Travel motor It is equipped with high pressure automatic independent variable equipment. When the gear is in high gear, the control circuit receives oil from the manual speed regulating oil hole to push the speed regulating valve to offset, so that the motor becomes small displacement; If the increase of friction resistance causes the hydraulic pressure to rise to the preset value, the gear oil pushes the speed control valve to the right, and the motor automatically changes to a large displacement low-speed gear to increase torque. Therefore, this type of motor can automatically change gear with the change of driving friction resistance.

In addition, the adjustment of the motor is mainly realized by the motor pressure regulating valve. Next, the basic working principle is analyzed by integrating the structural schematic diagram.

Assuming that oil is fed into port A and the motor rotates, the operation of the motor pressure regulating valve is as follows:

(1) Open the check valve, and the gear oil enters the right chamber of the motor.

(2) The gear oil can enter the balance valve through the orifice of the throttling device and make it offset, connect the brake oil passage to loosen the brake, and this operation also connects the return oil circuit of the motor port B.

(3) Gear oil can enter the buffer piston chamber through the middle throttling device hole of the safety valve and pull the buffer piston to the left. If the working pressure of the system exceeds the adjusted working pressure (10.2MPa) of the safety valve at this time, the safety valve will be opened in a flash to play a regulating role.

(4) If the motor overspeed (such as when going downhill), and the pump has not yet had time to supply oil, the working pressure of port A will drop, the balance valve will move to the right under the force of the compression spring, and the oil return channel of the motor will be turned down to limit the rotation speed of the motor.