Double-modulation magnet ring double-modulation double-rotor magnetic gear and new energy automobile hub motor

Abstract

The invention discloses a double-magnet-adjusting-ring double-modulation double-rotor magnetic gear and a new energy automobile hub motor, the magnetic gear comprises an inner rotor, an outer rotor, a salient pole magnet adjusting ring and an auxiliary magnet adjusting ring, the inner rotor is composed of an inner rotor iron yoke and an inner rotor permanent magnet, and the outer rotor is composed of an outer rotor permanent magnet; the inner rotor iron yoke, the salient pole magnetism adjusting ring, the outer rotor permanent magnet and the auxiliary magnetism adjusting ring are coaxially and sequentially nested from inside to outside; the inner rotor permanent magnet adopts a spoke type structure and is embedded in the inner rotor iron yoke; the inner rotor permanent magnet, the outer rotor permanent magnet and the salient pole magnetism adjusting ring form sum modulation, and the inner rotor permanent magnet, the outer rotor permanent magnet and the auxiliary magnetism adjusting ring form difference modulation; the inner rotor permanent magnets and the outer rotor permanent magnets are magnetized in a radial magnetizing mode. According to the invention, the torque density can be improved, the magnetic leakage phenomenon is reduced, magnetic field saturation is relieved, and the magnetic field energy conversion efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and in particular to a double-tuned magnetic ring, double-modulated double-rotor magnetic gear and a new energy vehicle hub motor. Background Art

[0002] With the growing global demand for green energy and low-carbon mobility, new energy vehicles (NEVs), with their significant advantages such as zero emissions, high energy efficiency, and low operating costs, have become a core focus of the automotive industry's transformation and upgrading. New energy vehicles (NEVs) that utilize distributed drive systems, by eliminating traditional centralized transmission systems (such as gearboxes and drive shafts), achieve a highly integrated and lightweight powertrain. These vehicles offer outstanding features such as short drive trains, high transmission efficiency, and flexible vehicle control, making them a key trend in the future development of new energy vehicle technology.

[0003] As the core actuator of a distributed drive system, direct-drive in-wheel motors are integrated directly with the wheels, eliminating the energy losses of traditional transmission systems and improving motor efficiency. However, in-wheel motors must simultaneously meet the vehicle's high torque output requirements under conditions such as acceleration, climbing, and frequent starts and stops, as well as stable operation in complex environments such as bumpy and slippery roads. This poses significant challenges to the motor's low-speed, high-torque characteristics, torque density (torque output per unit volume), and dynamic response performance. Limited by volume constraints and electromagnetic design bottlenecks, traditional in-wheel motors struggle to achieve high torque density within limited space, becoming a key technical barrier to the large-scale application of distributed drive systems.

[0004] Magnetic gears, as a contactless transmission device based on the principle of magnetic field modulation, achieve harmonic coupling between low-speed and high-speed magnetic fields by modulating the magnetic core on the inner and outer rotors, thereby transmitting input torque to the output. Compared to traditional mechanical gears, magnetic gears offer significant advantages such as no friction and wear, no lubrication and maintenance requirements, low operating noise, and a compact structure. They are particularly suitable for in-wheel motor applications where reliability and space utilization are extremely important. Research interest in these applications in the new energy vehicle sector has continued to grow in recent years.

[0005] Although magnetic gears show promising application prospects in in-wheel motors, their technological maturity is still limited by the following key issues: First, existing magnetic gears mostly use a single magnetic tuning structure (such as a planar magnetic tuning ring or a simple salient pole structure), resulting in a single magnetic field modulation effect. This makes it difficult to simultaneously meet the requirements of low-speed high torque and high-speed and efficient operation, resulting in limited torque density improvement. Second, the permanent magnets, as the core energy carriers of magnetic gears, are arranged in a manner (such as radial magnetization and surface-mounted structures) that easily causes magnetic leakage, resulting in wasted magnetic field energy and insufficient permanent magnet utilization. Third, during the magnetic field coupling process between traditional magnetic tuning rings and permanent magnets, localized magnetic field saturation is prone to occur due to magnetic flux concentration, resulting in increased torque fluctuations and reduced efficiency under high-load conditions. Fourth, the air gap design between the inner and outer rotors and the magnetic tuning structure parameters are not properly matched, further reducing the magnetic field energy conversion efficiency. These issues seriously restrict the practical application of magnetic gears in in-wheel motors, and there is an urgent need to overcome the existing technical bottlenecks through structural innovation and optimized design. Summary of the Invention

[0006] The purpose of the present invention is to provide a dual-tuning magnetic ring, dual-modulation dual-rotor magnetic gear and a new energy vehicle hub motor to improve torque density, reduce magnetic leakage, alleviate magnetic field saturation, and improve the conversion efficiency of magnetic field energy.

[0007] One aspect of the present invention provides a dual-magnetic-ring dual-modulation dual-rotor magnetic gear, comprising an inner rotor, an outer rotor, a salient-pole magnetic-modulating ring, and an auxiliary magnetic-modulating ring. The inner rotor is composed of an inner rotor iron yoke and an inner rotor permanent magnet, and the outer rotor is composed of an outer rotor permanent magnet. The inner rotor iron yoke, the salient pole magnetic adjustment ring, the outer rotor permanent magnet and the auxiliary magnetic adjustment ring are coaxially nested in sequence from the inside to the outside; The inner rotor permanent magnet adopts a spoke structure and is embedded in the inner rotor iron yoke; The inner rotor permanent magnet, the outer rotor permanent magnet and the salient pole magnetic modulation ring form and modulation, and the inner rotor permanent magnet, the outer rotor permanent magnet and the auxiliary magnetic modulation ring form differential modulation; The inner rotor permanent magnet and the outer rotor permanent magnet are magnetized by radial magnetization; An inner air gap is provided between the inner rotor permanent magnet and the salient pole magnetic adjustment ring, an intermediate air gap is provided between the salient pole magnetic adjustment ring and the outer rotor permanent magnet, and an outer air gap is provided between the outer rotor permanent magnet and the auxiliary magnetic adjustment ring; Among them, the salient pole magnetic tuning ring and the auxiliary magnetic tuning ring are fixed, and the inner rotor is used as the input rotor to drive the outer rotor to rotate through magnetic field coupling.

[0008] Another aspect of the present invention provides a new energy vehicle hub motor, which includes the magnetic gear mentioned above.

[0009] The dual-tuning magnetic ring, dual-modulation dual-rotor magnetic gear and new energy vehicle hub motor provided by the present invention have the following beneficial effects: (1) The present invention significantly enhances the magnetic field modulation effect through the synergistic effect of sum modulation and differential modulation. The inner rotor permanent magnets and the outer rotor permanent magnets are simultaneously coupled with the salient pole magnetic modulation ring (sum modulation) and the auxiliary magnetic modulation ring (differential modulation), forming a dual magnetic field modulation mechanism. Compared with the traditional single magnetic modulation ring or simple dual magnetic modulation ring structure, the present invention can more efficiently regulate the magnetic field distribution between the inner and outer rotors, enhance the effective harmonic components, and suppress the ineffective harmonic interference, thereby significantly improving the electromechanical energy conversion efficiency.

[0010] (2) The inner rotor permanent magnet adopts a spoke-type embedded structure, combined with a salient pole magnetic ring design, which effectively reduces the magnetic leakage of the permanent magnet and improves the torque density. At the same time, it enhances the mechanical strength of the inner rotor, enabling it to withstand the vibration and impact loads of the hub motor under complex road conditions (such as bumps and rapid acceleration), thereby improving the reliability of the rotor operation. In addition, the utilization rate of the permanent magnet of the spoke-type structure is significantly improved, and the magnetic field energy is more concentrated in the air gap area, providing a basis for high torque output.

[0011] (3) The composite magnetic tuning design of the salient pole magnetic tuning ring and the auxiliary magnetic tuning ring effectively disperses the magnetic flux density in the coupled magnetic field by optimizing the number, shape and material of the salient pole part, avoiding the magnetic field saturation problem in the local area. Under rated load, the output fluctuation of the outer rotor is effectively reduced compared with the traditional magnetic gear, thereby ensuring the stability of the torque output under high speed conditions and solving the pain point of large high load torque fluctuation in the existing technology.

[0012] (4) The transmission structure with dual magnetic adjustment rings (salient pole magnetic adjustment ring and auxiliary magnetic adjustment ring) fixed and the inner rotor as input simplifies the overall layout of the magnetic gear, reduces the number of moving parts, and reduces operating noise and maintenance costs. At the same time, this structure directly transmits torque through magnetic field coupling, avoiding the friction loss of traditional mechanical gears and further improving the overall efficiency of the hub motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A three-dimensional topological structure diagram of a dual-modulation magnetic ring dual-modulation dual-rotor magnetic gear in an embodiment of the present invention; Figure 2 A three-dimensional cross-sectional view of a dual-modulation magnetic ring dual-modulation dual-rotor magnetic gear in an embodiment of the present invention; Figure 3 Schematic diagram of the front structure of the double-modulation magnetic ring double-modulation double-rotor magnetic gear in an embodiment of the present invention; Figure 4 A 1 / 4 cross-sectional view of a dual-modulation magnetic ring dual-modulation dual-rotor magnetic gear in an embodiment of the present invention; Figure 5 Schematic diagram of the structure of the salient pole magnetic regulating ring; Figure 6 It is a structural diagram of the auxiliary magnetic adjustment ring; Figure 7 It is a structural diagram of the inner rotor; Figure 8 Schematic diagram of the structure of the outer rotor permanent magnet; Figure 9 It is a front cross-sectional view of a dual-modulation magnetic ring dual-modulation dual-rotor magnetic gear in an embodiment of the present invention; Figure 10 The figure is a comparison diagram of the spatial harmonic spectrum of the outer air gap magnetic induction intensity of the magnetic gear of the present invention and the traditional radial magnetic gear. DETAILED DESCRIPTION

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0015] See also Figures 1 to 9 The dual-magnetic-ring dual-modulation dual-rotor magnetic gear provided in an embodiment of the present invention includes an inner rotor, an outer rotor, a salient-pole magnetic-modulating ring 3 and an auxiliary magnetic-modulating ring 5, wherein the salient-pole magnetic-modulating ring 3 and the auxiliary magnetic-modulating ring 5 are fixed, and the inner rotor is used as the input rotor, and the outer rotor is driven to rotate through magnetic field coupling.

[0016] The inner rotor iron yoke 1, the salient pole magnetic adjustment ring 3, the outer rotor permanent magnet 4 and the auxiliary magnetic adjustment ring 5 are coaxially nested in sequence from the inside to the outside.

[0017] The inner rotor permanent magnet 2, the outer rotor permanent magnet 4 and the salient pole magnetic modulation ring 3 form sum modulation, and the inner rotor permanent magnet 2, the outer rotor permanent magnet 4 and the auxiliary magnetic modulation ring 5 form differential modulation.

[0018] The inner rotor permanent magnet 2 and the outer rotor permanent magnet 4 are both magnetized in a radial direction.

[0019] An inner air gap 6 is provided between the inner rotor permanent magnet 2 and the salient pole magnetic tuning ring 3 , an intermediate air gap 7 is provided between the salient pole magnetic tuning ring 3 and the outer rotor permanent magnet 4 , and an outer air gap 8 is provided between the outer rotor permanent magnet 4 and the auxiliary magnetic tuning ring 5 .

[0020] The inner rotor is composed of an inner rotor iron yoke 1 and inner rotor permanent magnets 2. In this embodiment, the inner rotor is composed of an inner rotor iron yoke 1 and 12 inner rotor permanent magnets 2. Please refer to Figure 7 , Figure 7 The middle arrow indicates the magnetization direction. The magnetization directions of any two adjacent inner rotor permanent magnets 2 are opposite, one of which is magnetized in the positive radial direction and the other in the negative radial direction.

[0021] The inner rotor permanent magnet 2 adopts a spoke structure and is embedded in the inner rotor iron yoke 1. The inner rotor permanent magnet 2 has an angle of 10° and an axial length of 50 mm.

[0022] The inner rotor permanent magnet 2 uses a neodymium iron boron (NdFeB) magnet with high remanence and high coercivity to improve the magnetic field strength and stability.

[0023] The outer rotor consists of 38 outer rotor permanent magnets 4, please refer to Figure 8 , Figure 8 The middle arrow indicates the magnetization direction. Any two adjacent outer rotor permanent magnets 4 have opposite magnetization directions, one magnetized in the positive radial direction and the other magnetized in the negative radial direction. The outer rotor permanent magnets 4 have an angle of 9.47° and an axial length of 50 mm.

[0024] The outer rotor permanent magnet 4 uses a neodymium iron boron (NdFeB) magnet with high remanence and high coercivity to improve the magnetic field strength and stability.

[0025] In this embodiment, the number of pole pairs of the inner rotor permanent magnet 2 is , the number of pole pairs of the outer rotor permanent magnet 4 , the number of salient pole magnetic adjustment cores on the salient pole magnetic adjustment ring 3 , the number of convex magnetic adjustment cores on the auxiliary magnetic adjustment ring 5 , satisfying the following conditional formula: ; .

[0026] Satisfy the conditions: , so that the inner rotor permanent magnet 2, the outer rotor permanent magnet 4 and the salient pole magnetic modulation ring 3 constitute a radial and modulated coaxial magnetic gear structure.

[0027] Satisfy the conditions: , so that the inner rotor permanent magnet 2, the outer rotor permanent magnet 4 and the auxiliary magnetic tuning ring 5 constitute a coaxial magnetic gear structure with radial difference modulation.

[0028] In this embodiment, the magnetic gear satisfies the following conditional formula:

[0029] in, is the transmission ratio of the magnetic gear, is the inner rotor speed, is the outer rotor speed.

[0030] The above transmission ratio relationship shows that the rotation speed of the magnetic gear is equal to the ratio of the number of permanent magnet pole pairs on the rotor.

[0031] The outer and inner surfaces of the salient pole tuning ring 3 are each provided with 25 salient pole tuning cores 9, each with a rectangular or trapezoidal cross-section. In this embodiment, the cross-section of the salient pole tuning cores 9 is rectangular. The salient pole tuning cores 9 are formed by laminating magnetically conductive materials, with a spacing of 7.2° between adjacent salient pole tuning cores 9. The axial length of the salient pole tuning ring 3 is 50 mm. The salient pole tuning ring 3 has radial modulation capabilities, capable of modulating the radial magnetic field of the permanent magnet.

[0032] The salient pole magnetic tuning ring 3 is made of high permeability soft magnetic material, such as silicon steel sheet or soft magnetic composite material.

[0033] The inner circumference of the auxiliary magnetic tuning ring 5 is provided with 25 salient pole portions 10, and the cross section of the salient pole portion 10 is rectangular or trapezoidal. In this embodiment, the salient pole portion 10 is rectangular.

[0034] The auxiliary magnetic tuning ring 5 is made of high permeability soft magnetic material, such as silicon steel sheet or soft magnetic composite material.

[0035] The spatial harmonic spectrum of the outer air gap magnetic induction intensity of the magnetic gear of the present invention is compared with that of the traditional radial magnetic gear. The results are as follows: Figure 10 As shown, from Figure 10 It can be seen that compared with the traditional radial field modulation magnetic gear, the peak value of the effective harmonic component in the outer air gap of the magnetic gear of the present invention is significantly improved, which is conducive to improving the output torque density of the magnetic gear.

[0036] An embodiment of the present invention further provides a new energy vehicle hub motor, which includes the magnetic gear described above.

[0037] In summary, the dual-tuning magnetic ring, dual-modulation dual-rotor magnetic gear and new energy vehicle hub motor provided by the present invention have the following beneficial effects: (1) The present invention significantly enhances the magnetic field modulation effect through the synergistic effect of sum modulation and differential modulation. The inner rotor permanent magnets and the outer rotor permanent magnets are simultaneously coupled with the salient pole magnetic modulation ring (sum modulation) and the auxiliary magnetic modulation ring (differential modulation), forming a dual magnetic field modulation mechanism. Compared with the traditional single magnetic modulation ring or simple dual magnetic modulation ring structure, the present invention can more efficiently regulate the magnetic field distribution between the inner and outer rotors, enhance the effective harmonic components, and suppress the ineffective harmonic interference, thereby significantly improving the electromechanical energy conversion efficiency.

[0038] (2) The inner rotor permanent magnet adopts a spoke-type embedded structure, combined with a salient pole magnetic ring design, which effectively reduces the magnetic leakage of the permanent magnet and improves the torque density. At the same time, it enhances the mechanical strength of the inner rotor, enabling it to withstand the vibration and impact loads of the hub motor under complex road conditions (such as bumps and rapid acceleration), thereby improving the reliability of the rotor operation. In addition, the utilization rate of the permanent magnet of the spoke-type structure is significantly improved, and the magnetic field energy is more concentrated in the air gap area, providing a basis for high torque output.

[0039] (3) The composite magnetic tuning design of the salient pole magnetic tuning ring and the auxiliary magnetic tuning ring effectively disperses the magnetic flux density in the coupled magnetic field by optimizing the number, shape and material of the salient pole part, avoiding the magnetic field saturation problem in the local area. Under rated load, the output fluctuation of the outer rotor is effectively reduced compared with the traditional magnetic gear, thereby ensuring the stability of the torque output under high speed conditions and solving the pain point of large high load torque fluctuation in the existing technology.

[0040] (4) The transmission structure with dual magnetic adjustment rings (salient pole magnetic adjustment ring and auxiliary magnetic adjustment ring) fixed and the inner rotor as input simplifies the overall layout of the magnetic gear, reduces the number of moving parts, and reduces operating noise and maintenance costs. At the same time, this structure directly transmits torque through magnetic field coupling, avoiding the friction loss of traditional mechanical gears and further improving the overall efficiency of the hub motor.

[0041] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0042] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A double-modulation magnetic ring double-modulation double-rotor magnetic gear, characterized in that: It includes an inner rotor, an outer rotor, a salient pole magnetic adjustment ring and an auxiliary magnetic adjustment ring. The inner rotor is composed of an inner rotor iron yoke and an inner rotor permanent magnet, and the outer rotor is composed of an outer rotor permanent magnet. The inner rotor iron yoke, the salient pole magnetic adjustment ring, the outer rotor permanent magnet and the auxiliary magnetic adjustment ring are coaxially nested in sequence from the inside to the outside; The inner rotor permanent magnet adopts a spoke structure and is embedded in the inner rotor iron yoke; The inner rotor permanent magnet, the outer rotor permanent magnet and the salient pole magnetic modulation ring form and modulation, and the inner rotor permanent magnet, the outer rotor permanent magnet and the auxiliary magnetic modulation ring form differential modulation; The inner rotor permanent magnet and the outer rotor permanent magnet are magnetized by radial magnetization; An inner air gap is provided between the inner rotor permanent magnet and the salient pole magnetic adjustment ring, an intermediate air gap is provided between the salient pole magnetic adjustment ring and the outer rotor permanent magnet, and an outer air gap is provided between the outer rotor permanent magnet and the auxiliary magnetic adjustment ring; Among them, the salient pole magnetic tuning ring and the auxiliary magnetic tuning ring are fixed, and the inner rotor is used as the input rotor to drive the outer rotor to rotate through magnetic field coupling.

2. The double-modulation magnetic ring double-modulation double-rotor magnetic gear according to claim 1, characterized in that: Number of pole pairs of inner rotor permanent magnets , the number of pole pairs of the outer rotor permanent magnet , the number of salient pole magnetic adjustment cores on the salient pole magnetic adjustment ring , the number of convex magnetic adjustment cores on the auxiliary magnetic adjustment ring , satisfying the following conditional formula: ； 。 3. The double-modulation magnetic ring double-modulation double-rotor magnetic gear according to claim 2, characterized in that: The magnetic gear satisfies the following conditional formula: in, is the transmission ratio of the magnetic gear, is the inner rotor speed, is the outer rotor speed.

4. The double-modulation magnetic ring double-modulation double-rotor magnetic gear according to claim 1, characterized in that: The inner rotor is composed of an inner rotor iron yoke and a plurality of inner rotor permanent magnets. The magnetization directions of any two adjacent inner rotor permanent magnets are opposite, one of which is magnetized in the positive radial direction and the other is magnetized in the reverse radial direction.

5. The double-modulation magnetic ring double-modulation double-rotor magnetic gear according to claim 1, characterized in that: A plurality of salient pole magnetic adjustment cores are respectively provided on the outer circumference and the inner circumference of the salient pole magnetic adjustment ring, and the cross section of the salient pole magnetic adjustment core is rectangular or trapezoidal.

6. The double-modulation magnetic ring double-modulation double-rotor magnetic gear according to claim 1, characterized in that: The outer rotor is composed of a plurality of outer rotor permanent magnets. The magnetization directions of any two adjacent outer rotor permanent magnets are opposite, one of which is magnetized in the positive radial direction and the other is magnetized in the reverse radial direction.

7. The double-modulation magnetic ring double-modulation double-rotor magnetic gear according to claim 1, characterized in that: The inner circumference of the auxiliary magnetic tuning ring is provided with a plurality of salient pole parts, and the cross section of the salient pole parts is rectangular or trapezoidal.

8. The double-modulation magnetic ring double-modulation double-rotor magnetic gear according to claim 1, characterized in that: The inner rotor permanent magnet and the outer rotor permanent magnet are made of neodymium iron boron magnets.

9. The double-modulation magnetic ring double-modulation double-rotor magnetic gear according to claim 1, characterized in that: The salient pole magnetic adjustment ring is made of silicon steel sheet or soft magnetic composite material, and the auxiliary magnetic adjustment ring is made of silicon steel sheet or soft magnetic composite material.

10. A new energy vehicle hub motor, characterized in that: The invention comprises the double-modulation magnetic ring double-modulation double-rotor magnetic gear according to any one of claims 1 to 9.

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