Pressure Compensator Design for a Swash Plate Axial Piston Pump

An in-line axial-piston swash-plate pump with pressure compensator is widely used for its fast speed of response and power economy. Although several simulation based design approaches exist to minimize issues like fluid-born noises, ample scope exists for more exhaustive design analysis. The most popular pressure compensator for a variable displacement pump with a spool valve actuating the control and bias cylinders has been taken up here. With an existing comprehensive flow dynamics model, an updated model for swiveling dynamics has been coupled. The dynamics also includes the force containment and friction effects on the swash plate. A design optimization has been accomplished for the pressure compensator. The target of the optimal design has been set as minimizing the transient oscillations of the swash plate, the compensator spool, pressures in the bias and control cylinders along with avoidance of both over-pressurization and cavitation in the bias cylinder. It has been found that the orifice diameters in the spring-side and at the metering port of the spool valve and in the backside of the bias cylinder have critical role in arriving at an optimum design. The study has led to a useful design procedure for a pressure compensated variable displacement pump.