Vacuum pump with eccentrically driven vane (eccentric pump design)

Patent metadata

Field	Value
Publication number	US-9803642-B2
Application number	US-201515324269-A
Country	US
Kind code	B2
Filing date	Aug 7, 2015
Priority date	Aug 22, 2014
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A rotating vane vacuum pump includes a housing defining a cavity having an inlet and an outlet, a drivable vane member for a rotary driven movement inside the cavity, a rotor inside the cavity, and a rotatable central shaft extending into the cavity. The vane member is coupled to the central shaft by an eccentric element on the central shaft and movably arranged in the rotor, the rotor being rotatable together with said vane member upon rotation of the vane member. A rotational axis of the central shaft is offset from a rotational axis of the rotor and a point of action of the vane member is offset from the rotational axis of the central shaft by the eccentric element on the central shaft. The rotor encloses radially the eccentric element of the central shaft.

First claim

The invention claimed is:

1. A rotating vane vacuum pump, comprising
a housing defining a cavity having an inlet and an outlet;
a drivable vane member for a rotary driven movement inside the cavity;
a rotor inside the cavity; and
a rotatable central shaft extending into the cavity;
wherein the vane member is coupled to the central shaft by an eccentric element on the central shaft and movably arranged in the rotor, the rotor being rotatable together with said vane member upon rotation of the vane member,
wherein a rotational axis of the central shaft is offset from a rotational axis of the rotor and a point of action of the vane member is offset from the rotational axis of the central shaft by the eccentric element on the central shaft, and
wherein the rotor encloses radially the eccentric element of the central shaft.

2. The vacuum pump according to claim 1 , wherein the rotor comprises an outer wall and defines an inner space, and
wherein the eccentric element of the central shaft moves back and forth in a radial direction of the rotor when the central shaft is in rotation.

3. The vacuum pump according to claim 2 , wherein the inner space of the rotor has an inner diameter which is at least twice a maximum offset of the central axis of the eccentric element and the rotational axis of the rotor.

4. The vacuum pump according to claim 2 , wherein the outer wall of the rotor comprises first and second slots in first and second opposing positions on a radial direction, and wherein the first and second slots are configured to allow the vane member to slide in the radial direction of the rotor when at least one of the central shaft or the rotor is in rotation.

5. The vacuum pump according to claim 1 , wherein the central shaft, the rotor, and the vane member are positively coupled together.

6. The vacuum pump according to claim 1 , wherein the central shaft rotates twice a rotational angle of the vane member and the rotor.

7. The vacuum pump according to claim 1 , wherein a radially outermost point of the eccentric element relative to the central shaft is located:
in a first rotational position on a longitudinal plane of the vane member; and
in a second rotational position distal from the longitudinal plane of the vane member;
wherein in the first rotational position only one tip of the vane member projects out of the rotor and in the second rotational position both tips project the same distance from the rotor.

8. The vacuum pump according to claim 7 , wherein a direction of a driving force at a point of force application is:
in the first rotational position perpendicular to the plane of the vane member; and
in the second rotational position parallel to the plane of the vane member.

9. The vacuum pump according to claim 1 , wherein the eccentric element is formed as a cam on the central shaft, and
wherein the vane member comprises a central hollow jacket and is seated about the cam by the jacket.

10. The vacuum pump according to claim 9 , wherein the vane member is formed as a single one-piece vane member having first and second vanes on the hollow jacket protruding in a radial direction on opposing sides of the jacket.

11. The vacuum pump according to claim 9 , wherein the cam extends along the central shaft from a first axial position to a second axial position, and
wherein both of the first and second positions are located within the cavity.

12. The vacuum pump according to claim 1 , wherein the central shaft extends through the rotor and through the cavity such that end portions of the central shaft project from opposing sides of the rotor and of the cavity.

13. The vacuum pump according to claim 1 , wherein an offset of the rotational axis of the central shaft relative to the rotational axis of the rotor is equal to an offset of the point of action of the vane member relative to the rotational axis of the central shaft.

14. The vacuum pump according to claim 1 , wherein the rotor comprises at least one bearing journal for bearing the rotor against at least one of a bottom plate or an end plate of the cavity.

15. The vacuum pump according to claim 14 , wherein the bearing journal is received in a bearing in the bottom plate and/or the end plate.

16. The vacuum pump according to claim 1 , wherein first and second tips of first and second vanes at first and second ends of the vane member are moved with a distance remaining between the tip and an inner circumferential wall of the cavity along the inner circumferential wall of the cavity.

17. The vacuum pump according to claim 1 , wherein the rotor is sealed in a fluid tight manner against at least one of a bottom plate or an end plate of the cavity.

18. The vacuum pump according to claim 1 , wherein at least one of vane member tips or first and second side portions of the vane member comprise seals for sealing the vane member against the cavity.

19. The vacuum pump according to claim 18 , wherein the seals are at least arranged at three sides of the vane member and comprise a pressure deforming seal having a lip in contact with a cavity wall and bent into the direction of rotation of the vane member.

20. The vacuum pump according to claim 1 , wherein the central shaft is a drive shaft and coupled to a driving motor for driving the vacuum pump.

21. The vacuum pump according to claim 1 , wherein the rotor is a drive rotor and coupled to a driving motor for driving the vacuum pump.

Assignees

• Wabco Europe Bvba

Inventors

• Heaps David
• Warner Simon

Classifications

• F04C25/02

  for producing high vacuum (sealing arrangements F04C27/00; silencing F04C29/06) · CPC title

• F04C29/0085

  Prime movers · CPC title

• F04C2220/10

  Vacuum · CPC title

• F04C18/3441 Primary

  the inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation · CPC title

• F04C2240/50

  Bearings · CPC title