Permanent magnet synchronous motor with inner rotor and outer rotor sharing same stator structure

Abstract

The utility model discloses a permanent magnet synchronous motor with an inner rotor and an outer rotor sharing the same stator structure, and a stator iron core is installed between a front end cover and a rear end cover. The stator winding is wound on the stator iron core; the rotating shaft penetrates through the front end cover and the rear end cover and is rotationally connected with the front end cover and the rear end cover through a first bearing and a second bearing respectively; the inner rotor and the outer rotor are arranged on the inner side and the outer side of the stator core respectively and fixedly connected with the rotating shaft, inner rotor permanent magnet strips are arranged on the outer side of the circumference of the inner rotor, and outer rotor permanent magnet strips are arranged on the inner side of the circumference of the outer rotor. The stator iron core comprises an annular stator main body and stator teeth which are uniformly distributed along the circumference of the stator main body; the stator body and the stator teeth are integrally formed. According to the utility model, the integrally formed stator core is adopted, the problem that the stator core may loosen when the motor operates can be solved, the motor only needs two bearings to realize that the inner rotor and the outer rotor share the same motor rotating shaft to output torque, and the difficulty of a manufacturing process is reduced.

Description

Technical Field

[0001] This utility model relates to the technical field of permanent magnet synchronous motors, and in particular to a permanent magnet synchronous motor in which the inner and outer rotors share the same stator structure. Background Technology

[0002] With the rapid development of power electronics technology and the improved cost-effectiveness of permanent magnet materials, permanent magnet synchronous motors have been widely used in recent years due to their advantages such as simple structure, good control performance, and high efficiency. Classified by rotor structure, permanent magnet synchronous motors can be divided into internal rotor permanent magnet synchronous motors and external rotor permanent magnet synchronous motors; classified by the number of rotors, they are generally divided into single-rotor permanent magnet synchronous motors and dual-rotor permanent magnet synchronous motors.

[0003] Currently, most applications utilize internal rotor permanent magnet synchronous motors. These motors have low rotor inertia and fast dynamic response, making them suitable as servo motors for applications requiring frequent starts and stops. Furthermore, internal rotor permanent magnet synchronous motors have a wide speed range, making them suitable for high-speed motors exceeding 10,000 revolutions per minute. External rotor permanent magnet synchronous motors, on the other hand, have high torque density, allowing for higher output torque for the same motor size, and also possess a large starting torque. However, their disadvantages include high rotor inertia, slow dynamic response, making them unsuitable for servo control and high-speed operation.

[0004] In some applications, a motor needs to have a large starting torque and be able to reach a high speed. Currently, it is difficult for a simple internal rotor motor or external rotor motor to meet the requirements of large starting torque and high speed at the same time. Dual rotor motors and permanent magnet synchronous motors are more suitable for this application.

[0005] In 2003, Academician TAL i Po and his team in the United States proposed a dual-rotor permanent magnet motor. In recent years, scholars have conducted extensive theoretical research on dual-rotor permanent magnet motors. Professor Lin Mingyao of Southeast University conducted electromagnetic analysis on dual-rotor motors, studying the influence of rotor pole width and stator slot chamfer on back electromotive force and cogging torque. Zhu Xiaoyong, Mo Lihong, and others from Jiangsu University conducted in-depth research on a stator permanent magnet dual-rotor motor. Bai Jingang and his team at Harbin Institute of Technology solved the contradiction between the electromagnetic performance and mechanical strength of the flux-modulated rotor in traditional flux-modulated dual-rotor motors. Professor Li Xianglin and his team proposed a dual-rotor flux-switching motor using high-temperature superconducting windings for direct-drive wind energy conversion. In addition, scholars have conducted extensive research on dual-rotor counter-rotating permanent magnet synchronous motors and dual parallel rotor permanent magnet synchronous motors. The above research has laid a theoretical foundation for the application of dual-rotor permanent magnet motors, but further verification and optimization are needed, combined with motor manufacturing processes and motor structures.

[0006] The radial flux dual-rotor permanent magnet motor with ring winding proposed by Academician TAL IPO and his team in the United States has significantly improved the power density and efficiency of the motor. Professor Qu Ronghai of Huazhong University of Science and Technology in China has also conducted further research on this motor. However, the inner and outer rotors of this motor adopt different rotor structures, making the motor structure complex and difficult to apply in engineering.

[0007] Among them, Chinese patent CN112838728B proposes a dual-rotor permanent magnet synchronous motor in which the inner and outer rotors share the same motor shaft to output torque. It has a simple structure, is easy to manufacture in an engineering manner, and has high operational stability. However, this type of motor has two sets of stator windings, requiring two drivers to control the stator windings corresponding to the inner and outer rotors respectively, which increases the difficulty and cost of the motor control system.

[0008] Chinese patent CN213782999U also proposes another type of dual-rotor permanent magnet synchronous motor, in which the inner and outer rotors share a single motor stator and only one set of stator windings, requiring only one motor drive. However, the stator core of this motor is formed by splicing together multiple circumferentially distributed core units, and the stator core may become loose during motor operation. In addition, in order to achieve the sharing of the same motor shaft for output torque between the inner and outer rotors, the motor uses four bearings. Ensuring the coaxiality of the four bearings during manufacturing will increase the complexity of the process. Summary of the Invention

[0009] The purpose of this utility model is to overcome the shortcomings of the prior art and provide a permanent magnet synchronous motor in which the inner and outer rotors share the same stator structure. It adopts an integrally formed stator core, which solves the problem that the stator core may loosen during motor operation. In addition, the motor only needs to use two bearings to realize that the inner and outer rotors share the same motor shaft to output torque, which makes it easier to reduce the difficulty of manufacturing process.

[0010] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0011] A permanent magnet synchronous motor with both inner and outer rotors sharing the same stator structure includes a stator core, stator windings, a front end cover, a rear end cover, an inner rotor, an outer rotor, a shaft, a first bearing, and a second bearing.

[0012] The stator core is installed between the front end cover and the rear end cover;

[0013] The stator windings are wound around the stator core;

[0014] The rotating shaft passes through the front end cover and the rear end cover, and is rotatably connected to the front end cover and the rear end cover through the first bearing and the second bearing, respectively;

[0015] The inner rotor and outer rotor are respectively located on the inner and outer sides of the stator core and are both fixedly connected to the rotating shaft. The inner rotor is provided with an inner rotor permanent magnet strip on the outer side of the circumference, and the outer rotor is provided with an outer rotor permanent magnet strip on the inner side of the circumference.

[0016] The stator core includes a ring-shaped stator body and stator teeth evenly distributed around the circumference of the stator body;

[0017] The stator body and stator teeth are integrally formed.

[0018] Furthermore, the stator teeth include internal stator teeth and external stator teeth that correspond one-to-one with the internal stator teeth;

[0019] The stator internal teeth are located on the inner side of the stator body;

[0020] The stator external teeth are located on the outside of the stator body.

[0021] Furthermore, the centerline of the internal stator teeth coincides with the centerline of the corresponding external stator teeth.

[0022] Furthermore, both the internal and external stator teeth are T-shaped, including a connecting portion and a limiting portion;

[0023] The limiting part is connected to the stator body through a corresponding connecting part.

[0024] Furthermore, it also includes a stator connecting rod;

[0025] The stator body has a stator through hole;

[0026] The stator via is located on the center line of the corresponding internal and external stator teeth;

[0027] The stator core is connected to the front and rear covers via a stator connecting rod that passes through the stator through-hole.

[0028] Furthermore, the number of permanent magnet strips in the inner rotor and the number of permanent magnet strips in the outer rotor are equal.

[0029] Furthermore, it also includes an outer rotor end cover;

[0030] The outer rotor is fixedly connected to the shaft via an outer rotor end cap.

[0031] Furthermore, the stator winding is wound around the connection portion of the internal stator teeth and the connection portion of the external stator teeth.

[0032] Furthermore, the stator winding is wound around the stator body and located between two stator teeth.

[0033] Furthermore, the stator windings include stator U1 winding, stator V1 winding, stator W1 winding, stator U2 winding, stator V2 winding, and stator W2 winding;

[0034] in,

[0035] The head end of the stator U1 winding serves as the lead-out terminal of the U-phase winding, and the tail end of the stator U1 winding is connected to the head end of the stator U2 winding.

[0036] The head end of the stator V1 winding serves as the lead-out terminal of the V-phase winding, and the tail end of the stator V1 winding is connected to the head end of the stator V2 winding.

[0037] The head end of the stator W1 winding serves as the lead-out terminal of the W phase winding, and the tail end of the stator W1 winding is connected to the head end of the stator W2 winding.

[0038] The tail ends of the stator U2 winding, the stator V2 winding, and the stator W2 winding are connected.

[0039] Compared with existing technologies, the principles and advantages of this technical solution are as follows:

[0040] 1. This technical solution not only requires only one set of stator windings and one motor drive, but also eliminates the problem of potential stator core loosening due to the integrated motor stator core structure. When the inner and outer rotors share the same motor shaft to output torque, the use of a two-bearing scheme can reduce the difficulty of the manufacturing process.

[0041] 2. In the starting and low-speed operating range, the external rotor torque plays a dominant role, which can obtain a large starting torque and low-speed output torque; in the medium and high-speed operating range, the internal rotor torque plays a dominant role, which can obtain a large high-speed output torque. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the services required in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a front sectional view of a permanent magnet synchronous motor with internal and external rotors sharing the same stator structure, according to one embodiment of the present invention.

[0044] Figure 2 This is a schematic diagram of the stator and rotor laminations of a permanent magnet synchronous motor with the same stator structure for both inner and outer rotors, according to Embodiment 1 of this utility model.

[0045] Figure 3 This is a schematic diagram of the winding method of each stator winding in a permanent magnet synchronous motor with both inner and outer rotors sharing the same stator structure, according to Embodiment 1 of this utility model.

[0046] Figure 4 This is a schematic diagram of the connection of each stator winding in a permanent magnet synchronous motor with both inner and outer rotors sharing the same stator structure, according to Embodiment 1 of this utility model.

[0047] Figure 5 This is a schematic diagram of the winding method of each stator winding in a permanent magnet synchronous motor with both inner and outer rotors sharing the same stator structure, according to Embodiment 2 of this utility model.

[0048] Figure label:

[0049] 1-Stator core; 2-Stator winding; 3-Front end cover; 4-Rear end cover; 5-Inner rotor; 6-Outer rotor; 7-Shaft; 8-First bearing; 9-Second bearing; 10-Inner rotor permanent magnet strip; 11-Outer rotor permanent magnet strip; 12-Stator internal teeth; 13-Stator external teeth; 14-Connecting part; 15-Limiting part; 16-Stator connecting rod; 17-Stator through hole; 18-Outer rotor end cover; 19-Stator body; 111-Stator U1 winding; 112-Stator V1 winding; 113-Stator W1 winding; 114-Stator U2 winding; 115-Stator V2 winding; 116-Stator W2 winding. Detailed Implementation

[0050] The present invention will be further described below with reference to specific embodiments:

[0051] Example 1

[0052] like Figures 1 to 4 As shown in the figure, the permanent magnet synchronous motor with the inner and outer rotors sharing the same stator structure described in this embodiment includes a stator core 1, a stator winding 2, a front end cover 3, a rear end cover 4, an inner rotor 5, an outer rotor 6, a shaft 7, a first bearing 8, a second bearing 9, a stator connecting rod 16, and an outer rotor end cover 18.

[0053] The stator core 1 is installed between the front end cover 3 and the rear end cover 4; the stator winding 2 is wound on the stator core 1; the rotating shaft 7 passes through the front end cover 3 and the rear end cover 4, and is rotatably connected to the front end cover 3 and the rear end cover 4 through the first bearing 8 and the second bearing 9 respectively.

[0054] The inner rotor 5 and the outer rotor 6 are respectively located on the inner and outer sides of the stator core 1, and are both fixedly connected to the rotating shaft 7 (the outer rotor 6 is fixedly connected to the rotating shaft 7 through the outer rotor end cover 18). The inner rotor 5 is provided with an inner rotor permanent magnet strip 10 on the outer circumference, and the outer rotor 6 is provided with an outer rotor permanent magnet strip 11 on the inner circumference. The number of inner rotor permanent magnet strips 10 and outer rotor permanent magnet strips 11 are equal.

[0055] The stator core 1 includes a stator body 19 in the shape of a ring and stator teeth evenly distributed around the circumference of the stator body 19; the stator body 19 and the stator teeth are integrally formed.

[0056] Specifically, in this embodiment, the stator teeth include stator inner teeth 12 and stator outer teeth 13 corresponding to the stator inner teeth 12; the stator inner teeth 12 are located on the inner side of the stator body 19; and the stator outer teeth 13 are located on the outer side of the stator body 19.

[0057] Moreover, the center line of the internal stator tooth 12 coincides with the center line of the corresponding external stator tooth 13.

[0058] Both the internal stator teeth 12 and the external stator teeth 13 are T-shaped and include a connecting portion 14 and a limiting portion 15; the limiting portion 15 is connected to the stator body 19 through the corresponding connecting portion 14.

[0059] Specifically, in this embodiment, the stator body 19 has a stator through hole 17; the stator through hole 17 is located on the center line of the corresponding stator internal teeth 12 and stator external teeth 13; the stator core 1 is connected to the front end cover 3 and the rear end cover 4 through the stator connecting rod 16 passing through the stator through hole 17.

[0060] Specifically, in this embodiment, the stator winding 2 includes stator U1 winding 111, stator V1 winding 112, stator W1 winding 113, stator U2 winding 114, stator V2 winding 115, and stator W2 winding 116. These windings are all wound around the connecting part 14 of the stator internal teeth 12 and the connecting part 14 of the stator external teeth 13.

[0061] Specifically, the head end of stator U1 winding 111 serves as the U-phase winding lead-out terminal, and the tail end of stator U1 winding 111 is connected to the head end of stator U2 winding 114; the head end of stator V1 winding 112 serves as the V-phase winding lead-out terminal, and the tail end of stator V1 winding 112 is connected to the head end of stator V2 winding 115; the head end of stator W1 winding 113 serves as the W-phase winding lead-out terminal, and the tail end of stator W1 winding 113 is connected to the head end of stator W2 winding 116; the tail ends of stator U2 winding 114, stator V2 winding 115, and stator W2 winding 116 are connected together.

[0062] This embodiment requires only one set of stator windings and one motor drive. Moreover, the integrated motor stator core structure eliminates the problem of potential stator core loosening. When the inner and outer rotors share the same motor shaft to output torque, the use of a two-bearing scheme can reduce the difficulty of the manufacturing process.

[0063] During operation, in the starting and low-speed operating range, the torque of the outer rotor 6 plays a dominant role, which can obtain a large starting torque and low-speed output torque; in the medium and high-speed operating range, the torque of the inner rotor 5 plays a dominant role, which can obtain a large high-speed output torque.

[0064] Example 2

[0065] like Figure 5As shown, compared with Embodiment 1, the permanent magnet synchronous motor with the inner and outer rotors sharing the same stator structure described in this embodiment has its stator winding 2 wound on the stator body 19 and located between two stator teeth.

[0066] The above-described embodiments are merely preferred embodiments of this utility model and are not intended to limit the scope of implementation of this utility model. Therefore, all changes made in accordance with the shape and principle of this utility model should be covered within the protection scope of this utility model.

Claims

1. A permanent magnet synchronous motor with internal and external rotors sharing the same stator structure, characterized in that, It includes a stator core, stator windings, front end cover, rear end cover, inner rotor, outer rotor, shaft, first bearing, and second bearing; The stator core is installed between the front end cover and the rear end cover; The stator windings are wound around the stator core; The rotating shaft passes through the front end cover and the rear end cover, and is rotatably connected to the front end cover and the rear end cover through the first bearing and the second bearing, respectively; The inner rotor and outer rotor are respectively located on the inner and outer sides of the stator core and are both fixedly connected to the rotating shaft. The inner rotor is provided with an inner rotor permanent magnet strip on the outer side of the circumference, and the outer rotor is provided with an outer rotor permanent magnet strip on the inner side of the circumference. The stator core includes a ring-shaped stator body and stator teeth evenly distributed around the circumference of the stator body; The stator body and stator teeth are integrally formed.

2. A permanent magnet synchronous motor with internal and external rotors sharing the same stator structure according to claim 1, characterized in that, The stator teeth include internal stator teeth and external stator teeth that correspond one-to-one with the internal stator teeth; The stator internal teeth are located on the inner side of the stator body; The stator external teeth are located on the outside of the stator body.

3. A permanent magnet synchronous motor with internal and external rotors sharing the same stator structure according to claim 2, characterized in that, The centerline of the internal stator teeth coincides with the centerline of the corresponding external stator teeth.

4. A permanent magnet synchronous motor with internal and external rotors sharing the same stator structure according to claim 2, characterized in that, Both the internal and external stator teeth are T-shaped, including a connecting portion and a limiting portion; The limiting part is connected to the stator body through a corresponding connecting part.

5. A permanent magnet synchronous motor with internal and external rotors sharing the same stator structure according to claim 1, characterized in that, It also includes stator connecting rods; The stator body has a stator through hole; The stator via is located on the center line of the corresponding internal and external stator teeth; The stator core is connected to the front and rear covers via a stator connecting rod that passes through the stator through-hole.

6. A permanent magnet synchronous motor with internal and external rotors sharing the same stator structure according to claim 1, characterized in that, The number of permanent magnet strips in the inner rotor and the number of permanent magnet strips in the outer rotor are equal.

7. A permanent magnet synchronous motor with internal and external rotors sharing the same stator structure according to claim 1, characterized in that, It also includes an outer rotor end cover; The outer rotor is fixedly connected to the shaft via an outer rotor end cap.

8. A permanent magnet synchronous motor with internal and external rotors sharing the same stator structure according to claim 4, characterized in that, The stator winding is wound around the connection part of the internal stator teeth and the connection part of the external stator teeth.

9. A permanent magnet synchronous motor with internal and external rotors sharing the same stator structure according to claim 4, characterized in that, The stator winding is wound around the stator body and located between two stator teeth.

10. A permanent magnet synchronous motor with internal and external rotors sharing the same stator structure according to claim 8 or 9, characterized in that, The stator windings include stator U1 winding, stator V1 winding, stator W1 winding, stator U2 winding, stator V2 winding, and stator W2 winding; in, The head end of the stator U1 winding serves as the lead-out terminal of the U-phase winding, and the tail end of the stator U1 winding is connected to the head end of the stator U2 winding. The head end of the stator V1 winding serves as the lead-out terminal of the V-phase winding, and the tail end of the stator V1 winding is connected to the head end of the stator V2 winding. The head end of the stator W1 winding serves as the lead-out terminal of the W phase winding, and the tail end of the stator W1 winding is connected to the head end of the stator W2 winding. The tail ends of the stator U2 winding, the stator V2 winding, and the stator W2 winding are connected.

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