Monotonic magnetic ring dual-mode modulated two-rotor axial magnetic gear and automobile wheel hub motor

Abstract

This invention provides a dual-mode magnetic gear with a single-tone magnetic ring and a dual-mode modulation dual-rotor axial magnetic gear and an automotive hub motor. The magnetic gear includes a high-speed rotor, a dual-mode magnetic ring, and a low-speed rotor arranged coaxially. The dual-mode magnetic ring is nested between the high-speed and low-speed rotors. The high-speed rotor consists of a first set of permanent magnets, a second set of permanent magnets, and a connecting bridge. The first and second sets of permanent magnets are connected by the connecting bridge and rotate together. The low-speed rotor consists of a first set of permanent magnets, a second set of permanent magnets, and a connecting bridge. The first and second sets of permanent magnets are connected by the connecting bridge and rotate together. This invention can improve the torque transmission capability of the magnetic gear, suppress magnetic saturation, enhance the magnetic field modulation effect, and increase the torque density of the magnetic gear.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, and in particular to a monotonic magnetic ring dual-synthetic modulation dual-rotor axial magnetic gear and an automobile wheel hub motor. Background Technology

[0002] New energy vehicles have garnered widespread attention from researchers due to their zero emissions and high energy efficiency. Among them, new energy vehicles with distributed drive systems represent a development trend due to their advantages such as simple transmission structure, high transmission efficiency, and flexible vehicle control. Direct-drive in-wheel motors, as the core power component of distributed drive systems, are typically directly connected to the wheels. They not only face the performance requirements of the vehicle's power system for output torque under acceleration, deceleration, and hill climbing conditions, but also need to meet the drive requirements for stable operation under complex road conditions such as rugged mountain roads and muddy roads. Therefore, how to obtain excellent low-speed, high-torque capability is a key focus in the field of in-wheel motor research. Simultaneously, the limited internal space of the vehicle wheel hub makes achieving higher torque density a challenging problem that urgently needs to be solved in the design of in-wheel motors.

[0003] Under the influence of a modulating magnetic core, magnetic gears can achieve bidirectional modulation of low-speed and high-speed magnetic fields, thereby realizing electromechanical energy conversion through harmonic magnetic field coupling. Because the inner and outer rotors transmit power through modulated magnetic field coupling, and the inner and outer rotors do not contact each other during transmission, magnetic gears have advantages over mechanical gears, such as frictionless vibration, no lubrication or maintenance required, no noise, and compact structure. They have broad application prospects in the field of modulated hub motors for new energy vehicles.

[0004] However, how to improve the torque transmission capability of magnetic gears, suppress magnetic saturation, enhance the magnetic field modulation effect, and increase the torque density of magnetic gears are technical problems that need to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a monotonic magnetic ring dual-modulation two-rotor axial magnetic gear and an automobile wheel hub motor, so as to improve the torque transmission capability of the magnetic gear, suppress magnetic saturation, enhance the magnetic field modulation effect, and increase the torque density of the magnetic gear.

[0006] One aspect of the present invention provides a monotonic magnetic ring dual-modulation two-rotor axial magnetic gear, comprising a high-speed rotor, a dual-modulation magnetic ring, and a low-speed rotor arranged coaxially; the dual-modulation magnetic ring is nested between the high-speed rotor and the low-speed rotor;

[0007] The high-speed rotor consists of a first set of permanent magnets, a second set of permanent magnets, and a connecting bridge. The first and second sets of permanent magnets are connected by the connecting bridge and rotate together. The low-speed rotor consists of a first set of permanent magnets, a second set of permanent magnets, and a connecting bridge. The first and second sets of permanent magnets are connected by the connecting bridge and rotate together.

[0008] The permanent magnets on the first group of permanent magnets of the high-speed rotor, the second group of permanent magnets of the high-speed rotor, the first group of permanent magnets of the low-speed rotor, and the second group of permanent magnets of the low-speed rotor are all tangentially magnetized. Furthermore, the magnetization directions of two adjacent permanent magnets in the high-speed rotor are opposite, and the magnetization directions of two adjacent permanent magnets in the low-speed rotor are opposite.

[0009] There is one axial magnetic path and two transverse magnetic paths between the first group of permanent magnets and the double-modulated magnetic ring of the high-speed rotor and the first group of permanent magnets of the low-speed rotor; there is one axial magnetic path and two transverse magnetic paths between the second group of permanent magnets and the double-modulated magnetic ring of the high-speed rotor and the second group of permanent magnets of the low-speed rotor.

[0010] The magnetic field modulation method between the first group of permanent magnets of the high-speed rotor and the first group of permanent magnets of the low-speed rotor adopts the same modulation method. The magnetic field modulation method between the second group of permanent magnets of the high-speed rotor and the second group of permanent magnets of the low-speed rotor also adopts the same modulation method. Both modulation methods share a single dual-modulation tuning ring to achieve the dual-modulation effect of the single-modulation ring. When the magnetic gear is working, the dual-modulation tuning ring is fixed. The external power is input by the high-speed rotor. The magnetic field generated by the magnetic poles of the first and second groups of permanent magnets of the high-speed rotor is modulated by the dual-modulation tuning ring. The resulting effective harmonics in the air gap are coupled with the magnetic fields generated by the magnetic poles of the first and second groups of permanent magnets of the low-speed rotor, respectively, so as to realize the power transmission from the high-speed rotor to the low-speed rotor.

[0011] Another aspect of the present invention provides an automotive wheel hub motor, which includes the aforementioned magnetic gear.

[0012] The monotonic magnetic ring dual-suppression modulated dual-rotor axial magnetic gear and automobile hub motor provided by the present invention have the following beneficial effects:

[0013] (1) The magnetic field modulation method between the first group of permanent magnets of the high-speed rotor and the first group of permanent magnets of the low-speed rotor adopts the same modulation method. The magnetic field modulation method between the second group of permanent magnets of the high-speed rotor and the second group of permanent magnets of the low-speed rotor adopts the same modulation method. The two modulation methods share a single dual-modulation magnetic ring to achieve the single-modulation magnetic ring dual-modulation effect. Compared with the traditional dual-modulation magnetic gear topology, the magnetic gear magnetic core provided by this invention has a smaller amount of magnetic core, a more compact structure, and a smaller volume, which is more advantageous in application scenarios with relatively small space, such as automobile wheel hub motors.

[0014] (2) The magnetic gear provided by the present invention has a stronger field modulation effect and a higher torque transmission capability compared with the traditional topology structure of the same size because the first group of permanent magnets of the high speed rotor and the first group of permanent magnets of the low speed rotor, and the second group of permanent magnets of the high speed rotor and the second group of permanent magnets of the low speed rotor are simultaneously modulated.

[0015] (3) The magnetic gear provided by the present invention uses tangential magnetization on the permanent magnets on the high-speed rotor and the low-speed rotor, and has pole shoes embedded in the two adjacent permanent magnets for auxiliary modulation, which makes the air gap magnetic flux density greater, the waveform is close to a sine waveform, the torque transmission capability is improved, and the transmission is more stable.

[0016] (4) There is an axial magnetic path and two transverse magnetic paths between the first group of permanent magnets of the high-speed rotor, the double modulation magnetic ring and the first group of permanent magnets of the low-speed rotor; there is an axial magnetic path and two transverse magnetic paths between the second group of permanent magnets of the high-speed rotor, the double modulation magnetic ring and the second group of permanent magnets of the low-speed rotor, forming a hybrid multi-magnetic path. Compared with the traditional topology, the magnetic gear provided by the present invention is less prone to magnetic leakage and has a higher utilization efficiency of the magnetic field generated by the permanent magnet.

[0017] (5) The magnetic gear provided by the present invention has a hybrid multi-magnetic circuit, which simultaneously has two magnetic flux paths, axial and transverse. It can reduce the influence of magnetic saturation effect without reducing the total flux generated by the permanent magnet, thus achieving the effect of resisting magnetic saturation effect. It also enhances the magnetic field modulation effect and improves the torque density of the magnetic gear. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the monotonic magnetic ring double-modulated dual-rotor axial magnetic gear in an embodiment of the present invention from a first perspective.

[0019] Figure 2 This is a schematic diagram of the monotonic magnetic ring double-modulated dual-rotor axial magnetic gear in an embodiment of the present invention from a second perspective.

[0020] Figure 3 This is an exploded structural diagram of the monotonic magnetic ring double-modulated dual-rotor axial magnetic gear in an embodiment of the present invention;

[0021] Figure 4 This is a cross-sectional view of the monotonic magnetic ring double-modulated dual-rotor axial magnetic gear in an embodiment of the present invention.

[0022] Figure 5 This is a schematic diagram of the high-speed rotor.

[0023] Figure 6 This is a schematic diagram of the low-speed rotor.

[0024] Figure 7 This is a schematic diagram of the structure of the dual-modulation tuning ring;

[0025] Figure 8 A schematic diagram of the structure of the dual-modulation tuning ring and epoxy resin jacket;

[0026] Figure 9 This is a schematic diagram of the magnetic circuit structure;

[0027] Figure 10 This is a schematic diagram of the field modulation principle;

[0028] Figure 11 This is a comparison diagram of the magnetic field strength in the air gap between the magnetic gear of the present invention and the conventional magnetic gear with a magnetic field of concentrated magnetization.

[0029] Figure 12 This is a comparison diagram of the spatial harmonic spectrum of magnetic induction intensity in the air gap of the magnetic gear of the present invention and that of the conventional magnetic gear with a magnetically concentrated magnet.

[0030] Figure 13 This is a comparison diagram of the steady-state torque output characteristics of the magnetic gear of the present invention and the traditional magnetic gear with a magnetic field. Detailed Implementation

[0031] 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.

[0032] Please see Figures 1 to 10 The axial magnetic gear with a single-modulation magnetic ring and dual modulation two-rotor configuration provided in this embodiment of the invention includes a high-speed rotor 1, a dual-modulation magnetic ring 2, and a low-speed rotor 3 arranged coaxially. The dual-modulation magnetic ring 2 is nested between the high-speed rotor 1 and the low-speed rotor 3.

[0033] The dual-modulation tuning ring 2 includes multiple tuning cores 4, each of which is made of multiple silicon steel sheets stacked together to reduce eddy current losses, and adjacent tuning cores 4 are separated by epoxy resin jackets 5.

[0034] The high-speed rotor 1 consists of a first set of permanent magnets 6, a second set of permanent magnets 7, and a connecting bridge 8. The first set of permanent magnets 6 and the second set of permanent magnets 7 are connected by the connecting bridge 8 and rotate together.

[0035] The low-speed rotor 3 consists of a first set of permanent magnets 9, a second set of permanent magnets 10, and a connecting bridge 11. The first set of permanent magnets 9 and the second set of permanent magnets 10 are connected by the connecting bridge 11 and rotate together.

[0036] Specifically, the left end face of the dual-modulation magnetic ring 2 is flush with the first group of permanent magnets 6 and the second group of permanent magnets 7 of the high-speed rotor; the right end face of the dual-modulation magnetic ring 2 is flush with the first group of permanent magnets 9 and the second group of permanent magnets 10 of the low-speed rotor.

[0037] A first axial air gap 12 is provided between the outer axial side of the first group of permanent magnets 6 of the high-speed rotor and the double modulation magnetic ring 2. A first radial air gap 13 is provided between the inner radial side of the first group of permanent magnets 6 of the high-speed rotor and the double modulation magnetic ring 2. A second radial air gap 14 is provided between the outer radial side of the first group of permanent magnets 6 of the high-speed rotor and the double modulation magnetic ring 2. A second axial air gap 15 is provided between the outer axial side of the second group of permanent magnets 7 of the high-speed rotor and the double modulation magnetic ring 2. A third radial air gap 16 is provided between the inner radial side of the second group of permanent magnets 7 of the high-speed rotor and the double modulation magnetic ring 2. A fourth radial air gap 17 is provided between the outer radial side of the second group of permanent magnets 7 of the high-speed rotor and the double modulation magnetic ring 2.

[0038] A first axial air gap 18 is provided between the inner side of the first group of permanent magnets 9 of the low-speed rotor and the double modulation magnetic ring 2. A first radial air gap 19 is provided between the inner side of the first group of permanent magnets 9 of the low-speed rotor and the double modulation magnetic ring 2. A second radial air gap 20 is provided between the outer side of the first group of permanent magnets 9 of the low-speed rotor and the double modulation magnetic ring 2. A second axial air gap 21 is provided between the inner side of the second group of permanent magnets 10 of the low-speed rotor and the double modulation magnetic ring 2. A third radial air gap 22 is provided between the inner side of the second group of permanent magnets 10 of the low-speed rotor and the double modulation magnetic ring 2. A fourth radial air gap 23 is provided between the outer side of the second group of permanent magnets 10 of the low-speed rotor and the double modulation magnetic ring 2.

[0039] The first group of permanent magnets 6 of the high-speed rotor, the second group of permanent magnets 7 of the high-speed rotor, the first group of permanent magnets 9 of the low-speed rotor, and the second group of permanent magnets 10 of the low-speed rotor all adopt a spoke structure.

[0040] The first set of permanent magnets 6 of the high-speed rotor includes a first permanent magnet 24 of the high-speed rotor and a pole piece 25 of the first permanent magnet of the high-speed rotor. The pole piece 25 of the first permanent magnet of the high-speed rotor is embedded between two adjacent first permanent magnets 24 of the high-speed rotor. The first permanent magnets 24 of the high-speed rotor and the pole piece 25 of the high-speed rotor support each other and work together with the dual modulation tuning ring 2 to modulate the magnetic field.

[0041] The second set of permanent magnets 7 of the high-speed rotor includes a second permanent magnet 26 of the high-speed rotor and a pole piece 27 of the second permanent magnet of the high-speed rotor. The pole piece 27 of the high-speed rotor is embedded between two adjacent second permanent magnets 26 of the high-speed rotor. The second permanent magnets 26 and the pole piece 27 of the high-speed rotor support each other and work together with the double modulation tuning ring 2 to modulate the magnetic field.

[0042] The first set of permanent magnets 9 of the low-speed rotor includes a first permanent magnet 28 of the low-speed rotor and a pole piece 29 of the first permanent magnet of the high-speed rotor. The pole piece 29 of the first permanent magnet of the low-speed rotor is embedded between two adjacent first permanent magnets 28 of the low-speed rotor. The first permanent magnets 28 and the pole piece 29 of the low-speed rotor support each other and are modulated together with the double modulation tuning ring 2 to perform magnetic field modulation.

[0043] The second set of permanent magnets 10 for the low-speed rotor includes a second permanent magnet 30 for the low-speed rotor and a pole piece 31 for the second permanent magnet of the high-speed rotor. The pole piece 31 for the low-speed rotor is embedded between two adjacent second permanent magnets 30 for the low-speed rotor. The second permanent magnets 30 for the low-speed rotor and the pole piece 31 for the low-speed rotor support each other and work together with the double modulation tuning ring 2 to modulate the magnetic field.

[0044] The permanent magnets on the first group of permanent magnets 6 and the second group of permanent magnets 7 of the high-speed rotor, the first group of permanent magnets 9 and the second group of permanent magnets 10 of the low-speed rotor are all tangentially magnetized. Furthermore, the magnetization directions of two adjacent permanent magnets in the high-speed rotor 1 are opposite, and the magnetization directions of two adjacent permanent magnets in the low-speed rotor 3 are also opposite. Figure 5 The arrows in the diagram indicate the magnetization direction of the permanent magnets on the high-speed rotor 1. Figure 6 The arrow in the figure indicates the magnetization direction of the permanent magnet on the low-speed rotor 3.

[0045] The magnetic field modulation method between the first group of permanent magnets 6 of the high-speed rotor and the first group of permanent magnets 9 of the low-speed rotor adopts a combined modulation method, forming axial combined modulation one. The magnetic field modulation method between the second group of permanent magnets 7 of the high-speed rotor and the second group of permanent magnets 10 of the low-speed rotor adopts a combined modulation method, forming axial combined modulation two. Both combined modulations share a single dual-modulation tuning ring, realizing the dual-modulation effect of the monotonic tuning ring. The field modulation principle is as follows: Figure 10 As shown.

[0046] There is one axial magnetic path and two transverse magnetic paths between the first group of permanent magnets 6 and the dual-modulation tuning ring 2 of the high-speed rotor and the first group of permanent magnets 9 of the low-speed rotor; there is one axial magnetic path and two transverse magnetic paths between the second group of permanent magnets 7 and the dual-modulation tuning ring 2 of the high-speed rotor and the second group of permanent magnets 10 of the low-speed rotor. These magnetic paths together constitute a hybrid multi-magnetic path, the structure of which is as follows: Figure 9 As shown.

[0047] Specifically, the number of pole pairs of the permanent magnets on the first group of permanent magnets 6 of the high-speed rotor is equal to the number of pole pairs of the permanent magnets on the second group of permanent magnets 7 of the high-speed rotor; the number of pole pairs of the permanent magnets on the first group of permanent magnets 9 of the low-speed rotor is equal to the number of pole pairs of the permanent magnets on the second group of permanent magnets 10 of the low-speed rotor.

[0048] The axial length of the first group of permanent magnets 6 of the high-speed rotor is equal to the axial length of the second group of permanent magnets 7 of the high-speed rotor; the axial length of the permanent magnets on the first group of permanent magnets 9 of the low-speed rotor is equal to the axial length of the second group of permanent magnets 10 of the low-speed rotor.

[0049] The radial length of the first group of permanent magnets 6 of the high-speed rotor is equal to the radial length of the first group of permanent magnets 9 of the low-speed rotor; the radial length of the second group of permanent magnets 7 of the high-speed rotor is equal to the radial length of the second group of permanent magnets 10 of the low-speed rotor.

[0050] The thickness of the first axial air gap 12 on the high-speed rotor side is equal to the thickness of the second axial air gap 15 on the high-speed rotor side; the thickness of the first axial air gap 18 on the low-speed rotor side is equal to the thickness of the second axial air gap 21 on the low-speed rotor side; the thickness of the first radial air gap 13 on the high-speed rotor side is equal to the thickness of the first radial air gap 19 on the low-speed rotor side; the thickness of the second radial air gap 14 on the high-speed rotor side is equal to the thickness of the second radial air gap 20 on the low-speed rotor side; the thickness of the third radial air gap 16 on the high-speed rotor side is equal to the thickness of the third radial air gap 22 on the low-speed rotor side; and the thickness of the fourth radial air gap 17 on the high-speed rotor side is equal to the thickness of the fourth radial air gap 23 on the low-speed rotor side.

[0051] In this embodiment, the magnetic gear satisfies the following formula:

[0052] ;

[0053]

[0054] in, This refers to the number of pole pairs of the permanent magnets on the first group of permanent magnets 6 of the high-speed rotor. This refers to the number of tuning magnet cores in the dual-modulation tuning ring 2. This refers to the number of magnetic pole pairs of the permanent magnets on the first group of permanent magnets 9 of the low-speed rotor. This is the transmission ratio between high-speed rotor 1 and low-speed rotor 3. This refers to the high-speed rotor speed. This refers to the low-speed rotor speed.

[0055] In this embodiment, the magnetic gear also satisfies the following formula:

[0056] ;

[0057] in, The axial length of the dual-modulation tuning ring 2 is given. This represents the axial thickness of the first set of permanent magnets in the high-speed rotor. The thickness of the first axial air gap 12 on the high-speed rotor side. The axial thickness of the dual-modulation tuning ring 2 is [missing information]. The thickness of the first axial air gap 18 on the low-speed rotor side. The axial thickness of the first set of permanent magnets 9 of the low-speed rotor.

[0058] The magnetic gear also satisfies the following formula:

[0059] ;

[0060] in, The radial length of the dual-modulation tuning ring 2 is... The radial thickness of the dual-modulation tuning ring 2 is... The radial length of the first set of permanent magnets 6 of the high-speed rotor. This is the radial length of the second set of permanent magnets 7 of the high-speed rotor. The thickness of the first radial air gap 13 on the high-speed rotor side. The thickness of the second radial air gap 14 on the high-speed rotor side. The thickness of the third radial air gap 16 on the high-speed rotor side. The thickness of the fourth radial air gap 17 on the high-speed rotor side.

[0061] In this embodiment, the permanent magnets of the first group 6 and the second group 7 of the high-speed rotor have 6 pole pairs, and the distance between adjacent permanent magnets is 15°. The permanent magnets of the first group 9 and the second group 10 of the low-speed rotor have 19 pole pairs, and the distance between adjacent permanent magnets is 4.74°.

[0062] When the magnetic gear is working, the double-modulation adjustment ring 2 is fixed, and the external power is input by the high-speed rotor 1. The magnetic field generated by the magnetic poles of the first group of permanent magnets 6 and the second group of permanent magnets 7 of the high-speed rotor is modulated by the double-modulation adjustment ring 2, and then generates effective harmonics in the air gap. These harmonics are coupled with the magnetic field generated by the magnetic poles of the first group of permanent magnets 9 and the magnetic field generated by the magnetic poles of the second group of permanent magnets 10 of the low-speed rotor, so that the power is transmitted from the high-speed rotor 1 to the low-speed rotor 3.

[0063] A comparative analysis of the magnetic gear of this invention with that of a traditional magnetic gear with concentrated magnets was conducted. Figure 11 It can be seen that the magnetic field strength in the air gap of the magnetic gear of the present invention is significantly higher than that of a conventional magnetic gear of the same size, and the magnetic field modulation effect of the magnetic gear of the present invention is significantly enhanced. Figure 12It can be seen that, compared with traditional magnetic gears of the same size, the peak value of the effective harmonic components in the air gap of the magnetic gear of this invention is significantly improved, which is beneficial to improving the torque density of the magnetic gear. From Figure 13 It can be seen that the output torque of the magnetic gear provided by this invention is significantly greater than that of the conventional magnetic gear of the same size.

[0064] An embodiment of the present invention also provides an automotive hub motor, which includes the aforementioned magnetic gear.

[0065] In summary, the monotonic magnetic ring dual-synthetic modulation dual-rotor axial magnetic gear and automobile wheel hub motor provided by the present invention have the following beneficial effects:

[0066] (1) The magnetic field modulation method between the first group of permanent magnets of the high-speed rotor and the first group of permanent magnets of the low-speed rotor adopts the same modulation method. The magnetic field modulation method between the second group of permanent magnets of the high-speed rotor and the second group of permanent magnets of the low-speed rotor adopts the same modulation method. The two modulation methods share a single dual-modulation magnetic ring to achieve the single-modulation magnetic ring dual-modulation effect. Compared with the traditional dual-modulation magnetic gear topology, the magnetic gear magnetic core provided by this invention has a smaller amount of magnetic core, a more compact structure, and a smaller volume, which is more advantageous in application scenarios with relatively small space, such as automobile wheel hub motors.

[0067] (2) The magnetic gear provided by the present invention has a stronger field modulation effect and a higher torque transmission capability compared with the traditional topology structure of the same size because the first group of permanent magnets of the high speed rotor and the first group of permanent magnets of the low speed rotor, and the second group of permanent magnets of the high speed rotor and the second group of permanent magnets of the low speed rotor are simultaneously modulated.

[0068] (3) The magnetic gear provided by the present invention uses tangential magnetization on the permanent magnets on the high-speed rotor and the low-speed rotor, and has pole shoes embedded in the two adjacent permanent magnets for auxiliary modulation, which makes the air gap magnetic flux density greater, the waveform is close to a sine waveform, the torque transmission capability is improved, and the transmission is more stable.

[0069] (4) There is an axial magnetic path and two transverse magnetic paths between the first group of permanent magnets of the high-speed rotor, the double modulation magnetic ring and the first group of permanent magnets of the low-speed rotor; there is an axial magnetic path and two transverse magnetic paths between the second group of permanent magnets of the high-speed rotor, the double modulation magnetic ring and the second group of permanent magnets of the low-speed rotor, forming a hybrid multi-magnetic path. Compared with the traditional topology, the magnetic gear provided by the present invention is less prone to magnetic leakage and has a higher utilization efficiency of the magnetic field generated by the permanent magnet.

[0070] (5) The magnetic gear provided by the present invention has a hybrid multi-magnetic circuit, which simultaneously has two magnetic flux paths, axial and transverse. It can reduce the influence of magnetic saturation effect without reducing the total flux generated by the permanent magnet, thus achieving the effect of resisting magnetic saturation effect. It also enhances the magnetic field modulation effect and improves the torque density of the magnetic gear.

[0071] 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.

[0072] 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 monotonic magnetic ring double-modulated dual-rotor axial magnetic gear, characterized in that, It includes a high-speed rotor, a dual-modulation magnetic ring, and a low-speed rotor arranged coaxially; the dual-modulation magnetic ring is nested between the high-speed rotor and the low-speed rotor. The high-speed rotor consists of a first set of permanent magnets, a second set of permanent magnets, and a connecting bridge. The first and second sets of permanent magnets are connected by the connecting bridge and rotate together. The low-speed rotor consists of a first set of permanent magnets, a second set of permanent magnets, and a connecting bridge. The first and second sets of permanent magnets are connected by the connecting bridge and rotate together. The permanent magnets on the first group of permanent magnets of the high-speed rotor, the second group of permanent magnets of the high-speed rotor, the first group of permanent magnets of the low-speed rotor, and the second group of permanent magnets of the low-speed rotor are all tangentially magnetized. Furthermore, the magnetization directions of two adjacent permanent magnets in the high-speed rotor are opposite, and the magnetization directions of two adjacent permanent magnets in the low-speed rotor are opposite. There is one axial magnetic path and two transverse magnetic paths between the first group of permanent magnets and the double-modulated magnetic ring of the high-speed rotor and the first group of permanent magnets of the low-speed rotor; there is one axial magnetic path and two transverse magnetic paths between the second group of permanent magnets and the double-modulated magnetic ring of the high-speed rotor and the second group of permanent magnets of the low-speed rotor. The magnetic field modulation method between the first group of permanent magnets of the high-speed rotor and the first group of permanent magnets of the low-speed rotor adopts the same modulation method. The magnetic field modulation method between the second group of permanent magnets of the high-speed rotor and the second group of permanent magnets of the low-speed rotor also adopts the same modulation method. The two modulation methods share a single dual-modulation magnetic ring to achieve the dual modulation effect of the single-modulation magnetic ring. When the magnetic gear is working, the double-modulation adjustment ring is fixed and the external power is input by the high-speed rotor. The magnetic fields generated by the magnetic poles of the first and second sets of permanent magnets of the high-speed rotor are modulated by the double-modulation adjustment ring, and then generate effective harmonics in the air gap. These harmonics are coupled with the magnetic fields generated by the magnetic poles of the first and second sets of permanent magnets of the low-speed rotor, respectively, so that the power is transmitted from the high-speed rotor to the low-speed rotor.

2. The monotonic magnetic ring double-modulated dual-rotor axial magnetic gear according to claim 1, characterized in that, A first axial air gap on the high-speed rotor side is provided between the outer axial side of the first group of permanent magnets of the high-speed rotor and the double modulation magnetic ring; a first radial air gap on the high-speed rotor side is provided between the inner radial side of the first group of permanent magnets of the high-speed rotor and the double modulation magnetic ring; a second radial air gap on the high-speed rotor side is provided between the outer radial side of the first group of permanent magnets of the high-speed rotor and the double modulation magnetic ring; a second axial air gap on the high-speed rotor side is provided between the outer axial side of the second group of permanent magnets of the high-speed rotor and the double modulation magnetic ring; a third radial air gap on the high-speed rotor side is provided between the inner radial side of the second group of permanent magnets of the high-speed rotor and the double modulation magnetic ring; and a fourth radial air gap on the high-speed rotor side is provided between the outer radial side of the second group of permanent magnets of the high-speed rotor and the double modulation magnetic ring. A first axial air gap is provided between the inner axial side of the first group of permanent magnets of the low-speed rotor and the double modulation adjustment ring. A first radial air gap is provided between the inner radial side of the first group of permanent magnets of the low-speed rotor and the double modulation adjustment ring. A second radial air gap is provided between the outer radial side of the first group of permanent magnets of the low-speed rotor and the double modulation adjustment ring. A second axial air gap is provided between the inner axial side of the second group of permanent magnets of the low-speed rotor and the double modulation adjustment ring. A third radial air gap is provided between the inner radial side of the second group of permanent magnets of the low-speed rotor and the double modulation adjustment ring. A fourth radial air gap is provided between the outer radial side of the second group of permanent magnets of the low-speed rotor and the double modulation adjustment ring.

3. The monotonic magnetic ring double-modulated dual-rotor axial magnetic gear according to claim 2, characterized in that, The first group of permanent magnets of the high-speed rotor, the second group of permanent magnets of the high-speed rotor, the first group of permanent magnets of the low-speed rotor, and the second group of permanent magnets of the low-speed rotor all adopt a spoke structure; The first set of permanent magnets of the high-speed rotor includes a first permanent magnet of the high-speed rotor and a pole piece of the first permanent magnet of the high-speed rotor. The pole piece of the first permanent magnet of the high-speed rotor is embedded between two adjacent first permanent magnets of the high-speed rotor. The first permanent magnet of the high-speed rotor and the pole piece of the first permanent magnet of the high-speed rotor support each other and work together with the dual modulation tuning ring to modulate the magnetic field. The second set of permanent magnets of the high-speed rotor includes a second permanent magnet of the high-speed rotor and a pole piece of the second permanent magnet of the high-speed rotor. The pole piece of the second permanent magnet of the high-speed rotor is embedded between two adjacent second permanent magnets of the high-speed rotor. The second permanent magnet of the high-speed rotor and the pole piece of the second permanent magnet of the high-speed rotor support each other and work together with the double modulation tuning ring to modulate the magnetic field. The first set of permanent magnets for the low-speed rotor includes a first permanent magnet for the low-speed rotor and a pole piece for the first permanent magnet for the high-speed rotor. The pole piece for the first permanent magnet for the low-speed rotor is embedded between two adjacent first permanent magnets for the low-speed rotor. The first permanent magnets for the low-speed rotor and the pole piece for the first permanent magnet for the low-speed rotor support each other and work together with the dual modulation tuning ring to modulate the magnetic field. The second set of permanent magnets for the low-speed rotor includes a second permanent magnet for the low-speed rotor and a pole shoe for the second permanent magnet for the high-speed rotor. The pole shoe for the second permanent magnet for the low-speed rotor is embedded between two adjacent second permanent magnets for the low-speed rotor. The second permanent magnets for the low-speed rotor and the pole shoe for the low-speed rotor support each other and work together with the dual modulation tuning ring to modulate the magnetic field.

4. The monotonic magnetic ring double-modulated dual-rotor axial magnetic gear according to claim 3, characterized in that, The number of pole pairs of the permanent magnets in the first group of permanent magnets of the high-speed rotor is equal to the number of pole pairs of the permanent magnets in the second group of permanent magnets of the high-speed rotor; The number of pole pairs of the permanent magnets in the first group of permanent magnets of the low-speed rotor is equal to the number of pole pairs of the permanent magnets in the second group of permanent magnets of the low-speed rotor; The axial length of the first set of permanent magnets of the high-speed rotor is equal to the axial length of the second set of permanent magnets of the high-speed rotor; The axial length of the permanent magnets in the first group of permanent magnets of the low-speed rotor is equal to the axial length of the permanent magnets in the second group of permanent magnets of the low-speed rotor; The radial length of the first group of permanent magnets in the high-speed rotor is equal to the radial length of the first group of permanent magnets in the low-speed rotor; the radial length of the second group of permanent magnets in the high-speed rotor is equal to the radial length of the second group of permanent magnets in the low-speed rotor. The thickness of the first axial air gap on the high-speed rotor side is equal to the thickness of the second axial air gap on the high-speed rotor side. The thickness of the first axial air gap on the low-speed rotor side is equal to the thickness of the second axial air gap on the low-speed rotor side; the thickness of the first radial air gap on the high-speed rotor side is equal to the thickness of the first radial air gap on the low-speed rotor side; the thickness of the second radial air gap on the high-speed rotor side is equal to the thickness of the second radial air gap on the low-speed rotor side; the thickness of the third radial air gap on the high-speed rotor side is equal to the thickness of the third radial air gap on the low-speed rotor side; and the thickness of the fourth radial air gap on the high-speed rotor side is equal to the thickness of the fourth radial air gap on the low-speed rotor side.

5. The monotonic magnetic ring double-modulated dual-rotor axial magnetic gear according to claim 4, characterized in that, The magnetic gear satisfies the following formula: ； in, This represents the number of pole pairs of the permanent magnets on the first group of permanent magnets of the high-speed rotor. The number of tuning magnet cores for the dual-modulation tuning ring. This represents the number of pole pairs of the permanent magnets on the first group of permanent magnets in the low-speed rotor. This is the transmission ratio between the high-speed rotor and the low-speed rotor. This is the high-speed rotor speed. This refers to the low-speed rotor speed.

6. The monotonic magnetic ring double-modulated dual-rotor axial magnetic gear according to claim 4, characterized in that, The magnetic gear satisfies the following formula: ； in, This is the axial length of the dual-modulation tuning ring. This represents the axial thickness of the first set of permanent magnets in the high-speed rotor. The thickness of the first axial air gap on the high-speed rotor side. The axial thickness is the value of the dual-modulation tuning ring. The thickness of the first axial air gap on the low-speed rotor side. The axial thickness of the first set of permanent magnets in the low-speed rotor.

7. The monotonic magnetic ring double-modulated dual-rotor axial magnetic gear according to claim 4, characterized in that, The magnetic gear satisfies the following formula: ； in, The radial length of the dual-modulation tuning ring. The radial thickness of the dual-modulation tuning ring. The radial length of the first set of permanent magnets in the high-speed rotor. This is the radial length of the second set of permanent magnets in the high-speed rotor. The thickness of the first radial air gap on the high-speed rotor side. The thickness of the second radial air gap on the high-speed rotor side. The thickness of the third radial air gap on the high-speed rotor side. The thickness of the fourth radial air gap on the high-speed rotor side.

8. The monotonic magnetic ring double-modulated dual-rotor axial magnetic gear according to claim 1, characterized in that, The dual-modulation tuning ring includes multiple tuning cores, each of which is made of multiple silicon steel sheets stacked together, and adjacent tuning cores are separated by epoxy resin jackets.

9. The monotonic magnetic ring double-modulated dual-rotor axial magnetic gear according to claim 1, characterized in that, The left end face of the dual-modulation magnetic ring is flush with the first group of permanent magnets and the second group of permanent magnets of the high-speed rotor; the right end face of the dual-modulation magnetic ring is flush with the first group of permanent magnets and the second group of permanent magnets of the low-speed rotor.

10. A hub motor for automobiles, characterized in that, Includes the monotonic magnetic ring double and modulated two-rotor axial magnetic gear as described in any one of claims 1 to 9.

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