Passive magnetic support and damping system

• US 20020074881A1
• Filed: 12/14/2000
• Published: 06/20/2002
• Est. Priority Date: 12/14/2000
• Status: Active Grant

• Current Assignee: Joseph Imlach
• Original Assignee: Joseph Imlach
• Inventors: Imlach, Joseph
• Granted Patent: US 6,448,679 B1
• Time in Patent Office: Days
• US Class Current: 310/90.5
• CPC Class Codes: F16C 2361/55 Flywheel systems in general F16F15/00
• CPC Class Codes: F16C 27/06 by means of parts of rubber or like materials F16C27/08 takes precedence; with sliding surfaces of rubber or synthetic rubber F16C33/22
• CPC Class Codes: F16C 32/0412 for radial load mainly
• CPC Class Codes: F16C 32/0425 for radial load mainly
• CPC Class Codes: F16C 39/063 Permanent magnets
• CPC Class Codes: F16C 39/066 with opposing permanent magnets repelling each other
• CPC Class Codes: F16F 9/306 of the constrained layer type, i.e. comprising one or more constrained viscoelastic layers
• CPC Class Codes: H02K 7/09 with magnetic bearings

Abstract

A type of passive magnetic bearing that provides for both positive radial stiffness and significant levels of passive radial damping. Axial damping and axial forces can also be generated with minor modifications to the basic configuration. The bearing is comprised of a series of magnet, damping, and rigid non-magnetic elements essentially defining a laminated or composite structure. The damping material is directly mounted between the magnets and a rigid material, resulting in constrained layer damping. The range of motion of these floating, or soft mounted, magnets may also be restricted to generate higher stiffness in response to large vibrations.

Claims

1. A passive magnetic support and damping system comprising:

a) a rotor, said rotor having at least one permanently magnetized element attached to said rotor;

b) a stator, said stator including at least one second permanently magnetized element, whereby said rotor and said stator being arranged in a relationship whereby the permanently magnetized element of the rotor and the permanently magnetized element of the stator are separated by a gap;

c) a support for said stator; and

d) a means for supporting the at least one second permanently magnetized element so as to dampen vibrations in said at least one second permanently magnetized element and, consequently, dampen vibrations in said at least one permanently magnetized element attached to said rotor.

2. The passive magnetic support and damping system of claim 1 further comprising a means for limiting the radial displacement of the at least one second permanently magnetized element, thereby resulting in increased stiffness of said passive magnetic support and damping system as a vibrational amplitude of the rotor increases.

3. The passive magnetic support and damping system of claim 1 wherein the at least one second permanently magnetized element has a range of motion, and further wherein said range of motion is limited, to create a non-linear stiffness in response to large displacements of said rotor.

4. The passive magnetic support and damping system of claim 1 wherein the at least one said second permanently magnetized element includes a first plurality of magnets and a second plurality of magnets, wherein the first plurality of magnets is surrounded by a damping material, and the second plurality of magnets is fixed in place.

5. The passive magnetic support and damping system of claim 1 wherein the at least one said second permanently magnetized element includes a means of producing axial forces between said rotor and said stator.

6. The passive magnetic support and damping system of claim 1 wherein the rotor is positioned outside of the stator.

7. The passive magnetic support and damping system of claim 6 wherein the at least one permanently magnetized element on said rotor is made of sections.

8. The passive magnetic support and damping system of claim 6 wherein the at least one said second permanently magnetized element is made of sections.

9. The passive magnetic support and damping system of claim 1 wherein the at least one permanently magnetized element on said rotor is made of sections.

10. The passive magnetic support and damping system of claim 1 wherein the at least one said second permanently magnetized element is made of sections.

11. The passive magnetic support and damping system of claim 1 wherein the rotor and the stator have a relative motion, and further wherein said relative motion is translational.

12. The passive magnetic support and damping system of claim 1 wherein the support for said stator is a machine housing.

13. The passive magnetic support and damping system of claim 1 wherein the means for supporting the at least one second permanently magnetized element so as to dampen vibrations, produces a primary support and dampening direction.

14. The passive magnetic support and damping system of claim 13 wherein the primary support and dampening direction of said means for supporting the at least one second permanently magnetized element so as to dampen vibrations is radial.

15. The passive magnetic support and damping system of claim 13 further comprising:

at least one first axial magnet attached to said rotor and at least one second axial magnet attached to said stator, whereby said first and second axial magnets generate axial forces.

16. The passive magnetic support and damping system of claim 1 wherein the means for supporting the at least one second permanently magnetized element so as to dampen vibrations includes a damping material located between said at least one second permanently magnetized element and said support for said stator.

17. The passive magnetic support and damping system of claim 16 wherein the damping material is a viscoelastic material.

18. The passive magnetic support and damping system of claim 16 wherein the damping material is a woven metal material.

20. The passive magnetic support and damping system of claim 19 further comprising a means for limiting the radial displacement of the at least one of the elements in said second array, thereby resulting in increased stiffness of the passive magnetic support and damping system as a vibrational amplitude of the rotor increases.

21. The passive magnetic support and damping system of claim 19 wherein at least one of the elements in said second array of permanently magnetized elements has a range of motion, and further wherein said range of motion is limited, to create a nonlinear stiffness in response to large displacements of said rotor.

22. The passive magnetic support and damping system of claim 19 wherein the a second array of permanently magnetized elements includes a first plurality of magnets and a second plurality of magnets, wherein the first plurality of magnets is surrounded by a damping material, and the second plurality of magnets is fixed in place.

23. The passive magnetic support and damping system of claim 19 wherein the a second array of permanently magnetized elements includes a means of producing axial forces between said rotor and said stator.

24. The passive magnetic support and damping system of claim 19 wherein the rotor is positioned outside of the stator.

25. The passive magnetic support and damping system of claim 24 wherein the first array of permanently magnetized elements is made of sections.

26. The passive magnetic support and damping system of claim 24 wherein the second array of permanently magnetized elements is made of sections.

27. The passive magnetic support and damping system of claim 19 wherein the first array of permanently magnetized elements is made of sections.

28. The passive magnetic support and damping system of claim 19 wherein the second array of permanently magnetized elements is made of sections.

29. The passive magnetic support and damping system of claim 19 wherein the means for damping the radial vibrations of at least one of the elements in said second array includes a damping material located between the at least one of the elements in said second array and said support for said stator.

30. The passive magnetic support and damping system of claim 29 wherein the damping material is a viscoelastic material.

31. The passive magnetic support and damping system of claim 29 wherein the damping material is a woven metal material.

19. A passive magnetic support and damping system comprising:

a) a rotor, said rotor being comprised of a first array of permanently magnetized elements arranged in a side-by-side relationship;

b) a stator said stator being comprised of a second array of permanently magnetized elements also arranged in a side-by-side relationship whereby, said rotor and said stator being arranged in a concentric relationship with a radially extending gap therebetween;

c) a support for said stator; and

d) a means for damping the radial vibrations of at least one of the elements in said second array.