Abstract
A magnetic bearing may include an inner ring and an outer ring arranged concentrically. The inner ring and the outer ring may be mounted rotatably relative to each other by way of axial and radial magnets. The magnetic bearing may also include a back-up bearing, which is integrated into at least one of the outer ring or the inner ring both in an axial direction and in a radial direction. The outer ring may be multipiece and may include a recess that opens inwards and receives the inner ring. Further, the back-up bearing may be made of aluminum, austenitic steel, bronze, or ceramic, and the back-up bearing may operate as a shielding device that shields magnetic fields emitted by the axial and radial magnets from one another.
Claims
1.-16. (canceled)
17. A magnetic bearing comprising: an inner ring; an outer ring, wherein the inner ring and the outer ring are concentric and are mounted rotatably relative to one another by way of axial and radial magnets; and a back-up bearing part of a back-up bearing that is integrated into at least one of the outer ring or the inner ring both in an axial direction and in a radial direction.
18. The magnetic bearing of claim 17 wherein the outer ring is multipiece and in an assembled state includes a recess that opens inwards, wherein the inner ring protrudes into the recess of the outer ring.
19. The magnetic bearing of claim 17 wherein the back-up bearing part is a first back-up bearing part, the back-up bearing further comprising a second back-up bearing part, wherein the first back-up bearing part is integrated into the inner ring and the second back-up bearing part is integrated into the outer ring.
20. The magnetic bearing of claim 17 wherein the back-up bearing comprises a flux separation for mutual decoupling of different magnetic circuits.
21. The magnetic bearing of claim 17 wherein the back-up bearing is comprised of at least one of aluminum, austenitic steel, bronze, or ceramic, the back-up bearing operating as a shielding device that shields magnetic fields emitted by the axial and radial magnets from one another.
22. The magnetic bearing of claim 17 wherein the axial and radial magnets comprise a pole shoe for orientation of magnetic fields.
23. The magnetic bearing of claim 22 wherein multiple of the axial or radial magnets are connected together via the pole shoe, which pole shoe is a one-piece pole shoe or a two-piece pole shoe.
24. The magnetic bearing of claim 22 wherein the pole shoe is a one-piece pole shoe that has a substantially annular base body or a partially circular base body, wherein a protrusion protrudes from the base body and is surrounded by a coil so as to form one of the axial or radial magnets.
25. The magnetic bearing of claim 22 wherein the pole shoe is a two-piece pole shoe, which in an assembled state surrounds a substantially annular base body or a partially circular base body, with the base body including a protrusion.
26. The magnetic bearing of claim 17 further comprising an air channel or a system of air channels disposed on at least one of the outer ring or the inner ring.
27. The magnetic bearing of claim 17 wherein at least one of the axial magnets or the radial magnets is actuatable individually or collectively.
28. The magnetic bearing of claim 17 wherein at least one of the magnetic bearing further comprises an emergency power supply, or the axial magnets are connected into a passive emergency braking circuit.
29. The magnetic bearing of claim 17 further comprising redundant sensor devices.
30. A method for operating a magnetic bearing that includes an inner ring; an outer ring, wherein the inner ring and the outer ring are concentric and are mounted rotatably relative to one another by way of axial and radial magnets; and a back-up bearing part of a back-up bearing that is integrated into at least one of the outer ring or the inner ring both in an axial direction and in a radial direction, the method comprising actuating at least one of the axial magnets or the radial magnets such that a gap with a width of less than 2 mm is formed between the inner ring and the outer ring.
31. The method of claim 30 wherein the width of the gap between the inner ring and the outer ring is between 1.2 mm and 1.8 mm.
32. The method of claim 30 wherein the width of the gap between the inner ring and the outer ring is 1.5 mm.
33. The method of claim 30 wherein at least one of the axial magnets or the radial magnets is actuated such that a nominal value is maintained for the width of the gap between the inner ring and the outer ring.
34. The method of claim 30 further comprising maintaining operation of the magnetic bearing upon failure of one of the axial magnets, one of the radial magnets, or a sensor device of the magnetic bearing.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0030] FIG. 1 shows in a perspective view an outer ring and an inner ring for a magnetic bearing according to an exemplary embodiment of the present invention.
[0031] FIG. 2 shows in a sectional view an outer ring and an inner ring for the magnetic bearing according to the exemplary embodiment of the present invention.
[0032] FIG. 3 shows the magnetic bearing composed of the outer ring and inner ring according to the exemplary embodiment of the present invention, in a sectional view (left) and in a perspective view (right).
[0033] FIG. 4 shows pole shoes for the outer ring or inner ring of a magnetic bearing according to the first exemplary embodiment of the present invention.
[0034] FIG. 5 shows an arrangement of sensor devices on the magnetic bearing according to the exemplary embodiment of the present invention.
EMBODIMENTS OF THE INVENTION
[0035] In the various figures, the same parts always carry the same reference signs and are therefore usually only mentioned or described once.
[0036] FIG. 1 shows on the left an inner ring 1 and on the right an outer ring 2 of a magnetic bearing 10 according to an exemplary embodiment of the present invention. It is here provided that the inner ring 1 forms a stator and the outer ring 2 forms a rotor. It is also conceivable that the inner ring 1 forms the rotor and the outer ring 2 forms the stator. For contactless mounting of the inner ring 1 and outer ring 2, axial magnets 11 and radial magnets 12 are provided which are part of the inner ring 1 or outer ring 2. In particular, it is provided that two axial magnets 11 are arranged in respective opposing regions of the inner ring 1 or outer ring 2, and two radial magnets 12 are arranged in respective opposing regions of the inner ring 1 or outer ring 2. A magnetic field is emitted by each individual axial and radial magnet, whereby finally the contactless arrangement and mounting of the outer ring 2 relative to the inner ring 1 is implemented. In the embodiment shown, the axial magnets 11 and the radial magnets 12 are arranged on the inner ring 1.
[0037] FIG. 2 shows in a sectional view on the left the inner ring 1, and on the right the outer ring 2 of the magnetic bearing 10 according to the exemplary embodiment of the present invention. In particular, the inner ring shown on the left of FIG. 2 comprises a back-up bearing 3, which captures the rotor in the event of a power failure and thus prevents the rotorwhich would otherwise leave the magnetic bearing 10from causing damage to its environment. For example, the back-up bearing 3 comprises a first back-up bearing part 3 and a second back-up bearing part 3, wherein the first back-up bearing part 3 is integrated in the inner ring and the second back-up bearing part 3 is integrated in the outer ring. The first back-up bearing part 3 and the second back-up bearing part 3 are configured such that they form a beveling plane in the magnetic bearing. Preferably, the first and second back-up bearing parts 3 and 3 are arranged curved along mutually opposing sides, or the edges are rounded. Furthermore, it is provided that the first back-up bearing part 3 and/or the second back-up bearing part 3 is arranged along the periphery of the inner ring 1 and/or the outer ring 2, between one of the axial magnets 11 and one of the radial magnets 12. Preferably, the first back-up bearing part 3 is arranged in an edge region of the inner ring 1, and the second back-up bearing part 3 is arranged in a corner region of the outer ring 2. It is preferably provided that, by the choice of material from which the back-up bearing 3 is made, the back-up bearing 3 forms a shielding device with which the various magnetic fields emitted by the different magnets, i.e. the axial magnets 11 and/or the radial magnets 12, can be shielded from each other. In this way, advantageously, the magnetic fields can each be set more precisely, since for example possible overlays which are difficult to estimate can remain substantially disregarded. In particular, it is provided here that the back-up bearing 3 is made of aluminum, austenitic steel, bronze and/or ceramic. Preferably, the back-up bearing 3 comprises lubrication bores via which the back-up bearing 3 can be supplied with lubricant at comparatively low cost. For the outer ring 2 shown on the right-hand side of FIG. 2, it is provided that this comprises an air channel 5 or a system of channels.
[0038] FIG. 3 shows in a sectional view and in a perspective view a magnetic bearing 10 assembled from the inner ring 1 and outer ring 2 according to the first exemplary embodiment of the present invention. It is provided here that the outer ring 2 is configured multipiece and, in assembled state, has a recess open towards the inside, into which the inner ring 1 protrudes. In this way, the outer ring 2 surrounds the inner ring 1 on its outside. Furthermore, it is provided that the distance between the outer ring 2 and the inner ring 1 is substantially less than 3 mm, preferably less than 2 mm, and particularly preferably amounts to 1.5 mm. In particular, the distance between the inner ring 1 and the outer ring 2 along a gap Z between the inner ring 1 and outer ring 2 remains substantially constant. Furthermore, it is conceivable that the magnetic bearing 10 has an emergency power supply which replaces a regular power supply on failure thereof.
[0039] FIG. 4 shows an axial magnet 11 and a radial magnet 12 which are suitable for forming the magnetic bearing 10 according to the first exemplary embodiment of the magnetic bearing, wherein an axial magnet 11 is illustrated on the left side, and a radial magnet 12 on the right side of FIG. 4. Both the axial magnet 11 and the radial magnet 12 shown comprise a pole shoe 6 which is surrounded at least partially, in particular along its periphery, by a coil 4. Use of the pole shoe 6 facilitates the orientation of the respective magnetic field, whereby finally the magnetic bearing of the inner ring 1 and outer ring 2 is further improved. Furthermore, it is provided that the pole shoe 6 is curved or arched, in particular in the form of a partial circle or segment. Preferably, it is provided that the curvature is matched to a radius of the inner ring 1 or outer ring 2, and the outer ring 2 or inner ring 1 is formed by the succession of several segment-like pole shoes 6 with respective coil.
[0040] FIG. 5 shows an arrangement of sensor devices for a magnetic bearing 10 according to the exemplary embodiment of the present invention. It is provided here that the magnetic bearing 10 has axial magnet sensors 21 and radial magnet sensors 22, which are preferably integrated peripherally in the air channel 5. In particular, the axial magnet sensors 21 are arranged at regular intervals around the magnetic bearing 10. For example, viewed from the bearing center point, an angle between two axial magnet sensors 21 has a value of approximately 22.5?. It is however also conceivable that the sensor devices, in particular redundant sensor devices, are arranged peripherally at irregular intervals. In particular, it is provided that the sensor devices are arranged at positions at which the greatest amplitudes are expected for a possible inherent frequency of the magnetic bearing 10. Furthermore, it is conceivable that the axial magnet sensors 21 and/or the radial magnet sensors 22 are in particular glued onto the axial magnets 11 or radial magnets 12, or bolted to the inner ring 1 or outer ring 2. In addition, it is conceivable that redundant sensor devices are fitted in order to maintain the operation of the magnetic bearing 10 to a sufficient extent, even on failure of a sensor device. Preferably, by a targeted redundant arrangement of the sensor devices, the position of the inner ring 1 or outer ring 2 is doubly secured, in particular if the magnetic bearing 10 is operated with a comparatively unfavorable inherent frequency. One example for a redundant arrangement of axial magnet sensors 21 and radial magnet sensors 22 is shown on the right-hand side of the magnetic bearing shown in FIG. 5.
LIST OF REFERENCE SIGNS
[0041] 1 Inner ring [0042] 2 Outer ring [0043] 3 Back-up bearing [0044] 3 First back-up bearing part [0045] 3 Second back-up bearing part [0046] 4 Coil [0047] 5 Air channels [0048] 6 Pole shoes [0049] 10 Magnetic bearing [0050] 11 Axial magnet [0051] 12 Radial magnet [0052] 21 Axial coil sensor [0053] 22 Radial coil sensor [0054] D Rotation axis [0055] Z Gap
