Key Points of REXROTH Vane Pump Management

Brand

REXROTH/German Rexroth

Rexroth Gear Pumps, Rexroth External Gear Pumps, Rexroth Internal Gear Pumps, Rexroth Gear Pump Faults, Rexroth Gear Pump Principles

REXROTH Vane Pumps

REXROTH Vane Pump Management Points

:

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

Vane Pumps

1. Changing the pump's rotation direction will also change its suction and discharge directions. Vane pumps have a specified rotation direction and cannot be reversed. This is because the rotor blades are inclined, the blades are chamfered, the blade 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 installation, so that the original suction area becomes the discharge area for continued use. 3. Disassembly and Assembly: Ensure the working surfaces are clean. The oil should be well filtered during operation.

4. Excessive clearance between the blades and the blade slots will increase leakage; insufficient clearance will prevent the blades from freely extending and retracting, leading to malfunction.

5. The axial clearance of the 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. Excessive viscosity will make oil suction difficult; insufficient viscosity will result in severe leakage.

-- The operating principle of the REXROTH vane pump is similar to that of a single-acting vane pump. The difference lies in the stator surface, which 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 this type of pump, each sealed working chamber completes two suction and two pressure actions per rotor revolution, hence the name double-acting vane pump. The two suction 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.

When the rotor of a Rexroth vane pump rotates, the tips of the vanes are pressed tightly against the inner surface of the stator under the action of centrifugal force and pressurized oil. The working volume formed by the two vanes, the rotor, and the inner surface of the stator first draws in oil from small to large, then discharges oil from large to small. Each rotation of the vane completes two oil suction and discharge cycles.

Key management points for Rexroth vane pumps, besides preventing dry running, overload, air intake, and excessive vacuum, also include:

1. Changing the pump's rotation direction changes its suction and discharge direction. Vane pumps have a designated 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 for the predetermined rotation direction. Reversible vane pumps must be specially designed.

2. Vane pump assembly: The distribution plate and stator must 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 to convert the original suction area into a discharge area for continued use.

3. Disassembly and assembly: Keep the working surfaces clean, and ensure the oil is well filtered during operation. 4. Excessive clearance between the blades and the blade slots increases leakage; insufficient clearance prevents the blades from freely expanding and contracting, leading to malfunction.

5. The axial clearance of a vane pump significantly affects 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. Excessive viscosity hinders oil suction; insufficient viscosity leads to severe leakage.

The full range of Rexroth models from Germany is as follows:

R901085689 4WRA10EA00-2X/G24K4/V-873

R901085669 4WRA10EA00-2X/G24K4/V-872

R901059583 4WRAE10W30-2X/G24K31/A1V-280

R901054483 Proportional directional valve, direct-acting type 4WRA10EA00-2X/G24K4/V-828 Rexroth

R901026400 4WRAE6W1-07-2X/G24K31/A1V

R901018004 4WRAE6W1-15-2X/G24K31/F1V

R900631278 Proportional directional valve, direct-acting type, FEDERTELLER 4WRAP6.-10/Rexroth

R900617493 4WRAE6E1-07-2X/G24K31/F1V

R900581368 4WRAP6W7-08-2X/24K4/M

R900581367 4WRAP6W7-07-2X/24K4/M

R900581366 Proportional directional valve, direct-acting type, 4WRAP6W7-04-2X/24K4/M, Rexroth

R900581365 4WRAP6W7-02-2X/24K4/M

R900577424 4WRA10W30-2X/G24K4/V

R900575765 4WRA10W1-60-2X/G24N9K4/V

Our company mainly deals in European and American brands and can source brands from any European country. For example, our key German brands include: BURKERT, DEMAG, HAWE, REXROTH, HYDAC, PILZ relays, FESTO, IFM sensors, E+H, HEIDENHAIN, P+F sensors, SICK, TURCK, and HIRSCHMANN industrial switches. German brands: Hengstler, Murr, Schmersal, Samson, EPRO (Emerson Group)

American brands: MOOG, ASCO, MAC, NUMATICS, PARKER, VICKERS, ROSS

British brands: Norgren

Italian brands: OMAL, ATOS, CAMOZZI, UNIVER, Camozzi