Dual-modulation magnetic ring, dual-rotor magnetic gear, and hub motor for new energy vehicles

Abstract

A dual-tuning magnetic ring, dual-modulation, dual-rotor magnetic gear and a hub motor for new energy vehicles are disclosed. The magnetic gear includes an inner rotor, an outer rotor, a salient-pole tuning ring, and an auxiliary tuning ring. The inner rotor consists of an inner rotor yoke and an inner rotor permanent magnet, while the outer rotor consists of an outer rotor permanent magnet. The inner rotor yoke, salient-pole tuning ring, outer rotor permanent magnet, and auxiliary tuning ring are coaxially nested from the inside to the outside. The inner rotor permanent magnet adopts a spoke-like structure and is embedded within the inner rotor yoke. The inner and outer rotor permanent magnets, together with the salient-pole tuning ring, form and modulate the magnetic gear, and the inner and outer rotor permanent magnets, together with the auxiliary tuning ring, form differential modulation. Both the inner and outer rotor permanent magnets are magnetized radially. This invention can improve torque density, reduce magnetic leakage, alleviate magnetic field saturation, and improve the energy conversion efficiency of the magnetic field.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, and in particular to a dual-modulation magnetic ring dual-rotor magnetic gear and a hub motor for new energy vehicles. Background Technology

[0002] With the growing global demand for green energy and low-carbon travel, new energy vehicles have become a core direction for the transformation and upgrading of the automotive industry due to their significant advantages such as zero emissions, high energy efficiency, and low operating costs. Among them, new energy vehicles using distributed drive systems achieve a high degree of integration and lightweighting of the power system by eliminating traditional centralized transmission systems (such as gearboxes and drive shafts). They have outstanding characteristics such as short drive chains, high transmission efficiency, and flexible vehicle control, and represent an important trend in the future development of new energy vehicle technology.

[0003] As the core actuator of a distributed drive system, the direct-drive hub motor is directly integrated with the wheel, eliminating the energy loss of traditional transmission systems and improving motor efficiency. However, hub motors must simultaneously meet the high torque output requirements of vehicles under conditions such as acceleration, hill climbing, and frequent start-stop, as well as the stable operation requirements in complex environments such as bumpy roads and slippery conditions. This poses extremely high challenges to the motor's low-speed, high-torque characteristics, torque density (torque per unit volume), and dynamic response performance. Traditional hub motors, constrained by size limitations and electromagnetic design bottlenecks, struggle to achieve high torque density within a limited space, becoming a key technological obstacle restricting the large-scale application of distributed drive systems.

[0004] Magnetic gears, as a non-contact 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 fields of the inner and outer rotors with a magnetic core, thereby transmitting input torque to the output end. Compared with traditional mechanical gears, magnetic gears have significant advantages such as no friction and wear, no need for lubrication and maintenance, low operating noise, and compact structure. They are particularly suitable for hub motor scenarios with extremely high requirements for reliability and space utilization, and their research interest in the field of new energy vehicles has been steadily increasing in recent years.

[0005] Although magnetic gears have shown promising application prospects in hub motors, their technological maturity is still limited by the following key issues: First, existing magnetic gears mostly adopt a single magnetic adjustment structure (such as a planar magnetic adjustment 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 high-efficiency operation, thus limiting the improvement of torque density. Second, as the core energy carrier of the magnetic gear, the arrangement of permanent magnets (such as radial magnetization or surface-mounted structures) is prone to magnetic leakage, resulting in wasted magnetic field energy and insufficient utilization of permanent magnets. Third, during the magnetic field coupling process between the traditional magnetic adjustment ring and the permanent magnet, local areas are prone to magnetic field saturation due to magnetic flux concentration, leading to increased torque fluctuations and decreased efficiency of the motor under high load conditions. Fourth, the unreasonable matching of the air gap design between the inner and outer rotors and the magnetic adjustment structure parameters further reduces the conversion efficiency of magnetic field energy. These problems seriously restrict the practical application effect of magnetic gears in hub motors, and it is urgent to break through the existing technological bottlenecks through structural innovation and optimized design. Summary of the Invention

[0006] The purpose of this invention is to provide a dual-modulation magnetic ring dual-rotor magnetic gear and a hub motor for new energy vehicles, so as 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-adjustment magnetic ring dual-modulation dual-rotor magnetic gear, comprising an inner rotor, an outer rotor, a salient pole adjusting magnetic ring and an auxiliary adjusting magnetic ring, wherein the inner rotor is composed of an inner rotor yoke and an inner rotor permanent magnet, and the outer rotor is composed of an outer rotor permanent magnet;

[0008] The inner rotor yoke, salient pole adjusting ring, outer rotor permanent magnet, and auxiliary adjusting ring are coaxially nested from the inside to the outside.

[0009] The permanent magnet of the inner rotor adopts a spoke structure and is embedded in the iron yoke of the inner rotor;

[0010] The inner rotor permanent magnet, the outer rotor permanent magnet, and the salient pole adjusting ring constitute and modulate the differential modulation; the inner rotor permanent magnet, the outer rotor permanent magnet, and the auxiliary adjusting ring constitute differential modulation.

[0011] Both the inner rotor permanent magnet and the outer rotor permanent magnet are magnetized using radial magnetization.

[0012] An inner air gap is provided between the inner rotor permanent magnet and the salient pole adjusting ring, an intermediate air gap is provided between the salient pole adjusting ring and the outer rotor permanent magnet, and an outer intermediate air gap is provided between the outer rotor permanent magnet and the auxiliary adjusting ring.

[0013] Among them, the salient pole adjusting ring and the auxiliary adjusting ring are fixed, and the inner rotor is used as the input rotor. Through the magnetic field coupling, the outer rotor is driven to rotate.

[0014] Another aspect of the present invention provides a hub motor for a new energy vehicle, the hub motor including the aforementioned magnetic gear.

[0015] The dual-modulation magnetic ring, dual-modulation, dual-rotor magnetic gear, and new energy vehicle hub motor provided by the present invention have the following beneficial effects:

[0016] (1) This invention significantly enhances the magnetic field modulation effect through the synergistic effect of sum modulation and differential modulation. The inner rotor permanent magnet and the outer rotor permanent magnet are simultaneously coupled with the salient pole tuning ring (sum modulation) and the auxiliary tuning ring (differential modulation) to form a dual magnetic field modulation mechanism. Compared with the traditional single tuning ring or simple double tuning ring structure, this invention can more efficiently control the magnetic field distribution between the inner and outer rotors, enhance the effective harmonic components, and suppress ineffective harmonic interference, thereby greatly improving the electromechanical energy conversion efficiency.

[0017] (2) The permanent magnet of the inner rotor adopts a spoke-type embedded structure and is combined with a salient pole adjusting magnetic ring design, which effectively reduces the leakage of permanent magnets, increases torque density, and 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), thus improving the reliability of rotor operation. In addition, the utilization rate of permanent magnets with spoke-type structure is significantly improved, and the magnetic field energy is more concentrated in the air gap area, providing a foundation for high torque output.

[0018] (3) The composite magnetic adjustment design of the salient pole adjusting ring and the auxiliary adjusting 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 problem of magnetic field saturation in the local area. Under rated load, the output fluctuation of the outer rotor is reduced compared with the traditional magnetic gear, thus ensuring the stability of torque output under high speed conditions and solving the problem of large torque fluctuation under high load in the existing technology.

[0019] (4) The transmission structure with fixed dual-adjusting magnetic rings (salient pole adjusting magnetic ring and auxiliary adjusting magnetic ring) and inner rotor as input simplifies the overall layout of magnetic gears, reduces the number of moving parts, and lowers 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 hub motor. Attached Figure Description

[0020] Figure 1 This is a three-dimensional topological structure diagram of the dual-tuning magnetic ring, dual-modulation, dual-rotor magnetic gear in an embodiment of the present invention;

[0021] Figure 2 This is a three-dimensional sectional view of the dual-tuning magnetic ring, dual-modulation, dual-rotor magnetic gear in an embodiment of the present invention.

[0022] Figure 3This is a front structural schematic diagram of the dual-tuning magnetic ring dual-modulation dual-rotor magnetic gear in an embodiment of the present invention.

[0023] Figure 4 This is a 1 / 4 sectional view of the dual-tuning magnetic ring dual-modulation dual-rotor magnetic gear in an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the structure of a salient pole adjusting magnetic ring;

[0025] Figure 6 A schematic diagram of the auxiliary adjusting magnetic ring;

[0026] Figure 7 This is a schematic diagram of the internal rotor structure;

[0027] Figure 8 This is a schematic diagram of the structure of the external rotor permanent magnet;

[0028] Figure 9 This is a front sectional view of the dual-tuning magnetic ring dual-modulation dual-rotor magnetic gear in an embodiment of the present invention.

[0029] Figure 10 This is a comparison diagram of the spatial harmonic spectrum of the external air gap magnetic induction intensity of the magnetic gear of the present invention and that of a conventional radial magnetic gear. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Please see Figures 1 to 9 The dual-adjustment magnetic ring dual-modulation dual-rotor magnetic gear provided in this embodiment of the invention includes an inner rotor, an outer rotor, a salient pole adjusting magnetic ring 3 and an auxiliary adjusting magnetic ring 5. The salient pole adjusting magnetic ring 3 and the auxiliary adjusting magnetic ring 5 are fixed. The inner rotor is used as the input rotor and drives the outer rotor to rotate through magnetic field coupling.

[0032] The inner rotor yoke 1, the salient pole adjusting ring 3, the outer rotor permanent magnet 4, and the auxiliary adjusting ring 5 are coaxially nested from the inside to the outside.

[0033] The inner rotor permanent magnet 2, the outer rotor permanent magnet 4, and the salient pole adjusting ring 3 constitute and modulate the differential modulation. The inner rotor permanent magnet 2, the outer rotor permanent magnet 4, and the auxiliary adjusting ring 5 constitute differential modulation.

[0034] Both the inner rotor permanent magnet 2 and the outer rotor permanent magnet 4 are magnetized by radial magnetization.

[0035] An inner air gap 6 is provided between the inner rotor permanent magnet 2 and the salient pole adjusting ring 3, an intermediate air gap 7 is provided between the salient pole adjusting ring 3 and the outer rotor permanent magnet 4, and an outer intermediate air gap 8 is provided between the outer rotor permanent magnet 4 and the auxiliary adjusting ring 5.

[0036] The inner rotor consists of an inner rotor yoke 1 and inner rotor permanent magnets 2. In this embodiment, the inner rotor consists of one inner rotor yoke 1 and 12 inner rotor permanent magnets 2. Please refer to the following for details. 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, with one being magnetized in the positive radial direction and the other in the reverse radial direction.

[0037] The inner rotor permanent magnet 2 adopts a spoke structure and is embedded in the inner rotor yoke 1. The angle of the inner rotor permanent magnet 2 is 10° and the axial length is 50mm.

[0038] 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.

[0039] The outer rotor consists of 38 outer rotor permanent magnets 4. Please refer to the following for details. Figure 8 , Figure 8 The middle arrow indicates the magnetization direction. The magnetization directions of any two adjacent outer rotor permanent magnets 4 are opposite, with one being magnetized radially and the other radially. The angle of the outer rotor permanent magnets 4 is 9.47°, and the axial length is 50 mm for each.

[0040] 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.

[0041] In this embodiment, the number of pole pairs of the inner rotor permanent magnet 2 Number of pole pairs of the external rotor permanent magnet 4 The number of salient pole adjusting magnet cores on salient pole adjusting magnet ring 3 The number of convex adjustment magnet cores on auxiliary adjustment ring 5 It satisfies the following condition:

[0042] ;

[0043] .

[0044] Satisfying the condition: This results in the inner rotor permanent magnet 2, the outer rotor permanent magnet 4, and the salient pole adjusting ring 3 forming a radial and modulated coaxial magnetic gear structure.

[0045] Satisfying the condition: This results in the inner rotor permanent magnet 2, the outer rotor permanent magnet 4, and the auxiliary adjusting ring 5 forming a coaxial magnetic gear structure with radial differential modulation.

[0046] In this embodiment, the magnetic gear satisfies the following condition:

[0047]

[0048] in, The transmission ratio of the magnetic gear is given. The internal rotor speed, This represents the rotational speed of the external rotor.

[0049] The above formula for the transmission ratio shows that the rotational speed of the magnetic gear is equal to the ratio of the number of permanent magnet pole pairs on the rotor.

[0050] The outer and inner circumferential surfaces of the salient pole adjusting magnetic ring 3 are each provided with 25 salient pole adjusting magnetic cores 9, the cross-section of which is rectangular or trapezoidal. In this embodiment, the cross-section of the salient pole adjusting magnetic core 9 is rectangular. The salient pole adjusting magnetic cores 9 are formed by a magnetic material lamination process, with a spacing of 7.2° between two adjacent salient pole adjusting magnetic cores 9. The axial length of the salient pole adjusting magnetic ring 3 is 50mm, and the salient pole adjusting magnetic ring 3 has radial modulation performance, which can modulate the radial permanent magnet magnetic field.

[0051] The salient pole adjusting magnetic ring 3 is made of a soft magnetic material with high magnetic permeability, such as silicon steel sheet or soft magnetic composite material.

[0052] The inner circumferential surface of the auxiliary magnetic 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.

[0053] The auxiliary magnetic ring 5 is made of a soft magnetic material with high magnetic permeability, such as silicon steel sheet or soft magnetic composite material.

[0054] 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 gear, and the results are as follows: Figure 10 As shown, from Figure 10 It can be seen that, compared with the traditional radial field modulated 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 beneficial to improving the output torque density of the magnetic gear.

[0055] An embodiment of the present invention also provides a hub motor for a new energy vehicle, which includes the aforementioned magnetic gear.

[0056] In summary, the dual-modulation magnetic ring dual-rotor magnetic gear and new energy vehicle hub motor provided by the present invention have the following beneficial effects:

[0057] (1) This invention significantly enhances the magnetic field modulation effect through the synergistic effect of sum modulation and differential modulation. The inner rotor permanent magnet and the outer rotor permanent magnet are simultaneously coupled with the salient pole tuning ring (sum modulation) and the auxiliary tuning ring (differential modulation) to form a dual magnetic field modulation mechanism. Compared with the traditional single tuning ring or simple double tuning ring structure, this invention can more efficiently control the magnetic field distribution between the inner and outer rotors, enhance the effective harmonic components, and suppress ineffective harmonic interference, thereby greatly improving the electromechanical energy conversion efficiency.

[0058] (2) The permanent magnet of the inner rotor adopts a spoke-type embedded structure and is combined with a salient pole adjusting magnetic ring design, which effectively reduces the leakage of permanent magnets, increases torque density, and 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), thus improving the reliability of rotor operation. In addition, the utilization rate of permanent magnets with spoke-type structure is significantly improved, and the magnetic field energy is more concentrated in the air gap area, providing a foundation for high torque output.

[0059] (3) The composite magnetic adjustment design of the salient pole adjusting ring and the auxiliary adjusting 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 problem of magnetic field saturation in the local area. Under rated load, the output fluctuation of the outer rotor is reduced compared with the traditional magnetic gear, thus ensuring the stability of torque output under high speed conditions and solving the problem of large torque fluctuation under high load in the existing technology.

[0060] (4) The transmission structure with fixed dual-adjusting magnetic rings (salient pole adjusting magnetic ring and auxiliary adjusting magnetic ring) and inner rotor as input simplifies the overall layout of magnetic gears, reduces the number of moving parts, and lowers 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 hub motor.

[0061] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate 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 invention. In this specification, the illustrative expressions 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 one or more embodiments or examples.

[0062] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A dual-modulation magnetic ring dual-rotor magnetic gear, characterized in that, It includes an inner rotor, an outer rotor, a salient pole adjusting ring, and an auxiliary adjusting ring. The inner rotor consists of an inner rotor yoke and an inner rotor permanent magnet, while the outer rotor consists of an outer rotor permanent magnet. The inner rotor yoke, salient pole adjusting ring, outer rotor permanent magnet, and auxiliary adjusting ring are coaxially nested from the inside to the outside. The permanent magnet of the inner rotor adopts a spoke structure and is embedded in the iron yoke of the inner rotor; The inner rotor permanent magnet, the outer rotor permanent magnet, and the salient pole adjusting ring constitute and modulate the differential modulation; the inner rotor permanent magnet, the outer rotor permanent magnet, and the auxiliary adjusting ring constitute differential modulation. Both the inner rotor permanent magnet and the outer rotor permanent magnet are magnetized using radial magnetization. An inner air gap is provided between the inner rotor permanent magnet and the salient pole adjusting ring, an intermediate air gap is provided between the salient pole adjusting ring and the outer rotor permanent magnet, and an outer intermediate air gap is provided between the outer rotor permanent magnet and the auxiliary adjusting ring. Among them, the salient pole adjusting magnetic ring and the auxiliary adjusting magnetic ring are fixed, and the inner rotor is used as the input rotor. Through the magnetic field coupling effect, the outer rotor is driven to rotate. Number of pole pairs of the inner rotor permanent magnet Number of pole pairs of the external rotor permanent magnet The number of salient pole adjusting magnet cores on the salient pole adjusting magnet ring The number of convex poles on the auxiliary adjusting magnetic ring adjusts the magnetic core. It satisfies the following condition: ； ； The magnetic gear satisfies the following condition: in, The transmission ratio of the magnetic gear is given. The internal rotor speed, This represents the rotational speed of the external rotor.

2. The dual-modulation magnetic ring dual-rotor magnetic gear according to claim 1, characterized in that, The inner rotor consists of an inner rotor yoke and multiple inner rotor permanent magnets. The magnetization directions of any two adjacent inner rotor permanent magnets are opposite, with one magnetized in the positive radial direction and the other in the reverse radial direction.

3. The dual-modulation magnetic ring dual-rotor magnetic gear according to claim 1, characterized in that, The outer and inner circumferential surfaces of the salient pole adjusting magnetic ring are respectively provided with multiple salient pole adjusting magnetic cores, and the cross-section of the salient pole adjusting magnetic core is rectangular or trapezoidal.

4. The dual-modulation magnetic ring dual-rotor magnetic gear according to claim 1, characterized in that, The outer rotor is composed of multiple outer rotor permanent magnets. Any two adjacent outer rotor permanent magnets are magnetized in opposite directions, one of which is magnetized in the positive radial direction and the other in the reverse radial direction.

5. The dual-modulation magnetic ring dual-rotor magnetic gear according to claim 1, characterized in that, The inner circumferential surface of the auxiliary magnetic ring is provided with multiple salient poles, and the cross-section of the salient poles is rectangular or trapezoidal.

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

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

8. A hub motor for a new energy vehicle, characterized in that, Includes the dual-modulation magnetic ring dual-rotor magnetic gear as described in any one of claims 1 to 7.

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