Three-degree-of-freedom hybrid magnetic bearing, rotary drive machine

Abstract

The application provides a three-degree-of-freedom hybrid magnetic suspension bearing and a rotary driving machine, the bearing comprises two bearing stator cores which are axially opposite, each bearing stator core comprises a first yoke ring and a second yoke ring, a permanent magnet and an axial annular gap are clamped between the first yoke ring and the second yoke ring, the inner wall of each of the first yoke ring and the second yoke ring forms a radial annular gap with a rotating shaft, control pole columns and control windings wound on the two yoke rings are formed respectively, the control windings can generate radial and axial control closed loops between each bearing stator core, a thrust disc corresponding to each bearing stator core and the rotating shaft respectively. Since the radial control and the axial control share the same set of control windings, the bearing structure can be simplified, the bearing design is more compact, the shaft length of the rotating shaft using the bearing can be shortened, and the critical speed of the rotor can be improved.

Description

Technical Field

[0001] This invention belongs to the field of magnetic levitation bearing design technology, specifically relating to a three-degree-of-freedom hybrid magnetic levitation bearing and a rotary drive mechanism. Background Technology

[0002] Magnetic bearings levitate the rotor shaft using electromagnetic force, keeping the shaft and stator in a non-contact state. This results in advantages such as no wear, high speed, high precision, and long lifespan. Magnetic bearings can be classified into three types based on their working principle: active magnetic bearings, passive magnetic bearings, and hybrid magnetic bearings.

[0003] Hybrid magnetic bearings, also known as magnetic levitation bearings that combine permanent magnet and electromagnetic elements, have a mechanical structure that includes permanent magnets and control coils. The permanent magnets provide static bias flux, and when the rotor is subjected to external disturbances or loads, the control coils generate the control flux required to return the rotor to its equilibrium position, thereby generating a levitation force that pulls the rotor back to its equilibrium position. Three-degree-of-freedom hybrid magnetic bearings integrate the functions of axial and radial magnetic bearings, improving the levitation force density. Using three-degree-of-freedom hybrid magnetic bearings to support the motor rotor greatly reduces the rotor length and can effectively increase the rotor's critical speed, showing broad application prospects.

[0004] The existing three-degree-of-freedom hybrid magnetic levitation bearing has a relatively complex and non-compact structure, resulting in a large axial thickness of the bearing and a large shaft length, which is not conducive to improving the critical speed of the rotor. Summary of the Invention

[0005] Therefore, the present invention provides a three-degree-of-freedom hybrid magnetic levitation bearing and a rotary drive mechanism, which can overcome the shortcomings of the related technology where the three-degree-of-freedom hybrid magnetic levitation bearing has a relatively complex structural design, is not compact enough, and results in a large axial thickness of the bearing, which in turn results in a large shaft length, which is not conducive to improving the critical speed of the rotor.

[0006] To address the aforementioned problems, this invention provides a three-degree-of-freedom hybrid magnetic levitation bearing, comprising a first bearing stator core and a second bearing stator core. The first bearing stator core includes a first yoke, and the second bearing stator core includes a second yoke. The first and second yokes are engaged with each other along the axial direction of the rotating shaft. A permanent magnet for providing an axial bias magnetic field is held between the radially peripheral regions of the first and second yokes. An axial annular gap for accommodating a thrust disk on the rotating shaft is formed between the radially inner regions of the first and second yokes. A first radial annular gap and a second radial annular gap are respectively formed between the inner annular walls of the first and second yokes and the rotating shaft. The first yoke has at least one... There are at least two pairs of first control poles, each of which is wound with a first control winding. At least two pairs of second control poles are formed on the second yoke, each of which is wound with a second control winding. Each of the first or second control poles is evenly spaced along the circumferential direction of the rotating shaft. The first control magnetic circuit generated by the first control winding passes through the first yoke, the first radial annular gap, the rotating shaft, the thrust disk, and the axial annular gap in sequence and returns to the first yoke to form a first radial and axial control closed loop. The second control magnetic circuit generated by the second control winding passes through the second yoke, the second radial annular gap, the rotating shaft, the thrust disk, and the axial annular gap in sequence and returns to the second yoke to form a first radial and axial control closed loop.

[0007] In some embodiments, the first control pole and the second control pole are respectively located near the thrust plate in the first yoke ring and the second yoke ring, the radial thickness of the first radial annular gap is d1, the range of d1 is 0.1~1mm, and the radial thickness of the second radial annular gap is d2, the range of d2 is 0.1~1mm.

[0008] In some embodiments, the first control pole and the second control pole are respectively located on the inner ring walls of the first yoke and the second yoke. A plurality of first axial guide magnetic poles protruding toward the thrust plate are formed on the end face of the first yoke near the thrust plate. The positions of each first axial guide magnetic pole and each first control pole are arranged in a one-to-one correspondence. A first axial air gap is formed between each first axial guide magnetic pole and the thrust plate. A plurality of second axial guide magnetic poles protruding toward the thrust plate are formed on the end face of the second yoke near the thrust plate. The positions of each second axial guide magnetic pole and each second control pole are arranged in a one-to-one correspondence. A second axial air gap is formed between each second axial guide magnetic pole and the thrust plate.

[0009] In some embodiments, the axial thickness of the first axial air gap is w1, and the range of w1 is 0.1~1mm; the axial thickness of the second axial air gap is w2, and the range of w2 is 0.1~1mm.

[0010] In some embodiments, the first control winding and the second control winding are aligned and overlapped one-to-one when projected along the axial direction of the rotating shaft.

[0011] In some embodiments, two first control windings that project axially coincidentally are connected in series with a second control winding, such that the direction of the control magnetic circuit formed by the first control winding in the first control pole or the first axial guide magnetic pole is the same as the direction of the bias magnetic circuit formed by the permanent magnet in the first control pole or the first axial guide magnetic pole, while the direction of the control magnetic circuit formed by the second control winding in the second control pole or the second axial guide magnetic pole is opposite to the direction of the bias magnetic circuit formed by the permanent magnet in the second control pole or the second axial guide magnetic pole.

[0012] In some embodiments, the permanent magnet includes a plurality of independent permanent magnet blocks, and a magnetic groove for accommodating each of the permanent magnet blocks is formed between the first yoke ring and the second yoke ring. The number of magnetic grooves is equal to the number of the first control poles, and they are arranged in a one-to-one correspondence with the positions of each of the first control poles. The permanent magnet blocks have the same polarity in the axial direction of the rotating shaft; and / or, the axis of the rotating shaft is in the vertical direction when in use.

[0013] In some embodiments, the magnet groove includes a first opening groove formed on the first yoke and a second opening groove formed on the second yoke, wherein the depth of each first opening groove and the axial depth of each second opening groove are equal.

[0014] In some embodiments, each of the first opening slots is formed by a plurality of first protrusions spaced apart on the side of the first yoke ring and facing the thrust disk, and each of the second opening slots is formed by a plurality of second protrusions spaced apart on the side of the second yoke ring and facing the thrust disk, with each of the first protrusions and each of the second protrusions respectively engaging one-to-one.

[0015] The present invention also provides a rotary drive mechanism, including the above-described three-degree-of-freedom hybrid magnetic levitation bearing.

[0016] The three-degree-of-freedom hybrid magnetic levitation bearing and rotary drive mechanism provided by this invention have the following beneficial effects:

[0017] Multiple first control windings and second control windings arranged around the rotating shaft are respectively set on the first bearing stator core and the second bearing stator core. The three degrees of freedom of the rotating shaft, namely axial and radial, can be synchronously adjusted simultaneously by controlling whether each control winding is energized and the magnitude of the energized current, ensuring that the rotating shaft is in the target floating position. Since the radial control and axial control share the same set of control windings, the bearing structure can be simplified, the bearing design can be more compact, the axial dimension of the bearing can be reduced, and the shaft length of the rotating shaft using it can be shortened, which is beneficial to increasing the critical speed of the rotor. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the three-dimensional structure of a three-degree-of-freedom hybrid magnetic levitation bearing in one embodiment of the present invention (partial cross-section, including the rotating shaft).

[0020] Figure 2 yes Figure 1 A three-dimensional structural diagram of the first bearing stator core or the second bearing stator core in the process;

[0021] Figure 3 yes Figure 1 A half-section diagram of the three-degree-of-freedom hybrid magnetic levitation bearing and the rotating shaft after assembly;

[0022] Figure 4 yes Figure 1 A schematic diagram of the projection of a three-degree-of-freedom hybrid magnetic levitation bearing along the axis of rotation to one side;

[0023] Figure 5 yes Figure 1 A schematic diagram of the axial and radial control magnetic circuits (solid arrows in the figure) and the axial offset magnetic circuit (dashed arrows in the figure) of the three-degree-of-freedom hybrid magnetic levitation bearing in use.

[0024] Figure 6 This is a schematic diagram of the axial and radial control magnetic circuits (solid arrows in the figure) and the axial bias magnetic circuit (dashed arrows in the figure) of the three-degree-of-freedom hybrid magnetic levitation bearing in use, according to another embodiment of the present invention.

[0025] Figure 7 yes Figure 6 A three-dimensional structural diagram of the first bearing stator core or the second bearing stator core in the process;

[0026] Figure 8 yes Figure 6 A half-section diagram of the three-degree-of-freedom hybrid magnetic levitation bearing and the rotating shaft after assembly.

[0027] The attached figures are labeled as follows:

[0028] 1. First bearing stator core; 11. First yoke ring; 111. First control pole; 112. First control winding; 113. First shaft guide magnet; 114. First protrusion; 115. Connecting hole; 2. Second bearing stator core; 21. Second yoke ring; 211. Second control pole; 212. Second control winding; 213. Second shaft guide magnet; 214. Second protrusion; 3. Permanent magnet; 31. Permanent magnet block; 4. Magnet slot; 41. First open slot; 42. Second open slot; 100. Rotating shaft; 101. Thrust disc. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0031] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90° or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0032] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0033] See also Figures 1 to 8 As shown, according to an embodiment of the present invention, a three-degree-of-freedom hybrid magnetic levitation bearing is provided, including a first bearing stator core 1 and a second bearing stator core 2. The first bearing stator core 1 includes a first yoke 11, and the second bearing stator core 2 includes a second yoke 21. The first yoke 11 and the second yoke 21 are fastened to each other along the axial direction of the rotating shaft 100. In a specific embodiment, the aforementioned first yoke 11 and second yoke 21 are mirror images of each other, that is, they are symmetrical in terms of structure. A permanent magnet 3 for providing an axial bias magnetic field is sandwiched between the radial peripheral regions of the first yoke 11 and the second yoke 21, that is, the magnetization direction of the permanent magnet 3 is axial. Figure 5 As shown, the permanent magnet 3 has an S pole at the top and an N pole at the bottom. An axial annular gap (not shown) is formed between the radial inner regions of the first yoke 11 and the second yoke 21 to accommodate the thrust disk 101 on the rotating shaft 100. A first radial annular gap (not shown) and a second radial annular gap (not shown) are formed between the inner annular walls (not shown) of the first yoke 11 and the second yoke 21 and the rotating shaft 100, respectively. At least two pairs of first control pole posts 111 are formed on the first yoke 11. Figure 4 In the specific embodiment shown, the aforementioned first control poles 111 are provided in two pairs, that is, four pairs, but it can also be three pairs, four pairs, etc. Each first control pole 111 is wound with a first control winding 112, and at least two pairs of second control poles 211 are formed on the second yoke 21. Figure 4 In the specific embodiment shown, two pairs (four pairs) of the aforementioned second control poles 211 are provided, although there could also be three or four pairs. Each second control pole 211 is wound with a second control winding 212. Each first control pole 111 or second control pole 211 is evenly spaced along the circumferential direction of the rotating shaft 100. The first control magnetic circuit generated by the first control winding 112 sequentially passes through the first yoke 11, the first radial annular gap, the rotating shaft 100, the thrust disk 101, and the axial annular gap before returning to the first yoke 11, forming a first radial and axial control closed loop. The second control magnetic circuit generated by the second control winding 212 sequentially passes through the second yoke 21, the second radial annular gap, the rotating shaft 100, the thrust disk 101, and the axial annular gap before returning to the second yoke 21, forming a first radial and axial control closed loop. See [link to documentation] for details. Figure 5 or Figure 6 As shown, with Figure 5 As shown in the figure, the solid arrows indicate the control magnetic circuit, while the dashed arrows indicate the bias magnetic circuit. As can be seen in the figure, the control magnetic circuit in the upper first bearing stator core 1 forms a closed control loop through the rotating shaft 100 and the thrust disk 101. Since the aforementioned first control winding 112 has multiple sets, the axial and radial suspension positions of the rotating shaft 100 can be adjusted simultaneously. Similarly, the control magnetic circuit in the lower first bearing stator core 1 can also adjust the axial and radial suspension positions of the rotating shaft 100.

[0034] In this technical solution, multiple first control windings 112 and second control windings 212 are respectively arranged around the rotating shaft 100 on the first bearing stator core 1 and the second bearing stator core 2. The three degrees of freedom of the rotating shaft 100, namely the axial and radial directions, can be synchronously adjusted simultaneously by whether each control winding is energized and the magnitude of the energized current, ensuring that the rotating shaft 100 is in the target suspension position. Since the radial control and axial control share the same set of control windings, the bearing structure can be simplified, the bearing design can be more compact, the axial dimension of the bearing can be reduced, and the shaft length of the rotating shaft 100 can be shortened, which is beneficial to increasing the critical speed of the rotor.

[0035] As a feasible implementation, in some embodiments, the first control pole 111 and the second control pole 211 are respectively located on the end faces of the first yoke 11 and the second yoke 21 near the thrust disk 101, such as... Figure 2 and Figure 3 As shown, the radial thickness of the first radial annular gap (i.e., air gap) is d1, and the range of d1 is 0.1~1mm. The radial thickness of the second radial annular gap (i.e., air gap) is d2, and the range of d2 is 0.1~1mm. In a specific embodiment, d1=d2.

[0036] In this technical solution, the thickness of the first radial annular gap and the second radial annular gap, which are far from the first control winding 112 and the second control winding 212, are limited to ensure that the rotating shaft 100 avoids contact with the yoke ring, while ensuring that the air gap is small enough, thereby ensuring that the radial output force of the control magnetic circuit is at a high level.

[0037] In some embodiments, the first control pole 111 and the second control pole 211 are respectively located on the inner ring walls of the first yoke 11 and the second yoke 21. A plurality of first axial guide magnetic poles 113 protruding towards the thrust disk 101 are formed on the end face of the first yoke 11 near the thrust disk 101. Each first axial guide magnetic pole 113 is positioned in a one-to-one correspondence with each first control pole 111. A first axial air gap (not labeled in the figure) is formed between each first axial guide magnetic pole 113 and the thrust disk 101. A plurality of second axial guide magnetic poles 213 protruding towards the thrust disk 101 are formed on the end face of the second yoke 21 near the thrust disk 101. Each second axial guide magnetic pole 213 is positioned in a one-to-one correspondence with each second control pole 211. A second axial air gap (not labeled in the figure) is formed between each second axial guide magnetic pole 213 and the thrust disk 101.

[0038] In this technical solution, the first control pole 111 and the second control pole 211 are respectively set on the inner ring wall of the corresponding yoke ring. At the same time, the aforementioned first axial guide magnetic pole 113 and the second axial guide magnetic pole 213 are respectively set on the end face of each yoke ring near the thrust disk 101. This can minimize the axial air gap and ensure the axial output of the control magnetic circuit.

[0039] In one specific embodiment, the axial thickness of the first axial air gap is w1, and the range of w1 is 0.1~1mm; the axial thickness of the second axial air gap is w2, and the range of w2 is 0.1~1mm. In one specific embodiment, w1=w2.

[0040] In this technical solution, the thickness of the first axial air gap and the second axial air gap, which are far away from the first control winding 112 and the second control winding 212, is limited to ensure that the thrust disk 101 and the yoke ring avoid contact, while ensuring that the air gap is small enough, thereby ensuring that the axial output force of the control magnetic circuit is at a high level.

[0041] In some embodiments, each of the first control windings 112 and each of the second control windings 212 are correspondingly overlapped along the axial projection of the rotating shaft 100.

[0042] In this technical solution, the first control winding 112 and the second control winding 212 are designed to coincide in the axial direction of the rotating shaft 100, which can ensure the balance of radial force and axial force.

[0043] In some embodiments, two first control windings 112 and a second control winding 212 that project axially coincidentally are connected in series, such that the direction of the control magnetic path formed by the first control winding 112 within the first control pole 111 or the first axial guide magnetic pole 113 is the same as the direction of the bias magnetic path formed by the permanent magnet 3 within the first control pole 111 or the first axial guide magnetic pole 113, while the direction of the control magnetic path formed by the second control winding 212 within the second control pole 211 or the second axial guide magnetic pole 213 is opposite to the direction of the bias magnetic path formed by the permanent magnet 3 within the second control pole 211 or the second axial guide magnetic pole 213. See details [link to documentation]. Figure 5 As shown, the direction of the control magnetic circuit generated by the first control winding 112 wound on the first control pole 111 within the first control pole 111 is the same as the direction of the axial bias magnetic circuit of the permanent magnet 3 within the first control pole 111, forming magnetic circuit superposition. Simultaneously, since the direction of the control magnetic circuit generated by the second control winding 212, which is in the same quadrant as the first control winding 112 (i.e., axially coincident), within the second control pole 211 is opposite to the direction of the axial bias magnetic circuit of the permanent magnet 3 within the second control pole 211, magnetic circuit reduction occurs. This forms a magnetic circuit on the rotating shaft 100. A large upward axial force ensures efficient adjustment of the axial suspension position of the shaft 100. Conversely, when it is necessary to control the axial downward movement of the shaft 100, the current in the first control winding 112 and the second control winding 212 in that quadrant can be reversed. In another feasible solution, when the shaft 100 is in use with its axis in the vertical direction, the axial downward movement of the shaft 100 can also be achieved by reducing the magnitude of the current in a pair of first control windings 112 and second control windings 212 in each quadrant (combining the weight of the shaft 100).

[0044] It should be specifically noted that the permanent magnet 3 in this technical solution is only intended to provide an axial bias magnetic field, not a radial bias magnetic field. The control of the radial suspension position of the rotating shaft 100 is achieved by the difference in current flowing through the first control winding 112 and the second control winding 212 in different quadrants. Figure 4 The orientation shown is for reference only. The figure shows four first control windings 112: the upper right winding (first quadrant), the upper left winding (second quadrant), the lower left winding (third quadrant), and the lower right winding (fourth quadrant). The first control windings 112 and second control windings 212 within the same quadrant together exert a radial force on the shaft 100. If it is necessary to control the shaft 100 to move in the direction of rotation... Figure 4The upward and leftward movement of the indicated position can control the increase of the current in the first control winding 112 in the second quadrant (i.e., the upper left) (while the second control winding 212 in the second quadrant is connected in series with it), and simultaneously decrease the current in the first control winding 112 in the fourth quadrant (i.e., the lower right). The radial suspension adjustment in other directions is similar and will not be described in detail.

[0045] It should be noted that, since the three-degree-of-freedom hybrid magnetic bearing of the present invention does not have a radial bias magnetic field, that is, the bias magnetic field of the permanent magnet 3 in the present invention does not have an effect on the radial direction, the axial output force is much greater than the radial output force under the same current. Therefore, this integrated hybrid three-degree-of-freedom magnetic bearing is suitable for situations where radial disturbance is small and radial balance and stability can be controlled. In other words, the magnetic levitation shaft of the present invention is particularly suitable for situations where the shaft 100 is vertical, that is, when the shaft 100 is vertical in use.

[0046] In some embodiments, the aforementioned permanent magnet 3 can adopt a permanent magnet ring structure. However, when using a permanent magnet ring, the assembly and connection structure of the first bearing stator core 1 and the second bearing stator core 2 is relatively complex. In another preferred embodiment, the permanent magnet 3 includes multiple independent permanent magnet blocks 31, each permanent magnet block 31 specifically adopting a sector-shaped magnet. A magnetic steel groove 4 for accommodating each of the permanent magnet blocks 31 is formed between the first yoke ring 11 and the second yoke ring 21. The number of magnetic steel grooves 4 is equal to the number of the first control poles 111, and they are arranged in a one-to-one correspondence with the positions of each of the first control poles 111. The permanent magnet blocks 31 have the same polarity in the axial direction of the rotating shaft 100. Figure 3 The orientation shown is for reference only. The top of each permanent magnet block 31 is the N pole and the bottom is the S pole, or vice versa.

[0047] In one specific embodiment, the magnetic groove 4 includes a first opening groove 41 formed on the first yoke 11 and a second opening groove 42 formed on the second yoke 21. The depth of each first opening groove 41 and the axial depth of each second opening groove 42 are equal to ensure that the intensity of the axial bias magnetic field is consistent on the two yokes.

[0048] In some embodiments, each of the first opening slots 41 is formed by a plurality of first protrusions 114 spaced apart, protruding from the first yoke ring 11 towards the thrust disk 101, and each of the second opening slots 42 is formed by a plurality of second protrusions 214 spaced apart, protruding from the second yoke ring 21 towards the thrust disk 101, with each of the first protrusions 114 and each of the second protrusions 214 respectively engaging one-to-one. See details below. Figure 4As shown, corresponding connecting holes 115 are respectively provided at the center positions of the first protrusion 114 and the second protrusion 214. In this way, the first bearing stator core 1 and the second bearing stator core 2 can be reliably connected axially by passing connecting bolts (not shown in the figure) through the connecting holes 115. At the same time, the bearing can also be reliably fixed to the bearing housing or assembly housing (not shown in the figure) through the connecting holes 115 and the connecting bolts.

[0049] It is understandable that the aforementioned first bearing stator core 1 and second bearing stator core 2 are both made of magnetically conductive materials, such as silicon steel sheets stacked together.

[0050] According to an embodiment of the present invention, a rotary drive mechanism is also provided, including the above-described three-degree-of-freedom hybrid magnetic levitation bearing, wherein the rotary drive mechanism is, for example, a magnetic levitation motor, a magnetic levitation blower, or a magnetic levitation centrifugal compressor.

[0051] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A three-degree-of-freedom hybrid magnetic levitation bearing, characterized in that, The bearing includes a first bearing stator core (1) and a second bearing stator core (2). The first bearing stator core (1) includes a first yoke (11), and the second bearing stator core (2) includes a second yoke (21). The first yoke (11) and the second yoke (21) are fastened to each other along the axial direction of the shaft (100). A permanent magnet (3) for providing an axial bias magnetic field is held between the radially peripheral regions of the first yoke (11) and the second yoke (21). An axial annular gap for accommodating a thrust disk (101) on the shaft (100) is formed between the radially inner regions of the first yoke (11) and the second yoke (21). A first radial annular gap and a second radial annular gap are formed between the inner annular walls of the first yoke (11) and the shaft (100), respectively. At least two pairs of first control poles (111) are formed on the first yoke (11). A first control winding (112) is wound on each pole post (111), and at least two pairs of second control pole posts (211) are formed on the second yoke (21). A second control winding (212) is wound on each of the second control pole posts (211). Each of the first control pole posts (111) or the second control pole posts (211) is evenly spaced along the circumferential direction of the rotating shaft (100). The first control magnetic circuit generated by the first control winding (112) passes through the first yoke (11), the first radial annular gap, the rotating shaft (100), the thrust disk (101), and the axial annular gap in sequence and returns to the first yoke (11) to form a first radial and axial control closed loop. The second control magnetic circuit generated by the second control winding (212) passes through the second yoke (21), the second radial annular gap, the rotating shaft (100), the thrust disk (101), and the axial annular gap in sequence and returns to the second yoke (21) to form a second radial and axial control closed loop.

2. The three-degree-of-freedom hybrid magnetic levitation bearing according to claim 1, characterized in that, The first control pole (111) and the second control pole (211) are respectively located on the side end face of the first yoke (11) and the second yoke (21) near the thrust plate (101). The radial thickness of the first radial annular gap is d1, and the range of d1 is 0.1~1mm. The radial thickness of the second radial annular gap is d2, and the range of d2 is d2=0.1~1mm and d1=d2.

3. The three-degree-of-freedom hybrid magnetic levitation bearing according to claim 1, characterized in that, The first control pole (111) and the second control pole (211) are respectively located on the inner ring walls of the first yoke (11) and the second yoke (21). A plurality of first axial guide magnetic poles (113) protruding towards the thrust plate (101) are formed on the end face of the first yoke (11) near the thrust plate (101). Each first axial guide magnetic pole (113) is positioned in a one-to-one correspondence with each first control pole (111). A first axial air gap is formed between the column (113) and the thrust plate (101). A plurality of second axial guide magnetic columns (213) protruding toward the side of the thrust plate (101) are formed on the end face of the second yoke (21) near the thrust plate (101). The positions of each second axial guide magnetic column (213) and each second control pole column (211) are arranged in a one-to-one correspondence. A second axial air gap is formed between each second axial guide magnetic column (213) and the thrust plate (101).

4. The three-degree-of-freedom hybrid magnetic levitation bearing according to claim 3, characterized in that, The axial thickness of the first axial air gap is w1, and the range of w1 is 0.1~1mm; the axial thickness of the second axial air gap is w2, and the range of w2 is 0.1~1mm.

5. The three-degree-of-freedom hybrid magnetic levitation bearing according to any one of claims 1 to 4, characterized in that, Projected along the axial direction of the rotating shaft (100), each of the first control windings (112) and each of the second control windings (212) correspond to each other.

6. The three-degree-of-freedom hybrid magnetic levitation bearing according to claim 5, characterized in that, Two first control windings (112) that project axially coincide with the second control winding (212) are connected in series, such that the direction of the control magnetic circuit formed by the first control winding (112) in the first control pole (111) or the first axial guide magnetic pole (113) is the same as the direction of the bias magnetic circuit formed by the permanent magnet (3) in the first control pole (111) or the first axial guide magnetic pole (113), while the direction of the control magnetic circuit formed by the second control winding (212) in the second control pole (211) or the second axial guide magnetic pole (213) is opposite to the direction of the bias magnetic circuit formed by the permanent magnet (3) in the second control pole (211) or the second axial guide magnetic pole (213).

7. The three-degree-of-freedom hybrid magnetic levitation bearing according to claim 1, characterized in that, The permanent magnet (3) includes a plurality of independent permanent magnet blocks (31). A magnetic steel groove (4) is formed between the first yoke (11) and the second yoke (21) for accommodating each of the permanent magnet blocks (31). The number of magnetic steel grooves (4) is equal to the number of the first control poles (111), and they are arranged in a one-to-one correspondence with the positions of each of the first control poles (111). The permanent magnet blocks (31) have the same polarity in the axial direction of the rotating shaft (100); and / or, the axis of the rotating shaft (100) is in the vertical direction when in use.

8. The three-degree-of-freedom hybrid magnetic levitation bearing according to claim 7, characterized in that, The magnetic groove (4) includes a first opening groove (41) formed on the first yoke (11) and a second opening groove (42) formed on the second yoke (21), wherein the depth of each first opening groove (41) and the axial depth of each second opening groove (42) are equal.

9. The three-degree-of-freedom hybrid magnetic levitation bearing according to claim 8, characterized in that, Each of the first opening slots (41) is formed by a plurality of first protrusions (114) that protrude from the first yoke ring (11) and face the thrust plate (101) at intervals, and each of the second opening slots (42) is formed by a plurality of second protrusions (214) that protrude from the second yoke ring (21) and face the thrust plate (101) at intervals, and each of the first protrusions (114) and each of the second protrusions (214) are respectively connected to each other.

10. A rotary drive mechanism, characterized in that, Includes the three-degree-of-freedom hybrid magnetic levitation bearing as described in any one of claims 1 to 9.

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