Rotor assembly of motor

Abstract

The invention provides a rotor assembly of an electric machine. The rotor assembly comprises a rotor magnetic ring, a rotor iron core ring and a rotor shell, the rotor iron core ring is arranged on the periphery of the rotor shell in a sleeving mode, and the rotor magnetic ring is arranged on the rotor iron core ring in a sleeving mode on the outer side. The mass of the rotor assembly according to the present invention is reduced, the magnetic flux harmonic component is reduced, and the noise vibration (NVH) performance is improved.

Description

Technical Field

[0001] The present invention relates to electric machines, and more particularly to rotor assemblies of electric machines. Background Art

[0002] Interior permanent magnet motors are widely used in electric vehicles due to their high efficiency and output torque. The rotor assembly of this motor generally includes a rotor core, magnetic steel, and a rotor shaft. The magnetic steel forms magnetic poles to generate a magnetic field, and the rotor core is used to support the magnetic poles and provide a magnetic flux path. Under the traditional interior permanent magnet rotor structure or spoke rotor structure, the rotor assembly usually has more magnetic flux harmonic components and has a higher inertia torque due to its large mass, resulting in poor noise and vibration (NVH) performance of the motor. Summary of the invention

[0003] The object of the present invention is to overcome the above-mentioned disadvantages existing in the prior art rotor construction.

[0004] In a first aspect, the present invention provides a rotor assembly for an electric motor, characterized in that it includes a rotor magnetic ring, a rotor core ring and a rotor housing, wherein the rotor core ring is sleeved on the outer periphery of the rotor housing, and the rotor magnetic ring is sleeved on the rotor core ring on the outside.

[0005] According to an embodiment, the rotor housing is generally an injection molded component, and the rotor magnetic ring and the rotor core ring are overmolded in the rotor housing. For example, the rotor housing is provided with a receiving groove on the outer circumference. With this arrangement, the rotor magnetic ring and the rotor core ring can be installed while the rotor housing is injection molded.

[0006] According to an embodiment, the rotor magnetic ring is a sinusoidal magnetized magnetic ring, for example, constructed as a Halbach magnet array, such as an integral magnetic ring formed by injection molding or compression molding. The magnetic ring material is, for example, NdFeB, Sm-Fe-N, or ferrite.

[0007] According to an embodiment, the material of the rotor core ring is magnetically conductive, for example magnetic steel.

[0008] According to an embodiment, the ratio of the radial thickness of the rotor magnetic ring to the rotor core ring is 3.5-5.5.

[0009] According to exemplary embodiments, the rotor magnet ring is designed with 10 poles, 14 poles, 12 poles, 18 poles or 24 poles.

[0010] According to an embodiment, the rotor housing comprises a central through hole, and bearing seats are arranged at both ends of the central through hole. With this arrangement, the rotor shaft can be easily installed.

[0011] According to an embodiment, the rotor housing is cylindrical, and a plurality of mounting columns are arranged on its end surface. With this arrangement, the rotor assembly can be connected to a load.

[0012] According to an embodiment, the rotor assembly further comprises a rotor shaft, which is mounted in the central through hole of the rotor housing by means of a bearing.

[0013] According to an embodiment, a plurality of positioning protrusions are arranged circumferentially at the bottom of the receiving groove near the end surface of the rotor housing, and a plurality of complementary positioning notches are arranged at corresponding positions of the rotor magnetic ring. This arrangement facilitates the positioning of the rotor magnetic ring in the receiving groove of the rotor housing.

[0014] In a second aspect, the present invention provides an electric machine comprising the above-mentioned rotor assembly.

[0015] Compared with a conventional rotor assembly, the rotor assembly according to the present invention has a reduced mass, reduced magnetic flux harmonic components, and improved noise and vibration (NVH) performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Embodiments of the invention will be explained in more detail in the accompanying drawings, in which:

[0017] Figure 1 is a schematic perspective view of a rotor assembly according to an embodiment of the present invention;

[0018] Figure 2 yes Figure 1 A schematic cross-sectional view of a rotor assembly in FIG.

[0019] Figure 3 yes Figure 1 A schematic perspective view of a rotor assembly in which the rotor housing is removed;

[0020] Figure 4 yes Figure 1 Schematic perspective view of the rotor housing in FIG.

[0021] In the drawings, embodiments of the invention are shown in a simplified manner for the sake of clarity. The drawings are not necessarily drawn to scale. DETAILED DESCRIPTION

[0022] Refer to the following Figure 1-4 The embodiments of the present invention will be described in detail, wherein directional terms are used with reference to directions in the accompanying drawings.

[0023] Figures 1 to 3The perspective view and the cross-sectional view of the rotor assembly 1 are shown respectively. As shown in the figure, the rotor assembly 1 includes a rotor magnetic ring 10, a rotor core ring 20 and a plastic rotor shell 30, the rotor core ring 20 is sleeved on the outer periphery of the rotor shell 30, and the rotor magnetic ring 10 is sleeved on the rotor core ring 20 on the outside. In this example, the rotor magnetic ring 10 and the rotor core ring 20 are overmolded in the rotor shell 30 when the rotor shell 30 is injection molded, so that the rotor magnetic ring 10 is located radially outside the rotor core ring 20 and surrounds the rotor core ring 20, and the rotor magnetic ring 10 and the rotor core ring 20 are accommodated in the accommodating groove 31 arranged on the outer periphery of the rotor shell 30.

[0024] Figure 3 The structure of the rotor magnetic ring 10 and the rotor core ring 20 is shown. The rotor magnetic ring 10 is a sinusoidal magnetized magnetic ring, for example, a Halbach magnet array, which can be an integral magnetic ring by injection molding or compression molding. The magnetic ring material is, for example, NdFeB, Sm-Fe-N, or ferrite. The rotor magnetic ring is configured with 10 poles, 14 poles, 12 poles, 18 poles or 24 poles. The material of the rotor core ring is magnetically conductive, for example, magnetic steel. The ratio of the radial thickness of the rotor magnetic ring to the rotor core ring is 3.5-5.5.

[0025] Figure 4 The structure of the rotor housing 30 is shown, which is cylindrical, with a receiving groove 31 surrounding the entire periphery, and includes a central through hole 32, with bearing seats 33 provided at both ends of the central through hole 32 to mount the rotor shaft, and 4 mounting columns 34 provided on the upper end surface, the mounting columns 34 are located radially outside the central through hole 32 and are equidistantly spaced from each other. In order to reinforce the bearing seat 33 and the mounting columns 34, the rotor housing 30 is provided with a plurality of reinforcing ribs 33a and 34a respectively at the junction of the bearing seat 33 and the mounting columns 34 with their end surfaces.

[0026] In addition, in order to facilitate the positioning of the rotor magnetic ring 10 in the receiving groove 31 of the rotor housing 30, a plurality of positioning protrusions 35 are circumferentially arranged at the bottom of the receiving groove 31 near the end surface, and the rotor magnetic ring 10 is provided with a plurality of complementary positioning recesses 11 at corresponding positions.

[0027] The above embodiments illustrate the principles of the present invention in specific applications, and the terms and expressions used are illustrative rather than restrictive. It will be understood by those skilled in the art that the use of these terms and expressions is not intended to exclude any equivalent examples of the features illustrated and described from the scope of the present invention. Without exercising creative ability, those skilled in the art may make various modifications to the above embodiments in form, use and implementation details without departing from the principles and concepts of the present invention as defined in the claims.

[0028] In some cases, features disclosed in the present invention may be used independently of other features. On the other hand, when necessary, features disclosed in the present invention may be combined to provide various combinations.

Claims

1. A rotor assembly of a motor, characterized in that The invention comprises a rotor magnetic ring, a rotor core ring and a rotor shell. The rotor core ring is sleeved on the outer periphery of the rotor shell, and the rotor magnetic ring is sleeved on the rotor core ring on the outer side.

2. The rotor assembly according to claim 1, characterized in that The rotor magnetic ring and the rotor core ring are plastic-encapsulated in the rotor housing.

3. The rotor assembly according to claim 2, characterized in that: The rotor housing is provided with a receiving groove on the outer periphery, and the rotor magnetic ring and the rotor core ring are received in the receiving groove.

4. The rotor assembly according to any one of claims 1 to 3, characterized in that: The rotor magnetic ring is a sinusoidal magnetized magnetic ring.

5. The rotor assembly according to any one of claims 1 to 3, characterized in that: The magnetic ring material is NdFeB, Sm-Fe-N, or ferrite.

6. The rotor assembly according to any one of claims 1 to 3, characterized in that: The material of the rotor core ring is magnetically conductive.

7. The rotor assembly according to any one of claims 1 to 3, characterized in that: The ratio of the radial thickness of the rotor magnetic ring to the rotor core ring is 3.5-5.

5.

8. The rotor assembly according to any one of claims 1 to 3, characterized in that: The rotor magnetic ring is constructed with 10 poles, 14 poles, 12 poles, 18 poles or 24 poles.

9. The rotor assembly according to any one of claims 1 to 3, characterized in that: The rotor housing comprises a central through hole, and bearing seats are arranged at both ends of the central through hole.

10. The rotor assembly according to any one of claims 1 to 3, characterized in that: The rotor housing is cylindrical, and a plurality of mounting columns are arranged on its end surface.

11. The rotor assembly according to claim 3, characterized in that A plurality of positioning protrusions are arranged along the circumferential direction at the bottom of the accommodating groove near the end surface of the rotor housing, and a plurality of complementary positioning recesses are arranged at corresponding positions of the rotor magnetic ring.

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