Direct-drive hub motor with modularized stator structure

Abstract

The invention discloses a direct-drive hub motor with a modular stator structure, belongs to the field of motors, and aims to solve the problems of the existing hub motor with a modular structure. The motor comprises a stator, a rotor and a cooling water jacket. The stator is arranged in the rotor, and a radial air gap exists between the stator and the rotor; a cooling water jacket is nested on the inner circle surface of the stator; the stator comprises m stator modules, the m stator modules are connected into a circle in the circumferential direction through first mortise and tenon structures, each stator module comprises stator teeth, a stator winding and a stator yoke, the stator teeth are arranged at the top end of each stator yoke, the stator teeth and the stator yokes are of an integrated structure, and first dovetail tenons and first dovetail mortises are symmetrically arranged on the stator yokes left and right. Every two adjacent stator yokes are fixedly connected through a first mortise and tenon joint structure formed by the first dovetail tenon and the first dovetail mortise, and stator windings are wound on the stator teeth.

Description

Technical Field

[0001] The invention relates to a novel modular stator structure of a hub motor and belongs to the field of motors. Background Art

[0002] The hub motor is limited by the wheel rim. Compared with the centralized drive motor, the motor has a larger outer diameter, which means that the utilization rate of the core material is lower and the processing technology of the whole core is more difficult. The stator block structure can not only effectively improve the utilization rate of silicon steel sheet materials, but also facilitate the batch winding embedding process, effectively improving the manufacturing efficiency of the motor.

[0003] The direct-drive permanent magnet synchronous hub motor is directly installed in the wheel hub and generally adopts a fully enclosed structure, which makes its working environment more harsh. Due to its high power density, it will generate a lot of heat. The enclosed structure will prevent the heat generated by the motor from being effectively transferred out. Therefore, the temperature rise of the permanent magnet synchronous hub motor is higher than that of other automotive drive motors.

[0004] Direct-drive permanent magnet synchronous hub motors usually use water cooling: the inner circle of the stator core and the water jacket are fixed by interference fit, and the heat dissipation area is small. For high-power density direct-drive hub motors, it is not conducive to the conduction of motor heat.

[0005] Modular design of direct-drive permanent magnet synchronous hub motors is a relatively common technical means. Commonly used modular schemes are as follows: the more commonly used is the E-type modular scheme. Due to its own characteristics, this structure uses less windings, resulting in low motor power density; another commonly used is the T-type modular scheme. The T-type stator module needs to be fixed by welding during the assembly process. In the large-size, multi-module assembly scheme, the roundness of the stator cannot be guaranteed, which seriously affects the performance of the motor. In addition, because the direct-drive hub motor adopts an outer rotor motor structure, the traditional T-type modular stator scheme is no longer applicable; the traditional T-type modular stator is connected to the motor housing by an interference fit, so most of the outer rotor motors adopt the traditional tooth yoke separation modular scheme, and the stator teeth in the tooth yoke separation modular scheme are wider on the slot side than on the slot bottom side, resulting in sliding during winding, sliding out from the yoke side of the tooth, and not easy to fix, which will lead to problems such as unqualified winding and damage to the insulating paint film. Summary of the invention

[0006] In view of the problems existing in the existing hub motors with modular structures, the present invention provides a direct-drive hub motor with a modular stator structure.

[0007] The direct-drive hub motor with a modular stator structure described in the present invention comprises a stator 1, a rotor 2 and a cooling water jacket 3; the stator 1 is arranged inside the rotor 2, and there is a radial air gap between the two; the cooling water jacket 3 is nested on the inner surface of the stator 1;

[0008] The stator 1 includes m stator modules, which are connected to form a circle along the circumferential direction through a first mortise and tenon structure 104. The stator modules include stator teeth 101, stator windings 102 and stator yokes 103. The stator teeth 101 are arranged at the top of the stator yoke 103 and the two are an integrated structure. The stator yoke 103 is symmetrically provided with a first dovetail tenon 104-1 and a first dovetail tenon groove 104-2. Two adjacent stator yokes 103 are fixedly connected by the first mortise and tenon structure 104 formed by the first dovetail tenon 104-1 and the first dovetail tenon groove 104-2. The stator windings 102 are wound on the stator teeth 101.

[0009] Preferably, it also includes a second mortise and tenon structure 4, which is composed of a second dovetail tenon 4-1 and a second dovetail tenon groove 4-2. The inner circular surface of the stator yoke 103 is provided with a second dovetail tenon 4-1, and the second dovetail tenon groove 4-2 is provided at a corresponding position on the outer circular surface of the cooling water jacket 3. The stator 1 and the cooling water jacket 3 are fixedly connected by the second mortise and tenon structure 4.

[0010] Preferably, the cooling water jacket 3 comprises an annular water jacket body 31 , an annular water channel 32 is provided inside the annular water jacket body 31 , and m second dovetail grooves 4 - 2 are evenly distributed on the outer circumferential surface of the annular water jacket body 31 .

[0011] Preferably, the stator winding 102 is a flat wire winding using a flat wire vertical winding process.

[0012] Preferably, the rotor 2 comprises a rotor core 201 and permanent magnets 202 , and a plurality of permanent magnets 202 are evenly distributed on the inner circumferential surface of the rotor core 201 .

[0013] Beneficial effects of the present invention:

[0014] 1. The present invention provides a novel hub motor with a modular structure. The stator module is circumferentially fixed by a dovetail groove. At the same time, the dovetail groove is combined with a cooling water jacket, which can increase the contact area between the stator and the water jacket to facilitate heat dissipation, and the stator module can be fixed by the dovetail groove to ensure the roundness of the stator core after assembly.

[0015] 2. The motor of the present invention adopts a flat wire vertical winding process, which is convenient for winding. Compared with the E-type modular solution, the structure and winding process of the present invention significantly increase the amount of windings and improve the power density of the motor.

[0016] 3. Compared with the commonly used modular solution of tooth-yoke separation, in the modular solution of the present invention, the stator teeth and the yoke are an integrated part, and the yoke serves as a limiting structure for the winding, so that the winding can be closely arranged when the flat wire is wound vertically, making the modular solution of the present invention more suitable for direct-drive hub motors with parallel slot solutions for the stator.

[0017] 4. Due to the influence of the processing technology, under the same tolerance and conditions, the modular stator solution of the present invention is more efficient and has higher power density than the traditional gear yoke separation modular solution. In addition, the new modular stator solution can effectively reduce the influence of the additional air gap caused by processing on the motor performance. Through finite element simulation analysis, the motor performance loss caused by the modular process is reduced by about 50% by the scheme of the present invention compared with the gear yoke separation modular solution. The design scheme of the present invention can also reduce the stator iron loss of the motor by 15%. As far as the hub motor is concerned, high efficiency, high power density and high torque density are the directions pursued by the hub motor. Therefore, in the case of limited space, a more reasonable modular solution is needed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a direct-drive hub motor with a modular stator structure according to the present invention;

[0019] Figure 2 It is a schematic diagram of the stator module structure, without winding;

[0020] Figure 3 It is a schematic diagram of the stator module structure and winding;

[0021] Figure 4 It is a schematic diagram of the stator structure, without winding;

[0022] Figure 5 It is a schematic diagram of the cooling water jacket structure;

[0023] Figure 6 It is a schematic diagram of the structure of the stator combined with the cooling water jacket, without winding;

[0024] Figure 7 It is a schematic diagram of the structure of the stator and cooling water jacket combined, winding. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0027] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0028] Specific implementation method 1: The following is combined Figures 1 to 7The present embodiment is described. The present embodiment describes a direct-drive hub motor with a modular stator structure, comprising a stator 1, a rotor 2 and a cooling water jacket 3. The stator 1 is arranged inside the rotor 2, and there is a radial air gap between the two. The cooling water jacket 3 is nested on the inner surface of the stator 1.

[0029] The stator 1 includes m stator modules, which are connected to form a circle along the circumferential direction through a first mortise and tenon structure 104. The stator modules include stator teeth 101, stator windings 102 and stator yokes 103. The stator teeth 101 are arranged at the top of the stator yoke 103 and the two are an integrated structure. The stator yoke 103 is symmetrically provided with a first dovetail tenon 104-1 and a first dovetail tenon groove 104-2. Two adjacent stator yokes 103 are fixedly connected by the first mortise and tenon structure 104 formed by the first dovetail tenon 104-1 and the first dovetail tenon groove 104-2. The stator windings 102 are wound on the stator teeth 101.

[0030] Different from the modular structure with separated tooth and yoke, in this embodiment, the stator teeth 101 and the stator yoke 103 are an integrated structure. The stator yoke is separated at the center of the stator slot bottom, and a first mortise and tenon structure 104 is added to the connecting part of the stator yoke of the two modules, so as to ensure the stability of the connection between the modules of the stator core and the roundness of the stator core.

[0031] Furthermore, it also includes a second mortise and tenon structure 4, which is composed of a second dovetail tenon 4-1 and a second dovetail tenon groove 4-2. The inner circular surface of the stator yoke 103 is provided with a second dovetail tenon 4-1, and the second dovetail tenon groove 4-2 is provided at a corresponding position of the outer circular surface of the cooling water jacket 3. The stator 1 and the cooling water jacket 3 are fixedly connected by the second mortise and tenon structure 4, and the first mortise and tenon structure cooperates with the second mortise and tenon structure to ensure the roundness of the stator core of the motor.

[0032] See also Figure 5 The cooling water jacket 3 comprises an annular water jacket body 31, an annular water channel 32 is provided inside the annular water jacket body 31, and m second dovetail grooves 4-2 are evenly distributed on the outer circumferential surface of the annular water jacket body 31.

[0033] The second dovetail tenon 4-1 on the inner side of the stator is combined with the second dovetail tenon groove 4-2 on the outer side of the cooling water jacket 3 to fix the modular stator, and the roundness of the stator core is further ensured through this structure.

[0034] In this embodiment, the stator modules are connected to each other via the first mortise and tenon structure 104 , which together with the second mortise and tenon structure 4 fix the stator core.

[0035] In this embodiment, a cooling water jacket 3 is added to the inner side of the stator 1 for motor heat dissipation. The modular stators are connected into a circle through mortise and tenon structures, and the cooling water jacket 3 is connected through the mortise and tenon structure. This design can increase the contact area between the stator 1 and the cooling water jacket to facilitate heat dissipation, and can also fix the modular stator through the dovetail groove.

[0036] The stator winding 102 is a flat wire winding, and a flat wire vertical winding process is used. The structure of the motor in this embodiment is convenient for the winding of the flat wire winding. First, the flat wire is wound on the stator teeth 101 of each stator module by a vertical winding process, and then the stator module is assembled and inserted into the cooling water jacket 3 to complete the stator structure of the hub motor. In this embodiment, the stator teeth 101 and the stator yoke 103 are an integral part, and the stator yoke 103 also serves as a limiting structure for the winding. At the same time, a limiting outward turning edge is set at the end of the stator tooth 101. The two limiting structures at the end and the bottom ensure that the winding is closely arranged on the stator tooth 101 when the flat wire is vertically wound, and it is not easy to fall out.

[0037] The rotor 2 includes a rotor core 201 and permanent magnets 202 . A plurality of permanent magnets 202 are evenly distributed on the inner circumferential surface of the rotor core 201 .

[0038] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. A direct-drive hub motor with a modular stator structure, characterized in that: It comprises a stator (1), a rotor (2) and a cooling water jacket (3); the stator (1) is arranged inside the rotor (2), and a radial air gap exists between the two; the cooling water jacket (3) is nested on the inner circular surface of the stator (1); The stator (1) comprises m stator modules, the m stator modules are connected to form a circle along the circumferential direction through a first mortise and tenon structure (104), the stator modules comprise stator teeth (101), stator windings (102) and a stator yoke (103), the stator teeth (101) are arranged at the top of the stator yoke (103) and the two are an integrated structure, the stator yoke (103) is symmetrically provided with a first dovetail tenon (104-1) and a first dovetail tenon groove (104-2), two adjacent stator yokes (103) are fixedly connected through the first mortise and tenon structure (104) formed by the first dovetail tenon (104-1) and the first dovetail tenon groove (104-2), and the stator windings (102) are wound on the stator teeth (101).

2. According to claim 1, a direct-drive hub motor with a modular stator structure is characterized in that: The invention also comprises a second mortise and tenon structure (4), the second mortise and tenon structure (4) being composed of a second dovetail tenon (4-1) and a second dovetail tenon groove (4-2), the inner circular surface of the stator yoke (103) being provided with the second dovetail tenon (4-1), the outer circular surface of the cooling water jacket (3) being provided with the second dovetail tenon groove (4-2) at a corresponding position, and the stator (1) and the cooling water jacket (3) being fixedly connected via the second mortise and tenon structure (4).

3. The direct-drive hub motor with a modular stator structure according to claim 2, characterized in that: The cooling water jacket (3) comprises an annular water jacket body (31), an annular water channel (32) is provided inside the annular water jacket body (31), and m second dovetail grooves (4-2) are evenly distributed on the outer circumferential surface of the annular water jacket body (31).

4. The direct-drive hub motor with a modular stator structure according to claim 1, characterized in that: The stator winding (102) is a flat wire winding using a flat wire vertical winding process.

5. The direct-drive hub motor with a modular stator structure according to claim 1, characterized in that: The rotor (2) comprises a rotor core (201) and permanent magnets (202), and a plurality of permanent magnets (202) are evenly distributed on the inner circular surface of the rotor core (201).

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