Magnetic bearing device and vacuum pump

• US 20070024138A1
• Filed: 09/02/2004
• Published: 02/01/2007
• Est. Priority Date: 09/17/2003
• Status: Active Grant

• Current Assignee: Mecos Traxler AG (Volkswagen AG)
• Original Assignee: Mecos Traxler AG (Volkswagen AG)
• Inventors: Bühler, Philipp, Larsonneur, René
• Granted Patent: US 7,633,201 B2
• Time in Patent Office: Days
• US Class Current: 310/90.500
• CPC Class Codes: F04D 19/048 comprising magnetic bearings
• CPC Class Codes: F04D 25/0693 Details or arrangements of the wiring
• CPC Class Codes: F16C 2360/45 Turbo-molecular pumps in general F04D19/04
• CPC Class Codes: F16C 32/0446 Determination of the actual position of the moving member, e.g. details of sensors
• CPC Class Codes: F16C 32/0468 of moving parts of the magnetic circuit, e.g. of the rotor
• CPC Class Codes: F16C 32/047 Details of housings; Mounting of active magnetic bearings
• CPC Class Codes: F16C 32/0489 with active support of five degrees of freedom, e.g. two radial magnetic bearings combined with an axial bearing
• CPC Class Codes: F16C 35/00 Rigid support of bearing units; Housings, e.g. caps, covers F16C23/00 takes precedence

Abstract

A magnetic bearing device (1) for rotatably supporting a shaft (20) for rotation about a rotation axis (101) is disclosed. The device (1) comprises a first active radial bearing (5), one or more first radial displacement sensors (81), and an axial bearing (6, 7). At least a part of the axial bearing (6, 7) is disposed between the first active radial bearing (5) and the first radial displacement sensors (81) when viewed in an orthogonal projection onto the rotation axis (101). A vacuum pump including the magnetic bearing device (1) and a multiple-sensing unit (8) are also disclosed.

Claims

1. A magnetic bearing device (1) for rotatably supporting a rotor (19) for rotation about a rotation axis (101), the magnetic bearing device (1) comprising;

a first active radial bearing (5), one or more first radial displacement sensors (81), and

an axial bearing (6, 7),

wherein at least a part of the axial bearing (6) is disposed between the first active radial bearing (5) and the first radial displacement sensors (81) when viewed in an orthogonal projection onto the rotation axis (101).

2. The magnetic bearing device according to claim 1,

wherein the magnetic bearing device comprises a second active radial bearing (2), and that the first active radial bearing (5) is disposed between the axial bearing (6, 7) and the second active radial bearing (2) when viewed in an orthogonal projection onto the rotation axis (101).

3. The magnetic bearing device according to claim 2,

wherein the magnetic bearing device further comprises a drive motor (4) and second radial displacement sensors (31),

wherein the drive motor is disposed between the first active radial bearing and the second active radial bearing when viewed in an orthogonal projection onto the rotation axis (101), and

wherein the second radial displacement sensors (31) are arranged between the second active radial bearing (2) and the drive motor (4) when viewed in an orthogonal projection onto the rotation axis (101).

4. The magnetic bearing device according to claim 3, characterized in that the axial bearing (6, 7) provides a void space and that the first radial displacement sensors (81) extend into the void space of the axial bearing (7).

5. The magnetic bearing device according claim 4, wherein the magnetic hearing device further comprises one or more axial displacement sensors (82), and that the first radial displacement sensors (81) and the axial displacement sensors (82) are integrated in a single multiple-sensing unit (8).

6. The magnetic bearing device according to claim 5, wherein it further comprises one or more angular velocity sensors (83), and that the angular velocity sensors (83) are integrated in the multiple-sensing unit (8).

7. A vacuum pump, comprising a magnetic bearing device (1) and a rotor (19) rotatably supported in the magnetic bearing device (1), wherein the magnetic bearing device (1) is a magnetic bearing device according to claim 1.

8. A multiple-sensing unit (8) for a magnetic bearing device according to claim 1, for determining characteristics of a rotor (19) of a pump, the multiple-sensing unit (8) comprising a holding member (809) and a plurality of sensors (81, 82, 83, 84) attached to the holding member, wherein at least one of the sensors (81, 82, 83, 84) is a radial displacement sensor (81) and at least one of the sensors (81, 82, 83, 84) is an axial displacement sensor (82).

9. The multiple-sensing unit (8) according to claim 8, wherein the holding member (809) is disposed in the magnetic bearing device such that at least a part of the axial bearing (6) is disposed between the first active radial bearing (5) and the multiple-sensing unit (8) when viewed in an orthogonal projection onto the rotation axis (101).

10. A multiple-sensing unit (8) according to claim 8, wherein the holding member (809) is at least partially disposed in the magnetic bearing device and extends into a void space provided in the axial bearing (6, 7) of the magnetic bearing device.

11. The multiple-sensing unit (8) according to claim 8, characterized in that at least one of the sensors (81, 82, 83, 84) comprised by the multiple-sensing unit is an angular velocity sensor (83).

12. The vacuum pump according to claim 7, wherein the vacuum pump is a turbo molecular vacuum pump.

13. The magnetic bearing device according to claim 2, characterized in that the axial bearing (6, 7) provides a void space and that the first radial displacement sensors (81) extend into the void space of the axial bearing (7).

14. A vacuum pump, comprising a magnetic bearing device (1) and a rotor (19) rotatably supported in the magnetic bearing device (1), wherein the magnetic bearing device (1) is a magnetic bearing device according to claim 2.

15. A vacuum pump, comprising a magnetic bearing device (1) and a rotor (19) rotatably supported in the magnetic bearing device (1), wherein the magnetic bearing device (1) is a magnetic bearing device according to claim 3.

16. A vacuum pump, comprising a magnetic bearing device (1) and a rotor (19) rotatably supported in the magnetic bearing device (1), wherein the magnetic bearing device (1) is a magnetic bearing device according to claim 4.

17. A vacuum pump, comprising a magnetic bearing device (1) and a rotor (19) rotatably supported in the magnetic bearing device (1), wherein the magnetic bearing device (1) is a magnetic bearing device according to claim 5.

18. A vacuum pump, comprising a magnetic bearing device (1) and a rotor (19) rotatably supported in the magnetic bearing device (1), wherein the magnetic bearing device (1) is a magnetic bearing device according to claim 6.

19. A multiple-sensing unit (8) according to claim 9, wherein the holding member (809) is at least partially disposed in the magnetic bearing device and extends into a void space provided in the axial bearing (6, 7) of the magnetic bearing device.

20. The multiple-sensing unit (8) according to claim 9, characterized in that at least one of the sensors (81, 82, 83, 84) comprised by the multiple-sensing unit is an angular velocity sensor (83).