rotatable cylinder block with cylinders defining piston chambers and each having a movable piston therein. A wobbler controls the stroke of the pistons and the motor-pump unit functions as both a pump and a motor by means of porting to said cylinders including a supply pressure port, an intensified pressure port and a return pressure port. The motor-pump unit has normal maximum and minimum speed limits and when operating at different flow rates the speed thereof varies accordingly. In order to maintain the speed of the motor-pump unit within normal limits, the wobbler is adjustable to vary the stroke of the pistons and thereby vary the speed of rotation of the cylinder block for the same rate of fluid flow. The wobbler can be infinitely variable between limit positions or only between limit positions and the adjustment can be made automatically in response to a speed-responsive flyweight governor-controlled valve structure.