Network optimization information:

When port A does not supply oil, the balance valve returns to the middle position. Due to the inertia of the machine, the motor continues to rotate, and the motor becomes a pump. Hydraulic Motor Company Because the closing of the balance valve causes the pressure at port B to rise, High pressure hydraulic motor The pressure oil enters the buffer chamber through the orifice in the middle of the left safety valve, pushes the buffer piston to move to the right, and at the same time, opens the left safety valve to supplement oil to chamber A. As the buffer piston moves to the rightmost end, the pressure of chamber B rises and the left safety valve is completely closed.

When the pressure rises further, the pressure of chamber B acts on the safety valve on the right, which limits the pressure of the engine (41.2MPa), which is the brake pressure.

When the engine just starts to stop rotating, two safety valves are connected in parallel. The pressure in cavity B acts on port a (the whole circumference area) of the left safety valve, and the valve rod moves to the left to discharge oil into port b (note that port b is connected to port A of the engine control circuit). After the buffer piston moves to the rightmost end, due to the difference in valve stem diameter, the valve stem moves to the right under the effect of spring force and pressure difference, so that the left safety valve is closed. The pressure at this time is called level 1. This process is very short. The purpose is to eliminate the pulse pressure at Port B and prevent the suction of Port A.