Rotor assembly adopting Halbach array magnetic steel arrangement and outer rotor hub motor

Abstract

The utility model provides a rotor assembly adopting Halbach array magnetic steel arrangement and an outer rotor hub motor. The outer rotor hub motor comprises a rotor assembly, a stator assembly, a gear transmission assembly and a hub motor housing. The rotor assembly internally comprises a rotor support, first magnetic steel and second magnetic steel. The plurality of first magnetic steels and the plurality of second magnetic steels are arranged in the rotor bracket along the circumference, and the first magnetic steels and the second magnetic steels are arranged at intervals; the magnetic flux directions of the two ends of the first magnetic steel are transverse and opposite, the magnetic flux directions of the two ends of the second magnetic steel are transverse and opposite, and the magnetic flux directions of the middle parts of the first magnetic steel and the second magnetic steel are longitudinal and opposite. According to the invention, the Halbach array arrangement magnetic steel is used, so that the magnetic field can be more concentrated on the working area side under the condition of the same material consumption, the utilization rate of the space is not increased, and the magnetic field intensity is also increased.

Description

Technical Field

[0001] The utility model relates to the field of outer-rotor hub motors, and particularly to a rotor assembly and an outer-rotor hub motor adopting Halbach array magnet arrangement. Background Art

[0002] Currently, the hub motors applied to power-assisted vehicles often pursue miniaturization and light weight. However, during cycling, in special situations such as on mountains, in forests, or when climbing slopes, stronger power is also desired, that is, to increase the output torque of the hub motor. On the one hand, a gear transmission component can be added to increase the reduction ratio and improve the torque at the same power; on the other hand, consideration can be given to improving the utilization efficiency of the stator and rotor. Then, a rotor assembly arranged with a halbach array can effectively increase the torque of the hub motor while basically not changing the size.

[0003] For the rotor assemblies used in the existing hub motors in the industry, the adjacent magnets inside generally adopt the ordinary arrangement method of positive and negative opposite poles. Without changing the performance of the material itself, to increase the torque of the motor, it can only be achieved by increasing the material consumption and volume. This runs counter to the goals of miniaturization and light weight required by the industry development. Therefore, it is necessary to apply a halbach array rotor assembly to improve the performance of the hub motor. Summary of the Utility Model

[0004] Aiming at the defects in the prior art, the purpose of the utility model is to provide a rotor assembly and an outer-rotor hub motor adopting Halbach array magnet arrangement.

[0005] According to a rotor assembly based on Halbach (Halbach) array arrangement provided by the utility model, it includes: a rotor bracket, a first magnet, and a second magnet;

[0006] A plurality of the first magnets and a plurality of the second magnets are arranged along the circumference inside the rotor bracket, and the first magnets and the second magnets are arranged at intervals;

[0007] The magnetic flux directions at both ends of the first magnet are transverse and facing each other, the magnetic flux directions at both ends of the second magnet are transverse and opposite, and the magnetic flux directions in the middle parts of the first magnet and the second magnet are longitudinal and opposite.

[0008] Preferably, the first magnet includes: a left section of the first magnet, a middle section of the first magnet, and a right section of the first magnet;

[0009] Both ends of the middle section of the first permanent magnet are respectively connected to the left section and the right section of the first permanent magnet. The magnetic flux direction of the left section of the first permanent magnet faces the right section of the first permanent magnet, the magnetic flux direction of the right section of the first permanent magnet faces the left section of the first permanent magnet, and the magnetic flux direction of the middle section of the first permanent magnet faces the center direction of the rotor bracket.

[0010] Preferably, the second permanent magnet includes: a left section of the second permanent magnet, a middle section of the second permanent magnet, and a right section of the second permanent magnet;

[0011] Both ends of the middle section of the second permanent magnet are respectively connected to the left section and the right section of the second permanent magnet. The magnetic flux direction of the left section of the second permanent magnet faces the right section of the second permanent magnet, the magnetic flux direction of the right section of the second permanent magnet faces the left section of the second permanent magnet, and the magnetic flux direction of the middle section of the second permanent magnet faces away from the center direction of the rotor bracket.

[0012] Preferably, the rotor bracket is arranged in a circular ring shape, a magnet groove is arranged on the inner ring side of the rotor bracket, the first permanent magnet and the second permanent magnet are installed in the magnet groove at intervals, the magnet groove has multiple sections, and the magnet groove has a flat groove surface.

[0013] Preferably, it includes: a rotor assembly, a stator assembly, a gear transmission assembly, and a hub motor housing;

[0014] The rotor assembly, the stator assembly, and the gear transmission assembly are installed in the hub motor housing. The rotor assembly is arranged outside the stator assembly, and the rotor assembly is drivingly connected to the gear transmission assembly.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] 1. The present application uses a Halbach array to arrange permanent magnets. This rotor assembly is applied to an assistive wheel hub motor. With the same amount of material used, the magnetic field can be more concentrated on the working area side, increasing the magnetic field strength without increasing the space utilization rate.

[0017] 2. Due to the annular uniform distribution in the present application, during use, the magnetic field change is relatively small, and the magnetic field has high stability.

[0018] 3. The present application uses a square permanent magnet with three-segment magnetization. The manufacturing and forming are simple. With the matching rotor bracket, the inner magnet groove is a multi-segment plane, which is convenient for positioning and assembling when pasting the permanent magnet, avoiding problems such as the last permanent magnet being unable to be installed or the gap between the last two adjacent permanent magnets being too large due to the cumulative tolerance of the similar arc groove rotor bracket. Description of the Drawings

[0019] By reading the detailed description of the non-restrictive embodiments with reference to the following drawings, other features, purposes, and advantages of the utility model will become more obvious:

[0020] Figure 1 Schematic diagram of a rotor assembly arranged in a Halbach array;

[0021] Figure 2 Schematic diagram of the magnetic flux directions of two types of permanent magnets;

[0022] Figure 3 Schematic diagram of an outer rotor hub motor using a Halbach permanent magnet array structure;

[0023] As shown in the figure:

[0024]

[0025] Specific implementation manners

[0026] The present utility model will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present utility model, but do not limit the present utility model in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several changes and improvements can still be made. These all belong to the protection scope of the present utility model.

[0027] As Figure 3 shown, this embodiment includes: a rotor assembly 100, a stator assembly 200, a gear transmission assembly 300, and a hub motor housing 400; the rotor assembly 100, the stator assembly 200, and the gear transmission assembly 300 are installed in the hub motor housing 400, the rotor assembly 100 is rotatably arranged outside the stator assembly 200, the rotor assembly 100 is drivingly connected to the gear transmission assembly 300, and the rotor assembly 100 adopts a Halbach array permanent magnet arrangement.

[0028] As Figure 1 and Figure 2 shown, the rotor assembly 100 includes: a rotor bracket 1, a first permanent magnet 2, and a second permanent magnet 3; a plurality of first permanent magnets 2 and a plurality of second permanent magnets 3 are arranged in a circumferential direction inside the rotor bracket 1, and the first permanent magnets 2 and the second permanent magnets 3 are arranged at intervals; the magnetic flux directions at both ends of the first permanent magnet 2 are transverse and facing each other, the magnetic flux directions at both ends of the second permanent magnet 3 are transverse and opposite, and the magnetic flux directions in the middle parts of the first permanent magnet 2 and the second permanent magnet 3 are longitudinal and opposite. The rotor bracket 1 is arranged in a circular ring shape, a magnet groove is provided on the inner ring side of the rotor bracket 1, the first permanent magnet 2 and the second permanent magnet 3 are installed at intervals in the magnet groove, and the magnet groove is provided with a plurality of continuous sections and has a flat groove surface.

[0029] In one embodiment, the first permanent magnet 2 includes: a first left segment 21 of the permanent magnet, a first middle segment 22 of the permanent magnet, and a first right segment 23 of the permanent magnet; both ends of the first middle segment 22 of the permanent magnet are respectively connected to the first left segment 21 and the first right segment 23 of the permanent magnet. The magnetic flux direction of the first left segment 21 of the permanent magnet faces the first right segment 23 of the permanent magnet, the magnetic flux direction of the first right segment 23 of the permanent magnet faces the first left segment 21 of the permanent magnet, and the magnetic flux direction of the first middle segment 22 of the permanent magnet faces the center direction of the rotor bracket 1. The second permanent magnet 3 includes: a second left segment 31 of the permanent magnet, a second middle segment 32 of the permanent magnet, and a second right segment 33 of the permanent magnet; both ends of the second middle segment 32 of the permanent magnet are respectively connected to the second left segment 31 and the second right segment 33 of the permanent magnet. The magnetic flux direction of the second left segment 31 of the permanent magnet faces the second right segment 33 of the permanent magnet, the magnetic flux direction of the second right segment 33 of the permanent magnet faces the second left segment 31 of the permanent magnet, and the magnetic flux direction of the second middle segment 32 of the permanent magnet faces away from the center direction of the rotor bracket 1.

[0030] Embodiment 2

[0031] Embodiment 2 is a preferred example of Embodiment 1.

[0032] This embodiment is based on the rotor structure arranged in a Halbach array, which improves the unilateral magnetic density, improves the air gap distribution, and achieves the purpose of enhancing the power density of the motor.

[0033] Specifically, the rotor assembly 100 is composed of a rotor bracket 1, a first permanent magnet 2, and a second permanent magnet 3. Several pairs of permanent magnets (the first permanent magnet 2 and the second permanent magnet 3) are evenly distributed circumferentially within the rotor bracket 1 and are attached to the magnet slots of the rotor bracket 1. The magnetic flux directions within the permanent magnets are distributed in a Halbach manner, and the magnetic flux directions within a single permanent magnet are distributed in three segments. Magnetization is performed in a special fixture so that the magnetic flux directions of each segment are different. For each group of adjacent first permanent magnet 2 and second permanent magnet 3, the internal magnetic flux directions are opposite. As Figure 2 shown, the magnetic fluxes of the first left segment 21 and the first right segment 23 of the first permanent magnet 2 are horizontal and in opposite directions, and the first middle segment 22 is vertical; each segment of the second permanent magnet 3 is similar to the first permanent magnet 2. However, the direction of each segment of the second left segment 31 is opposite to that of the first left segment 21, the direction of the second middle segment 32 is opposite to that of the first middle segment 22, and the direction of the second right segment 33 is opposite to that of the first right segment 23.

[0034] The permanent magnets are arranged regularly in the above manner, and the magnetic force lines gather inside the rotor assembly 100 to form a denser magnetic field circuit. When the amount of permanent magnet material used is the same, this arrangement method is more concentrated on the unilateral magnetic field, increasing the field strength in the working area.

[0035] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0036] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A rotor assembly with a Halbach array magnet arrangement, characterized in that, Including: A rotor bracket (1), a first permanent magnet (2), and a second permanent magnet (3); A plurality of the first permanent magnets (2) and a plurality of the second permanent magnets (3) are arranged in a circumferential direction within the rotor bracket (1), and the first permanent magnets (2) and the second permanent magnets (3) are arranged at intervals; The magnetic flux directions at both ends of the first permanent magnet (2) are transverse and facing each other, the magnetic flux directions at both ends of the second permanent magnet (3) are transverse and opposite, and the magnetic flux directions in the middle portions of the first permanent magnet (2) and the second permanent magnet (3) are longitudinal and opposite.

2. The rotor assembly with Halbach array magnet arrangement according to claim 1, wherein The first permanent magnet (2) includes: a left section of the first permanent magnet (21), a middle section of the first permanent magnet (22), and a right section of the first permanent magnet (23); Both ends of the middle section of the first permanent magnet (22) are respectively connected to the left section of the first permanent magnet (21) and the right section of the first permanent magnet (23). The magnetic flux direction of the left section of the first permanent magnet (21) faces the right section of the first permanent magnet (23), the magnetic flux direction of the right section of the first permanent magnet (23) faces the left section of the first permanent magnet (21), and the magnetic flux direction of the middle section of the first permanent magnet (22) faces the center direction of the rotor bracket (1).

3. The rotor assembly with Halbach array magnet arrangement according to claim 1, characterized in that, The second permanent magnet (3) includes: a left section of the second permanent magnet (31), a middle section of the second permanent magnet (32), and a right section of the second permanent magnet (33); Both ends of the middle section of the second permanent magnet (32) are respectively connected to the left section of the second permanent magnet (31) and the right section of the second permanent magnet (33). The magnetic flux direction of the left section of the second permanent magnet (31) faces the right section of the second permanent magnet (33), the magnetic flux direction of the right section of the second permanent magnet (33) faces the left section of the second permanent magnet (31), and the magnetic flux direction of the middle section of the second permanent magnet (32) faces away from the center direction of the rotor bracket (1).

4. The rotor assembly with Halbach array magnet arrangement according to claim 1, characterized in that: The rotor bracket (1) is arranged in a circular ring shape, and a magnet groove is provided on the inner ring side of the rotor bracket (1). The first permanent magnet (2) and the second permanent magnet (3) are installed at intervals in the magnet groove.

5. The rotor assembly with Halbach array magnet arrangement according to claim 4, characterized in that: The magnet groove has multiple sections, and the magnet groove has a flat groove surface.

6. An outer rotor hub motor, characterized in that: A rotor assembly using the Halbach array magnet arrangement according to any one of claims 1-5.

7. The outer rotor hub motor according to claim 6, wherein Including: A rotor assembly (100), a stator assembly (200), a gear transmission assembly (300), and a hub motor housing (400); The rotor assembly (100), the stator assembly (200), and the gear transmission assembly (300) are installed within the hub motor housing (400). The rotor assembly (100) is rotatably arranged outside the stator assembly (200), and the rotor assembly (100) is drivingly connected to the gear transmission assembly (300).

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