Composite motor with magnetic saturation suppression and high efficiency utilization of harmonic and differential double modulation magnetic gear

Abstract

The application discloses a kind of inhibiting magnetic saturation and high efficiency utilization harmonic and difference double-modulation magnetic gear composite motor, including stator, armature winding, outer rotor, magnetism adjusting ring and inner rotor;Stator adopts E type tooth structure, including main tooth and the auxiliary tooth being located in the circumferential two sides of main tooth;Outer rotor includes radial magnetization permanent magnet and spoke formula tangential magnetization permanent magnet, radial magnetization permanent magnet and spoke formula tangential magnetization permanent magnet are configured according to Halbach array rule;Magnetism adjusting ring includes radial modulation part, non-magnetic connection part and axial modulation part, radial modulation part is used to form radial and modulation path, axial modulation part is used to form axial difference modulation path, radial and modulation and axial difference modulation jointly act, realize the magnetic field coupling between outer rotor and inner rotor;Inner rotor includes a plurality of convex-T type permanent magnet units being arranged at intervals along circumferential direction.The application improves the effective working magnetic density and output torque of inner side modulation air gap and outer motor air gap, and can inhibit local magnetic saturation.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a composite motor of magnetic gears that suppresses magnetic saturation and utilizes harmonic sum and difference dual modulation. Background Technology

[0002] With the development of new energy vehicles, aerospace, robotics, and high-end equipment manufacturing, motor systems are facing higher demands on output torque, torque density, operating efficiency, noise level, and operational reliability. While traditional mechanical gear transmission systems can achieve speed matching and torque amplification, the mechanical contact involved in the transmission process can easily lead to problems such as tooth surface wear, difficult lubrication and maintenance, and significant vibration and noise over long-term operation.

[0003] Magnetic gears utilize the harmonics of the magnetic field generated by permanent magnets for non-contact torque transmission, featuring no mechanical contact, low noise, low maintenance, and overload protection. Magnetic gear composite motors typically integrate the motor drive and magnetic gear transmission components into the same electromagnetic device. Through the magnetic field coupling between the stator armature windings, the permanent magnet rotor, and the adjusting ring, they achieve the conversion between electrical and mechanical energy, as well as the transmission of torque between components operating at different speeds.

[0004] Existing magnetic gear composite motors typically employ a coaxial structure consisting of a stator, a permanent magnet outer rotor, a magnetic adjusting ring, and a permanent magnet inner rotor. The magnetic adjusting ring mainly comprises magnetically conductive adjusting teeth and non-magnetically conductive parts distributed along the circumference, primarily utilizing the radial magnetic field for spatial harmonic modulation. Due to the relatively singular magnetic field transmission path, the magnetic field coupling between the outer and inner rotors is mainly concentrated in the radial modulation air gap, resulting in insufficient utilization of the axial magnetic field and difficulty in fully utilizing magnetic field harmonics in different directions. In some structures with axial magnetic circuits, the lack of reasonable harmonic matching and magnetic circuit distribution between the radial and axial modulation magnetic circuits easily leads to magnetic field interference and local magnetic flux concentration, thereby limiting the magnetic field modulation capability and torque transmission capability.

[0005] Furthermore, existing magnetic gear composite motors typically employ surface-mounted, radially embedded, or relatively simple permanent magnet arrangements for their permanent magnet rotors, limiting the ability to concentrate and directionally utilize permanent magnet flux. For an external rotor with both an outer motor air gap and an inner modulation air gap, a single permanent magnet structure cannot adequately meet the requirements of both air gaps for magnetic field strength and waveform, easily leading to problems such as magnetic leakage, insufficient magnetic flux density in the working air gap, and low flux utilization on the non-working side, thereby affecting the motor's output torque and operating efficiency.

[0006] Existing stators typically employ a conventional toothed structure, with stator flux primarily transmitted through a single main tooth. This leads to magnetic concentration and localized magnetic saturation in the stator tooth tip region. Furthermore, the conventional stator tooth structure has limited capabilities in shunting, shaping, and harmonic regulation of the external motor air gap magnetic field. This is detrimental to enhancing the electromagnetic coupling between the stator armature magnetic field and the external rotor permanent magnet magnetic field, and it is also difficult to balance the air gap magnetic field strength and the quality of the magnetic field waveform. Summary of the Invention

[0007] Based on this, the present invention provides a magnetic gear composite motor that suppresses magnetic saturation and utilizes harmonic sum and difference dual modulation to construct a sum and difference dual modulation magnetic circuit that combines radial sum modulation and axial difference modulation. It also improves the magnetic flux distribution by using Halbach permanent magnet rotors and E-type stators with different structures, suppresses local magnetic saturation at the stator tooth ends, magnetic rings and rotor yokes, increases the effective working magnetic flux density of the inner modulation air gap and the outer motor air gap, and improves the output torque density.

[0008] A magnetic gear composite motor that suppresses magnetic saturation and utilizes harmonic sum and difference dual modulation includes a stator, an armature winding, an outer rotor, a magnetic adjusting ring, and an inner rotor; the stator, outer rotor, magnetic adjusting ring, and inner rotor are arranged coaxially from the outside to the inside, and the armature winding is embedded in the stator slot of the stator; The stator adopts an E-type tooth structure, including main teeth and auxiliary teeth located on both sides of the main teeth in the circumferential direction; The outer rotor includes radially magnetized permanent magnets and Spoke-type tangentially magnetized permanent magnets. The radially magnetized permanent magnets and Spoke-type tangentially magnetized permanent magnets are arranged according to the Halbach array pattern to form a Spoke-type Halbach outer rotor structure. The magnetic adjustment ring is fixedly connected to the fixed part of the motor to remain stationary during motor operation. The magnetic adjustment ring includes a radial modulation part, a non-magnetic connection part, and an axial modulation part. The radial modulation part is used to form a radial modulation path, and the axial modulation part is used to form an axial differential modulation path. The inner rotor includes multiple convex-T-shaped permanent magnet units arranged at intervals along the circumferential direction. The convex-T-shaped permanent magnet units are configured according to the Halbach array pattern to form a convex-T-shaped Halbach inner rotor structure. The outer rotor, the adjusting magnetic ring, and the inner rotor together form a sum-difference dual-modulation magnetic gear coupling structure. The sum-difference dual-modulation magnetic gear coupling structure includes a radial sum modulation magnetic field transmission path formed by the radial modulation part and an axial difference modulation magnetic field transmission path formed by the axial modulation part.

[0009] The aforementioned magnetic saturation suppression and high-efficiency harmonic and differential dual-modulation magnetic gear composite motor comprises an outer motor air gap between the outer side of the outer rotor and the stator, an inner modulation air gap between the inner side of the outer rotor and the adjusting ring, and an inner magnetic gear air gap between the adjusting ring and the inner rotor. The outer motor air gap is used to realize the electromagnetic energy conversion between the armature magnetic field of the stator and the permanent magnet magnetic field of the outer rotor. The inner modulation air gap and the inner magnetic gear air gap are used to realize the magnetic field modulation coupling between the outer rotor and the inner rotor.

[0010] The aforementioned magnetic saturation suppression and high-efficiency harmonic sum-difference dual-modulation magnetic gear composite motor includes a stator comprising multiple E-type stator core units evenly distributed along the circumferential direction. Each E-type stator core unit includes one main tooth and two auxiliary teeth. The main tooth extends radially toward the outer rotor, and the two auxiliary teeth are respectively disposed on both sides of the main tooth in the circumferential direction. The main tooth and the two auxiliary teeth together form an E-type tooth structure with three tooth ends. The main teeth are used to form the main magnetic flux channel on the stator side, and the auxiliary teeth are used to form the auxiliary magnetic flux channel on the stator side. They also shunt and shape the air gap magnetic field on both sides of the main teeth to reduce the local magnetic concentration in the tooth tip region of the main teeth.

[0011] The aforementioned magnetic gear composite motor, which suppresses magnetic saturation and utilizes harmonic sum and difference dual modulation, features a three-phase armature winding with a specific number of pole pairs. Number of permanent magnet pole pairs of the outer rotor satisfy:

[0012] This ensures that the rotating armature magnetic field generated by the armature winding is synchronously coupled with the permanent magnet magnetic field generated by the outer rotor.

[0013] The aforementioned magnetic gear composite motor that suppresses magnetic saturation and utilizes harmonic sum and difference dual modulation includes an outer rotor yoke. Radial magnetized permanent magnets are spaced along the circumferential direction on the outer rotor yoke and magnetized in the radial direction. Spoke-type tangential magnetized permanent magnets are arranged between adjacent radial magnetized permanent magnets and magnetized in the circumferential tangential direction. The magnetization directions of the radial magnetized permanent magnets and adjacent Spoke-type tangential magnetized permanent magnets are configured according to the Halbach array law, which enhances the magnetic field on the side of the outer rotor facing the working air gap and reduces the leakage magnetic field on the side away from the working air gap.

[0014] The aforementioned magnetic gear composite motor that suppresses magnetic saturation and utilizes harmonic sum and difference dual modulation has a radial modulation section that is spaced along the circumferential direction and located in the radial magnetic field transmission region, an axial modulation section that extends along the axial direction and is located in the axial magnetic field transmission region, and a non-magnetic connection section that connects the radial modulation section and the axial modulation section to reduce magnetic field interference between the radial modulation magnetic circuit and the axial modulation magnetic circuit.

[0015] The aforementioned magnetic saturation suppression and high-efficiency harmonic sum-difference dual-modulation magnetic gear composite motor, wherein the radial modulation section has a certain number of tuning teeth. Number of tuning teeth in the axial modulation section Number of permanent magnet pole pairs of the inner rotor Number of permanent magnet pole pairs of the outer rotor satisfy:

[0016]

[0017] The radial modulation section is used to achieve radial sum modulation between the permanent magnet magnetic fields of the outer rotor and the inner rotor, while the axial modulation section is used to achieve axial difference modulation. The radial sum modulation path and the axial difference modulation path jointly bear the magnetic field coupling between the outer and inner rotors, thereby sharing the modulation flux and reducing flux concentration in local areas of the tuning ring, the outer rotor yoke, and the inner rotor yoke. The axial difference modulation magnetic circuit can share part of the flux transmission task, reducing local flux concentration at the radial tuning teeth, the outer rotor yoke, and the inner rotor yoke, thus suppressing local magnetic saturation.

[0018] The aforementioned magnetic gear composite motor that suppresses magnetic saturation and utilizes harmonic sum and difference dual modulation, wherein the convex-T type permanent magnet unit includes a radially magnetized permanent magnet unit, a circumferentially magnetized permanent magnet unit, and an inner rotor yoke; the radially magnetized permanent magnet unit protrudes towards the magnetic ring side in the radial direction, and the circumferentially magnetized permanent magnet unit extends in the circumferential direction, and the radially magnetized permanent magnet unit and the circumferentially magnetized permanent magnet unit together constitute a convex-T type cross-sectional structure.

[0019] The aforementioned magnetic gear composite motor that suppresses magnetic saturation and utilizes harmonic sum and difference dual modulation, wherein the magnetization direction of adjacent convex-T permanent magnet units is deflected sequentially according to the Halbach array law to form a convex-T Halbach inner rotor structure, thereby enhancing the working air gap magnetic field of the inner rotor facing the magnetic ring side and reducing the leakage magnetic field and non-working harmonic content on the non-working side of the inner rotor.

[0020] The aforementioned magnetic gear composite motor, which suppresses magnetic saturation and utilizes harmonic sum and difference dual modulation, has a transmission ratio that is [not specified] when the adjusting magnetic ring remains stationary. satisfy:

[0021] in, The mechanical angular velocity of the inner rotor. The mechanical angular velocity of the outer rotor. is the number of permanent magnet pole pairs of the inner rotor. denoted as the number of permanent magnet pole pairs of the external rotor.

[0022] The magnetic gear composite motor for suppressing magnetic saturation and utilizing harmonic sum and difference dual modulation provided by the present invention has the following beneficial effects: 1. This invention employs a sum-difference dual modulation method combining radial sum modulation and axial difference modulation. This method simultaneously utilizes radial and axial magnetic field harmonics, increasing the magnetic field transmission path between the outer and inner rotors and improving magnetic field coupling capability. The axial difference modulation path can share some of the magnetic flux transmission workload, reducing local magnetic flux concentration at the radial adjustment teeth, the outer rotor yoke, and the inner rotor yoke, thereby suppressing local magnetic saturation and improving the magnetic flux density distribution within the adjustment ring and the rotor.

[0023] 2. The present invention adopts a convex-T type Halbach inner rotor structure. By combining radially magnetized permanent magnet units and circumferentially magnetized permanent magnet units, the permanent magnet flux is concentrated on the side facing the adjusting ring, thereby enhancing the effective working magnetic field in the air gap of the inner magnetic gear.

[0024] 3. The present invention adopts a Spoke-type Halbach external rotor structure formed by combining radially magnetized permanent magnets and Spoke-type tangentially magnetized permanent magnets, which can enhance the effective magnetic field of the external rotor toward the stator and the adjusting ring, reduce leakage magnetic field on the non-working side, and improve the utilization rate of the permanent magnet magnetic field of the external rotor.

[0025] 4. The present invention adopts an E-type stator structure, which forms a main magnetic flux channel and an auxiliary magnetic flux channel through the main teeth and auxiliary teeth, thereby diverting and shaping the stator air gap magnetic field, reducing the local magnetic concentration at the tip of the main teeth, and enhancing the electromagnetic coupling between the stator armature magnetic field and the external rotor permanent magnet magnetic field.

[0026] 5. The comparison results of torque and torque density under the same simulation conditions show that the average torque of the inner rotor and the average torque of the outer rotor of the present invention are significantly improved compared with the traditional structure. The comparison results of magnetic flux density cloud diagrams show that the present invention can reduce the magnetic flux density at the stator tooth ends, the adjusting magnetic ring and the rotor yoke, and suppress local magnetic saturation. Compared with the radial modulation structure only, the present invention enhances the target working harmonics and reduces some non-working harmonics in the outer air gap, indicating that the T-type adjusting magnetic ring achieves the dual modulation effect of radial modulation and axial differential modulation. In the inner modulation air gap and the outer motor air gap, the target working harmonic magnetic flux density amplitude of the present invention is also improved compared with the traditional structure, indicating that the present invention can improve the effective working magnetic field strength in the inner modulation air gap and the outer motor air gap, and improve the torque density.

[0027] 6. Through the coordinated operation of the above-mentioned E-type stator, Spoke-type Halbach external rotor, convex-T-type Halbach internal rotor, and sum-difference dual-modulation magnetic ring, this invention improves the output torque density and effective working magnetic flux density of the air gap while reducing some non-working harmonics and leakage flux, thereby improving the magnetic field waveform and the overall electromagnetic performance of the motor. Attached Figure Description

[0028] Figure 1 This is a partial cross-sectional perspective view of the magnetic gear composite motor for suppressing magnetic saturation and utilizing harmonic sum and difference dual modulation in an embodiment of the present invention. Figure 2 This is a front view schematic diagram of the overall structure of the magnetic gear composite motor that suppresses magnetic saturation and utilizes harmonic sum and difference dual modulation in an embodiment of the present invention. Figure 3 This is a schematic diagram of the stator structure; Figure 4 This is a schematic diagram of the armature winding structure; Figure 5 This is a schematic diagram of the external rotor structure; Figure 6 This is a schematic diagram of the adjusting magnetic ring structure; Figure 7 This is a schematic diagram of the internal rotor structure; Figure 8 This is a schematic diagram showing the magnetization direction of the outer rotor; Figure 9 This is a schematic diagram showing the magnetization direction of the inner rotor; Figure 10 This is a magnetic density cloud diagram of the present invention and a traditional magnetic gear composite motor; Figure 11 Comparison of the magnetic induction intensity of the air gap between the outer rotor and the stator in this invention and a traditional magnetic gear composite motor; Figure 12 This is a comparison diagram of the spatial harmonics of magnetic induction intensity in the outer motor air gap between the present invention and a traditional magnetic gear composite motor; Figure 13 This is a comparison diagram of the magnetic induction intensity of the inner modulated air gap between the outer rotor and the adjusting ring in the present invention and a traditional magnetic gear composite motor. Figure 14 This is a comparison diagram of the spatial harmonics of magnetic induction intensity in the inner modulated air gap between the present invention and a traditional magnetic gear composite motor; Figure 15 This is a comparison diagram of the air gap magnetic induction intensity of the outer motor of the present invention and the radially modulated magnetic gear composite motor; Figure 16 This is a comparison diagram of the harmonics in the air gap space of the outer motor of the present invention and the radially modulated magnetic gear composite motor; Figure 17 This is a comparison diagram of the external rotor output torque and internal rotor output torque of the present invention and a traditional magnetic gear composite motor; Figure 18 This is a comparison chart of the torque density of the present invention and a traditional magnetic gear composite motor. Detailed Implementation

[0029] To facilitate understanding of the present invention, a more complete description will be given below with reference to various embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] Please see Figures 1 to 9 The present invention provides a magnetic gear composite motor that suppresses magnetic saturation and utilizes harmonic sum and difference for high efficiency, including a stator 1, an armature winding 2, an outer rotor 3, a magnetic ring 4, and an inner rotor 5.

[0032] Stator 1, outer rotor 3, adjusting ring 4 and inner rotor 5 are arranged coaxially from the outside to the inside, and armature winding 2 is embedded in the stator slot of stator 1.

[0033] The outer rotor 3 and the inner rotor 5 are two rotating components connected to their respective shafts. The outer rotor 3 obtains electromagnetic torque through the rotating magnetic field generated by the stator armature winding 2, while the inner rotor 5 obtains torque transmitted by magnetic gears through the permanent magnet magnetic field modulated by the adjusting ring 4.

[0034] The stator 1 adopts an E-type tooth structure, including main teeth 1-1 and auxiliary teeth 1-2 located on both sides of the main teeth 1-1 in the circumferential direction.

[0035] Specifically, the stator 1 includes multiple E-type stator core units evenly distributed along the circumferential direction. Each E-type stator core unit includes a main tooth 1-1 and two auxiliary teeth 1-2. The main tooth 1-1 extends radially toward the outer rotor 3, and the two auxiliary teeth 1-2 are respectively disposed on both sides of the main tooth 1-1 in the circumferential direction. The main tooth 1-1 and the two auxiliary teeth 1-2 together form an E-type tooth structure with three tooth ends.

[0036] In this embodiment, the stator 1 includes 8 E-type stator core units evenly distributed along the circumference. The 8 E-type stator core units are arranged sequentially along the circumference to form a total of 24 tooth ends. Stator slots for embedding armature windings 2 are formed between adjacent tooth ends.

[0037] The main tooth 1-1 is used to form the main magnetic flux channel on the stator side and to bear the main magnetic flux coupling between the armature magnetic field of stator 1 and the permanent magnet magnetic field of outer rotor 3.

[0038] The auxiliary tooth 1-2 is used to form an auxiliary magnetic flux channel on the stator side and to divert and shape the air gap magnetic field on both sides of the main tooth 1-1 in order to reduce the local magnetic concentration in the tooth tip region of the main tooth 1-1.

[0039] The main tooth 1-1 and the auxiliary tooth 1-2 work together to reduce the local magnetic concentration in the tooth tip region of the main tooth and improve the magnetic field distribution in the air gap of the outer motor.

[0040] Armature winding 2 is a three-phase armature winding, and the number of pole pairs of armature winding 2 is... Number of permanent magnet pole pairs of outer rotor 3 satisfy:

[0041] So that the rotating armature magnetic field generated by the armature winding 2 is kept synchronously coupled with the permanent magnet magnetic field generated by the outer rotor 3.

[0042] In this embodiment, the armature winding 2 forms a 17-pole rotating armature magnetic field, which corresponds to 34 magnetic poles. , The value of is 17.

[0043] The outer rotor 3 includes an outer rotor yoke 3-1, a radially magnetized permanent magnet 3-2, and a Spoke-type tangentially magnetized permanent magnet 3-3. Please refer to [link / reference]. Figure 8 , Figure 8 The arrows indicate the magnetization direction of the permanent magnets. The radially magnetized permanent magnet 3-2 and the Spoke-type tangentially magnetized permanent magnet 3-3 are arranged according to the Halbach array pattern. The two types of permanent magnets are arranged according to the Halbach array pattern to form a 17-pole Spoke-type Halbach outer rotor structure. This structure can guide and concentrate the permanent magnet flux, improve the magnetic flux density distribution of the outer rotor towards the two working areas of stator 1 and adjusting ring 4, and reduce leakage flux on the non-working side.

[0044] Specifically, radially magnetized permanent magnets 3-2 are spaced apart on the outer rotor yoke 3-1 along the circumferential direction and magnetized in the radial direction. Spoke-type tangentially magnetized permanent magnets 3-3 are arranged between adjacent radially magnetized permanent magnets 3-2 and magnetized in the circumferential tangential direction. The magnetization directions of the radially magnetized permanent magnets 3-2 and the adjacent Spoke-type tangentially magnetized permanent magnets 3-3 are configured according to the Halbach array law, so that the magnetic field on the side of the outer rotor 3 facing the working air gap is enhanced and the leakage magnetic field on the side away from the working air gap is reduced.

[0045] The magnetic ring 4 is fixedly connected to the fixed part of the motor to remain stationary during motor operation. The magnetic ring 4 includes a radial modulation part 4-1, a non-magnetic connection part 4-2, and an axial modulation part 4-3. The radial modulation part 4-1 is used to form a radial modulation path, and the axial modulation part 4-3 is used to form an axial differential modulation path.

[0046] Specifically, the radial modulation part 4-1 is distributed along the circumferential direction and located in the radial magnetic field transmission region, and the axial modulation part 4-3 extends along the axial direction and is located in the axial magnetic field transmission region. The radial modulation part 4-1, the non-magnetic connection part 4-2, and the axial modulation part 4-3 together form a T-shaped composite magnetic tuning structure.

[0047] The radial modulation section 4-1 is used to radially modulate the permanent magnet magnetic field between the outer rotor 3 and the inner rotor 5, while the axial modulation section 4-3 is used to axially differentially modulate the permanent magnet magnetic field between the outer rotor 3 and the inner rotor 5. The non-magnetic connection section 4-2 is used to realize the mechanical connection between the radial modulation section 4-1 and the axial modulation section 4-3, and to reduce the magnetic field interference between the radial modulation magnetic circuit and the axial modulation magnetic circuit. Thus, the axial differential modulation magnetic circuit can share part of the magnetic flux transmission task, reduce the local magnetic flux concentration at the radial adjustment teeth, the outer rotor yoke, and the inner rotor yoke, thereby suppressing local magnetic saturation.

[0048] In this embodiment, the radial modulation section 4-1 is provided with 21 radial magnetic adjustment teeth, that is, the number of magnetic adjustment teeth in the radial modulation section 4-1. The value is 21. The permanent magnet magnetic field of the outer rotor is modulated by 21 radial tuning teeth to form a radial and modulated working harmonic that matches the 4-pole pair permanent magnet magnetic field of the inner rotor 5.

[0049] The axial modulation section 4-3 is provided with 13 axial adjustment teeth, that is, the number of adjustment teeth in the axial modulation section 4-3. The value is 13. The axial difference modulation working harmonics, which correspond to the difference in the number of pole pairs of the two rotors, are formed by the 13 axial tuning teeth, so that part of the permanent magnet flux participates in the magnetic field coupling between the outer rotor 3 and the inner rotor 5 through the axial modulation part 4-3.

[0050] The inner rotor 5 includes multiple convex-T-shaped permanent magnet units arranged at intervals along the circumference. The convex-T-shaped permanent magnet units are configured according to the Halbach array pattern to form a convex-T-shaped Halbach inner rotor structure.

[0051] The outer rotor 3, the adjusting magnetic ring 4, and the inner rotor 5 together form a sum-difference dual-modulation magnetic gear coupling structure. The sum-difference dual-modulation magnetic gear coupling structure includes a radial sum modulation magnetic field transmission path formed by the radial modulation part 4-1 and an axial difference modulation magnetic field transmission path formed by the axial modulation part 4-3.

[0052] In this embodiment, an outer motor air gap is formed between the outer side of the outer rotor 3 and the stator 1, an inner modulation air gap is formed between the inner side of the outer rotor 3 and the adjusting ring 4, and an inner magnetic gear air gap is formed between the adjusting ring 4 and the inner rotor 5. The outer motor air gap is used to realize the electromagnetic energy conversion between the armature magnetic field of the stator 1 and the permanent magnet magnetic field of the outer rotor 3, and the inner modulation air gap and the inner magnetic gear air gap are used to realize the magnetic field modulation coupling between the outer rotor 3 and the inner rotor 5.

[0053] Radial modulation portions 4-1 are spaced apart along the circumference and located in the radial magnetic field transmission region. Axial modulation portions 4-3 extend along the axial direction and are located in the axial magnetic field transmission region. Non-magnetic connection portions 4-2 connect radial modulation portions 4-1 and axial modulation portions 4-3 to reduce magnetic field interference between the radial modulation magnetic circuit and the axial modulation magnetic circuit.

[0054] Number of tuning teeth in radial modulation section 4-1 The number of tuning teeth in the axial modulation section 4-3 Number of permanent magnet pole pairs of inner rotor 5 Number of permanent magnet pole pairs of outer rotor 3 satisfy:

[0055]

[0056] The radial modulation section 4-1 is used to achieve radial modulation between the permanent magnet magnetic field of the outer rotor 3 and the permanent magnet magnetic field of the inner rotor 5, and the axial modulation section 4-3 is used to achieve axial differential modulation between the permanent magnet magnetic field of the outer rotor 3 and the permanent magnet magnetic field of the inner rotor 5. The radial modulation path and the axial differential modulation path jointly undertake the magnetic field coupling between the outer rotor 3 and the inner rotor 5, so as to share the modulation flux and reduce the flux concentration in the local area of ​​the magnetic adjustment ring, the outer rotor yoke and the inner rotor yoke. The axial differential modulation path can share part of the flux transmission task, reduce the local flux concentration in the radial magnetic adjustment teeth, the outer rotor yoke and the inner rotor yoke, thereby suppressing local magnetic saturation.

[0057] In this embodiment, the convex-T-shaped permanent magnet unit includes a radially magnetized permanent magnet unit 5-1, a circumferentially magnetized permanent magnet unit 5-2, and an inner rotor yoke 5-3; the radially magnetized permanent magnet unit 5-1 protrudes towards the magnetizing ring 4 in the radial direction, and the circumferentially magnetized permanent magnet unit 5-2 extends in the circumferential direction. The radially magnetized permanent magnet unit 5-1 and the circumferentially magnetized permanent magnet unit 5-2 together constitute a convex-T-shaped cross-sectional structure.

[0058] Please see Figure 9 , Figure 9The arrows indicate the magnetization direction of the permanent magnets. In this embodiment, the inner rotor 5 adopts a 4-pole convex-T type Halbach permanent magnet structure. The magnetization direction of adjacent convex-T type permanent magnet units deflects sequentially according to the Halbach array pattern, forming a convex-T type Halbach inner rotor structure. This enhances the working air gap magnetic field of the inner rotor 5 facing the magnetic adjustment ring 4 and reduces the leakage magnetic field and non-working harmonic content on the non-working side of the inner rotor 5.

[0059] Specifically, when the motor is running, three-phase alternating current is supplied to the armature winding 2, which generates a 17-pole rotating armature magnetic field. This armature magnetic field interacts with the 17-pole permanent magnet magnetic field of the outer rotor 3 through the outer motor air gap, generating an electromagnetic torque that drives the outer rotor 3 to rotate.

[0060] When the outer rotor 3 rotates, its permanent magnet magnetic field enters the tuning ring 4 through the inner modulation air gap. The radial modulation section 4-1 uses 21 radial tuning teeth to perform spatial harmonic modulation on the permanent magnet magnetic field of the outer rotor, forming radial and modulated harmonics that match the 4-pole pair permanent magnet magnetic field of the inner rotor 5, and performs magnetic field coupling and torque transmission with the inner rotor 5 through the inner magnetic gear air gap.

[0061] Meanwhile, the axial modulation section 4-3 uses 13 axial tuning teeth to form axial differential modulation harmonics. Part of the permanent magnet flux is transmitted through the axial modulation section 4-3, so that the radial modulation path and the axial differential modulation path jointly undertake the task of magnetic field coupling between the outer rotor 3 and the inner rotor 5.

[0062] Therefore, this invention does not rely solely on radial magnetic field modulation for torque transmission, but rather employs a dual-modulation magnetic gear coupling structure that combines radial modulation and axial differential modulation. This dual-path modulation method helps improve the effective operating harmonic magnetic flux density, enhances the magnetic flux distribution within the tuning ring, and reduces the risk of local magnetic saturation.

[0063] When the adjusting magnetic ring 4 remains stationary, the transmission ratio of the magnetic gear compound motor is... satisfy:

[0064] in, The mechanical angular velocity of the inner rotor 5, The mechanical angular velocity of the outer rotor 3, Let be the number of permanent magnet pole pairs of the inner rotor 5. denoted as the number of permanent magnet pole pairs of the outer rotor 3.

[0065] Through the above conditional formula, a sum-difference dual-modulation magnetic gear coupling structure is formed between the outer rotor 3, the magnetic adjustment ring 4, and the inner rotor 5, where the radial and modulated magnetic field transmission paths coexist with the axial differential modulated magnetic field transmission paths.

[0066] To verify the electromagnetic performance of this invention, a traditional single radially modulated magnetic gear composite motor was used as a comparison object. Under the same simulation conditions, the magnetic flux density distribution, the magnetic induction intensity and spatial harmonics of the outer motor air gap, the magnetic induction intensity and spatial harmonics of the inner modulated air gap, the output torque of the outer rotor and the inner rotor, and the output torque density were compared and analyzed. Furthermore, a radially modulated magnetic gear composite motor was used as a comparison object, and only the magnetic induction intensity and spatial harmonics of the outer motor air gap were compared and analyzed to verify the role of the axial modulation portion in the T-shaped magnetic adjustment ring.

[0067] Figure 10 The magnetic flux density cloud diagrams of the present invention and a conventional magnetic gear composite motor are shown. The maximum magnetic flux density of the present invention is approximately 2.828T, while that of the conventional magnetic gear composite motor is approximately 3.181T, representing a reduction of approximately 0.353T, or about 11.10%. Based on the magnetic flux density distribution, it can be seen that the present invention can reduce the degree of local high magnetic flux density in areas such as the stator tooth ends, the adjusting magnetic ring, and the rotor yoke, improving the magnetic flux distribution and thus suppressing the local magnetic saturation effect. This provides a magnetic flux density distribution basis for the technical effect of the present invention in suppressing magnetic saturation.

[0068] like Figure 11 As shown, in the outer motor air gap between the outer rotor 3 and the stator 1, the horizontal axis represents the calculated angle, and the vertical axis represents the magnetic flux density. The curve corresponding to this invention has a higher overall effective working magnetic flux density, indicating that the E-type stator structure and the Spoke-type Halbach outer rotor structure can enhance the electromagnetic coupling between the stator armature magnetic field and the outer rotor permanent magnet magnetic field.

[0069] like Figure 12 As shown, in the spatial harmonic analysis results of the outer motor air gap, the magnetic induction intensity of the 17th target operating harmonic of the present invention is approximately 0.874T, while that of the conventional magnetic gear composite motor is approximately 0.382T, representing an improvement of approximately 128.83%. Simultaneously, the 4th harmonic intensity decreases from approximately 0.306T to approximately 0.188T, and the 49th harmonic intensity decreases from approximately 0.253T to approximately 0.062T, indicating that the present invention can reduce some non-operating harmonics while enhancing the target operating harmonics.

[0070] like Figure 13 As shown, in the inner modulation air gap between the inner side of the outer rotor 3 and the adjusting ring 4, the overall effective working magnetic flux density of the present invention is higher than that of the traditional magnetic gear composite motor, indicating that the Spoke-type Halbach outer rotor can provide a stronger modulation magnetic field for the adjusting ring 4 and improve the magnetic field coupling capability between the outer rotor and the inner rotor.

[0071] like Figure 14As shown, in the spatial harmonic analysis results of the inner modulation air gap, the magnetic induction intensity of the 17th target operating harmonic of the present invention is approximately 0.710T, while that of the conventional magnetic gear composite motor is approximately 0.597T, representing an improvement of approximately 18.93%; the 4th harmonic is reduced from approximately 0.486T to approximately 0.301T, a reduction of approximately 37.94%. Therefore, the present invention can improve the utilization rate of the target operating harmonic in the inner modulation air gap.

[0072] like Figure 15 As shown, compared with the radially modulated magnetic gear composite motor, the magnetic induction intensity in the outer motor air gap of the present invention is improved overall, indicating that the axial modulation part in the T-shaped magnetic ring can participate in magnetic field modulation and magnetic flux transmission, thereby enhancing the effective working magnetic field in the outer motor air gap.

[0073] like Figure 16 As shown, in the spatial harmonic analysis results of the outer motor air gap, compared with the radially modulated magnetic gear composite motor, the magnetic induction intensity of the 17th target working harmonic of the present invention is increased from about 0.802T to about 0.874T, an increase of about 8.88%; the 4th non-working harmonic is reduced from about 0.215T to about 0.188T, a decrease of about 12.58%; and the 16th non-working harmonic is reduced from about 0.023T to about 0.014T, a decrease of about 40.03%. This shows that the T-shaped magnetic ring can achieve a sum and difference dual modulation effect through the combined action of radial sum modulation and axial difference modulation, thereby enhancing the target working harmonic while reducing some non-working harmonics.

[0074] like Figure 17 As shown, the horizontal axis represents time in milliseconds (ms), with a comparison time range of 0–50 ms. The figure shows the output torque of the outer rotor and the inner rotor of the present invention and the conventional magnetic gear composite motor, respectively. It can be seen that within the comparison range of 0–50 ms, the average output torque of the outer rotor of the present invention is approximately 58.319 N·m, while the average output torque of the outer rotor of the conventional magnetic gear composite motor is approximately 32.246 N·m, representing an improvement of approximately 80.86%. The average output torque of the inner rotor of the present invention is approximately 14.587 N·m, while the average output torque of the inner rotor of the conventional magnetic gear composite motor is approximately 7.990 N·m, representing an improvement of approximately 82.56%.

[0075] like Figure 18As shown in the figure, the horizontal axis represents time in milliseconds (ms), with a comparison time range of 0–50 ms. The figure illustrates the torque density of the present invention and the conventional magnetic gear composite motor. It can be seen that within the comparison range of 0–50 ms, the average torque density of the present invention is approximately 37.127 N·m / L, while the average torque density of the conventional magnetic gear composite motor is approximately 20.528 N·m / L, representing an improvement of approximately 80.86%. This demonstrates that the present invention can improve both the output torque and the torque output capacity per unit volume.

[0076] The above comparative results show that the present invention, through the synergistic cooperation of a 24-slot, 17-pole-pair E-type stator, a 17-pole-pair Spoke-type Halbach outer rotor, a 21-tooth radial modulation structure, a 13-tooth axial differential modulation structure, and a 4-pole-pair convex-T-type Halbach inner rotor, improves the magnetic flux density distribution and suppresses local magnetic saturation at the stator tooth ends, the adjusting ring, and the rotor yoke. Simultaneously, it increases the effective working magnetic flux density and target working harmonic amplitude in both the outer motor air gap and the inner modulation air gap. Compared to a purely radially modulated magnetic gear composite motor, the T-type adjusting ring achieves the synergistic effect of radial modulation and axial differential modulation, enhancing the target working harmonics and reducing some non-working harmonics. Compared to a traditional magnetic gear composite motor, the present invention also improves the output torque and torque density of both the outer and inner rotors.

[0077] It should be noted that, in other embodiments, the number of stator slots, the number of inner and outer rotor pole pairs, the number of radial adjustment teeth, and the number of axial adjustment teeth can be adjusted according to the rated speed, target transmission ratio, air gap size, and output torque requirements; however, the number of radial adjustment teeth should satisfy the relationship between the sum of the number of outer rotor permanent magnet pole pairs and the number of inner rotor permanent magnet pole pairs, and the number of axial adjustment teeth should satisfy the relationship between the difference between the number of outer rotor permanent magnet pole pairs and the number of inner rotor permanent magnet pole pairs.

[0078] The outer rotor permanent magnet and the inner rotor permanent magnet can be made of neodymium iron boron permanent magnet material or other permanent magnet materials with similar magnetic properties; the stator, adjusting ring and rotor yoke can be formed by stacking silicon steel sheets to reduce eddy current loss and improve magnetic permeability.

[0079] In addition, the tooth width of the main and auxiliary teeth, the thickness of the permanent magnet, the Halbach magnetization angle, the dimensions of the radial modulation section and the axial modulation section, and the length of each working air gap can all be optimized based on the rated operating conditions of the motor and the results of electromagnetic simulation.

[0080] In summary, the magnetic gear composite motor for suppressing magnetic saturation and utilizing harmonic sum and difference dual modulation provided by the present invention has the following beneficial effects: 1. This invention employs a sum-difference dual modulation method combining radial sum modulation and axial difference modulation. This method simultaneously utilizes radial and axial magnetic field harmonics, increasing the magnetic field transmission path between the outer and inner rotors and improving magnetic field coupling capability. The axial difference modulation path can share some of the magnetic flux transmission workload, reducing local magnetic flux concentration at the radial adjustment teeth, the outer rotor yoke, and the inner rotor yoke, thereby suppressing local magnetic saturation and improving the magnetic flux density distribution within the adjustment ring and the rotor.

[0081] 2. The present invention adopts a convex-T type Halbach inner rotor structure. By combining radially magnetized permanent magnet units and circumferentially magnetized permanent magnet units, the permanent magnet flux is concentrated on the side facing the adjusting ring, thereby enhancing the effective working magnetic field in the air gap of the inner magnetic gear.

[0082] 3. The present invention adopts a Spoke-type Halbach external rotor structure formed by combining radially magnetized permanent magnets and Spoke-type tangentially magnetized permanent magnets, which can enhance the effective magnetic field of the external rotor toward the stator and the adjusting ring, reduce leakage magnetic field on the non-working side, and improve the utilization rate of the permanent magnet magnetic field of the external rotor.

[0083] 4. The present invention adopts an E-type stator structure, which forms a main magnetic flux channel and an auxiliary magnetic flux channel through the main teeth and auxiliary teeth, thereby diverting and shaping the stator air gap magnetic field, reducing the local magnetic concentration at the tip of the main teeth, and enhancing the electromagnetic coupling between the stator armature magnetic field and the external rotor permanent magnet magnetic field.

[0084] 5. The comparison results of torque and torque density under the same simulation conditions show that the average torque of the inner rotor and the average torque of the outer rotor of the present invention are significantly improved compared with the traditional structure. The comparison results of magnetic flux density cloud diagrams show that the present invention can reduce the magnetic flux density at the stator tooth ends, the adjusting magnetic ring and the rotor yoke, and suppress local magnetic saturation. Compared with the radial modulation structure only, the present invention enhances the target working harmonics and reduces some non-working harmonics in the outer air gap, indicating that the T-type adjusting magnetic ring achieves the dual modulation effect of radial modulation and axial differential modulation. In the inner modulation air gap and the outer motor air gap, the target working harmonic magnetic flux density amplitude of the present invention is also improved compared with the traditional structure, indicating that the present invention can improve the effective working magnetic field strength in the inner modulation air gap and the outer motor air gap, and improve the torque density.

[0085] 6. Through the coordinated operation of the above-mentioned E-type stator, Spoke-type Halbach external rotor, convex-T-type Halbach internal rotor, and sum-difference dual-modulation magnetic ring, this invention improves the output torque density and effective working magnetic flux density of the air gap while reducing some non-working harmonics and leakage flux, thereby improving the magnetic field waveform and the overall electromagnetic performance of the motor.

Claims

1. A composite magnetic gear motor that suppresses magnetic saturation and utilizes harmonic sum and difference dual modulation for high efficiency, characterized in that, It includes a stator (1), an armature winding (2), an outer rotor (3), a magnetic adjusting ring (4), and an inner rotor (5); the stator (1), the outer rotor (3), the magnetic adjusting ring (4), and the inner rotor (5) are arranged coaxially from the outside to the inside, and the armature winding (2) is embedded in the stator slot of the stator (1); The stator (1) adopts an E-type tooth structure, including main teeth (1-1) and auxiliary teeth (1-2) located on both sides of the main teeth (1-1) in the circumferential direction; The outer rotor (3) includes a radially magnetized permanent magnet (3-2) and a Spoke-type tangentially magnetized permanent magnet (3-3). The radially magnetized permanent magnet (3-2) and the Spoke-type tangentially magnetized permanent magnet (3-3) are arranged according to the Halbach array pattern to form a Spoke-type Halbach outer rotor structure. The magnetic ring (4) is fixedly connected to the fixed part of the motor to remain stationary during motor operation. The magnetic ring (4) includes a radial modulation part (4-1), a non-magnetic connection part (4-2), and an axial modulation part (4-3). The radial modulation part (4-1) is used to form a radial modulation path, and the axial modulation part (4-3) is used to form an axial differential modulation path. The inner rotor (5) includes multiple convex-T-type permanent magnet units arranged at intervals along the circumferential direction. The convex-T-type permanent magnet units are configured according to the Halbach array pattern to form a convex-T-type Halbach inner rotor structure. Among them, the outer rotor (3), the adjusting ring (4) and the inner rotor (5) together form a sum and difference dual-modulation magnetic gear coupling structure. The sum and difference dual-modulation magnetic gear coupling structure includes a radial sum modulation magnetic field transmission path formed by the radial modulation part (4-1) and an axial difference modulation magnetic field transmission path formed by the axial modulation part (4-3).

2. The magnetic gear composite motor for suppressing magnetic saturation and utilizing harmonic sum and difference dual modulation as described in claim 1, characterized in that, An outer motor air gap is formed between the outer side of the outer rotor (3) and the stator (1), an inner modulation air gap is formed between the inner side of the outer rotor (3) and the adjusting ring (4), and an inner magnetic gear air gap is formed between the adjusting ring (4) and the inner rotor (5). The outer motor air gap is used to realize the electromagnetic energy conversion between the armature magnetic field of the stator (1) and the permanent magnet magnetic field of the outer rotor (3). The inner modulation air gap and the inner magnetic gear air gap are used to realize the magnetic field modulation coupling between the outer rotor (3) and the inner rotor (5).

3. The magnetic gear composite motor for suppressing magnetic saturation and utilizing harmonic sum and difference dual modulation as described in claim 1, characterized in that, The stator (1) includes multiple E-type stator core units evenly distributed along the circumferential direction. Each E-type stator core unit includes a main tooth (1-1) and two auxiliary teeth (1-2). The main tooth (1-1) extends radially toward the outer rotor (3), and the two auxiliary teeth (1-2) are respectively disposed on both sides of the circumferential direction of the main tooth (1-1). The main tooth (1-1) and the two auxiliary teeth (1-2) together form an E-type tooth structure with three tooth ends. The main tooth (1-1) is used to form the main magnetic flux channel on the stator side, and the auxiliary tooth (1-2) is used to form the auxiliary magnetic flux channel on the stator side, and to shunt and shape the air gap magnetic field on both sides of the main tooth (1-1) to reduce the local magnetic concentration in the tooth tip region of the main tooth (1-1).

4. The magnetic gear composite motor for suppressing magnetic saturation and utilizing harmonic sum and difference dual modulation as described in claim 1, characterized in that, The armature winding (2) is a three-phase armature winding, and the number of pole pairs of the armature winding (2) is... Number of permanent magnet pole pairs of the outer rotor (3) satisfy: So that the rotating armature magnetic field generated by the armature winding (2) is synchronously coupled with the permanent magnet magnetic field generated by the outer rotor (3).

5. The composite magnetic gear motor for suppressing magnetic saturation and utilizing harmonic sum and difference modulation with high efficiency as described in claim 1, characterized in that, The outer rotor (3) also includes an outer rotor yoke (3-1), radially magnetized permanent magnets (3-2) are spaced on the outer rotor yoke (3-1) along the circumferential direction and magnetized in the radial direction, and Spoke-type tangentially magnetized permanent magnets (3-3) are arranged between adjacent radially magnetized permanent magnets (3-2) and magnetized in the circumferential tangential direction; the magnetization directions of the radially magnetized permanent magnets (3-2) and adjacent Spoke-type tangentially magnetized permanent magnets (3-3) are arranged according to the Halbach array law, so that the magnetic field of the outer rotor (3) facing the working air gap is enhanced and the leakage magnetic field facing away from the working air gap is reduced.

6. The magnetic gear composite motor for suppressing magnetic saturation and utilizing harmonic sum and difference dual modulation according to claim 1, characterized in that, The radial modulation section (4-1) is distributed at intervals along the circumferential direction and located in the radial magnetic field transmission region. The axial modulation section (4-3) extends along the axial direction and is located in the axial magnetic field transmission region. The non-magnetic connection section (4-2) connects the radial modulation section (4-1) and the axial modulation section (4-3) to reduce magnetic field interference between the radial modulation magnetic circuit and the axial modulation magnetic circuit.

7. The magnetic gear composite motor for suppressing magnetic saturation and utilizing harmonic sum and difference dual modulation according to claim 1, characterized in that, Number of tuning teeth in the radial modulation section (4-1) The number of tuning teeth in the axial modulation section (4-3) The number of permanent magnet pole pairs of the inner rotor (5) Number of permanent magnet pole pairs of the outer rotor (3) satisfy: The radial modulation section (4-1) is used to achieve radial modulation between the permanent magnet magnetic field of the outer rotor (3) and the permanent magnet magnetic field of the inner rotor (5), and the axial modulation section (4-3) is used to achieve axial differential modulation between the permanent magnet magnetic field of the outer rotor (3) and the permanent magnet magnetic field of the inner rotor (5). The radial modulation path and the axial differential modulation path jointly undertake the magnetic field coupling between the outer rotor (3) and the inner rotor (5) to share the modulation flux and reduce the flux concentration in the local area of ​​the magnetic ring, the outer rotor yoke and the inner rotor yoke. The axial differential modulation path can share part of the flux transmission task, reduce the local flux concentration in the radial magnetic ring, the outer rotor yoke and the inner rotor yoke, thereby suppressing local magnetic saturation.

8. The magnetic gear composite motor for suppressing magnetic saturation and utilizing harmonic sum and difference dual modulation according to claim 1, characterized in that, The convex-T type permanent magnet unit includes a radially magnetized permanent magnet unit (5-1), a circumferentially magnetized permanent magnet unit (5-2), and an inner rotor yoke (5-3). The radially magnetized permanent magnet unit (5-1) protrudes radially toward the magnetizing ring (4), and the circumferentially magnetized permanent magnet unit (5-2) extends circumferentially. The radially magnetized permanent magnet unit (5-1) and the circumferentially magnetized permanent magnet unit (5-2) together constitute a convex-T type cross-sectional structure.

9. The magnetic gear composite motor for suppressing magnetic saturation and utilizing harmonic sum and difference dual modulation according to claim 8, characterized in that, The magnetization direction of the adjacent convex-T permanent magnet units is deflected sequentially according to the Halbach array law to form a convex-T Halbach inner rotor structure, which enhances the working air gap magnetic field of the inner rotor (5) facing the magnetic ring (4) and reduces the leakage magnetic field and non-working harmonic content of the non-working side of the inner rotor (5).

10. The magnetic gear composite motor for suppressing magnetic saturation and utilizing harmonic sum and difference dual modulation according to claim 1, characterized in that, When the adjusting magnetic ring (4) remains stationary, the transmission ratio of the magnetic gear compound motor is... satisfy: in, The mechanical angular velocity of the inner rotor (5) is... The mechanical angular velocity of the outer rotor (3) is... Let be the number of permanent magnet pole pairs of the inner rotor (5). is the number of permanent magnet pole pairs of the outer rotor (3).

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