CN216851480U

CN216851480U - Rotor of motor and motor

Info

Publication number: CN216851480U
Application number: CN202122353228.7U
Authority: CN
Inventors: 吴建刚
Original assignee: Emerson Climate Technologies Suzhou Co Ltd
Current assignee: Gulun Environmental Technology Suzhou Co ltd
Priority date: 2021-09-27
Filing date: 2021-09-27
Publication date: 2022-06-28
Anticipated expiration: 2031-09-27

Abstract

The utility model provides a rotor of motor and motor including this rotor. The rotor of the electron includes a plurality of magnets and a rotor core. The rotor core has a cylindrical shape with a first central axis and is provided with a plurality of slots for respectively accommodating the plurality of magnets, each two slots of the plurality of slots being arranged in a V-shape with respect to the first central axis, the two V-shaped slots defining a sector. The periphery of at least one sector includes eccentric circular arc section and is located along the circumferential direction the concave section of eccentric circular arc section both sides, eccentric circular arc section has the follow the second the central axis of first the radial outside offset of central axis, concave section for the radial inside concave of eccentric circular arc section. The rotor according to the present application may reduce air gap flux density harmonics and radial force harmonics, thereby reducing undesirable vibration and noise.

Description

Rotor of motor and motor

Technical Field

The present application relates to a rotor for an electric machine and an electric machine comprising the rotor.

Background

This section provides background information related to the present invention, which does not necessarily constitute prior art.

The motor is an electromagnetic device for realizing electric energy conversion or transmission according to the electromagnetic induction law, and the motor is mainly used for generating driving torque to serve as a power source of electric appliances or various machines. The electric machine includes a stationary stator and a rotor rotatable relative to the stator. The stator includes a stator core and stator windings through which current flows to generate a magnetic field. The rotor includes a rotor core and a magnet disposed in the rotor core. The magnetic field generated by the stator windings interacts with the magnets to produce torque.

The torque generated by the windings of the stator and the magnetic flux field of the rotor forms a uniform torque component and a varying torque component. The total output torque of the motor is a combination of these two components. Due to the varying torque component, a torque ripple phenomenon is generated, which results in motor torque output and rotational speed oscillations when the electric machine is used as a motor. Torque ripple in electric motors is caused by the interaction between harmonic flux generated by the magnets and the current in the stator windings. The presence of torque ripple may cause the motor to produce undesirable vibration and noise.

Therefore, it is desirable to provide a motor capable of effectively improving torque ripple and thus reducing vibration and noise.

SUMMERY OF THE UTILITY MODEL

The general summary of the invention is provided in this section, not an exhaustive scope of the invention or a comprehensive disclosure of all of the features of the invention.

The utility model aims at providing a reduce the motor of vibration and noise through improving air gap magnetic flux distribution.

According to one aspect of the present disclosure, there is provided a rotor of an electric machine including a plurality of magnets and a rotor core. The rotor core has a cylindrical shape with a first central axis and is provided with a plurality of slots for respectively accommodating the plurality of magnets, each two slots of the plurality of slots being arranged in a V-shape with respect to the first central axis, the two V-shaped slots defining a sector. The periphery of at least one sector includes eccentric circular arc section and is located along the circumferential direction the concave section of eccentric circular arc section both sides, eccentric circular arc section has the follow the second the central axis of first the radial outside offset of central axis, concave section for the radial inside concave of eccentric circular arc section.

The rotor according to the present application may reduce air gap flux density harmonics and radial force harmonics by providing an eccentric arc section and a concave section, thereby reducing undesirable vibration and noise.

In some examples of the present disclosure, a slot extending from a radially inner side toward a radially outer side is provided in the at least one sector.

In some examples of the present disclosure, the slots include a first slot and second slots on both sides of the first slot, wherein the first slot extends along a radial centerline of the sector.

In some examples of the present disclosure, the first slot and the second slot are symmetrically arranged about the radial centerline.

In some examples of the present disclosure, the second slot is obliquely arranged with respect to the first slot.

In some examples of the present disclosure, the angle of the second slot relative to the first slot is in a range between 11 degrees and 21 degrees.

In some examples of the present disclosure, the slot has a width between 0.5mm and 1.5 mm.

In some examples of the present disclosure, the recessed sections are positioned adjacent to the respective slots along the circumferential direction.

In some examples of the present disclosure, the concave section has the same second central axis as the eccentric circular arc section.

In some examples of the present disclosure, the recessed section is recessed radially inward relative to the eccentric arc section by a thickness in a range between 0.2mm and 0.8 mm.

In some examples of the disclosure, a width of the recessed section in the circumferential direction is in a range between 5mm and 6 mm.

In some examples of the present disclosure, the second central axis is offset with respect to the first central axis in a range of 7mm to 8 mm.

In some examples of the present disclosure, all the sectors have the same structure, and the eccentric arc section and the concave section are symmetrically arranged with respect to a radial center line of the sectors.

According to another aspect of the present disclosure, there is also provided an electric machine including the rotor as described above and a stator disposed radially outside the rotor.

Similarly, an electrical machine according to the invention comprising the above-mentioned rotor provides at least similar advantageous effects as the above-mentioned rotor, i.e. air gap flux density harmonics and radial force harmonics can be reduced, thereby reducing undesired vibrations and noise.

Drawings

The foregoing and additional features and characteristics of the present invention will become more apparent from the following detailed description, taken with reference to the accompanying drawings, which are given by way of example only and which are not necessarily drawn to scale. Like reference numerals are used to indicate like parts in the accompanying drawings, in which:

fig. 1 is a schematic plan view of a rotor of an electric machine according to an embodiment of the present disclosure; and

figure 2 is a schematic view of a sector of the rotor of figure 1.

Detailed Description

Exemplary embodiments of the present application will now be described more fully with reference to the accompanying drawings.

The exemplary embodiments are provided so that this disclosure will be thorough and will more fully convey the scope to those skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

Fig. 1 is a schematic plan view of a rotor 10 of an electric machine according to an embodiment of the present disclosure. As shown in fig. 1, the rotor 10 includes a rotor core 110 and a plurality of magnets (e.g., the example of fig. 1 includes 6 magnets) arranged in the rotor core. In the example of fig. 1, the rotor 10 includes 6 magnets 111 to 122 each having a substantially rectangular parallelepiped shape. It should be understood that the number, size, shape, and arrangement of magnets (e.g., angles between adjacent magnets, etc.) may be varied as desired and is not limited to the specific examples shown in the figures and described herein.

The rotor core 110 may be formed by stacking laminations, for example. The rotor core 110 is generally cylindrical, having a center axis (also referred to herein as a first center axis) O1 extending in an axial direction. A plurality of slots 131 to 142 are provided in the rotor core 110 for accommodating the magnets 111 to 122, respectively. The slots 131 to 142 may have a shape matching the corresponding magnets 111 to 122. For example, if the magnet has a rectangular parallelepiped shape, the groove has a rectangular parallelepiped shape in general. The magnets of the rotor may be positioned or oriented in different ways to produce the desired magnetic field. Accordingly, the arrangement of the plurality of slots 131 to 142 depends on the arrangement of the plurality of magnets 111 to 122.

In the example of fig. 1, each two magnets are arranged in a V-shape with respect to the central axis O1. That is, the adjacent ends of the two magnets are close to the central axis O1, and thus may also be referred to as radially inner ends. For example, the radially inner end of the magnet may be spaced from the central axis O1 by, for example, 25.5 mm. The distal ends of the two magnets are close to the outer peripheral surface of the rotor core 110, and thus may also be referred to as radially outer ends. Specifically, the magnet 111 and the magnet 112 are arranged in a V shape; the

magnets

113 and 114 are arranged in a V-shape; the

magnets

115 and 116 are arranged in a V-shape; magnet 117 and magnet 118 are arranged in a V-shape; the magnet 119 and the magnet 120 are arranged in a V-shape; the magnet 121 and the magnet 122 are arranged in a V-shape. The two magnets of the V-shaped arrangement may for example be at an angle of 120 degrees. The poles of the rotor 20 may be formed by pairs of magnets arranged in a V-shape. For example, adjacent ends of two magnets may have the same magnetic pole, thereby forming a magnetic pole of the rotor 20.

Accordingly, each two slots of the rotor core 110 are arranged in a V-shape with respect to the central axis O1. That is, the adjacent ends of the two slots (ends 131a and 132a shown in fig. 2) are close to the central axis O1, and the distant ends of the two magnets (ends 131b and 132b shown in fig. 2) are close to the outer peripheral surface of the rotor core 110. The

slots

131 and 132 are arranged in a V-shape and are used to accommodate the magnets 111 and 112, respectively; the

grooves

133 and 134 are arranged in a V-shape and are used to accommodate the

magnets

113 and 114, respectively; the

slots

135 and 136 are arranged in a V-shape and are used to accommodate the

magnets

115 and 116, respectively;

grooves

137 and 138 are arranged in a V-shape and are used to accommodate

magnets

117 and 118, respectively;

slots

139 and 140 are arranged in a V-shape and are used to receive

magnets

119 and 120, respectively; the

grooves

141 and 142 are arranged in a V-shape and receive the

magnets

121 and 122, respectively.

The radial ends of each slot (such as

ends

131a and 131b or ends 132a and 132b shown in fig. 2) may extend a further length relative to the magnet. This limits leakage of magnetic flux between the north and south poles of the respective magnets. The voids or slots in the rotor core impede the magnetic flux because the vacuum has a relatively low magnetic permeability compared to the rotor core material.

The sectors are defined by two grooves of the V-shape. As shown in fig. 1, the slot 131 and the slot 132 define a scallop S1; the slot 133 and the slot 134 define a sector S2; the

slots

135 and 136 define a sector S3;

slots

137 and 138 define a scallop S4; slot 139 and slot 140 define a sector S5; the

slots

141 and 142 define scallops S6. In fig. 1, each of the sectors S1 to S6 has substantially the same structure. The fan S1 will be described below with reference to fig. 2.

As shown in fig. 2, the sector S1 has a radial center line L1 (which may also be referred to as a D-axis or a straight axis) extending in the radial direction. The

grooves

131 and 132 may be symmetrically arranged about the radial center line L1. The outer peripheral surface of the sector S1 includes an eccentric circular arc section 152 and

concave sections

151 and 153 located on both sides of the eccentric circular arc section 152 in the circumferential direction. The

concave sections

151 and 153 are recessed radially inward with respect to the eccentric arc section 152. The eccentric circular arc section 152 and the

concave sections

151 and 153 may be symmetrically arranged about the radial center line L1.

The eccentric circular arc segment 152 has a central axis (also referred to herein as a second central axis) O2 that is offset radially outward from the central axis O1. In the example shown in fig. 2, the central axis O2 may be offset from the central axis O1 along a radial centerline L1. For example, the central axis O2 may be offset relative to the central axis O1 in a range of about 7mm to about 8 mm. For example, the central axis O2 may be offset by about 7.5mm relative to the central axis O1.

An air gap 100 is provided between the eccentric circular arc section 152 and the stator 20. The distance between the circumferential end of the eccentric arc section 152 and the outer circumferential surface of the stator 20 is the largest, while the distance between the circumferential end of the eccentric arc section 152 and the outer circumferential surface of the stator 20 is the smallest along the radial center line L1. That is, the air gap 100 has a non-uniform thickness. The thickness distribution of the air gap, i.e., the offset of the central axis O2 relative to the central axis O1, may be determined based on the desired radial component of the magnetic flux density of the air gap 100.

The

concave sections

151 and 153 are recessed radially inward with respect to the eccentric arc section 152. For example, the concave thickness t of the

concave sections

151 and 153 is in a range between about 0.2mm and about 0.8 mm. For example, the recess thickness t is about 0.5 mm. Recessed section 151 is positioned adjacent to slot 131 (specifically, end 131b of slot 131). In other words, the concave section 151 is located between the eccentric arc section 152 and the groove 131 in the circumferential direction and adjacent to the groove 131. Similarly, the recessed section 153 is positioned adjacent to the slot 132 (specifically, the end 132b of the slot 132). In other words, the concave section 153 is located between the eccentric circular arc section 152 and the groove 132 in the circumferential direction and adjacent to the groove 132. The

concave sections

151 and 153 may have the same central axis O2 as the eccentric circular arc section 152. In one example, the width w of the recessed

sections

151 and 153 in the circumferential direction is in a range between about 5mm and about 6 mm. For example, the width w may be about 5.7 mm.

It should be understood that the configuration (including shape, size, etc.) of the eccentric arc segment and the concave segment may be varied as desired and is not necessarily limited to the specific examples described herein or shown in the figures.

The shape of the rotor 10 (particularly the shape of the outer circumferential surface) may influence the magnetic flux distribution along the surface of the rotor 10. The flux distribution affects the torque ripple and the core loss of the motor. The rotor 10 has a gradually varying air gap thickness so that the magnetic resistance varies smoothly. This effectively reduces rotor flux harmonics, thereby achieving a reduction in torque ripple and core loss.

Further, each of the sectors S1-S6 may be provided with a slot extending from the radially inner side toward the radially outer side. For example, each sector may include at least two slots. In the example shown in fig. 2, each sector comprises three slots, a first slot 162 located on a radial median line L1 and

second slots

161 and 163 located on either side of first slot 162. The first and

second slots

162, 161, 163 may be symmetrically arranged about the radial center line L1. The

second slots

161 and 163 may be obliquely arranged with respect to the first slot 162. In one example, the radially inner end of the second slot may be inclined toward the first slot to form an angle. For example, the angle of the

second slots

161 and 163 relative to the first slot 162 ranges between about 11 degrees and about 21 degrees. For example, the

second slots

161 and 163 are angled at about 16 degrees relative to the first slot 162. The slot may have a width of between about 0.5mm and about 1.5mm, for example, a width of about 1mm, i.e., a dimension substantially perpendicular to the radial extension direction of the slot.

It is to be understood that the configuration of the slots (including number, shape, size, arrangement, etc.) may be varied as desired and is not necessarily limited to the specific examples described herein or shown in the figures.

The slots may also affect the flux distribution along the surface of the rotor 10. The provision of slots can also effectively reduce rotor flux harmonics, thereby achieving a reduction in torque ripple and core loss.

According to another aspect of the present disclosure, there is provided an electric motor including the above-described rotor 10 and a stator 20 located radially outside the rotor 10, as shown in fig. 2. The stator 20 may have an existing structure and thus will not be described in detail herein.

The inventors have tested electric machines comprising a rotor according to the present disclosure under various operating conditions. Test results show that the vibration of the motor according to the present disclosure can be reduced by 50% to 90% compared to the existing motor.

As required, detailed embodiments of the present invention are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Furthermore, features of various implementing embodiments may be combined to form further embodiments of the invention.

Claims

1. A rotor of an electric machine comprising:

a plurality of magnets; and

a rotor core having a cylindrical shape with a first central axis and provided with a plurality of slots for respectively accommodating the plurality of magnets, each two slots of the plurality of slots being arranged in a V-shape with respect to the first central axis, the two slots of the V-shape defining a sector,

its characterized in that, at least one the periphery of sector includes the eccentric circular arc section and is located along the circumferential direction the concave section of eccentric circular arc section both sides, the eccentric circular arc section has the follow the second the central axis of first the radial outside offset of central axis, concave section for the radial inside concave of eccentric circular arc section.

2. The rotor of an electric machine of claim 1, wherein at least one of the sectors is provided with a slot extending from a radially inner side towards a radially outer side.

3. The rotor of an electric machine of claim 2, wherein the slots include a first slot and second slots on either side of the first slot, wherein the first slot extends along a radial centerline of the sector.

4. The rotor of an electric machine of claim 3, wherein the first slot and the second slot are symmetrically arranged about the radial centerline.

5. The rotor of an electric machine of claim 3, wherein the second slot is arranged obliquely relative to the first slot.

6. The rotor of an electric machine of claim 5, wherein the angle of the second slot relative to the first slot is in a range between 11 degrees and 21 degrees.

7. The rotor of an electric machine of claim 2, wherein the slots have a width of between 0.5mm and 1.5 mm.

8. The rotor of an electric machine according to any one of claims 1 to 7, wherein the recessed sections are located adjacent to the respective slots in the circumferential direction.

9. The rotor of an electric machine according to any one of claims 1 to 7, wherein the recessed section has the same second central axis as the eccentric circular arc section.

10. The rotor of an electric machine of claim 9, wherein the recessed section is recessed radially inward relative to the eccentric arc section by a thickness in a range between 0.2mm and 0.8 mm.

11. The rotor of an electric machine according to claim 9, wherein the width of the recessed section in the circumferential direction is in a range between 5mm and 6 mm.

12. The rotor of an electric machine according to any one of claims 1 to 7, characterized in that the second central axis is offset with respect to the first central axis in the range of 7mm to 8 mm.

13. The rotor of an electric machine according to any one of claims 1 to 7, characterized in that all the sectors have the same structure, and the eccentric circular arc section and the concave section are symmetrically arranged about a radial center line of the sectors.

14. An electric machine, characterized in that the electric machine comprises:

a rotor according to any one of claims 1-13; and

a stator disposed radially outward of the rotor.