Magnetic mounting of a rotor shaft relative to a stator, using a high-Tc superconductor

• US 20050127765A1
• Filed: 11/07/2002
• Published: 06/16/2005
• Est. Priority Date: 11/07/2001
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Kummeth, Peter
• Granted Patent: US 7,256,523 B2
• Time in Patent Office: Days
• US Class Current: 310/90.500
• CPC Class Codes: F16C 32/0438 with a superconducting body, e.g. a body made of high temperature superconducting material such as YBaCuO
• CPC Class Codes: F16C 33/72 Sealings
• CPC Class Codes: F16C 35/00 Rigid support of bearing units; Housings, e.g. caps, covers F16C23/00 takes precedence
• CPC Class Codes: F16C 37/005 of magnetic bearings

Abstract

A first bearing part is arranged fixedly in terms of rotation on a rotor shaft with permanent magnetic elements arranged next to one another and flux guide elements arranged between them. A second bearing part, separated from the first bearing part by a bearing gap, is provided on the stator and has a structure formed of superconductive high-T_c material. The bearing gap is sealed against penetration of ambient air, but allows movement of the first bearing part with respect to the second bearing part while maintaining the seal.

Claims

1. A magnetic mounting of a rotor shaft relative to a stator, comprising:

a first bearing part arranged fixedly in terms of rotation on the rotor shaft, including permanent-magnetic elements arranged next to one another and having flux guide elements arranged therebetween;

a second bearing part provided on the stator, including a structure formed of superconductive high-T_c material, said first and second bearing parts being separated by a bearing gap; and

sealing means for providing a seal of the bearing gap against penetration of ambient air and for allowing movement of said first bearing part with respect to said second bearing part while maintaining the seal.

2. The magnetic mounting as claimed in claim 1, wherein said sealing means include annular sealing elements which seal off in relation to one of the rotor shaft and said first bearing part.

3. The magnetic mounting as claimed in claim 2, wherein the annular sealing elements have a sufficient intrinsic elasticity allowing the movement of said first bearing part with respect to said second bearing part.

4. The magnetic mounting as claimed in claim 2, wherein the stator is disposed inside a stator housing, and

wherein the annular sealing elements are held on the stator housing at a portion having sufficient elasticity.

5. The magnetic mounting as claimed in claim 4, wherein said sealing means further include an elastic housing portion running essentially parallel to the rotor shaft on the stator housing on both sides of the bearing gap.

6. The magnetic mounting as claimed in claim 5, wherein the elastic housing portion is designed in the form of a corrugated-tube or corrugated-hose portion.

7. The magnetic mounting as claimed in claim 6, further comprising at least one feed line for feeding a scavenging gas into the bearing gap.

8. The magnetic mounting as claimed in claim 7, wherein said sealing elements include at least one of lamella sealing rings, labyrinth sealing rings, radial packing rings and at least one ferrofluidic seal.

9. The magnetic mounting as claimed in claim 8,

wherein a ferrofluidic seal has a first seal part, arranged on the stator, and a second seal part, arranged on the rotor-shaft, each seal part including an annular permanent-magnetic element with an associated annular flux guide element, with ferrofluid enclosed in an air gap between the flux guide elements located opposite one another, and

wherein, upon movement of the rotor shaft with respect to the stator, the first and second seal parts are displaceable relative to one another, while maintaining enclosure of the ferrofluid.

10. The magnetic mounting as claimed in claim 9, wherein the permanent-magnetic elements and the flux guide elements of each of the first and second seal parts have substantially identical inside and outside diameters.

11. The magnetic mounting as claimed in claim 10, wherein the flux guide elements have an overlap area with a width which delimits the air gap such that during maximum displacement of the first and second seal parts in relation to one another, a minimum overlap ensuring enclosure of all of the ferrofluid remains.

12. The magnetic mounting as claimed in claim 11, wherein at least one spacer is provided, by which the first and second seal parts are spaced apart even during displacement.

13. The magnetic mounting as claimed in claim 12, wherein the spacer is a nonpositive bearing allowing a rotation of the two seal parts with respect to one another.

14. The magnetic mounting as claimed in claim 13, wherein the nonpositive bearing includes a bearing ring acted upon by a return force and to press the first and second seal parts away from one another.

15. A magnetic mounting of a rotor shaft relative to a stator, comprising:

a first bearing part arranged fixedly in terms of rotation on the rotor shaft, including permanent-magnetic elements arranged next to one another and having flux guide elements arranged therebetween;

a second bearing part provided on the stator, including a structure formed of superconductive high-T_c material, said first and second bearing parts being separated by a bearing gap; and

sealing elements to provide a seal of the bearing gap against penetration of ambient air and for allowing movement of said first bearing part with respect to said second bearing part while maintaining the seal.