The variable method of single-acting vane pump has two kinds of manual and automatic adjustment. According to the different working characteristics, the automatic variable pump can be divided into three types: pressure limiting type, constant voltage type and constant flow type. The most applied.

The pressure-limiting variable vane pump uses the feedback action of the pump discharge pressure to realize the variable. It has two forms of internal feedback and external feedback. The following     Vickers Vane Pump    respectively explain how they work.

1. The working principle of the external feedback variable vane pump

The center of the rotor is fixed, and the stator can be moved to the left and right. Under the action of the pressing spring, the stator is pushed to the left end, so that there is an initial eccentricity between the center of the stator and the center of the rotor. It determines the maximum flow of the pump. The left side of the stator is equipped with a feedback hydraulic cylinder whose oil chamber communicates with the pump outlet. During operation of the pump, the piston of the hydraulic cylinder applies a rightward feedback force to the stator.

2. Internal feedback variable vane pump works

The internal feedback variable vane pump works similarly to the external feedback type. However, the change in the eccentricity of the pump does not depend on the external feedback hydraulic cylinder, but on the direct action of the internal feedback hydraulic pressure. Due to the existence of the yaw angle, the force of the pressure oil in the pressure oil zone on the stator has a component force in the direction parallel to the center line of the rotor and the stator. As the working pressure of the hydraulic pump increases, this component force also increases. When this component force is greater than the preload of the pressure regulating spring, the stator moves to the right, reducing the eccentricity of the stator and the rotor, thereby making the flow rate correspondingly smaller.