Homopolar quadrupole magnetic bearings

Abstract

The invention discloses a homopolar quadrupole magnetic bearing, comprising a stator and a rotor located in the inner ring of the stator. The stator is an axially symmetrical structure, comprising a left X stator core, a left Y stator core, a right X stator core, and a right Y stator core, and the rotor comprises a rotor core and a rotating shaft; the left and right X stator cores and the left and right Y stator cores are respectively connected by inserting a connector with four permanent magnets having the same axial magnetization direction, and the left and right X stator cores are evenly distributed with a pair of suspension teeth along the inner circumference; the left and right Y stator cores are evenly distributed with a pair of suspension teeth along the inner circumference; the suspension teeth are a zigzag structure, and the suspension teeth on the left and right sides are radially coplanar, respectively, and a radial air gap with an equal air gap length is formed between the suspension teeth and the rotor core, and a centralized radial control winding is wound on it. The invention has independent suspension designs in the X and Y directions, so that the suspension force is non-coupled in the X-Y direction, the permanent magnet is located in the axial direction, does not occupy radial space, and has a large radial suspension force.

Description

Technical Field

[0001] The invention relates to a non-mechanical contact magnetic bearing, in particular to a homopolar quadrupole magnetic bearing, which can be used as a non-contact suspension support for high-speed transmission components such as flywheel systems, machine tool electric spindles, centrifuges, etc. Background Art

[0002] Magnetic bearings are a new type of high-performance bearing that uses the electromagnetic force between the stator and the rotor to suspend the rotor in space, so that there is no mechanical contact between the stator and the rotor. With the emergence of high magnetic energy product rare earth permanent magnetic materials, in order to fully utilize the magnetic energy provided by permanent magnetic materials, permanent magnetic bias magnetic bearings have emerged. In their excitation windings, there is only control current, no bias current is required, which can significantly reduce the loss of magnetic bearings and the power consumption of power amplifier circuits. At present, permanent magnetic bias magnetic bearings can be divided into heteropolar and homopolar magnetic bearings according to the difference in the magnetic poles formed by the bias magnetic flux on the stator magnetic poles: (1) Heterpolar magnetic bearings, the magnetic polarities generated by the permanent magnets on the magnetic poles are different, the polarities are arranged alternately, and the bias magnetic flux and the control magnetic flux flow on the same plane; (2) Homopolar magnetic bearings, the magnetic polarities generated by the permanent magnets on the stator magnetic poles are the same, and the flow paths of the bias magnetic flux and the control magnetic flux are not on the same plane. This type of magnetic bearing has a small hysteresis loss on the rotor core and is simple to control. It has been widely used in high-speed occasions such as momentum flywheels and flywheel energy storage.

[0003] The commonality of existing homopolar magnetic bearing structures is that all radial suspension teeth are in a monolithic structure design on the same plane. The radial suspension teeth are wound with control windings to generate radial control flux, which interacts with the corresponding bias flux to generate radial suspension force. The hybrid magnetic bearing of this structure realizes radial two-degree-of-freedom suspension in a monolithic piece, resulting in coupling of suspension force in the XY direction and complex control. Summary of the invention

[0004] The purpose of the present invention is to provide a homopolar quadrupole magnetic bearing structure, which adopts a multi-piece structure, and the suspension in the XY directions is respectively realized by independent stator cores, and the suspension force is uncoupled in the XY directions and is easy to control.

[0005] The present invention is achieved through the following technical solutions:

[0006] A homopolar quadrupole magnetic bearing comprises a stator and a rotor located in the inner ring of the stator, wherein the stator is an axially symmetrical structure, comprising a left X stator core, a left Y stator core, a right X stator core, and a right Y stator core arranged in sequence from left to right; the rotor comprises a rotor core and a rotating shaft, and the rotating shaft runs through the rotor core;

[0007] The left and right X stator cores are connected by a pair of connectors inserted with permanent magnets having the same axial magnetization direction, and the left and right Y stator cores are connected by another pair of connectors inserted with permanent magnets having the same structure and the same axial magnetization direction; the left X stator core has a pair of suspended teeth evenly distributed along the inner circumference and symmetrically with the +x axis and -x axis directions; the left Y stator core also has a pair of suspended teeth evenly distributed along the inner circumference and symmetrically with the +y axis and -y axis directions; the right X stator core and the right Y stator core are provided with the same suspended teeth at symmetrical positions with the left X stator core and the left Y stator core;

[0008] The suspended teeth are all zigzag structures, and the four suspended teeth on the left X stator core and the left Y stator core have the same axial width close to one end face of the rotor core, are radially coplanar, and the curvature of the circumferential surface of the rotor core matches; the four suspended teeth on the right X stator core and the right Y stator core have the same axial width close to one end face of the rotor core, are radially coplanar, and the curvature of the circumferential surface of the rotor core matches; a radial air gap with equal air gap length is formed between the suspended teeth and the rotor core, and centralized radial control windings are wound on the suspended teeth.

[0009] Further, the outer diameters of the left and right Y stator cores are smaller than the inner diameters of the left and right X stator cores, and the difference between the two is greater than two radial air gap lengths.

[0010] Furthermore, the four connectors are all arc-shaped, have the same radial dimensions, and are respectively located on circular rings whose outer diameters are the same as the outer diameters of the left and right X stator cores. Both ends of the inner surfaces of a pair of connectors for connecting the left and right Y stator cores close to the center of the circle are respectively provided with termination parts, and the left Y stator core is connected to the right Y stator core through the four termination parts.

[0011] Furthermore, the left X stator core, the left Y stator core, the right X stator core, the Y stator core, the connector, the terminal part and the rotor core are made of magnetic conductive material.

[0012] Furthermore, the permanent magnet is made of rare earth permanent magnet material.

[0013] Furthermore, the rotating shaft is made of non-magnetic material. Beneficial Effects

[0014] 1. The present invention adopts a multi-piece structure, and the suspension in the XY direction is realized by independent stator cores respectively. The suspension teeth are designed into a zigzag structure so that the four suspension teeth in the X direction and the Y direction are radially coplanar. The suspension force is uncoupled in the XY direction and is easy to control.

[0015] 2. In order to ensure that the four permanent magnets have the same size, the present invention has terminal parts fixed at both ends of the connector for connecting the left Y stator core and the right Y stator core with a smaller outer diameter, and the two are connected by the terminal parts, so that the radial dimensions of the two connectors and the other two connectors for connecting the left X stator core and the right X stator core can be the same, so that the sizes of the four permanent magnets can be the same. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural diagram of a homopolar quadrupole magnetic bearing of the present invention;

[0017] Figure 2 It is a transverse cross-sectional view of the left X stator core and the right X stator core of the same polarity quadrupole magnetic bearing of the present invention;

[0018] Figure 3 This is the suspension flux diagram of the same polarity quadrupole magnetic bearing of the present invention.

[0019] 1-left X stator core, 101-suspended tooth A l , 102-suspended tooth B l , 2-left Y stator core, 201-suspended tooth C l ,202-suspended gear D l , 3-right Y stator core, 301-suspended tooth C r ,302-suspended tooth D r , 4-right X stator core, 401-suspended tooth A r ,402-suspended tooth B r , 5-permanent magnet E x , 6-permanent magnet F x , 7-permanent magnet E y , 8-permanent magnet F y , 9-first connector, 10-second connector, 11-third connector, 12-fourth connector, 13-first termination part, 14-second termination part, 15-third termination part, 16-fourth termination part, 17-radial control winding, 18-rotor core, 19-rotating shaft, 20-radial air gap, 21-static bias flux, 22-radial control flux in X direction, 23-radial control flux in Y direction. DETAILED DESCRIPTION

[0020] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0021] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0023] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Specific structure such as Figure 1-3 As shown, the present invention discloses a four-degree-of-freedom heteropolar multi-piece structure magnetic bearing, which includes a stator and a rotor located in the inner ring of the stator.

[0025] The stator is an axially symmetrical structure, including a left X stator core 1, a left Y stator core 2, a right X stator core 4, and a right Y stator core 3 arranged from left to right. The rotor includes a rotor core 18 and a rotating shaft 19. The rotor core 18 is a cylindrical structure, and the rotating shaft 19 runs through the inside thereof. The axial width of the rotor core 18 is relatively long. The magnetic bearing also includes four permanent magnets, which are curved sheet magnets, see the attached Figure 1 The four permanent magnets are inserted into the connector, inserted in the middle of the connector and arranged vertically. The four permanent magnets have the same size and are respectively denoted as permanent magnets E and x 5. Permanent magnet F x 6. Permanent magnet E y 7. Permanent magnet F y 8, they are all axially magnetized with the same magnetization direction, see Appendix Figure 1 .

[0026] The four connectors are all arc-shaped, with the same radial dimensions and different axial dimensions. The axial lengths of the third connector 11 and the fourth connector 12 are shorter than those of the first connector 9 and the second connector 10, and they are respectively located on cylindrical rings with the same outer diameter as the left X-stator core 1 and the right X-stator core 4.

[0027] The left X stator core 1 and the right X stator core 4 are connected by a first connector 9 and a second connector 10, both ends of which are fixed on the left X stator core 1 and the right X stator core 4, and the first connector 9 and the second connector 10 are arranged opposite to each other. The arc thickness of the four connectors is the same as the ring thickness of the left X stator core 1, the right X stator core 4, the left Y stator core 2, and the right Y stator core.

[0028] The third connector 11 and the fourth connector 12 are located at upper and lower positions and are arranged opposite to each other. Because the left Y stator core 2 and the right Y stator core 3 have the same size, the left X stator core 1 and the right X stator core 4 have the same size, and the outer diameters of the left Y stator core 2 and the right Y stator core 3 are smaller than the inner diameters of the left X stator core 1 and the right X stator core 4. In order to ensure that the four permanent magnets have the same size, the four connectors need to have the same size. Then, the four connectors need to be located on the same ring and have the same size. In this case, the left Y stator core 2 and the right Y stator core 3 cannot be connected through the third connector 11 and the fourth connector 12. In order to solve this problem, a terminal portion is added to both ends of the third connector 11 and the fourth connector 12, see the attached Figure 1 The two ends of the third connector 11 are fixed with two terminal parts, namely the first terminal part 13 and the second terminal part 14. The two ends of the fourth connector 12 are fixed with two terminal parts, namely the third terminal part 15 and the fourth terminal part 16. The four terminal parts are arc-shaped sheet structures, and their curvature is the same as that of the connector. They are fixed on the inner surfaces of the third connector 11 and the fourth connector 12, so that the left Y stator core 2 and the right Y stator core 3 are connected through the four terminal parts.

[0029] The suspended teeth A are evenly distributed along the inner circumference of the left X stator core 1 l 101 and suspension gear B l 102, right X stator core 4 has suspended teeth A evenly distributed along the inner circumference r 401 and suspension gear B r 402, respectively aligned with the +x axis and -x axis directions, i.e., suspended tooth A l 101 and suspension gear B l 102 The line connecting the two passes through the center of the ring, and the suspended tooth A r 401, Suspended tooth B r402 is set on the suspension gear A l 101. Suspended tooth B l The position corresponding to 102.

[0030] The left Y stator core 2 has suspended teeth C evenly distributed along the inner circumference l 201 and suspension gear D l 202, the right Y stator core 3 has evenly distributed suspended teeth C along the inner circumference r 301 and suspension gear D r 302, respectively aligned with the +y axis and -y axis directions, i.e., the suspended tooth C l 201 and suspension gear D l 202 The line connecting the two passes through the center of the ring, and the suspended tooth C l 201 and suspension gear D l 202 The line connecting the two is perpendicular to the suspension tooth A l 101 and suspension gear B l 102 connects the two. Suspended tooth C r 301, Suspended tooth D r 302 is set on the suspension gear C l 201. Suspended tooth D l The position corresponding to 202.

[0031] The eight suspended teeth are all zigzag structures. The four suspended teeth (suspended teeth A l , Suspended tooth B l , Suspended gear C l , Suspended tooth D l ) has the same axial width as the end face of the rotor core 18, is radially coplanar, and matches the circumferential curvature of the rotor core 18. The four suspended teeth (A) on the right X stator core 3 and the right Y stator core 4 r , B r , C r , D r ) is close to the axial width of one end face of the rotor core 18, is radially coplanar and matches the curvature of the circumferential surface of the rotor core 18.

[0032] The 4 suspension teeth on the left (suspension teeth A l , Suspended tooth B l , Suspended gear C l , Suspended tooth D l ) and the rotor core 18, the four floating teeth on the right (floating teeth A r , Suspended tooth B r , Suspended gear C r , Suspended tooth D r) and the rotor core 18 form radial air gaps 20, and the lengths of the formed radial air gaps 20 are equal. The outer diameters of the left and right Y stator cores (2, 3) are smaller than the inner diameters of the left and right X stator cores (1, 4), and the difference between the two is greater than the lengths of two radial air gaps 20. Each suspended tooth (suspended tooth A l , Suspended tooth B l , Suspended gear C l , Suspended tooth D l , Suspended tooth A r , Suspended tooth B r , Suspended gear C r , Suspended tooth D r ) are wound with centralized radial control windings 17.

[0033] In this embodiment, the left X stator core 1, the right X stator core 4, the left Y stator core 2, the right Y stator core 3, the four connectors (the first connector 9, the second connector 10, the third connector 11, the fourth connector 12), the four terminal portions (the first terminal portion 13, the second terminal portion 14, the third terminal portion 15, the fourth terminal portion 16) and the rotor core 18 are all made of magnetic conductive materials. The four permanent magnets (permanent magnet E x 5. Permanent magnet F x 6. Permanent magnet E y 7. Permanent magnet F y 8) Made of rare earth permanent magnetic material. The rotating shaft 19 is made of non-magnetic material.

[0034] 4 permanent magnets (permanent magnet E x 5. Permanent magnet F x 6. Permanent magnet E y 7. Permanent magnet F y 8) The generated static bias flux 21, see Appendix Figure 3 , from the permanent magnet E y 7. Permanent magnet F y 8N pole, through the third connector 11, the fourth connector 12, the first terminal part 13, the third terminal part 15, the floating tooth C l 201. Suspended tooth D l 202, radial air gap 20, rotor core 18, radial air gap 20, then through the suspended tooth C r , Suspended tooth D r , second terminal part 14, fourth terminal part 16, third connector 11, fourth connector 12, back to permanent magnet E y 7. Permanent magnet F y 8's S pole; permanent magnet E x 5. Permanent magnet F x Starting from the 6N pole, passing through the first connector 9 and the second connector 10, the floating tooth A l , Suspended tooth Bl , radial air gap 20, rotor core 18, radial air gap 20, suspended tooth A r , Suspended tooth B r , first connector 9, second connector 10, back to permanent magnet E x 5. Permanent magnet F x 6's S pole.

[0035] Winding on the suspension gear A l 101. Suspended tooth B l 102, Suspended tooth A r 401, Suspended tooth B r The radial control magnetic flux 22 in the X direction generated by the radial control winding 17 of 402 passes through the yoke of the left X stator core 1 and the right X stator core 4, respectively, and the suspension tooth A l , Suspended tooth B l and suspension gear A r , Suspended tooth B r The rotor core 18 forms a closed loop. l 201. Suspended tooth D l 202. Suspended tooth C r 301, Suspended tooth D r The radial control magnetic flux 23 in the Y direction generated by the radial control winding on 302 passes through the yoke of the left Y stator core 2 and the right Y stator core 3, respectively, and the suspension tooth C l , Suspended tooth D l and suspension gear C r , Suspended tooth D r It forms a closed loop with the rotor core 18.

[0036] Suspension principle: The static bias magnetic flux 21 interacts with the X-direction radial control magnetic flux 22 and the Y-direction radial control magnetic flux 23, so that the air gap magnetic field on the same side as the radial eccentricity of the rotor is superimposed and weakened, while the air gap magnetic field on the opposite direction is superimposed and enhanced, generating a force on the rotor opposite to the rotor offset direction, pulling the rotor back to the radial equilibrium position.

[0037] The technical means disclosed in the scheme of the present invention are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical schemes composed of any combination of the above-mentioned technical features. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications are also regarded as the protection scope of the present invention.

Claims

1. A homopolar quadrupole magnetic bearing, comprising a stator and a rotor located in the inner ring of the stator, characterized in that: The stator is an axially symmetrical structure, including a left X stator core, a left Y stator core, a right X stator core, and a right Y stator core arranged from left to right; the rotor includes a rotor core and a rotating shaft, and the rotating shaft runs through the rotor core; The left X stator core and the right X stator core are connected by a pair of connectors inserted with permanent magnets, and the left Y stator core and the right Y stator core are connected by another pair of connectors inserted with permanent magnets of the same structure; the four permanent magnets are axially magnetized with the same magnetization direction; the left X stator core has a pair of suspended teeth evenly distributed along the inner circumference and symmetrically with the +x axis and -x axis directions; the left Y stator core has a pair of suspended teeth evenly distributed along the inner circumference and symmetrically with the +y axis and -y axis directions; the right X stator core and the right Y stator core are provided with the same suspended teeth at symmetrical positions with the left X stator core and the left Y stator core; The suspended teeth are all zigzag structures, and the four suspended teeth on the left X stator core and the left Y stator core have the same axial width near one end face of the rotor core, are radially coplanar, and match the radian of the circumferential surface of the rotor core; the four suspended teeth on the right X stator core and the right Y stator core have the same axial width near one end face of the rotor core, are radially coplanar, and match the radian of the circumferential surface of the rotor core; a radial air gap with equal air gap length is formed between the suspended teeth and the rotor core, and centralized radial control windings are wound on the suspended teeth; The outer diameters of the left Y stator core and the right Y stator core are smaller than the inner diameters of the left X stator core and the right X stator core, and the difference between the two is greater than two radial air gap lengths; The four connectors are all arc-shaped and have the same radial dimensions. They are respectively located on a circular ring with the same outer diameter as the left X stator core and the right X stator core. Both ends of the inner surface of a pair of connectors close to the center of the circle for connecting the left Y stator core and the right Y stator core are respectively provided with terminal parts, and the left Y stator core is connected to the right Y stator core through the four terminal parts.

2. The homopolar quadrupole magnetic bearing according to claim 1, characterized in that: The left X stator core, the left Y stator core, the right X stator core, the right Y stator core, the connector, the terminal part and the rotor core are made of magnetic conductive material.

3. The homopolar quadrupole magnetic bearing according to claim 1, characterized in that: The permanent magnet is made of rare earth permanent magnet material.

4. The homopolar quadrupole magnetic bearing according to claim 1, characterized in that: The rotating shaft is made of non-magnetic material.

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