Low-frequency oscillation test data for a certain model of plunger pump

This hydraulic pump is equipped with an oil circuit that draws high-pressure oil from the outlet to the high-pressure valve, and an oil circuit that flows into the accompanying piston chamber after passing through the high-pressure valve. When the pump outlet pressure is less than the maximum full-flow pressure, the hydraulic pressure acting on the high-pressure valve is balanced by the preload force of the valve spring, allowing the hydraulic pump to operate at full flow.

When the pressure at the pump's oil supply port (system) drops, the valve spring quickly pushes the high-pressure valve. Under the combined action of hydraulic torque and return spring, the tilt γ angle of the swash plate rapidly increases, plunger stroke increases, and the oil supply increases. When the pressure at the hydraulic pump's oil supply port drops to or below the maximum full-flow pressure, the hydraulic pump returns to its maximum (rated) fuel supply state.