Single magnetic ring double rotor radial axis composite modulation magnetic gear

Abstract

This invention discloses a monotonic magnetic ring dual-rotor radial-axis composite modulation magnetic gear. The magnetic gear includes an inner rotor yoke, an inner rotor permanent magnet, a tuning ring, an outer rotor permanent magnet, and an outer rotor yoke. The inner rotor yoke and the inner rotor permanent magnet constitute the inner rotor, and the outer rotor permanent magnet and the outer rotor yoke constitute the outer rotor. The inner and outer rotors are coaxially arranged to form a dual-rotor structure, capable of relative rotation. The tuning ring, a single tuning structure, is positioned between the inner and outer rotors to simultaneously achieve radial modulation and axial differential modulation, thus forming a radial-axis dual-modulation magnetic gear. Both the inner and outer rotor permanent magnets employ an asymmetric Halbach array structure. This application achieves radial modulation and differential modulation, constructing a radial-axis coupled dual-modulation magnetic field structure, improving magnetic field utilization and torque transmission capability.

Description

Technical Field

[0001] This invention relates to the fields of new energy vehicle technology and wind power transmission, and in particular to a monotonic magnetic ring dual rotor radial shaft composite modulated magnetic gear. Background Technology

[0002] Against the backdrop of continuous energy structure transformation and rapid development of transportation electrification, new energy vehicles and new energy equipment such as wind power generation place higher demands on the efficiency, reliability, and torque density of transmission systems. In the field of new energy vehicles, drive systems are evolving from traditional centralized structures to distributed drive forms. Hub motors, by placing the drive unit directly inside the wheel, eliminate intermediate transmission links such as gearboxes and drive shafts, offering advantages such as short transmission chains, high efficiency, and fast response speeds. In the field of wind power generation, wind turbines also require low-speed, high-torque transmission devices to achieve stable energy transfer between the turbine and the generator. While traditional mechanical gearboxes can achieve large transmission ratios, they suffer from problems such as mechanical wear, complex lubrication and maintenance, high operating noise, and insufficient long-term reliability, especially under complex operating conditions such as offshore wind power. Therefore, magnetic gear technology, which achieves non-contact transmission based on the principle of magnetic field coupling, is gradually gaining attention. It offers advantages such as no lubrication required, low noise, high reliability, and overload protection capabilities, showing promising application prospects in hub drive systems for new energy vehicles and low-speed, high-torque transmission systems for wind power generation.

[0003] However, in-wheel motors are constrained by both space and performance in practical applications. On the one hand, their structural dimensions are limited by the wheel rim space, requiring high-performance output within a compact structure. On the other hand, when vehicles start, climb hills, and operate under complex conditions, the drive system is required to deliver high torque output at low speeds and exhibit good dynamic response characteristics. These requirements make it challenging for in-wheel motors to achieve high torque density and high efficiency within a limited volume, and traditional electromagnetic drive structures struggle to meet these performance requirements. Similarly, wind power transmission systems also face the demands of high torque at low speeds, high reliability, and high efficiency, placing higher demands on the torque density and long-term stable operation capabilities of the transmission device.

[0004] To address the aforementioned issues, magnetic gear technology based on the principle of magnetic field modulation has gradually gained attention. This technology spatially modulates the magnetic field generated by a permanent magnet through a magnetizing structure, enabling the coupling of magnetic field components with different pole pairs, thereby achieving non-contact torque transmission. Compared to traditional mechanical gears, magnetic gears avoid the wear and lubrication requirements associated with mechanical contact, and offer advantages such as low operating noise, high reliability, and strong overload protection. They show promising application prospects in high-reliability and high-integration applications. This type of structure is not only suitable for hub drive systems in new energy vehicles but also for low-speed, high-torque transmission scenarios such as wind power generation.

[0005] Despite the progress made in theoretical and applied research, existing magnetic gear structures still have several shortcomings in practical applications. First, existing structures mostly employ a single modulation method, typically radial magnetic field modulation, resulting in a relatively simple magnetic field path and insufficient utilization of spatial magnetic field resources, thus limiting further improvements in torque density. Second, the arrangement of permanent magnets is relatively fixed, leading to uneven magnetic flux distribution and some flux not participating in the effective modulation process, resulting in low magnetic energy utilization. Third, under high-load operating conditions, the significant magnetic flux concentration effect can easily cause magnetic saturation in local areas, leading to increased torque pulsation and decreased efficiency, affecting system stability. Furthermore, existing magnetic gears still have room for improvement in terms of transmission capacity, space utilization, and adaptability to multiple operating conditions when facing the low-speed, high-torque applications such as hub drives in new energy vehicles and wind power generation. Summary of the Invention

[0006] Based on this, the present invention provides a monotonic magnetic ring dual rotor radial shaft composite modulated magnetic gear to improve torque density and magnetic energy utilization, and ensure stable system operation.

[0007] A monotonic magnetic ring dual-rotor radial-axis composite modulated magnetic gear includes an inner rotor yoke, an inner rotor permanent magnet, a magnetic ring, an outer rotor permanent magnet, and an outer rotor yoke; the inner rotor yoke and the inner rotor permanent magnet constitute the inner rotor, and the outer rotor permanent magnet and the outer rotor yoke constitute the outer rotor. The inner rotor and the outer rotor are coaxially arranged and form a dual-rotor structure, and the two can rotate relative to each other. The magnetic ring is a single magnetic adjustment structure, which is set between the inner rotor and the outer rotor to simultaneously realize radial modulation and axial differential modulation, thereby forming a radial-axis dual-modulation magnetic gear. The inner rotor yoke, inner rotor permanent magnet, adjusting ring, outer rotor permanent magnet, and outer rotor yoke are coaxially nested from the inside to the outside. The inner rotor permanent magnet adopts an asymmetric Halbach array structure, with multiple inner trapezoidal permanent magnet units distributed circumferentially. The permanent magnets in the inner trapezoidal permanent magnet units are arranged in combination according to a predetermined magnetization direction to form a single-sided magnetic distribution that enhances the magnetic field on the air gap side and weakens the magnetic field on the back magnet side, thereby forming a magnetic circuit structure with concentrated magnetization. Inner magnetic guiding units are set at predetermined positions in the array to form a composite magnetic circuit structure. The outer rotor permanent magnet adopts an asymmetric Halbach array structure, with multiple outer trapezoidal permanent magnet units distributed circumferentially. The permanent magnets in the outer trapezoidal permanent magnet units are arranged in combination according to a predetermined magnetization direction to form a single-sided magnetic distribution that enhances the magnetic field on the air gap side and weakens the magnetic field on the back magnet side, thereby forming a magnetic circuit structure with a magnetic concentration. External magnetic guiding units are set at predetermined positions in the array to form a composite magnetic circuit structure. The inner rotor permanent magnet, the adjusting ring, and the outer rotor permanent magnet are configured and modulated in the radial direction, and differential modulation is formed in the axial direction at both ends of the adjusting ring. There are radial inner air gaps and axial inner air gaps between the inner rotor permanent magnet and the adjusting ring, and radial outer air gaps and axial outer air gaps between the adjusting ring and the outer rotor permanent magnet, thus forming a radial main magnetic circuit and an axial auxiliary magnetic circuit respectively in terms of structure. In this system, the magnetic ring is fixed, the inner rotor serves as the input rotor, and the outer rotor serves as the output rotor. Through the synergistic effect of radial modulation and axial differential modulation, non-contact magnetic field coupling transmission between the two rotors is achieved.

[0008] The monotonic magnetic ring dual-rotor radial shaft composite modulation magnetic gear provided by the present invention has the following beneficial effects: (1) This invention introduces radial and axial differential modulation mechanisms into a single magnetic ring structure to construct a dual-modulation magnetic field system with synergistic radial and axial effects. Compared with existing structures that rely solely on single radial modulation or discrete modulation by multiple magnetic rings, this invention expands the magnetic field modulation dimension without increasing structural complexity, significantly enhancing the effective harmonic components, thereby improving magnetic energy utilization and torque transmission capability.

[0009] (2) By constructing a dual-rotor structure with the inner and outer rotors coaxially arranged, and combining a monotonic magnetic ring to achieve magnetic field coupling transmission, the torque is transmitted between the two rotors in a non-contact manner, avoiding the contact wear and energy loss of traditional mechanical gears, while improving the system's operational reliability and overload protection capability, which is particularly suitable for high-reliability transmission scenarios.

[0010] (3) Both the inner rotor permanent magnet and the outer rotor permanent magnet adopt an asymmetric Halbach array and are combined with magnetic permeable units to form a magnetically concentrated composite magnetic circuit structure, so that the magnetic flux is highly concentrated on the air gap side and effectively suppressed on the back magnetic side, thereby reducing leakage magnetic loss from the source and significantly improving the air gap magnetic induction intensity and magnetic field utilization efficiency, providing a basis for improving torque density.

[0011] (4) The magnetic ring adopts an integrated design of radial magnetic adjustment unit and axial magnetic adjustment unit, and forms an I-shaped structure through non-magnetic connection part to divide the magnetic flux modulation area into functional zones, effectively blocking non-working magnetic flux paths, reducing magnetic flux coupling interference, suppressing local magnetic saturation phenomenon, thereby improving the uniformity of magnetic field distribution and output torque stability.

[0012] (5) By constructing the main magnetic circuit and the auxiliary magnetic circuit in the radial air gap and the axial air gap respectively, a multi-magnetic circuit cooperative coupling structure is formed, so that the magnetic flux is orderly distributed and transmitted in multiple spatial paths. This not only improves the flexibility of magnetic field modulation, but also effectively disperses the peak value of magnetic flux density, thereby improving the load-bearing capacity and operational stability of the device under high load conditions.

[0013] (6) The present invention realizes dual modulation function based on monotonic magnetic ring. Compared with the traditional multi-adjustment magnetic ring structure, it significantly reduces the number of structural layers and components while ensuring modulation performance, which is conducive to reducing manufacturing and assembly difficulty and realizing the miniaturization and high integration of the device. It is particularly suitable for space-constrained occasions such as hub motors.

[0014] (7) Through the coordinated design of dual rotor structure, magnetic circuit and multi-magnetic circuit modulation mechanism, the air gap magnetic field distribution is more concentrated and controllable, and it has better performance under low speed, high torque and high dynamic response requirements. At the same time, it has the potential to be extended to high torque transmission systems such as wind power generation. Attached Figure Description

[0015] Figure 1 This is a three-dimensional topological structure diagram of the monotonic magnetic ring dual rotor radial shaft composite modulation magnetic gear in an embodiment of the present invention; Figure 2 This is a three-dimensional partial cross-sectional view of the monotonic magnetic ring dual rotor radial shaft composite modulation magnetic gear in an embodiment of the present invention; Figure 3 This is a schematic diagram of the inner rotor structure of the monotonic magnetic ring dual rotor radial shaft composite modulation magnetic gear in an embodiment of the present invention. Figure 4 This is a schematic diagram of the adjusting magnetic ring structure of the monotonic magnetic ring dual rotor radial shaft composite modulation magnetic gear in an embodiment of the present invention. Figure 5 This is a schematic diagram of the outer rotor structure of the monotonic magnetic ring dual rotor radial shaft composite modulated magnetic gear in an embodiment of the present invention; Figure 6 A schematic diagram showing the excitation direction of the inner rotor yoke and the inner rotor permanent magnet; Figure 7 A schematic diagram showing the excitation direction of the outer rotor yoke and the outer rotor permanent magnet; Figure 8 This is a comparison diagram of the spatial harmonic spectrum of the magnetic induction intensity in the inner air gap of the magnetic gear of the present invention and that of a conventional radial magnetic gear. Detailed Implementation

[0016] 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.

[0017] 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 description of the 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.

[0018] Please see Figures 1 to 7 An embodiment of the present invention provides a single-adjustment magnetic ring dual-rotor radial-axis composite modulation magnetic gear, comprising an inner rotor yoke 1, an inner rotor permanent magnet 2, an adjusting magnetic ring 3, an outer rotor permanent magnet 4, and an outer rotor yoke 5. The inner rotor yoke 1 and the inner rotor permanent magnet 2 constitute the inner rotor, and the outer rotor permanent magnet 4 and the outer rotor yoke 5 constitute the outer rotor. The inner and outer rotors are coaxially arranged and form a dual-rotor structure, which can rotate relative to each other without mechanical contact. The adjusting magnetic ring 3 is fixedly arranged, and the inner rotor serves as the input rotor, driving the outer rotor to rotate through magnetic field coupling.

[0019] The adjusting ring 3 is a single adjusting structure, which is set between the inner rotor and the outer rotor to simultaneously realize radial modulation and axial differential modulation, thereby forming a radial-axis dual-modulation magnetic gear.

[0020] Specifically, the inner rotor yoke 1, the inner rotor permanent magnet 2, the adjusting ring 3, the outer rotor permanent magnet 4, and the outer rotor yoke 5 are coaxially nested from the inside to the outside.

[0021] The inner rotor permanent magnet 2 adopts an asymmetric Halbach array structure with multiple inner trapezoidal permanent magnet units 21 distributed circumferentially. The permanent magnets in the inner trapezoidal permanent magnet units 21 are arranged in combination according to a predetermined magnetization direction to form a single-sided magnetic distribution that enhances the magnetic field on the air gap side and weakens the magnetic field on the back magnetic side, thereby forming a magnetic circuit structure with a magnetic concentration. Inner magnetic guiding units 22 are set at predetermined positions in the array to form a composite magnetic circuit structure, which is used to guide the magnetic flux distribution and suppress leakage magnetic field.

[0022] The outer rotor permanent magnet 4 adopts an asymmetric Halbach array structure with multiple outer trapezoidal permanent magnet units 41 distributed circumferentially. The permanent magnets in the outer trapezoidal permanent magnet units 41 are arranged in combination according to a predetermined magnetization direction to form a single-sided magnetic distribution that enhances the magnetic field on the air gap side and weakens the magnetic field on the back magnet side, thereby forming a magnetic circuit structure with concentrated magnetization. An outer magnetic guiding unit 42 is set at a predetermined position in the array to form a composite magnetic circuit structure and achieve efficient magnetic field coupling.

[0023] Specifically, the inner trapezoidal permanent magnet unit 21 includes a first inner trapezoidal permanent magnet 211, a second inner trapezoidal permanent magnet 212, a third inner trapezoidal permanent magnet 213, and a fourth inner trapezoidal permanent magnet 214 arranged sequentially. An inner magnetic guiding unit 22 is disposed at the bottom of the first inner trapezoidal permanent magnet 211. Furthermore, the sum of the thicknesses of the first inner trapezoidal permanent magnet 211 and the inner magnetic guiding unit 22 is equal to the thicknesses of the second inner trapezoidal permanent magnet 212, the third inner trapezoidal permanent magnet 213, and the fourth inner trapezoidal permanent magnet 214.

[0024] The outer trapezoidal permanent magnet unit 41 includes a first outer trapezoidal permanent magnet 411, a second outer trapezoidal permanent magnet 412, a third outer trapezoidal permanent magnet 413, and a fourth outer trapezoidal permanent magnet 414 arranged sequentially. An outer magnetic guiding unit 42 is disposed at the bottom of the first outer trapezoidal permanent magnet 411. The sum of the thicknesses of the first outer trapezoidal permanent magnet 411 and the outer magnetic guiding unit 42 is equal to the thicknesses of the second outer trapezoidal permanent magnet 412, the third outer trapezoidal permanent magnet 413, and the fourth outer trapezoidal permanent magnet 414.

[0025] Preferably, the inner rotor permanent magnet 2 and the outer rotor permanent magnet 4 are made of neodymium iron boron magnets with high remanence and high coercivity to improve magnetic field strength and operational stability.

[0026] The inner rotor permanent magnet 2, the adjusting ring 3, and the outer rotor permanent magnet 4 are configured and modulated in the radial direction, and differential modulation is formed in the axial direction at both ends of the adjusting ring 3.

[0027] In this embodiment, a radial inner air gap and an axial inner air gap are provided between the inner rotor permanent magnet 2 and the adjusting ring 3, and a radial outer air gap and an axial outer air gap are provided between the adjusting ring 3 and the outer rotor permanent magnet 4, thereby forming a radial main magnetic circuit and an axial auxiliary magnetic circuit respectively in terms of structure.

[0028] Among them, the magnetic ring 3 is fixed, the inner rotor is used as the input rotor, and the outer rotor is used as the output rotor. Through the synergistic effect of radial modulation and axial differential modulation, non-contact magnetic field coupling transmission between the two rotors is realized.

[0029] The magnetic adjustment ring 3 is a key component for achieving magnetic field modulation. It includes a radial magnetic adjustment unit 31 and an axial magnetic adjustment unit 32 disposed at both ends.

[0030] Radial magnetic modulation units 31 are distributed circumferentially and stacked according to the number of modulation units to form a central structure, which is used to realize harmonic modulation of the radial magnetic field.

[0031] Axial magnetic adjustment unit 32 is disposed at both ends of radial magnetic adjustment unit 31 and stacked according to the number of differential modulations to form an end structure, which is used to realize differential modulation of magnetic field.

[0032] The radial magnetic adjustment unit 31 and the axial magnetic adjustment unit 32 are connected by a non-magnetic connection part 33, so that the magnetic adjustment ring 3 has an overall I-shaped structure. The non-magnetic connection part 33 is used to form magnetic flux isolation between the radial magnetic adjustment area and the axial magnetic adjustment area, suppress the diffusion of magnetic flux in the non-working path, and make the magnetic flux preferentially close along the radial air gap and the axial air gap, thereby forming a multi-magnetic circuit structure in which the radial main magnetic circuit and the axial auxiliary magnetic circuit cooperate.

[0033] Specifically, the radial main magnetic route is formed by the radial air gap between the inner rotor permanent magnet 2, the adjusting ring 3, and the outer rotor permanent magnet 4, and is used to realize the main modulation transmission of the magnetic field; the axial auxiliary magnetic route is formed by the axial air gap at both ends of the adjusting ring 3, and is used to realize the differential coupling modulation of the magnetic flux. The radial main magnetic route and the axial auxiliary magnetic route work together to distribute and transmit the magnetic flux in multiple paths, so as to enhance the magnetic field modulation effect and torque transmission capability.

[0034] Based on the above structure, the inner rotor permanent magnet 2, the adjusting ring 3, and the outer rotor permanent magnet 4 form a magnetic field and modulation in the radial direction to realize the main magnetic field coupling and torque transmission; at the same time, magnetic field difference modulation is formed in the axial direction at both ends of the adjusting ring 3 to perform differential adjustment and enhancement of the magnetic field.

[0035] By leveraging the synergistic effect of radial modulation and axial differential modulation, a dual-modulation magnetic field structure with radial and axial coupling is constructed. This allows the magnetic flux to preferentially close along the radial main magnetic path and the axial auxiliary magnetic path, thereby effectively suppressing magnetic leakage, increasing the magnetic induction intensity on the air gap side, and enhancing the effective harmonic components, thus improving the magnetic field modulation capability and energy transfer efficiency.

[0036] Preferably, the adjusting ring 3 is made of a high magnetic permeability material, such as silicon steel sheet or soft magnetic composite material, to improve magnetic flux guiding capability and reduce magnetic reluctance loss.

[0037] In this embodiment, the number of pole pairs of the inner rotor permanent magnet 2 is The number of pole pairs of the external rotor permanent magnet 4 is The number of radial magnetic adjustment units in magnetic adjustment ring 3 is The number of axial magnetic adjustment units in magnetic adjustment ring 3 is It satisfies the following condition: ; .

[0038] By matching the parameters as described above, effective harmonic component coupling can be achieved.

[0039] The magnetic gear satisfies the following condition:

[0040] in, The transmission ratio of the magnetic gear is given. The internal rotor speed, This refers to the external rotor speed. This indicates that the inner and outer rotors rotate in opposite directions, suggesting a fixed proportional relationship between the speed of the outer rotor and the speed of the inner rotor.

[0041] In this embodiment, the inner rotor permanent magnet 2 is evenly distributed along the circumference, and the number of the first outer trapezoidal permanent magnet 411, the second outer trapezoidal permanent magnet 412, the third outer trapezoidal permanent magnet 413, and the fourth outer trapezoidal permanent magnet 414 are all 4, for a total of 16 permanent magnets.

[0042] Please refer to this carefully. Figure 6 , Figure 6 This is a schematic diagram of the excitation direction structure of the inner rotor yoke 1 and the inner rotor permanent magnet 2, where the arrows indicate the magnetization direction of each permanent magnet unit. The inner rotor permanent magnet 2 adopts an asymmetric Halbach array structure, and each permanent magnet unit is arranged in combination by changing the magnetization direction sequentially according to a predetermined angle, so as to form a unilateral magnetic focusing effect that enhances the magnetic field on the air gap side and weakens the magnetic field on the back magnet side.

[0043] Specifically, the magnetization directions of adjacent permanent magnet units are distributed in a stepped rotational pattern along the circumference, with a phase difference of approximately 90° between the magnetization directions of each permanent magnet unit. This forms a periodic sequence of magnetization directions, rather than a simple radially opposite arrangement. This magnetization method achieves the concentration and guidance of magnetic flux on the air gap side. In this embodiment, the magnetization directions are arranged in a cycle of four permanent magnet units, thus forming a corresponding pole pair distribution with an axial length of 50 mm.

[0044] In this embodiment, the outer rotor permanent magnets 4 are uniformly distributed circumferentially, and their number is determined according to the number of pole pairs to form a magnetic field distribution of 17 pole pairs.

[0045] Please refer to this carefully. Figure 7 , Figure 7 This is a schematic diagram of the excitation direction structure of the outer rotor yoke 5 and the outer rotor permanent magnet 4, where the arrows indicate the magnetization direction of each permanent magnet unit. The outer rotor permanent magnet 4 adopts an asymmetric Halbach array structure, with each permanent magnet unit arranged sequentially along the circumference at a predetermined angle. Its magnetization direction is distributed in a stepped rotational manner to achieve a unilateral magnetizing effect, forming an enhanced magnetic field on the air gap side and a weakened magnetic field on the back magnet side.

[0046] Specifically, the magnetization directions of adjacent permanent magnet units sequentially form a phase difference of approximately 90° and change cyclically along the circumference, thereby constituting a periodic sequence of magnetization directions. This achieves the concentration and guidance of magnetic flux on the air gap side, rather than a simple radially opposite arrangement. In this embodiment, the magnetization directions are arranged cyclically in groups of four permanent magnet units, forming a complete magnetization direction cycle, thus corresponding to a magnetic field distribution of 17 pole pairs.

[0047] Preferably, each permanent magnet unit has a trapezoidal structure to adapt to the circumferential arrangement of the ring structure and improve the uniformity of the magnetic field distribution.

[0048] The spatial harmonic spectrum of the external air gap magnetic induction intensity of the magnetic gear of the present invention was compared with that of a conventional radial magnetic field modulated magnetic gear, and the results are as follows: Figure 8 As shown. By Figure 8 As can be seen, compared with the traditional radial magnetic gear structure, the present invention significantly improves the amplitude of the effective harmonic components in the outer air gap, while suppressing the ineffective harmonics, thereby enhancing the magnetic field modulation capability and improving the torque density and transmission stability.

[0049] The above results show that the present invention enhances the main harmonic components involved in energy transfer through radial and axial dual modulation and multi-magnetic circuit coupling structure, thereby improving magnetic field modulation efficiency and magnetic energy utilization, which is conducive to achieving higher output torque density and more stable transmission performance.

[0050] In summary, the monotonic magnetic ring dual-rotor radial shaft composite modulation magnetic gear provided by the present invention has the following beneficial effects: (1) This invention introduces radial and axial differential modulation mechanisms into a single magnetic ring structure to construct a dual-modulation magnetic field system with synergistic radial and axial effects. Compared with existing structures that rely solely on single radial modulation or discrete modulation by multiple magnetic rings, this invention expands the magnetic field modulation dimension without increasing structural complexity, significantly enhancing the effective harmonic components, thereby improving magnetic energy utilization and torque transmission capability.

[0051] (2) By constructing a dual-rotor structure with the inner and outer rotors coaxially arranged, and combining a monotonic magnetic ring to achieve magnetic field coupling transmission, the torque is transmitted between the two rotors in a non-contact manner, avoiding the contact wear and energy loss of traditional mechanical gears, while improving the system's operational reliability and overload protection capability, which is particularly suitable for high-reliability transmission scenarios.

[0052] (3) Both the inner rotor permanent magnet and the outer rotor permanent magnet adopt an asymmetric Halbach array and are combined with magnetic permeable units to form a magnetically concentrated composite magnetic circuit structure, so that the magnetic flux is highly concentrated on the air gap side and effectively suppressed on the back magnetic side, thereby reducing leakage magnetic loss from the source and significantly improving the air gap magnetic induction intensity and magnetic field utilization efficiency, providing a basis for improving torque density.

[0053] (4) The magnetic ring adopts an integrated design of radial magnetic adjustment unit and axial magnetic adjustment unit, and forms an I-shaped structure through non-magnetic connection part to divide the magnetic flux modulation area into functional zones, effectively blocking non-working magnetic flux paths, reducing magnetic flux coupling interference, suppressing local magnetic saturation phenomenon, thereby improving the uniformity of magnetic field distribution and output torque stability.

[0054] (5) By constructing the main magnetic circuit and the auxiliary magnetic circuit in the radial air gap and the axial air gap respectively, a multi-magnetic circuit cooperative coupling structure is formed, so that the magnetic flux is orderly distributed and transmitted in multiple spatial paths. This not only improves the flexibility of magnetic field modulation, but also effectively disperses the peak value of magnetic flux density, thereby improving the load-bearing capacity and operational stability of the device under high load conditions.

[0055] (6) The present invention realizes dual modulation function based on monotonic magnetic ring. Compared with the traditional multi-adjustment magnetic ring structure, it significantly reduces the number of structural layers and components while ensuring modulation performance, which is conducive to reducing manufacturing and assembly difficulty and realizing the miniaturization and high integration of the device. It is particularly suitable for space-constrained occasions such as hub motors.

[0056] (7) Through the coordinated design of dual rotor structure, magnetic circuit and multi-magnetic circuit modulation mechanism, the air gap magnetic field distribution is more concentrated and controllable, and it has better performance under low speed, high torque and high dynamic response requirements. At the same time, it has the potential to be extended to high torque transmission systems such as wind power generation.

Claims

1. A monotonic magnetic ring dual-rotor radial shaft composite modulation magnetic gear, characterized in that, It includes an inner rotor yoke (1), an inner rotor permanent magnet (2), a magnetic adjustment ring (3), an outer rotor permanent magnet (4), and an outer rotor yoke (5); the inner rotor yoke (1) and the inner rotor permanent magnet (2) constitute the inner rotor, and the outer rotor permanent magnet (4) and the outer rotor yoke (5) constitute the outer rotor. The inner rotor and the outer rotor are coaxially arranged and form a dual rotor structure, which can rotate relative to each other. The magnetic ring (3) is a single magnetic adjustment structure, which is set between the inner rotor and the outer rotor to simultaneously realize radial and modulation and axial differential modulation, thereby forming a radial-shaft dual-modulation magnetic gear. The inner rotor yoke (1), inner rotor permanent magnet (2), adjusting ring (3), outer rotor permanent magnet (4) and outer rotor yoke (5) are coaxially nested from the inside to the outside; The inner rotor permanent magnet (2) adopts an asymmetric Halbach array structure, with multiple inner trapezoidal permanent magnet units (21) distributed circumferentially. The permanent magnets in the inner trapezoidal permanent magnet units (21) are arranged in a predetermined magnetization direction to form a single-sided magnetic distribution that enhances the magnetic field on the air gap side and weakens the magnetic field on the back magnetic side, thereby forming a magnetic circuit structure with a magnetic concentration. Inner magnetic conductive units (22) are set at predetermined positions in the array to form a composite magnetic circuit structure. The outer rotor permanent magnet (4) adopts an asymmetric Halbach array structure, with multiple outer trapezoidal permanent magnet units (41) distributed circumferentially. The permanent magnets in the outer trapezoidal permanent magnet units (41) are arranged in a predetermined magnetization direction to form a single-sided magnetic distribution that enhances the magnetic field on the air gap side and weakens the magnetic field on the back magnetic side, thereby forming a magnetic circuit structure with a magnetic concentration. An outer magnetic conductive unit (42) is set at a predetermined position in the array to form a composite magnetic circuit structure. The inner rotor permanent magnet (2), the adjusting ring (3) and the outer rotor permanent magnet (4) are configured and modulated in the radial direction, and differential modulation is formed in the axial direction at both ends of the adjusting ring (3); A radial inner air gap and an axial inner air gap are provided between the inner rotor permanent magnet (2) and the adjusting ring (3), and a radial outer air gap and an axial outer air gap are provided between the adjusting ring (3) and the outer rotor permanent magnet (4), thereby forming a radial main magnetic circuit and an axial auxiliary magnetic circuit respectively in terms of structure. Among them, the adjusting ring (3) is fixed, the inner rotor is used as the input rotor, and the outer rotor is used as the output rotor. Through the synergistic effect of radial and modulation and axial differential modulation, non-contact magnetic field coupling transmission between the two rotors is realized.

2. The monotonic magnetic ring dual-rotor radial shaft composite modulation magnetic gear according to claim 1, characterized in that, The magnetic adjustment ring (3) includes a radial magnetic adjustment unit (31) and an axial magnetic adjustment unit (32) disposed at both ends. The radial magnetic adjustment units (31) are distributed circumferentially and stacked according to the number of modulations to form a central structure. The axial magnetic adjustment units (32) are disposed at both ends of the radial magnetic adjustment units (31) and stacked according to the number of differential modulations to form an end structure. The radial magnetic adjustment units (31) and the axial magnetic adjustment units (32) are connected by a non-magnetic connection part (33), so that the magnetic adjustment ring (3) has an overall I-shaped structure. The non-magnetic connection part (33) is used to form magnetic flux isolation between the radial magnetic adjustment area and the axial magnetic adjustment area.

3. The monotonic magnetic ring dual-rotor radial shaft composite modulation magnetic gear according to claim 1, characterized in that, The inner trapezoidal permanent magnet unit (21) includes a first inner trapezoidal permanent magnet (211), a second inner trapezoidal permanent magnet (212), a third inner trapezoidal permanent magnet (213), and a fourth inner trapezoidal permanent magnet (214) arranged in sequence, and an inner magnetic conductive unit (22) is located at the bottom of the first inner trapezoidal permanent magnet (211).

4. The monotonic magnetic ring dual-rotor radial shaft composite modulation magnetic gear according to claim 1, characterized in that, The outer trapezoidal permanent magnet unit (41) includes a first outer trapezoidal permanent magnet (411), a second outer trapezoidal permanent magnet (412), a third outer trapezoidal permanent magnet (413), and a fourth outer trapezoidal permanent magnet (414) arranged in sequence, and an outer magnetic conductive unit (42) is located at the bottom of the first outer trapezoidal permanent magnet (411).

5. The monotonic magnetic ring dual-rotor radial shaft composite modulation magnetic gear according to claim 1, characterized in that, The number of pole pairs of the inner rotor permanent magnet (2) is The number of pole pairs of the external rotor permanent magnet (4) is The number of radial magnetic adjustment units of the magnetic adjustment ring (3) is The number of axial magnetic adjustment units of the magnetic adjustment ring (3) is It satisfies the following condition: ； 。 6. The monotonic magnetic ring dual-rotor radial shaft composite modulation magnetic gear according to claim 5, characterized in that, The magnetic gear satisfies the following condition: in, The transmission ratio of the magnetic gear is given. The internal rotor speed, This refers to the external rotor speed. This indicates that the inner and outer rotors rotate in opposite directions.

7. The monotonic magnetic ring dual-rotor radial shaft composite modulation magnetic gear according to claim 1, characterized in that, The radial main magnetic circuit is formed by the radial air gap between the inner rotor permanent magnet (2), the adjusting ring (3) and the outer rotor permanent magnet (4) to realize the main modulation transmission of the magnetic field; the axial auxiliary magnetic circuit is formed by the axial air gap at both ends of the adjusting ring (3) to realize the differential coupling modulation of the magnetic flux. The radial main magnetic circuit and the axial auxiliary magnetic circuit work together to enhance the magnetic field modulation effect and torque transmission capability.

8. The monotonic magnetic ring dual-rotor radial shaft composite modulation magnetic gear according to claim 1, characterized in that, The inner rotor permanent magnet (2) and the outer rotor permanent magnet (4) are made of neodymium iron boron magnets.

9. The monotonic magnetic ring dual-rotor radial shaft composite modulation magnetic gear according to claim 1, characterized in that, The adjusting ring (3) is made of silicon steel sheet or soft magnetic composite material.

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