The internal gear pump draws the hydraulic fluid from the tank and pumps it into the accumulator. As soon as the pressure in the accumulator has risen, the accumulator charging valve switches the pump over to circulation, the pump discharges back into the tank trough the accumulator charging valve at practically no pressure.
A non-return valve prevents the hydraulic fluid from flowing back out of the accumulator. If the pressure in the accumulator drops by 10%, the charging valve switches over and the accumulators are charged again. A pressure reducing valve,downstream of the accumulator,supplies oil to the actuators at a constant, controlled system pressure.