ATOS vane pump working principle

Brand

ATOS/Italian Atos

ATOS Vane Pump Product Introduction

The ATOS vane pump is a pump in which vanes in the rotor slots contact the pump casing (stator ring), pushing the sucked-in liquid from the inlet side to the outlet side.

ATOS Vane Pump Working Principle

When the ATOS vane pump rotor rotates, the vanes, under the action of centrifugal force and pressurized oil, have their tips pressed tightly against the inner surface of the stator. Thus, the working volume formed by the two vanes, the rotor, and the inner surface of the stator first increases in suction volume and then decreases in discharge volume. Two suction and discharge cycles are completed in one rotation of the vanes.

I. Working Principle of a Single-Acting Vane Pump

The ATOS vane pump consists of rotor 1, stator 2, vanes 3, a distribution plate, and end covers. The inner surface of the stator has cylindrical holes. There is an eccentricity between the rotor and the stator. The blades slide freely within the rotor slots. Under the centrifugal force of the rotating rotor and the pressure of the oil flowing through the blade roots, the blade tips adhere tightly to the inner surface of the stator, thus forming sealed working chambers between adjacent blades, the distribution plate, the stator, and the rotor. When the rotor rotates counterclockwise, the blades on the right side of the diagram extend outwards, gradually increasing the volume of the sealed working chambers and creating a vacuum. Oil is then drawn in through the suction port 6 and the window on the distribution plate 5. On the left side of the diagram, the blades retract inwards, gradually decreasing the volume of the sealed chambers. The oil in the sealed chambers is forced out through another window on the distribution plate and the pressure port 1, and discharged into the system. This type of pump performs one suction and one pressure cycle per rotor revolution, hence it is called a single-acting pump. The rotor is subjected to radial hydraulic imbalance forces, therefore it is also called an unbalanced pump, and its bearing load is relatively large. Changing the eccentricity between the stator and rotor changes the pump's displacement; therefore, this type of pump is a variable displacement pump.

II. Working Principle of a Double-Acting Vane Pump

The working principle of an ATOS vane pump is similar to that of a single-acting vane pump, the only difference being that the stator surface consists of eight parts: two long-radius circular arcs, two short-radius circular arcs, and four transition curves. Furthermore, the stator and rotor are concentric. When the rotor rotates clockwise as shown in the diagram, the volume of the sealed working chamber gradually increases at the upper left and lower right corners (the suction zone), and gradually decreases at the lower left and upper right corners (the pressure zone). A sealing zone separates the suction and pressure zones. With each rotor revolution, each sealed working chamber completes two suction and two pressure actions, hence the name double-acting vane pump. The two suction zones and two pressure zones are radially symmetrical, and the hydraulic pressure acting on the rotor is radially balanced, thus it is also called a balanced vane pump.

The instantaneous flow rate of a double-acting vane pump is pulsating; the pulsation rate is small when the number of vanes is a multiple of 4. Therefore, the number of vanes in a double-acting vane pump is generally 12 or 16.

ATOS Vane Pump Management Points (Folded)

Besides preventing dry running, overload, air intake, and excessive vacuum, the following points should also be noted regarding vane pumps:

Vane Pumps

1. Changing the pump's rotation direction changes its suction and discharge directions. Vane pumps have a specified rotation direction and cannot be reversed. This is because the rotor vane slots are inclined, the vanes are chamfered, the vane bottoms communicate with the discharge chamber, and the throttling grooves and suction/discharge ports on the distribution plate are designed according to the predetermined rotation direction. Reversible vane pumps must be specially designed.

2. Vane Pump Assembly: The distribution plate and stator should be correctly positioned using locating pins. The vanes, rotor, and distribution plate must not be installed backwards. The suction area on the inner surface of the stator is most prone to wear; if necessary, it can be flipped over for continued use, making the original suction area the discharge area.

3. Disassembly and Assembly: Keep the working surfaces clean. The oil should be well filtered during operation.

4. If the clearance between the vanes and the vane slots is too large, leakage will increase; if it is too small, the vanes cannot freely extend and retract, leading to malfunction.

5. The axial clearance of a vane pump has a significant impact on ηv.

1) Small pumps - 0.015～0.03mm

2) Medium pumps - 0.02～0.045mm

6. Oil temperature and viscosity: Generally, the temperature should not exceed 55℃, and the viscosity should be between 17～37mm²/s. Too high a viscosity will make oil suction difficult; too low a viscosity will result in serious leakage.

ATOS piston pumps, ATOS gear pumps, ATOS axial piston pumps, ATOS vane pumps, ATOS cylinders, ATOS relief valves