Principle and Usage Introduction of Hydraulic Vane Pump

Hydraulic Vane Pumps play an important role in modern hydraulic systems. Their efficient flow delivery and stable working performance have made them widely used in various industrial applications. This article will provide a detailed introduction to the working principle, types, and the characteristics of hydraulic vane pumps in practical use.

Single-Acting Hydraulic Vane Pumps

Single-acting hydraulic vane pumps are favored for their simple structure and relatively low cost. They mainly consist of a pump body, rotor, stator, vanes, and oil distribution plate (end cover). The working principle of a single-acting hydraulic vane pump is as follows:

Structure and Working Principle

In a single-acting hydraulic vane pump, radially inclined slots evenly distributed on the rotor house slidable vanes. As the rotor spins inside the stator, the eccentric distance between the rotor and the stator allows the vanes to slide freely within the rotor slots. The rotation of the rotor causes the vanes to form several sealed volumes against the inner wall of the stator. In the suction area, the vanes gradually extend, increasing the sealed volume and creating a local vacuum that draws in liquid through the suction port. In the discharge area, the vanes are pressed into the rotor slots by the inner wall of the stator, decreasing the sealed volume and forcing the liquid out through the discharge port.

Flow Adjustment

A notable feature of single-acting hydraulic vane pumps is their adjustable flow rate. By changing the eccentric distance and the direction between the center of the rotor and the center of the stator, the output flow rate can be regulated. These pumps are commonly used in low-pressure hydraulic systems where variable flow is desired, making them suitable for applications requiring flow variation.

Applications and Limitations

During operation, single-acting hydraulic vane pumps experience radial pressure imbalance, subjecting the rotor shaft and bearings to significant radial forces. Therefore, the working pressure should not be too high. These pumps are mainly used in scenarios where adjustable flow is needed, such as low-pressure hydraulic systems.

Double-Acting Hydraulic Vane Pumps

Double-acting hydraulic vane pumps differ structurally from single-acting hydraulic vane pumps. Their design allows them to provide higher pressure and more stable flow during operation.

Structure and Working Principle

Double-acting hydraulic vane pumps consist of a pump body, rotor, stator, vanes, and oil distribution plate (end cover). However, their rotor and stator centers are coaxial, and the inner surface of the stator is approximately elliptical. This design enables the pump to complete two suction and discharge processes for each rotation.

Pressure and Flow

Since double-acting hydraulic vane pumps complete two suction and discharge cycles for each rotor revolution, they exhibit higher working pressure and stable flow output. Often referred to as unloading vane pumps, they are ideal for applications requiring high pressure and stable flow, such as precision machine tools.

Application Scope

Due to the coaxial design of the rotor and stator, double-acting hydraulic vane pumps cannot adjust output flow, so they are mainly used as fixed displacement pumps. Their excellent pressure balance performance makes them suitable for hydraulic systems that require stable, high-pressure operation.