Vane pump

Abstract

A vane pump (1) is disclosed comprising a housing (2) having a stator bore, a rotor (4) being rotatably mounted within said stator bore, and having a number of vanes (5) slidably mounted in said rotor (4) in radial direction of said rotor (4), an inlet (11) and an outlet (12). Such a vane pump should have a good efficiency. To this end said inlet (11) opens in an axial end wall of said stator bore (3) and said outlet (12) is connected to an outflow area formed in a circumferential wall (3) of said stator bore.

Claims

1. A vane pump comprising: a housing having a stator bore; a rotor rotatably mounted within said stator bore; a number of vanes slidably mounted in said rotor in radial direction of said rotor; an inlet; and an outlet; wherein said inlet opens into an inlet recess in an axial end wall of said stator bore and said outlet is connected to an outflow area formed in a circumferential wall of said stator bore; and wherein a radially inner border of said inlet recess runs parallel to a circle line around a rotational axis of said rotor and a radially outer border of said inlet recess runs parallel to said circumferential wall of said stator bore.

2. The vane pump according to claim 1, wherein said outflow area is formed as an outlet recess in said circumferential wall.

3. The vane pump according to claim 1, wherein said inlet recess is kidney-shaped, said inlet recess having a width in radial direction, said width increasing in a direction of rotation of said rotor.

4. The vane pump according to claim 1, wherein said rotor has a core, wherein said radially inner border of said inlet recess is on a same radius as an radially outer face of said core.

5. The vane pump according to claim 1, wherein said inlet recess comprises a trailing border running parallel to a radial direction of said rotor.

6. The vane pump according to claim 3, wherein a slit-like opening is located in a bottom of said inlet recess connecting said inlet recess to said input.

7. The vane pump according to claim 1, wherein said outlet recess has a depth in radial direction, said depth increasing in direction of rotation of said rotor.

8. The vane pump according to claim 1, wherein outlet recess is shorter in axial direction than said vanes.

9. The vane pump according to claim 1, wherein said outlet is inclined with respect to a radial direction of said stator bore by an angle in a range from 30 to 60.

10. The vane pump according to claim 1, wherein said inlet is structured and arranged to be directly connected to another hydraulic machine.

11. The vane pump according to claim 2, wherein said inlet recess is kidney-shaped, said inlet recess having a width in radial direction, said width increasing in a direction of rotation of said rotor.

12. The vane pump according to claim 4, wherein said inlet recess comprises a trailing border running parallel to a radial direction of said rotor.

13. The vane pump according to claim 1, wherein a slit-like opening is located in a bottom of said inlet recess connecting said inlet recess to said input.

14. The vane pump according to claim 4, wherein a slit-like opening is located in a bottom of said inlet recess connecting said inlet recess to said input.

15. The vane pump according to claim 5, wherein a slit-like opening is located in a bottom of said inlet recess connecting said inlet recess to said input.

16. The vane pump according to claim 2, wherein said outlet recess has a depth in radial direction, said depth increasing in direction of rotation of said rotor.

17. The vane pump according to claim 3, wherein said outlet recess has a depth in radial direction, said depth increasing in direction of rotation of said rotor.

18. The vane pump according to claim 4, wherein said outlet recess has a depth in radial direction, said depth increasing in direction of rotation of said rotor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A preferred embodiment of the invention is now described in more detail with reference to the drawing, wherein:

(2) FIG. 1 is a front view of a vane pump; and

(3) FIG. 2 is a section II-II of FIG. 1.

DETAILED DESCRIPTION

(4) A vane pump 1 comprises a housing 2 having a stator bore 3 of, for example, cylinder form. The stator bore has a circumferential wall 3.

(5) A rotor 4 is located within said stator bore. The rotor 4 carries a number of vanes 5. Each vane is moveable in radial direction with respect to the rotor 4. To this end the rotor 4 comprises a core 6 and, for each vane 5, a protrusion 7 in which a slit 8 is formed. The vane 5 is slidably positioned within said slit 8.

(6) The rotor 4 is fixed to a shaft 9 in rotational direction. When the shaft 9 is rotated the rotor 4 is driven. The direction of rotation is indicated with an arrow 10.

(7) An inlet 11 is provided at an axial end of the housing 2. Furthermore, an outlet 12 having an outlet axis 13 is provided at a circumferential outside of the housing 2.

(8) The inlet 11 can be structured and arranged to be directly connected to another hydraulic machine, for example, to a pressure exchanger. In this case it is possible to form the connection between the hydraulic machine and the vane pump without any tubing or other external piping. In such case it would be preferable to make the inlet 11 flush with the side of the housing 2 in which it is arranged.

(9) The inlet 11 is connected to a kidney-shaped inlet recess 14 in an axial end wall of the stator bore 3 on the side of the housing 2 near the inlet 11. The inlet recess 14 has a width in radial direction. As can be seen in FIG. 2 this width increases in the direction 10, i.e. in the direction of rotation of the rotor 4.

(10) As can be seen in FIG. 2, the rotor 4 is positioned eccentrically within the stator bore. When the rotor 4 is rotated in direction 10, each pumping chamber 15 which is formed by the core 6, the protrusions 7, two vanes 5, the housing 2 and two axial end walls of the housing (not shown) increase and decrease its volume. In a region in which the inlet recess 14 is formed the pumping chambers 15 increase the volume and in a region between the inlet recess 14 and the outlet 12 the pumping chambers 15 decrease their volume.

(11) The inlet recess 14 has a radially inner border 16 which runs parallel to a circle line around a rotational axis 17 of the rotor 4, more precisely the radially inner border 16 coincides with the radially outer face of the core 6 of the rotor.

(12) The inlet recess furthermore has a radially outer border 18 running parallel to a circumferential wall of said stator bore 3. The radially outer border 18 can have, as shown, a small distance to the circumferential wall 3 of the stator bore. However, it is possible as well that the radially outer border 18 has the same radius as the stator bore.

(13) The inlet recess has a trailing edge 19 (or trailing border) which runs parallel to a radial direction of the rotor 4. Since the vanes 5 are arranged radially within the rotor 4, each vane 5 is parallel to the trailing edge 19 in the moment the vane 5 passes the trailing edge 19. In other words, the pumping chamber 15 is closed immediately once the vane 5 passes the trailing edge 19.

(14) A slit-like opening 20 is provided in a bottom of the inlet recess 14. The slit-like opening 20 connects inlet 11 and inlet recess 14 and allows for a smooth distribution of incoming liquid in circumferential direction of the inlet recess 14.

(15) The stator bore has an outflow area formed as an outlet recess 21 in the circumferential wall 3 of the stator bore. This outlet recess 21 has an axial length which is a bit shorter than the axial length of the vanes 5 so that a guiding face 22 remains within stator bore controlling the movement of the vanes 5.

(16) As can be seen in FIG. 2, the outlet recess has a depth in radial direction, said depth increasing in direction 10 of rotation of the rotor 4.

(17) During rotation of the rotor 5 liquid trapped in a pumping chamber 15 experiences a centrifugal force, i.e. a force acting on the liquid radially to the outside of the rotor 4. At the same time the liquid trapped in the pumping chamber 15 has a rotational velocity corresponding to the rotational speed of the rotor 4. The axis 13 of the outlet 12 can be inclined with respect to a radial direction of the rotor 4 (not shown) so that the advantageous effect of the centrifugal force moving the liquid in radial direction once the pumping chamber 15 has come in overlapping relation with the outlet recess 21 and furthermore the tangential velocity of the trapped fluid 15 can be used to move the liquid with low losses out of the pumping chambers 15 and into the outlet 12.

(18) Therefore, the vane pump 1 can be used with low losses and a good efficiency.

(19) While the present disclosure has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this disclosure may be made without departing from the spirit and scope of the present disclosure.