Working principle

- Initial state: both A and B working oil ports are in low pressure state, the motor has not started working, and the anti-sway valves on the left and right sides are in a connected state.

- During rotation: the oil inlet of B working oil port is high pressure, and the oil return of A working oil port is low pressure. The anti-sway valve on the left is affected by the oil inlet pressure, and the pressure oil enters the inner cavity of the anti-sway valve through the throttle hole a, overcoming the spring of the anti-sway valve on the right, so that the left side is in a closed state.

- When the rotation stops, rebound begins: After the rotation stops, under the action of inertia, the A working oil port becomes high pressure, and the B working oil port is in low pressure. The pressure of the anti-sway valve on the A side increases, ready to overcome the spring of the anti-sway valve on the B side and the oil in the inner cavity of the anti-sway valve. The oil in the inner cavity of the anti-sway valve on the B side must be squeezed out through the throttle hole a. At this time, the channels on both sides of A and B are still in a closed state, but ready to rebound.

- Rebound damping: Due to the effects of throttle holes a and b, the pressure oil on the A side enters the B side through the throttle hole b. The throttle hole b plays the role of rebound damping, which makes the channels of A and B unable to be maintained all the time.

- End of 1ST rebound: Due to the effect of rebound damping b, the pressure on the A side is higher, so that the anti-sway valve on the A side continues to overcome the spring force on the B side. Finally, the anti-sway valve on the A side closes the channel and completes the first rebound.

Function

- Prevent swinging: When the excavator stops rotating, it effectively avoids the instantaneous positive and reverse alternating action of the hydraulic motor caused by inertia, prevents the upper part from swinging back and forth, and makes the rotation action smoother.

- Protect the hydraulic system: Reduce the damage to the hydraulic system caused by pressure shock and pressure fluctuation during rotation braking, and extend the service life of hydraulic components.

- Improve operating comfort: Let the driver feel a smoother action when operating the excavator to rotate, and improve the comfort and accuracy of operation.