Stator consequent pole three-degree-of-freedom magnetic suspension permanent magnet motor

Abstract

The invention discloses a stator consequent pole three-degree-of-freedom magnetic suspension permanent magnet motor, which belongs to the field of magnetic suspension motors, and comprises an axial suspension stator, a bias permanent magnet, a radial suspension stator, a magnetic isolation bracket, a torque stator, a rotor and a rotating shaft which are sequentially and radially mounted, the rectangular grooves are arranged on teeth and a yoke part of the torque stator iron core, the permanent magnets are embedded in the rectangular grooves, air magnetic barriers exist in the rectangular grooves, and iron core bridges exist between the adjacent rectangular grooves. According to the invention, through a double-magnetic-circuit decoupling design, a torque magnetic circuit is isolated from a permanent magnet bias magnetic circuit, and a short magnetic circuit structure is constructed; the stator permanent magnet type magnetic suspension motor is provided with the iron core bridge and the air magnetic barrier, so that magnetic leakage is reduced, air gap flux density low-order harmonics are improved, axial and radial three-degree-of-freedom suspension active control is effectively achieved, it is guaranteed that torque is generated and adjusted to be independent of suspension force, the output torque of the stator permanent magnet type magnetic suspension motor is improved, and the system integration degree is improved.

Description

Technical Field

[0001] The present invention relates to the field of magnetic levitation motors, and particularly to a stator alternating pole three-degree-of-freedom magnetic levitation permanent magnet motor. Background Art

[0002] The rotor of a stator permanent magnet type alternating pole motor has a salient pole structure. There is no permanent magnet on the rotor. It has high mechanical strength, good high-speed performance, high power density and efficiency, good heat dissipation performance, and high reliability, and has good application prospects in the fields of aerospace, transportation, intelligent manufacturing, etc. However, such motors generally use mechanical bearings as support components. Under high-speed conditions, the wear of mechanical bearings will cause high noise and temperature rise, resulting in a short service life and low reliability of the motor system, and there are pollution problems in bearing lubrication.

[0003] In order to avoid a series of problems caused by mechanical bearing support, magnetic levitation technology will be introduced to form a stator permanent magnet type magnetic levitation motor, avoiding the use of mechanical bearings and realizing non-contact suspension of the rotor, improving the high-speed performance and torque capacity of the motor, and being particularly suitable for high-vacuum and high-cleanliness fields.

[0004] However, most of the existing five-degree-of-freedom magnetic levitation motors use axial magnetic levitation bearings to control the axial position of the rotor. The axial magnetic bearings and the magnetic circuit of the motor affect each other, and the system has strong coupling, and its performance is limited in ultra-high-speed and high-power application scenarios. Summary of the Invention

[0005] The present invention aims to overcome the problem that the axial magnetic bearing and the magnetic circuit of the magnetic levitation motor interfere with each other in the prior art, and provides a stator alternating pole three-degree-of-freedom magnetic levitation permanent magnet motor.

[0006] To achieve the above object, the technical solution of the present invention is: providing a stator alternating pole three-degree-of-freedom magnetic levitation permanent magnet motor, which includes an axially suspended stator, a bias permanent magnet, a radially suspended stator, a magnetic isolation bracket, a torque stator, a rotor and a rotating shaft that are radially installed in sequence. The torque stator includes a plurality of torque stator units, the torque stator units are spaced apart, the torque stator unit includes a torque stator core, a permanent magnet and a rectangular slot. The rectangular slot is provided on the teeth and yoke of the torque stator core, and the permanent magnet is embedded in the rectangular slot.

[0007] In one embodiment, the long side of the rectangular slot is greater than the long side of the permanent magnet, and there is an air magnetic barrier in the rectangular slot.

[0008] In one embodiment, there is an iron core bridge between adjacent rectangular slots.

[0009] In one embodiment, the rectangular slots are all magnetized along the short side, the permanent magnets installed on the yoke of the torque stator core are magnetized radially, with the N pole pointing to the center of the motor; the permanent magnets installed on the teeth of the torque stator core are magnetized circumferentially, and the N pole points from the torque stator core tooth where the permanent magnet is located to the adjacent torque stator core tooth.

[0010] In one embodiment, the ratio of the slot width of the rectangular slot to the wall thickness of the two adjacent torque stator core teeth on both sides thereof is 2:3.

[0011] In one embodiment, the torque stator further includes the torque winding, the torque winding is wound on the teeth of each torque stator core, the torque winding is a concentrated winding, and the torque windings within the same torque stator unit are connected in series to form a phase winding.

[0012] In one embodiment, the radial suspension stator includes a radial suspension stator core and a radial suspension winding, the radial suspension winding is wound on the teeth of the radial suspension stator core and is star-connected; the radial suspension winding is a concentrated winding; the axial lengths of the radial suspension stator, the magnetic isolation bracket, and the torque stator are the same, and the center lines of the teeth of the radial suspension stator core coincide with those of the bias permanent magnets.

[0013] In one embodiment, the magnetization direction of the bias permanent magnet is along the radial direction from the outer edge to the center of the radial suspension stator.

[0014] In one embodiment, the axial suspension stator includes a sleeve, an axial suspension stator disk, axial salient poles, and an axial suspension winding. The axial suspension stator disk is axially aligned and installed with the sleeve. The axial salient poles are arranged on the inner upper surface of the axial suspension stator disk. The axial suspension winding is wound on the axial salient poles. The radial width of the axial salient poles is the same as the radial thickness of the sleeve. The axial lengths of the rotor core and the torque stator are equal.

[0015] The rotor includes a rotor core and salient poles. A plurality of salient poles are evenly distributed on the circumference of the rotor core.

[0016] The rotor is axially aligned with the axial salient poles of the axial suspension stator disk to form an axial air gap. There is a radial air gap between the teeth of the radial suspension stator core and the rotor, and there is a radial air gap between the rotor and the teeth of the radial suspension stator core.

[0017] In one embodiment, the axial suspension stator includes a sleeve, an axial suspension stator disk, axial salient poles, and an axial suspension winding. The axial salient poles are disposed on the outer upper surface of the axial suspension stator disk, and are axially aligned and installed with the sleeve. The axial suspension winding is wound on the inner side of the axial suspension stator disk. The radial width of the axial salient poles is the same as the radial thickness of the sleeve.

[0018] The rotor includes a rotor core, rotor magnetic isolation slots, rotor suspension teeth, and rotor torque teeth. The rotor core is provided with an annular rotor magnetic isolation slot along the circumference. The two ends of the rotor magnetic isolation slot are connected with rotor suspension teeth, and the rotor torque teeth are arranged in the rotor magnetic isolation slot. The axial lengths of the rotor torque teeth, the torque stator, and the radial suspension stator are the same.

[0019] The outer side wall of the rotor suspension teeth does not contact the inner side wall of the axial suspension stator disk, but there is an axially overlapping portion.

[0020] There is an axial air gap between the rotor and the axial suspension stator disk, a radial air gap between the teeth of the radial suspension stator core and the rotor, and a radial air gap between the rotor and the teeth of the radial suspension stator core.

[0021] The beneficial effects of the present invention include:

[0022] Active suspension control for three-degree-of-freedom translation in the axial and radial directions is achieved. The torque and the suspension force are unidirectionally decoupled, and the axial suspension force and the radial suspension force are naturally decoupled. It has the characteristics of good suspension performance and strong axial load-bearing capacity.

[0023] The torque magnetic circuit and the permanent magnet bias magnetic circuit are isolated from each other and have no coupling. Both are short magnetic circuit structures, which can effectively reduce the energy loss during the suspension operation and realize the efficient utilization of the iron core, significantly improving the energy efficiency ratio and space utilization rate of the electromagnetic system.

[0024] The iron core bridge and the air magnetic barrier of the torque stator help to reduce the stator leakage flux, effectively suppress the leakage magnetic phenomenon, improve the low-order harmonic characteristics of the air-gap magnetic density, and improve the magnetic concentration effect, utilization rate, and output torque of the permanent magnet. Moreover, the modular structure of the torque stator is convenient for processing and manufacturing.

[0025] The rotor structure is flexible. The salient pole rotor has a simple structure, a short axial length, a high power density, a high integration degree, and a large axial suspension force. The inner diameter of the axial stator of the cylindrical rotor is larger than the outer diameter of the rotor, there is no thrust disk, and the critical speed is high, which is convenient for assembly and dynamic balance adjustment.

[0026] To make the above features and advantages of the invention more obvious and understandable, specific embodiments are hereinafter given, and detailed descriptions are made in conjunction with the accompanying drawings as follows. Description of the Drawings

[0027] Figure 1 This is a schematic diagram of the stator alternate-pole three-degree-of-freedom magnetic levitation permanent magnet motor in the first embodiment of the present invention.

[0028] Figure 2 This is a schematic diagram of the torque stator unit (with torque windings) in the first embodiment of the present invention.

[0029] Figure 3 This is a schematic diagram of the torque stator unit (without torque windings) in the first embodiment of the present invention.

[0030] Figure 4 This is a schematic diagram of the permanent magnet bias flux and the axial control flux in the axial suspension stator when the axial suspension winding is energized in the first embodiment of the present invention.

[0031] Figure 5 This is a schematic diagram of the permanent magnet bias flux and the radial control flux in the radial suspension stator when the radial suspension winding is energized in the first embodiment of the present invention.

[0032] Figure 6 This is a schematic diagram of the permanent magnet flux in the torque stator when the rotor position angle is θ1 in the first embodiment of the present invention.

[0033] Figure 7 This is a schematic diagram of the permanent magnet flux in the torque stator when the rotor position angle is θ2 in the first embodiment of the present invention.

[0034] Figure 8 This is a schematic diagram of the stator alternate-pole three-degree-of-freedom magnetic levitation permanent magnet motor in the second embodiment of the present invention;

[0035] Figure 9 This is a schematic diagram of the rotor in the second embodiment of the present invention;

[0036] Figure 10 This is a schematic diagram of the permanent magnet bias flux and the axial control flux in the axial suspension stator when the double axial suspension winding is energized in the second embodiment of the present invention.

[0037] Reference numerals:

[0038] Axial suspension stator - 1;

[0039] Sleeve - 11; Axial suspension stator disc - 12, Axial suspension winding - 13; Axial salient pole teeth - 14; Axial control flux - 15;

[0040] Bias permanent magnet - 2;

[0041] Bias permanent magnet flux - 21;

[0042] Radial suspension stator - 3;

[0043] Radial suspension stator core - 31; Radial suspension winding - 32; Radial control magnetic flux - 33;

[0044] Magnetic isolation bracket - 4;

[0045] Torque stator - 5;

[0046] Torque stator unit - 51;

[0047] Torque stator core - 511; Permanent magnet - 512; Torque winding - 513; Torque magnetic flux - 514;

[0048] Rectangular slot - 5111; Core bridge - 5112; Air magnetic barrier - 5113; First permanent magnet - 5121; Second permanent magnet - 5122; Third permanent magnet - 5123;

[0049] Rotor - 6;

[0050] Rotor core - 61; Salient pole tooth - 62; Rotor magnetic isolation slot - 63; Rotor suspension tooth - 64; Rotor torque tooth - 65;

[0051] Rotating shaft - 7. Detailed implementation manners

[0052] For the purpose of making the objectives and technical solutions of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0053] In order to overcome the problems in the prior art that when an axial magnetic suspension bearing is used to control the axial position of a rotor in a magnetic suspension motor, the motor has a long axial length, a large volume, a complex structure, a low critical speed, a low system integration level, and the improvement of the motor torque density and power density is restricted; and to avoid the strong coupling effect existing between the axial magnetic bearing and the magnetic circuit of the motor, the present invention provides a stator alternate - pole three - degree - of - freedom magnetic suspension permanent - magnet motor.

[0054] Embodiment 1

[0055] Figure 1 This is a schematic diagram of the stator alternate - pole three - degree - of - freedom magnetic suspension permanent - magnet motor provided in Embodiment 1 of the present invention. As Figure 1As shown, the motor includes an axial magnetic suspension stator 1, a bias permanent magnet 2, a radial magnetic suspension stator 3, a magnetic isolation bracket 4, a torque stator 5, a rotor 6, and a rotating shaft 7. The radial magnetic suspension stator 3 is axially arranged inside the axial magnetic suspension stator 1. The bias permanent magnet 2 is arranged between the radial magnetic suspension stator 3 and the axial magnetic suspension stator 1. The torque stator 5 is installed inside the radial magnetic suspension stator 3. The magnetic isolation bracket 4 is arranged between the torque stator 5 and the radial magnetic suspension stator 3. The rotor 6 is radially installed inside the torque stator 5 and the radial magnetic suspension stator 3. The rotating shaft 7 penetrates through the rotor 6. X, Y, and Z are the three coordinate axes of a rectangular coordinate system, where the X-axis is in the horizontal direction, the Y-axis is in the vertical direction, and the Z-axis is in the axial direction.

[0056] The axial magnetic suspension stator 1 includes a sleeve 11, an axial magnetic suspension stator disk 12, an axial magnetic suspension winding 13, and axial salient poles 14. The axial magnetic suspension stator disk 12 is radially installed inside the sleeve 11. The axial salient poles 14 are provided on the upper surface of the inner side of the axial magnetic suspension stator disk 12. The axial magnetic suspension winding 13 is wound around the axial salient poles 14. The axial magnetic suspension stator disk 12 and the sleeve 11 are aligned and installed without a gap, and the radial width of the axial salient poles 14 is equal to the radial thickness of the sleeve 11.

[0057] The bias permanent magnet 2 can be set as a rectangle. The bias permanent magnet 2 connects the outer circumference of the radial magnetic suspension stator 3 and the inner wall of the axial magnetic suspension stator 1. The center line of the bias permanent magnet 2 coincides with the center line of the teeth of the radial magnetic suspension stator 3. The magnetization direction of the bias permanent magnet 2 is along the radial direction from the outer edge to the center of the radial magnetic suspension stator 3.

[0058] The radial magnetic suspension stator 3 includes a radial magnetic suspension stator core 31 and a radial magnetic suspension winding 32. The radial magnetic suspension winding 32 is wound around the radial magnetic suspension stator core 31. The radial magnetic suspension stator core 31 is a salient pole structure with 3 teeth. The teeth of the radial magnetic suspension stator core 31 are evenly distributed in space, and the interval between two adjacent teeth is 120°. There is a gap between the teeth of the radial magnetic suspension stator core 31 and the axial magnetic suspension stator disk 12. The radial magnetic suspension winding 32 is a concentrated winding and is star-connected. Installation grooves are provided on the inner wall of the radial magnetic suspension stator 3 for installing the magnetic isolation bracket 4.

[0059] The magnetic isolation bracket 4 is a fan-shaped ring structure with a central angle of 110°. Small grooves are provided on the inner wall of the magnetic isolation bracket 4 for installing the torque stator 5. The axial lengths of the magnetic isolation bracket 4, the radial magnetic suspension stator 3, and the torque stator 5 are equal.

[0060] As Figure 2 andFigure 3 As shown, the torque stator 5 includes three torque stator units 51, and the torque stator units 51 are spaced 120°. The torque stator unit 51 includes a torque stator core 511, a permanent magnet 512, and a torque winding 513. The torque winding 513 is wound around the teeth of the torque stator core 511, and the permanent magnet 512 is embedded in the torque stator core 511. The torque stator unit 51 is U-shaped. The number of teeth of the torque stator core 511 is 2, and the torque winding 513 is wound around each tooth of the torque stator core 511. There is a 15° interval between the teeth of the torque stator core 511 and the teeth of the radial suspension stator 3. Rectangular slots 5111 are provided on both the teeth and the yoke of the torque stator core 511. Among them, the width of the rectangular slot 5111 is 5°, and the ratio of the slot width L1 of the rectangular slot 5111 to the wall thickness L2 of any one of the teeth of the torque stator core 511 on its two sides is 2:3. There is an iron core bridge 5112 between adjacent rectangular slots 5111, and there is an air magnetic barrier 5113 in the rectangular slot 5111. The iron core bridge 5112 provides a path for the low-order harmonics of the air-gap magnetic density, improves the low-order harmonics of the effective air-gap magnetic density, and enhances the torque output ability; while the air magnetic barrier 5113 reduces the leakage magnetic flux of the permanent magnet 512 and improves the torque output ability. The torque winding 513 is a concentrated winding, and the two torque windings 513 wound around the two teeth of the torque stator core 511 are connected in series to form a phase winding. The permanent magnet 512 is rectangular, and the long side of the permanent magnet 512 is smaller than the long side of the rectangular slot 5111 to ensure the formation of the air magnetic barrier 5113. The permanent magnet 512 includes a first permanent magnet 5121, a second permanent magnet 5122, and a third permanent magnet 5123. The first permanent magnet 5121 is installed in the rectangular slot 5111 on the yoke of the torque stator core 511, and the second permanent magnet 5122 and the third permanent magnet 5123 are installed in the rectangular slot 5111 on the teeth of the torque stator core 511. The first permanent magnet 5121 is magnetized along the radial direction of the torque stator, and the N pole points to the center of the motor; the second permanent magnet 5122 and the third permanent magnet 5123 are magnetized along the short side of the rectangle. The N pole of the second permanent magnet 5122 points clockwise along the circumference, and the N pole of the third permanent magnet 5123 points counterclockwise along the circumference.

[0061] Combined with Figures 1 to 3 As shown, there are ten salient pole teeth 62 provided on the rotor core 61 of the rotor 6. The salient pole teeth 62 are evenly arranged along the circumferential direction of the rotor core 61, and the central angle corresponding to each salient pole tooth 62 is 10°. The salient pole teeth 62 are axially aligned with the axial salient pole teeth 14 on the axial suspension stator disc 12. The axial length of the rotor core 61 is the same as that of the torque stator 5. Combined with Figures 4 to 7 ​As shown, there is an axial air gap a between the rotor core 61 and the axial suspension stator disc 12, a radial air gap b between the teeth of the rotor core 61 and the torque stator core 511, and a radial air gap c between the teeth of the rotor core 61 and the radial suspension stator core 31.

[0062] Figure 4 This is a schematic diagram of the principle for generating the axial suspension force in this embodiment. As Figure 4 shown, the bias permanent magnetic flux 21 is generated by the bias permanent magnet 2 and sequentially passes through the teeth of the radial suspension stator core 31, the radial air gap c, the rotor 6, the axial air gap a, the axial suspension stator disc 12, and the sleeve 11 to form a closed loop. At the same time, when the axial suspension winding 13 is energized with a current as Figure 4 shown, an axial control flux 15 is generated to enhance the air gap magnetic field on the positive Z-axis side and weaken the air gap magnetic field on the negative Z-axis side, generating an axial suspension force in the positive Z-axis direction to control the axial suspension of the rotor 6. When the current direction is changed, an axial suspension force in the negative Z-axis direction is generated. It should be noted that the axial control flux 15 only passes through the axial suspension stator 1 and does not pass through the radial suspension stator 3 and the torque stator 5.

[0063] Figure 5 This is a schematic diagram of the principle for generating the radial suspension force in this embodiment. When a current as Figure 5 shown is applied to the radial suspension winding 32, a radial control flux 33 is generated. The radial control flux 33 passes through the teeth of the radial suspension stator 3, the radial air gap c, and the yoke of the radial suspension stator 3 to form a closed loop. In the radial air gap c, when the radial control flux 33 adjusts the bias permanent magnetic flux 21 generated by the bias permanent magnet 2, a radial suspension force is generated. Defining the positive X-axis direction as the zero-degree space angle position and the space angle as positive when changing counterclockwise, when a current as Figure 5 shown is applied to the radial suspension winding 32, the air gap fluxes of the teeth of the radial suspension stator 3 at the space angles of 90° and 210° are weakened, and the air gap flux of the teeth of the radial suspension stator 3 at the space angle of 330° is enhanced, generating a radial suspension force in the X-axis direction. It should be noted that the radial control flux 33 only passes through the radial suspension stator 3 and does not pass through the axial suspension stator 1 and the torque stator 5.

[0064] Figure 6 and Figure 7 This is a schematic diagram of the principle for generating torque in this embodiment. According to the principle of minimum reluctance, the torque flux 514 is provided by the permanent magnet 512 and passes through the torque stator core 511, the core bridge 5112, the radial air gap b, and the rotor 6 to form a closed loop. CombiningFigure 2 and Figure 3 It can be seen that the first permanent magnet 5121 is located in the rectangular slot 5111 of the yoke of the torque stator core 511, and an air magnetic barrier 5113 is provided in each rectangular slot 5111. This design effectively reduces the magnetic leakage of the permanent magnet in the torque stator core 511. At the same time, the core bridge 5112 provides a channel for the magnetic flux of the first permanent magnet 5121, the second permanent magnet 5122 and the third permanent magnet 5123, ensuring the magnetic flux concentration effect of the permanent magnet 512 on the torque stator 5, improving the utilization rate of the permanent magnet 512, improving the effective low-order harmonic path of the air-gap magnetic density, and improving the torque output ability.

[0065] As Figure 6 shown, the positive direction of the Y-axis is defined as the zero-degree space angle position, and the space angle is positive when changing in the clockwise direction. When the space position angle of the rotor 6 is θ1, the magnetic flux linked in the coils A11 and A12 reaches the positive maximum value, and the magnetic flux of phase A is the positive maximum value. When the space position angle of the rotor 6 is θ2, as Figure 7 shown, the magnetic flux linked in the coils A11 and A12 reaches the negative maximum value, and the magnetic flux of phase A is the negative maximum value. Therefore, as the rotor 6 rotates, the magnetic flux of phase A alternates between positive and negative, inducing an alternating back electromotive force in the phase A winding. When three-phase sinusoidal alternating current with the corresponding frequency is applied, a stable electromagnetic torque can be generated. Among them, the torque magnetic flux 514 only passes through the torque stator 5 and does not pass through the axial suspension stator 1 and the radial suspension stator 3.

[0066] In the present invention, the torque magnetic circuit and the permanent magnet bias magnetic circuit are isolated from each other and have no coupling. Both are short magnetic circuit structures, which can effectively reduce the energy loss during the suspension operation and realize the efficient utilization of the iron core, significantly improving the energy efficiency ratio and space utilization rate of the electromagnetic system. At the same time, the torque stator 5 is provided with the core bridge 5112 and the air magnetic barrier 5113, effectively suppressing the magnetic leakage phenomenon and improving the low-order harmonic characteristics of the air-gap magnetic density, thereby realizing the improvement of the output torque; and the tangentially magnetized permanent magnet 512 has strong demagnetization resistance, good magnetic flux concentration effect, and high utilization rate of the permanent magnet 512. In addition, the torque stator 5 adopts a modular structure, which is convenient for processing and manufacturing.

[0067] Embodiment 2

[0068] Furthermore, in addition to the salient-pole rotor used in Embodiment 1, a cylindrical rotor can also be used. Figure 8 is a schematic diagram of the stator alternate-pole three-degree-of-freedom magnetic suspension permanent magnet motor provided in Embodiment 2 of the present invention, Figure 9 is a schematic diagram of another rotor, combined with Figure 8 and Figure 9As shown, the rotor 6 includes a rotor core 61, rotor magnetic isolation slots 63, rotor suspension teeth 64, and rotor torque teeth 65. The rotor core 61 is provided with the annular rotor magnetic isolation slots 63 along the circumference. The two ends of the rotor magnetic isolation slots 63 are connected with the rotor suspension teeth 64, and the rotor torque teeth 65 are arranged in the rotor magnetic isolation slots 63. The number of teeth of the rotor torque teeth 65 is 10. The rotor torque teeth 65 are evenly arranged along the circumferential direction, and the included angle between the two sides of the rotor torque teeth 65 and the center of the motor is 10°. The axial lengths of the rotor torque teeth 65, the torque stator 5, and the radial suspension stator 3 are the same. The outer side wall of the rotor suspension teeth 64 does not contact the inner side wall of the axial suspension stator disk 12 but has an axially overlapping part.

[0069] Correspondingly, the axial suspension stator 1 includes a sleeve 11, an axial suspension stator disk 12, axial salient poles 14, and an axial suspension winding 13. The axial suspension stator disk 12 is axially aligned and installed with the sleeve 11. The axial salient poles 14 are arranged on the outer upper surface of the axial suspension stator disk 12. The axial suspension winding 13 is wound on the inner side of the axial suspension stator disk 12. The radial width of the axial salient poles 14 is the same as the radial thickness of the sleeve 11.

[0070] Combined Figure 10 It can be seen that there is an axial air gap a between the rotor 6 and the axial suspension stator disk 12, a radial air gap c between the teeth of the radial suspension stator core 31 and the rotor 6, and a radial air gap b between the teeth of the rotor 6 and the torque stator core 511.

[0071] Figure 10 This is a schematic diagram of the principle for generating the axial suspension force in this embodiment. As Figure 10 shown, the bias permanent magnetic flux 21 generated by the bias permanent magnet 2 will pass through the teeth of the radial suspension stator core 31, the radial air gap c, the rotor torque teeth 65, the yoke of the rotor 6, the rotor suspension teeth 64, the axial air gap a, the axial suspension stator disk 12, and the sleeve 11 to form a closed loop. When the axial suspension winding 13 is energized with the current as Figure 10 shown, the axial control flux 15 will be generated, enhancing the air gap magnetic field on the positive Z-axis side and weakening the air gap magnetic field on the negative Z-axis side, generating an axial suspension force in the positive Z-axis direction to control the axial suspension of the rotor 6; when the current direction is changed, an axial suspension force in the negative Z-axis direction will be generated. It should be noted that on the surface of the rotor 6, the axial control flux 15 only passes through the rotor suspension teeth 64 and does not pass through the rotor torque teeth 65; and the axial control flux 15 only passes through the axial suspension stator 1 and does not pass through the radial suspension stator 3 and the torque stator 5.

[0072] In the second embodiment of the present invention, the arrangement of the permanent magnets 512 is the same as that in the first embodiment. Therefore, the torque generation principle is the same, and reference can be made to the torque generation principle in the first embodiment, which will not be elaborated here. When a current is applied to the radial suspension winding 32, the path of the radial control magnetic flux 33 generated is the same as that Figure 5 shown, so the principle of generating and controlling the radial suspension force in the second embodiment is the same as that in the first embodiment, and reference can be made to the principle of generating the radial suspension force in the first embodiment, which will not be elaborated here.

[0073] In summary, the present invention provides a stator alternating pole three-degree-of-freedom magnetic suspension motor, which realizes the active suspension control of three-degree-of-freedom translation in the axial and radial directions, unidirectionally decouples the torque and the suspension force, and naturally decouples the axial suspension force and the radial suspension force, and has the characteristics of good suspension performance and strong axial bearing capacity. In addition, the iron core bridge 5112 and the air magnetic barrier 5113 of the torque stator 5 help to reduce the stator leakage magnetic flux, improve the magnetic concentration effect, utilization rate and output torque of the permanent magnet 512; and the modular structure of the torque stator 5 is convenient for processing and manufacturing. In addition, the rotor 6 has a flexible structure, a salient pole rotor structure is simple, the axial length is short, the power density is high, the integration degree is high, and the axial suspension force is large; the inner diameter of the axial stator of the cylindrical rotor is larger than the outer diameter of the rotor, there is no thrust disc, the critical speed is high, and it is convenient for assembly and dynamic balance adjustment.

[0074] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field to which the present invention pertains may make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to that defined by the appended patent application scope.

Claims

1. Stator Alternating Pole Three-Degree-of-Freedom Magnetic Levitation Permanent Magnet Motor, comprising an axially levitating stator, a bias permanent magnet, a radially levitating stator, a magnetic isolation bracket, a torque stator, a rotor and a rotating shaft that are successively installed radially, characterized in that, The torque stator includes a number of torque stator units which are distributed at intervals. Each torque stator unit includes a torque stator core, a permanent magnet, and a rectangular slot. The rectangular slot is provided on the teeth and yoke of the torque stator core, and the permanent magnet is embedded in the rectangular slot.

2. The stator alternating pole three-degree-of-freedom magnetic levitation permanent magnet motor according to claim 1, wherein The long side of the rectangular slot is longer than the long side of the permanent magnet, and there is an air magnetic barrier in the rectangular slot.

3. The stator alternating pole three-degree-of-freedom magnetic suspension permanent magnet motor according to claim 1, wherein There is an iron core bridge between adjacent rectangular slots.

4. The stator alternating pole three-degree-of-freedom magnetic suspension permanent magnet motor according to claim 1, characterized in that, The permanent magnets installed on the yoke of the torque stator core are magnetized radially, with the N pole pointing to the center of the motor; the permanent magnets installed on the teeth of the torque stator core are magnetized circumferentially, and the N pole points from the torque stator core tooth where the permanent magnet is located to the adjacent torque stator core tooth.

5. The stator alternating pole three-degree-of-freedom magnetic levitation permanent magnet motor according to claim 4, wherein The ratio of the slot width of the rectangular slot to the wall thickness of the torque stator core teeth on both sides thereof is 2:

3.

6. The stator alternating pole three-degree-of-freedom magnetic suspension permanent magnet motor according to claim 5, characterized in that, The torque stator further includes the torque winding which is wound around the teeth of each torque stator core. The torque winding is a concentrated winding, and the torque windings within the same torque stator unit are connected in series to form a phase winding.

7. The stator alternating-pole three-degree-of-freedom magnetic levitation permanent magnet motor according to claim 1, characterized in that The radial suspension stator includes a radial suspension stator core and a radial suspension winding. The radial suspension winding is wound around the teeth of the radial suspension stator core and is star-connected; the radial suspension winding is a concentrated winding; the axial lengths of the radial suspension stator, the magnetic isolation bracket, and the torque stator are the same, and the center lines of the teeth of the radial suspension stator core coincide with those of the bias permanent magnets.

8. The stator alternating pole three-degree-of-freedom magnetic levitation permanent magnet motor according to claim 7, wherein The magnetization direction of the bias permanent magnet is along the radial direction from the outer edge of the radial suspension stator to the center.

9. The stator alternating pole three-degree-of-freedom magnetic levitation permanent magnet motor according to claim 1, characterized in that, The axial suspension stator includes a sleeve, an axial suspension stator disc, axial salient poles, and an axial suspension winding. The axial suspension stator disc is aligned and installed with the sleeve. The axial salient poles are arranged on the inner upper surface of the axial suspension stator disc. The axial suspension winding is wound around the axial salient poles. The radial width of the axial salient poles is the same as the radial thickness of the sleeve. The axial length of the rotor core is equal to that of the torque stator. The rotor includes a rotor core and salient poles. A number of evenly distributed salient poles are provided on the circumference of the rotor core. The rotor is axially aligned and installed with the torque radial suspension stator. An axial air gap is formed between the rotor and the axial salient poles of the axial suspension stator disc. A radial air gap exists between the teeth of the radial suspension stator core and the rotor. A radial air gap exists between the teeth of the rotor and the torque stator.

10. The stator alternating pole three-degree-of-freedom magnetic levitation permanent magnet motor according to claim 1, characterized in that, The axial suspension stator includes a sleeve, an axial suspension stator disc, axial salient poles, and an axial suspension winding. The axial salient poles are arranged on the outer upper surface of the axial suspension stator disc. The axial salient poles are axially aligned and installed with the sleeve. The axial suspension winding is wound around the inner side of the axial suspension stator disc. The radial width of the axial salient poles is the same as the radial thickness of the sleeve. The rotor includes a rotor core, rotor magnetic isolation slots, rotor suspension teeth, and rotor torque teeth. The rotor core is provided with the annular rotor magnetic isolation slots along the circumference. The two ends of the rotor magnetic isolation slots are connected with the rotor suspension teeth, and the rotor torque teeth are arranged in the rotor magnetic isolation slots. The axial lengths of the rotor torque teeth, the torque stator, and the radial suspension stator are the same; The outer sidewall of the rotor suspension teeth does not contact the inner sidewall of the axial suspension stator disk but has an axially overlapping part; There is an axial air gap between the rotor and the axial suspension stator disk, a radial air gap between the teeth of the radial suspension stator core and the rotor, and a radial air gap between the teeth of the rotor and the torque stator core.

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