Kawasaki Series

Oil suction stage: forming negative pressure – breathing moment

When the engine drives the pump shaft to start rotating, the plunger on the swash plate is pulled away from the oil distribution plate, and the internal volume of the cavity where the plunger is located increases rapidly, generating negative pressure. At this time, the oil suction valve opens and hydraulic oil that meets the viscosity specification is sucked from the oil tank. Good oil suction patency can avoid air entrainment, otherwise, once cavitation occurs, fine cracks on the metal surface will occur, shortening the life of the pump unit.

Pressurization stage: from volume reduction to high-pressure output

As the swash plate continues to rotate, the inclination angle enters the positive area, the plunger is pushed into the cylinder by the swash plate, the cavity volume decreases, and the oil pressure rises rapidly. Ideally, the system pressure is kept constant between the specified values ​​to meet the power output requirements.

Delivery stage: High-pressure oil circuit – refueling the actuator

The pressurized oil enters the main oil circuit through the drain valve and is transported to the boom cylinder, stick cylinder, swing motor and travel motor along the high-quality high-pressure oil pipe. Accumulators and buffers are usually installed in parallel in the system to balance impact and energy storage for smooth operation.

Pressure relief protection: “life-saving operation” of the overload valve

When the actuator is suddenly blocked or the pipeline resistance is too large, causing the system pressure to exceed the preset value, the overload valve opens instantly to return the excess oil to the tank to keep the system pressure within a safe range. This “overflow protection” mechanism is the last line of defense for the safe operation of the hydraulic system.