A hybrid gas dynamic pressure bearing

Abstract

A hybrid gas dynamic pressure bearing, in particular, an elastic foil gas dynamic pressure bearing with permanent magnet and ultrasonic assisted output, wherein permanent magnets are installed in the front stator, thrust plate, and rear stator, and ultrasonic generators are installed in the front stator and rear stator, and the thrust plate is supported for axial suspension by the combined effect of the repulsive force generated between the permanent magnet in the thrust plate and the same poles of the permanent magnets in the front and rear stators; and / or the sound pressure generated by the ultrasonic waves in the front and rear stators on the thrust plate, and the air film generated by the foil of the elastic support foil. Through the above arrangement, the axial support reliability of the bearing is doubled, avoiding failure to operate normally due to failure of the elastic foil.

Description

Technical Field

[0001] The invention relates to a hybrid gas dynamic pressure bearing, in particular to a gas dynamic pressure bearing with ultrasonically coupled elastic foil. Background Art

[0002] The elastic foil gas dynamic pressure bearing is a special bearing with high speed, high running accuracy, low loss and high temperature resistance. Among them, the elastic foil gas dynamic pressure bearing includes radial elastic foil gas dynamic pressure bearing and axial elastic foil gas dynamic pressure bearing. The radial bearing is mainly composed of top foil, arch foil, bearing seat and other parts, and the axial bearing is composed of top foil, arch foil, bearing seat and thrust bearing.

[0003] In the prior art, elastic foil gas dynamic pressure bearings are Figure 1 As shown, it includes: a bearing seat (stator) 100, an arch foil 200, a top foil 300, and a thrust bearing (thrust plate) 400. Each bearing seat 100 is composed of multiple fan-shaped arch foils 200 and top foils 300. One end of the arch foil 200 and the top foil 300 is welded to the bearing seat 100, and the other end is free. The welded end is slightly lower than the free end to form an air wedge angle. When the bearing is operating normally, a layer of air film is formed between the top foil 300 and the thrust bearing 400, so that the thrust bearing 400 is axially suspended. The arch foil 200 is a foil with multiple arches, which provides an elastic basis for the top foil 300 and determines the support stiffness of the surface of the top foil 300.

[0004] The flat foil that constitutes the top foil 300 and the corrugated foil that constitutes the arch foil 200 are both fan-shaped. The surface of the top foil 300 is relatively smooth. Its function is to rotate relative to the thrust bearing 400 to form a wedge-shaped gap in the circumferential direction and generate a dynamic pressure air film to provide axial support force. The corrugated foil is placed under the flat foil and fixed to the bearing seat. Its main function is to provide stiffness and damping. Summary of the invention

[0005] In view of this, the present invention proposes a hybrid gas dynamic pressure bearing (gas bearing) that solves at least one of the following problems: 1. By utilizing the principle of ultrasonic wave to generate sound pressure and / or the principle of repulsion between magnets of the same polarity, preferably permanent magnets, the pressure of the thrust plate (thrust bearing) on ​​the axial bearing stator (bearing seat) before the bearing takes off is reduced, thereby reducing the friction between the thrust plate and the bearing stator, and reducing the wear of the wear-resistant coating on the surface of the top foil and the thrust plate;

[0006] 2. The bearing of the present invention has reduced friction before take-off (before starting), reduced friction torque before take-off, faster starting response, and shortened the time required for the rotor to take off;

[0007] 3. Permanent magnets and / or ultrasonic waves assist in output, improving the bearing capacity of the axial foil gas dynamic pressure bearing, solving the problem of small bearing capacity of the foil gas dynamic pressure bearing, while improving the bearing support stiffness and improving the stability of the rotor during operation;

[0008] 4. The take-off speed of the elastic foil gas dynamic pressure bearing is greatly reduced, so that the rotor can run stably for a long time at a low speed, solving the shortcoming that the elastic foil gas dynamic pressure bearing cannot run for a long time at a low speed.

[0009] Specifically: a hybrid gas dynamic pressure bearing, comprising: a front stator, a rear stator and a thrust plate, wherein: the front stator comprises a front stator housing, and a front elastic support foil is fixedly connected to the front stator housing; the rear stator comprises a rear stator housing, and a rear elastic support foil is fixedly connected to the rear stator housing; the front stator housing and the rear stator housing are spaced apart, the front elastic support foil and the rear elastic support foil are face-to-face arranged correspondingly, the thrust plate is located between the front elastic support foil and the rear elastic support foil, a gap is formed between the front side of the thrust plate and the front elastic support foil, a gap is formed between the rear side of the thrust plate and the rear elastic support foil, a front sound wave generator is provided inside or outside the front stator housing, and a rear sound wave generator is provided inside or outside the rear stator housing.

[0010] Preferably, a first magnet is provided inside or outside the front stator housing, the thrust plate includes a thrust plate housing, a second magnet is provided inside or outside the thrust plate housing, and a third magnet is provided inside or outside the rear stator housing. The second magnet located in the middle position and the first magnet and the third magnet on both sides of it all generate repulsive force.

[0011] Preferably, there are multiple front sound wave generators, which are evenly distributed in the circumferential direction of the front stator housing; and there are multiple rear sound wave generators, which are evenly distributed in the circumferential direction of the rear stator housing.

[0012] Preferably, the front elastic support foil comprises a front arch foil and a front top foil, wherein the front arch foil is located between the front stator housing and the front top foil, and the front arch foil can provide elastic support to the front top foil;

[0013] The rear elastic support foil comprises a rear arch foil and a rear top foil, wherein the rear arch foil is located between the rear stator housing and the rear top foil, and the rear arch foil can provide elastic support to the rear top foil.

[0014] Preferably, the front sound wave generator is a front ultrasonic wave generator; and the rear sound wave generator is a rear ultrasonic wave generator.

[0015] Preferably, one end of the front elastic support foil is fixed on the front stator housing, and the other end is free relative to the front stator housing, and the height of one end of the front elastic support foil is lower than the other end; one end of the rear elastic support foil is fixed on the rear stator housing, and the other end is free relative to the rear stator housing, and the height of one end of the rear elastic support foil is lower than the other end.

[0016] Preferably, the number of the front elastic support foils is plural, the number of the rear elastic support foils is plural,

[0017] Preferably, the front stator housing includes a front stator end plate and a front stator shell, the front stator shell is provided with a front receiving groove, and the front receiving groove is used to accommodate the first magnet and the front sound wave generator; the rear stator housing includes a rear stator end plate and a rear stator shell, the rear stator shell is provided with a rear receiving groove, and the rear receiving groove is used to accommodate the third magnet and the rear sound wave generator.

[0018] Preferably, at least one of the first magnet, the second magnet and the third magnet is a permanent magnet.

[0019] Preferably, the thrust plate housing comprises a front thrust plate housing and a rear thrust plate housing, and a space for accommodating the second magnet is formed between the front thrust plate housing and the rear thrust plate housing.

[0020] It is to be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other objects, features and advantages of the present disclosure will become more apparent by describing in detail its exemplary embodiments with reference to the accompanying drawings. The accompanying drawings described below are only some embodiments of the present disclosure, and it is clear to a person skilled in the art that other accompanying drawings can be obtained from these accompanying drawings without creative work.

[0022] Figure 1 Schematic diagram of a prior art gas hydrodynamic bearing.

[0023] Figure 2 A three-dimensional exploded schematic diagram of some components of the gas dynamic pressure bearing of the present invention.

[0024] Figure 3 A schematic cross-sectional view of a gas dynamic pressure bearing according to the present invention.

[0025] Among them: 100-bearing seat of the prior art, 200-arch foil of the prior art, 300-top foil of the prior art; 400-thrust bearing of the prior art;

[0026] 1-front stator end plate, 2-first magnet, 3-front stator housing, 4-front arch foil, 5-front top foil, 6-front ultrasonic generator, 7-front thrust plate housing, 8-second magnet, 9-rear thrust plate housing, 10-rear ultrasonic generator, 11-rear top foil, 12-rear arch foil, 13-rear stator housing, 14-third magnet, 15-rear stator end plate. DETAILED DESCRIPTION

[0027] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.

[0028] In addition, the described features, structures or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. may be adopted. In other cases, known methods, devices, implementations or operations are not shown or described in detail to avoid blurring the various aspects of the present disclosure.

[0029] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0030] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0031] It should be understood that although the terms first, second, third, etc. may be used herein to describe various structures, these structures should not be limited by these terms. These terms are used to distinguish one structure from another structure. Therefore, the first structure discussed below can be referred to as the second structure without departing from the teachings of the disclosed concepts. As used herein, the term "and / or" includes any one of the associated listed items and all combinations of one or more.

[0032] Those skilled in the art will appreciate that the drawings are merely schematic diagrams of example embodiments, and the modules or processes in the drawings are not necessarily necessary for implementing the present disclosure, and therefore cannot be used to limit the protection scope of the present disclosure.

[0033] The following is combined with Figure 2 , 3 describes in detail the contents of the specific implementation methods of the present invention:

[0034] A hybrid gas dynamic pressure bearing comprises: a front stator, a rear stator and a thrust plate, wherein: the front stator comprises a front stator housing, and a front elastic support foil is fixedly connected to the front stator housing; the rear stator comprises a rear stator housing, and a rear elastic support foil is fixedly connected to the rear stator housing; it is characterized in that: the front stator housing and the rear stator housing are spaced apart, the front elastic support foil and the rear elastic support foil are face-to-face correspondingly arranged, the thrust plate is located between the front elastic support foil and the rear elastic support foil, a gap is formed between the front side of the thrust plate and the front elastic support foil, a gap is formed between the rear side of the thrust plate and the rear elastic support foil, a front sound wave generator is provided inside or outside the front stator housing, and a rear sound wave generator is provided inside or outside the rear stator housing.

[0035] Preferably, a first magnet is provided inside or outside the front stator housing, the thrust plate includes a thrust plate housing, a second magnet is provided inside or outside the thrust plate housing, and a third magnet is provided inside or outside the rear stator housing. The second magnet located in the middle position and the first magnet and the third magnet on both sides of it all generate repulsive force.

[0036] Preferably, there are multiple front sound wave generators, which are evenly distributed in the circumferential direction of the front stator housing; and there are multiple rear sound wave generators, which are evenly distributed in the circumferential direction of the rear stator housing.

[0037] Preferably, the front elastic support foil comprises a front arch foil 4 and a front top foil 5, wherein the front arch foil 4 is located between the front stator housing and the front top foil 5, and the front arch foil 4 can provide elastic support to the front top foil 5;

[0038] The rear elastic support foil comprises a rear arch foil 12 and a rear top foil 11 , wherein the rear arch foil 12 is located between the rear stator housing and the rear top foil 11 , and the rear arch foil 12 can provide elastic support to the rear top foil 11 .

[0039] Preferably, the front sound wave generator is the front ultrasonic generator 6 ; and the rear sound wave generator is the rear ultrasonic generator 10 .

[0040] Preferably, one end of the front elastic support foil is fixed on the front stator housing, and the other end is free relative to the front stator housing, and the height of one end of the front elastic support foil is lower than the other end; one end of the rear elastic support foil is fixed on the rear stator housing, and the other end is free relative to the rear stator housing, and the height of one end of the rear elastic support foil is lower than the other end.

[0041] Preferably, the number of the front elastic supporting foils is plural, and the number of the rear elastic supporting foils is plural.

[0042] Preferably, the front stator housing includes a front stator end plate 1 and a front stator shell 3, the front stator shell 3 is provided with a front receiving groove, and the front receiving groove is used to receive the first magnet 2 and the front sound wave generator; the rear stator housing includes a rear stator end plate 15 and a rear stator shell 13, the rear stator shell 13 is provided with a rear receiving groove, and the rear receiving groove is used to receive the third magnet 14 and the rear sound wave generator.

[0043] Preferably, the thrust plate housing comprises a front thrust plate housing and a rear thrust plate housing, and a space for accommodating the second magnet is formed between the front thrust plate housing and the rear thrust plate housing.

[0044] Preferably, at least one of the first magnet 2 , the second magnet 8 and the third magnet 14 is a permanent magnet.

[0045] The following is combined with Figure 2 ,3 Describe the principle and process of the present invention:

[0046] The hybrid gas dynamic pressure bearing of the present invention is preferably an axial elastic foil gas dynamic pressure bearing such as Figure 2 As shown, a permanent magnet and / or ultrasonic assisted elastic foil gas dynamic pressure bearing, the bearing stator (bearing seat) includes a front stator (front bearing seat) and a rear stator (rear bearing seat), and the thrust plate is located between the front stator and the stator. The bearing includes: a front stator housing 3, a rear stator housing 13, a front stator end plate 1, and a rear stator end plate 15, wherein the front and rear stator end plates 15 are also called bearing stator end plates, permanent magnets, ultrasonic generators, arch foils, top foils, thrust plates and other parts. It is a hybrid axial bearing that uses the repulsive force generated by the permanent magnet, the sound pressure generated by the ultrasonic wave and the preferably wedge-shaped elastic foil, i.e., the elastic support foil, to generate air film pressure to jointly support the thrust plate and make the rotor axially suspended.

[0047] The stator includes a front stator and a rear stator, and the front stator includes: a front stator shell, the front stator shell includes a front stator shell 3 and a front stator end plate 1; a front ultrasonic generator 6 and a first magnet 2 in the front stator shell; a plurality of front arch foils 4 and a plurality of front top foils 5; the front stator shell is equipped with the first magnet 2 and the front ultrasonic generator 6, the first magnet 2 in the front stator shell and the second magnet 8 in the thrust plate have the same polarity, so that the thrust plate and the front stator generate repulsive force, the front ultrasonic generator 6 is used to emit ultrasonic waves, and the sound waves pass through the front stator shell, the front arch foil 4, and the front top foil 5, and then generate sound pressure in the air gap between the front top foil 5 and the thrust plate. The rear stator comprises: a rear stator shell, which comprises a rear stator outer shell 13 and a rear stator end plate 15; a rear ultrasonic generator 10 and a third magnet 14 in the rear stator shell; a plurality of rear arch foils 12 and a plurality of rear top foils 11; the rear stator shell is equipped with the third magnet 14 and the rear ultrasonic generator 10, the third magnet 14 in the rear stator shell has the same polarity as the second magnet 8 in the thrust plate, so that the thrust plate and the rear stator generate repulsive force, the rear ultrasonic generator 10 is used to emit ultrasonic waves, and the sound waves pass through the rear stator shell, the rear arch foil 12 and the rear top foil 11, and then generate sound pressure in the air gap between the rear top foil 11 and the thrust plate.

[0048] The sound pressure generated by the front ultrasonic generator 6 and the rear ultrasonic generator 10 acts in opposite directions on the thrust plate to assist the thrust plate in suspension. And / or the repulsion generated by the first magnet 2 in the front stator housing and the second magnet 8 in the thrust plate, and the repulsion generated by the third magnet 14 in the rear stator housing and the second magnet 8 in the thrust plate; so that the thrust plate is affected by the front and rear magnetic repulsion forces. The first magnet 2 and the third magnet 14, the front ultrasonic generator 6 and the rear ultrasonic generator 10 are installed in the front stator housing and the rear stator housing of the bearing respectively; the first magnet 2 and the third magnet 14 on the bearing stator and the second magnet 8 on the thrust plate repel each other, and the magnetic pole distribution is NS, SN, NS (or SN, NS, SN, to ensure that the magnetic steel polarity on the thrust plate and the stator is the same.

[0049] When the thrust plate deviates to one side (the front side or the rear side) (the distance between the thrust plate and the bearing stator on this side decreases), the thickness of the dynamic pressure air film on this side decreases, the air film pressure increases, the distance between the thrust plate and the ultrasonic transmitter on the bearing stator on this side decreases, and the repulsive force between the two increases; and / or the repulsive force between the second magnet 8 in the thrust plate and the permanent magnet in the bearing stator on this side increases; on the side to which the thrust plate deviates, the air film pressure, the repulsive force between the magnet (magnetic steel), and the sound pressure of the ultrasonic wave increase simultaneously and act together on the thrust plate, causing the thrust plate to move toward the middle of the front stator and the rear stator (at this time, when the thrust plate is in the middle, the forces on the left and right sides are equal in magnitude and opposite in direction, and the resultant force is 0).

[0050] When the thrust plate is close to one side of the bearing stator, the sound pressure generated by the sound wave is the largest. The farther the thrust plate is from the sound pressure bearing, the smaller the sound pressure generated. Similarly, the closer the thrust plate is to the other side, the greater the sound pressure it is subjected to. Therefore, the thrust plate is affected by the sound pressure and tends to remain in the middle of the sound pressure bearings on both sides. The sound waves are emitted from the sound wave generators at both ends, preferably the front ultrasonic generator 6 and the rear ultrasonic generator 10. The sound waves emitted from the front ultrasonic generator 6 pass through the front bearing stator housing, the front arch foil 4, and the front top foil 5 respectively, and then act on the thrust plate to generate sound pressure, which plays a role in supporting the thrust plate; the sound waves emitted from the rear ultrasonic generator 10 pass through the rear bearing stator housing, the rear arch foil 12, and the rear top foil 11 respectively, and then act on the thrust plate to generate sound pressure, which plays a role in supporting the thrust plate; and improve the problems of insufficient bearing capacity of the foil gas dynamic pressure bearing at low speed and severe friction and wear during the starting and stopping process.

[0051] When the present invention is used, the first magnet 2, the third magnet 14 and the front and rear ultrasonic generators 10 are installed on the front and rear stators, and the second magnet 8 in the thrust plate housing is installed; the front and rear stator end plates 15 and the front and rear stator housings 13 are welded, and the power lines of the front and rear ultrasonic generators 10 are led out from the holes opened on the front and rear stator housings 13.

[0052] The front and rear arch foils 12 and the front and rear top foils 11 are welded or fixed with rivets on the front and rear stators (bearing seats). The front and rear arch foils 12 and the front and rear top foils 11 are fixed at one end and free at the other end. Figure 3 As shown, the wedge-shaped angle ends of the front and rear arch foils 12 and the front and rear top foils 11 are fixed and the other ends are free. The thrust plate rotates from the wedge-shaped angle end to the free end when rotating. When the present invention is applied, it is ensured that the wedge angle directions of the front and rear top foils 11 are consistent after the front and rear stators are installed, and the rotation of the rotor must make the thickness of the air film between the thrust plate and the front and rear stators smaller and smaller. The thrust plate is composed of a front thrust plate housing 7, a rear thrust plate housing 9 and a second magnet 8 (magnetic steel). The magnetic steel is installed on one of the thrust plate housings, and the other thrust plate housing is covered with one of the thrust plate housings. The two thrust plate housings are welded into one or other fixing methods are adopted. The thrust plate is covered on the rotor, and an interference fit or screw locking method is adopted. The thrust plate is fixed on the rotor, and the front and rear stators provide axial force to make the thrust plate axially suspended to prevent the rotor from axial movement during operation.

[0053] Beneficial effects:

[0054] The elastic foil gas dynamic pressure bearing with permanent magnet and ultrasonic assisted output of the present invention has permanent magnets installed in the front stator, thrust plate and rear stator, and ultrasonic generators installed in the front stator and rear stator, and uses the repulsion generated between the same poles of the permanent magnet in the thrust plate and the permanent magnets in the front and rear stators, the sound pressure generated by the ultrasonic wave, and the air film generated by the foil to support the axial suspension of the rotor. Compared with the traditional gas foil bearing, the ultrasonic assisted output improves the bearing capacity and rigidity of the bearing, making the rotor run more stable; in the process from the start to the take-off of the rotor, due to the repulsion generated by the permanent magnet and / or the sound pressure generated by the ultrasonic wave, the pressure between the thrust plate and the top foil is reduced, so the friction between the thrust plate and the top foil is also reduced, and the wear of the wear-resistant coating on the surface of the two is reduced, which greatly extends the life of the bearing. Since the friction between the thrust plate and the top foil is reduced, the heat generated by the friction between the two is small, the temperature resistance level requirement of the wear-resistant layer is reduced, and the cost of the coating is reduced. Because of the ultrasonic auxiliary output, the take-off speed of the rotor is reduced, the rotor can run at a lower speed for a long time, and the operating speed range is widened. In addition, because the repulsive force of the permanent magnet, the sound pressure generated by the ultrasonic wave, and the air film pressure generated by the elastic foil jointly support the thrust plate suspension, the reliability of the bearing is doubled, avoiding the failure of normal operation due to the failure of the elastic foil or the other two support methods.

[0055] The exemplary embodiments of the present disclosure are specifically shown and described above. It should be understood that the present disclosure is not limited to the detailed structures, configurations or implementations described herein; on the contrary, the present disclosure is intended to cover various modifications and equivalent configurations included in the spirit and scope of the appended claims.

Claims

1. A hybrid gas dynamic pressure bearing, comprising: A front stator, a rear stator and a thrust plate, wherein: the front stator comprises a front stator housing, and the front elastic support foil is fixedly connected to the front stator housing; the rear stator comprises a rear stator housing, and the rear elastic support foil is fixedly connected to the rear stator housing; the characteristics are: the front stator housing and the rear stator housing are arranged at a distance, the front elastic support foil and the rear elastic support foil are arranged face to face, the thrust plate is located between the front elastic support foil and the rear elastic support foil, a gap is formed between the front side of the thrust plate and the front elastic support foil, and a gap is formed between the rear side of the thrust plate and the rear elastic support foil, a front sound wave generator is arranged inside the front stator housing, and a rear sound wave generator is arranged inside the rear stator housing; a first magnet (2) is arranged inside the front stator housing, the thrust plate comprises a thrust plate housing, a second magnet (8) is arranged inside the thrust plate housing, and a third magnet (14) is arranged inside the rear stator housing, and the second magnet (8) located in the middle position and the first magnet (2) and the third magnet (14) on both sides thereof all generate repulsive force.

2. The bearing according to claim 1, characterized in that: There are multiple front sound wave generators, which are evenly distributed in the circumferential direction of the front stator shell; there are multiple rear sound wave generators, which are evenly distributed in the circumferential direction of the rear stator shell.

3. The bearing according to claim 1, characterized in that: The front elastic support foil comprises a front arch foil (4) and a front top foil (5), wherein the front arch foil (4) is located between the front stator housing and the front top foil (5), and the front arch foil (4) can provide elastic support to the front top foil (5); The rear elastic support foil comprises a rear arch foil (12) and a rear top foil (11), wherein the rear arch foil (12) is located between the rear stator housing and the rear top foil (11), and the rear arch foil (12) can provide elastic support to the rear top foil (11).

4. The bearing according to claim 1, characterized in that: The front sound wave generator is a front ultrasonic wave generator (6), and the rear sound wave generator is a rear ultrasonic wave generator (10).

5. The bearing according to claim 1, characterized in that: One end of the front elastic support foil is fixed on the front stator housing, and the other end is free relative to the front stator housing, and the height of one end of the front elastic support foil is lower than that of the other end of the front elastic support foil; one end of the rear elastic support foil is fixed on the rear stator housing, and the other end is free relative to the rear stator housing, and the height of one end of the rear elastic support foil is lower than that of the other end of the rear elastic support foil.

6. The bearing according to claim 5, characterized in that: The number of the front elastic supporting foils is plural, and the number of the rear elastic supporting foils is plural.

7. The bearing according to claim 1, characterized in that: The front stator housing comprises a front stator end plate (1) and a front stator shell (3), the front stator shell (3) being provided with a front receiving groove, the front receiving groove being used to receive the second magnet (2) and the front sound wave generator; the rear stator housing comprises a rear stator end plate (15) and a rear stator shell (13), the rear stator shell (13) being provided with a rear receiving groove, the rear receiving groove being used to receive the third magnet (14) and the rear sound wave generator.

8. The bearing according to claim 1, characterized in that: At least one of the first magnet (2), the second magnet (8) and the third magnet (14) is a permanent magnet.

9. The bearing according to claim 1, characterized in that: The thrust plate housing comprises a front thrust plate housing (7) and a rear thrust plate housing (9), and a space for accommodating a second magnet (8) is formed between the front thrust plate housing (7) and the rear thrust plate housing (9).

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