Compact flat wire motor stator
Patent Information
- Application Number
- CN202522179942.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-15
- Publication Date
- 2026-10-23
- Estimated Expiration
- 2035-10-15
AI Technical Summary
[0003]针对现有技术的不足，本实用新型的目的在于提供一种紧凑型扁线电机定子，解决了现有技术中存在着扁线电机出线分散，不利于在紧凑空间内集成布局的问题
[0022]通过将用于形成绕组对应电机相数的各个出线端及中性点的多根直线导体集中布设于同一扇形区域内连续的多个定子槽中，并保持各直线导体位于定子槽内的同一径向层内，从而在结构上实现了扁线电机中各电气连接的出线端的空间集中，便于外部零件做整体避让并进行对接安装，更加适用于E-bike的中置电机模组中狭小的电机安装空间的安装需求，使得中置电机模组整体结构更加紧凑。
Smart Images
Figure CN224890420U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of flat wire motor technology, specifically relating to a compact flat wire motor stator. Background Technology
[0002] Currently, due to extremely limited installation space, mid-drive motor modules in electric-assist bicycles (E-bikes) generally employ short-end, compact, concentrated-winding (or on-tooth winding) permanent magnet synchronous motors. However, these motors, limited by their structure, suffer from low slot fill factor and high cogging torque, making it difficult to improve power density and efficiency, and resulting in poor electromagnetic vibration and noise (NVH) performance. To improve performance, flat-wire motor technology has been introduced into this field, as its high slot fill factor and excellent heat dissipation help achieve higher power density and efficiency. However, the winding terminals and neutral point of traditional flat-wire motor stators are relatively dispersed in the circumferential direction, resulting in a lack of centralized end electrical interfaces. This is not conducive to bus integration and peripheral structural avoidance within the limited radial and axial space of the E-bike mid-drive motor; therefore, existing technologies suffer from the problem of dispersed flat-wire motor leads, which is not conducive to integration and layout within a compact space. Utility Model Content
[0003] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a compact flat wire motor stator, which solves the problem that the wires of the flat wire motor are scattered and it is not conducive to the integrated layout in a compact space.
[0004] The objective of this utility model can be achieved through the following technical solutions:
[0005] A compact flat wire motor stator includes a stator core and a flat wire winding with multiple straight conductors, the multiple straight conductors being used to form the output terminals and neutral point of the winding corresponding to the number of phases of the motor.
[0006] The stator core has multiple stator slots, which are evenly distributed in a ring around the central axis of the stator core.
[0007] The number of linear conductors is twice the number of phases of the motor. Each linear conductor is placed sequentially in multiple stator slots within the same sector area on the stator core, and each linear conductor is located in the same radial layer within the corresponding stator slot.
[0008] The flat wire windings correspond to the output terminals and neutral point of each phase of the motor, all located within a sector-shaped area where multiple straight conductors are placed.
[0009] Furthermore, the number of stator slots is an integer multiple of the number of motor phases.
[0010] Furthermore, the flat wire winding also includes multiple cross coils, each cross coil having two legs and a transition section connecting the two legs. The two legs of the cross coil extend from one end of the stator core through two different stator slots to the other end of the stator core, and the spacing between the two stator slots corresponding to the two legs of each cross coil is equal.
[0011] Furthermore, the stator slot is divided into four radial layers along the stator core: layer a, layer b, layer c, and layer d. Layer a is located at the end of the stator slot away from the central axis of the stator core, and all straight conductors are located in layer d of the stator slot.
[0012] Furthermore, the cross coils include same-layer cross coils and different-layer cross coils. The two legs of the same-layer cross coils are located in the same radial layer of different stator slots; the two legs of the different-layer cross coils are located in different radial layers of different stator slots. The number of same-layer cross coils is equal to the number of phases of the motor.
[0013] Furthermore, the two legs of the cross coil in the same layer are located in the nth stator slot and the (n+Y)th stator slot in the (n+Y)th layer, respectively, where n and Y are both positive integers and Y is the number of phases of the motor.
[0014] Each cross coil in the same layer is arranged sequentially and occupies multiple adjacent stator slots. Each stator slot in the area occupied by each cross coil in the same layer has one and only one support foot.
[0015] If the stator slot number occupied by the foremost support foot in the clockwise direction of each cross coil in the same layer is l, then the stator slot number occupied by the straight conductor at the foremost point in the clockwise direction is l+Y.
[0016] Furthermore, the cross-layer cross-coil includes a first cross-layer cross-coil, a second cross-layer cross-coil, and a third cross-layer cross-coil, which together occupy the radial layers in each stator slot that are not occupied by straight conductors or same-layer cross-coils. The cross-layer connection method of the first cross-layer cross-coil, the second cross-layer cross-coil, and the third cross-layer cross-coil is as follows:
[0017] The two ends of the first cross-coil are located in layer b of stator slot m and layer c of stator slot m+Y after extending clockwise Y positions, where m is a positive integer;
[0018] The two legs of the second cross-coil are located in layer a of stator slot m and layer b of stator slot m+Y, which is Y positions clockwise.
[0019] The two ends of the third cross-coil are located in the d layer of the m-th stator slot and the c layer of the (m+Y)-th stator slot, which is Y positions clockwise.
[0020] Furthermore, the number of phases Y of the motor is equal to 3, and the output terminals corresponding to each phase number include the U-phase output terminal, the V-phase output terminal, and the W-phase output terminal.
[0021] The beneficial effects of this utility model are:
[0022] By concentrating multiple straight conductors used to form the winding corresponding to the number of motor phases and the neutral point in multiple consecutive stator slots within the same sector area, and keeping each straight conductor in the same radial layer within the stator slot, the spatial concentration of the output terminals of each electrical connection in the flat wire motor is achieved structurally. This facilitates the overall avoidance and docking installation of external parts, making it more suitable for the installation requirements of the narrow motor installation space in the mid-drive motor module of E-bike, and making the overall structure of the mid-drive motor module more compact. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0025] Figure 2 This is a schematic diagram of a portion of the stator slot structure of this utility model;
[0026] Figure 3 This is a schematic diagram of the radial layer division of the stator slots according to this utility model;
[0027] Figure 4 This is a schematic diagram of the linear conductor structure of this utility model;
[0028] Figure 5 This is a schematic diagram of the same-layer cross-coil structure of this utility model;
[0029] Figure 6 This is a schematic diagram of the first heterogeneous cross-coil structure of this utility model;
[0030] Figure 7 This is a schematic diagram of the second heterogeneous cross-coil structure of this utility model;
[0031] Figure 8 This is a schematic diagram of the third layer cross-coil structure of this utility model. Detailed Implementation
[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.
[0033] like Figures 1 to 8 A compact flat wire motor stator includes a stator core 6 and a flat wire winding with multiple straight conductors 7, the multiple straight conductors 7 being used to form the output terminals and neutral point 4 of the winding corresponding to the number of motor phases.
[0034] The stator core 6 has multiple stator slots 61, which are evenly distributed in a ring around the central axis of the stator core 6.
[0035] The number of linear conductors 7 is twice the number of phases of the motor. Each linear conductor 7 is placed in a series of stator slots 61 in the same sector area on the stator core 6. Each linear conductor 7 is located in the same radial layer within the corresponding stator slot 61.
[0036] The output terminals of the flat wire windings corresponding to each phase of the motor and the neutral point 4 are all located in the fan-shaped area where multiple straight conductors 7 are placed.
[0037] To address the issues of dispersed output terminals and complex external interfaces in existing flat wire motors, this application addresses these problems by centrally arranging multiple straight conductors 7 (U-phase output terminal 1, V-phase output terminal 2, W-phase output terminal 3, and neutral point 4) within a continuous series of stator slots 61 in the same sector area. Furthermore, it maintains that each straight conductor 7 is located within the same radial layer of the stator slot 61. This structurally achieves spatial centralization of the output terminals for each electrical connection in the flat wire motor, facilitating the overall avoidance and docking of external components. This approach is more suitable for the limited installation space required in the mid-drive motor module of E-bikes, resulting in a more compact overall structure for the mid-drive motor module.
[0038] The linear conductor 7 is made of linear conductive metal and can be bent under external force.
[0039] It should be noted that three of the multiple straight conductors 7 are configured as three-phase leads, and their ends used for electrical connection are separated from each other or insulated. These three straight conductors 7 serve as the U-phase lead 1, V-phase lead 2, and W-phase lead 3 of the flat wire winding, respectively. Among the remaining straight conductors 7, the ends of the multiple straight conductors 7 belonging to different phases are welded together to form the neutral point 4 of the flat wire winding.
[0040] The number of stator slots 61 is an integer multiple of the number of motor phases.
[0041] The flat wire winding also includes multiple cross coils, each with two legs and a transition section connecting the two legs. The two legs of the cross coil extend from one end of the stator core 6 through two different stator slots 61 to the other end of the stator core 6, and the spacing between the two stator slots 61 corresponding to the two legs of each cross coil is equal. The cross coil is an important component of the hairpin-type flat wire winding in the prior art. The two legs of the cross coil are inserted into different stator slots 61, and after passing through the stator core 6, the two legs are welded and fixed, thereby forming a continuous winding circuit between the stator slots 61.
[0042] The stator slot 61 is divided into four radial layers along the stator core 6: layer a, layer b, layer c, and layer d. Layer a is located at the end of the stator slot 61 away from the central axis of the stator core 6, and each straight conductor 7 is located in layer d of the stator slot 61.
[0043] By uniformly arranging the linear conductors 7 in the d layer of the stator slot 61 closest to the central axis of the stator core 6, each linear conductor 7 forms a flat welding plane, providing a direct and interference-free installation interface for the external busbars, facilitating assembly and processing. At the same time, the uniform arrangement of the linear conductors 7 in the d layer reserves the a, b, and c layers in each stator slot 61 for installing cross coils. This not only provides sufficient operating space for the installation of cross coils and effectively reduces the interference of the linear conductors 7 on the installation of cross coils, but also ensures the regularity of the cross coil arrangement in the flat wire winding, thereby optimizing the electromagnetic performance of the flat wire winding.
[0044] The cross coils include same-layer cross coils 8 and different-layer cross coils. The two legs of the same-layer cross coil 8 are located in the same radial layer of different stator slots 61. The two legs of the different-layer cross coils are located in different radial layers of different stator slots 61. The number of same-layer cross coils 8 is equal to the number of phases of the motor.
[0045] Since the two legs of the same-layer cross coil 8 are located in the same radial layer, a low-profile end-face welding plane is formed, which significantly reduces the axial dimension of the motor and simplifies the installation of the external electrical interface; the cross coils of different layers are bridging between different radial layers to construct a complete current loop, determine the balance of the parallel branches and the stable output of electromagnetic torque.
[0046] The two legs of the cross coil 8 in the same layer are located in the nth stator slot 61 and the (n+Y)th stator slot 61 in the a layer, respectively, after Y positions in the clockwise direction. n and Y are both positive integers, and Y is the number of phases of the motor.
[0047] Each cross coil 8 in the same layer is arranged sequentially and occupies multiple adjacent stator slots 61. Each stator slot 61 in the area occupied by each cross coil 8 in the same layer has only one support foot.
[0048] If the stator slot 61 occupied by the foremost support foot in the clockwise direction of each cross coil 8 in the same layer is l, then the stator slot 61 occupied by the straight conductor 7 at the foremost position in the clockwise direction is l+Y.
[0049] The cross-layer cross-coil includes a first cross-layer cross-coil 9, a second cross-layer cross-coil 10, and a third cross-layer cross-coil 11, which together occupy the radial layers in each stator slot 61 that are not occupied by the straight conductor 7 and the same-layer cross-coil 8. The cross-layer connection method of the first cross-layer cross-coil 9, the second cross-layer cross-coil 10, and the third cross-layer cross-coil 11 is as follows:
[0050] The two ends of the first cross-coil 9 are located in layer b of stator slot m and layer c of stator slot m+Y after extending clockwise Y positions, where m is a positive integer;
[0051] The two ends of the second layer cross coil 10 are located in layer a of stator slot m and layer b of stator slot m+Y after extending clockwise Y positions.
[0052] The two ends of the third cross-coil 11 are located in the d layer of the mth stator slot 61 and the c layer of the (m+Y)th stator slot 61 after extending clockwise by Y positions.
[0053] By using the first interlayer cross-coil 9, the second interlayer cross-coil 10, and the third interlayer cross-coil 11, they collectively fill the radial layers in each stator slot 61 that are not occupied by the straight conductor 7 and the same-layer cross-coil 8. This maximizes the utilization rate and electromagnetic performance of the flat wire windings, not only eliminating the waste of space in the stator slots 61, but also ensuring the highest slot fill factor. Furthermore, it constructs a symmetrical and complete interlayer current loop, effectively ensuring the impedance balance of the parallel branches. This effectively suppresses torque pulsation and circulating current loss, thereby improving the power density of the motor while ensuring its smooth operation.
[0054] The number of phases Y of the motor is 3, and the output terminals corresponding to each phase include U-phase output terminal 1, V-phase output terminal 2 and W-phase output terminal 3.
[0055] It should be noted that after the straight conductor 7, the same-layer cross coil 8, the first different-layer cross coil 9, the second different-layer cross coil 10 and the third different-layer cross coil 11 are all plugged in and installed, only the stator assembly is completed. Subsequent welding and other processes are required to achieve complete electrical connection. Since the subsequent welding process for electrical connection is prior art in this field, it will not be described in detail in this application.
[0056] This application provides the following embodiment, wherein the outer diameter of the stator core 6 is 80mm and the total number of stator slots 61 is 48;
[0057] Marking points are provided on the 6th circumferential wall of the stator core. Counting clockwise from the marking point, the first stator slot 61 encountered is stator slot number 1, and the last one is stator slot number 48.
[0058] There are 6 straight conductors 7, which are located in the d layer of stator slots 61 from No. 2 to No. 7 respectively;
[0059] There are 3 cross coils 8 in the same layer. The six legs of the three cross coils 8 in the same layer occupy the a layer of stator slots 47, 48, 1 and 2, 3 and 4 respectively.
[0060] The number of first-layer cross coils 9 is 6. Any first-layer cross coil 9 occupies layer b in positioning slots 2-7 and layer c in positioning slots 5-10 according to the set bc cross-layer connection method.
[0061] The second layer cross coil 10 occupies the a layer position in the stator slot 61 except for the 47th, 48th and 1-4th positioning slots, and occupies the b layer position in the stator slot 61 except for the 2nd-7th positioning slots, according to the preset ab layer connection method.
[0062] The third cross-coil 11 occupies the c-layer position in stator slot 61 (excluding positioning slots 5-10) and the d-layer position in stator slot 61 (excluding positioning slots 2-7) according to the preset d-layer connection method.
[0063] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0064] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims of this utility model.
Claims
1. A compact flat wire motor stator, comprising a stator core (6) and a flat wire winding having multiple straight conductors (7), wherein the multiple straight conductors (7) are used to form the output terminals and neutral point (4) of the winding corresponding to the number of phases of the motor, characterized in that: The stator core (6) has multiple stator slots (61) which are evenly distributed in a ring around the central axis of the stator core (6). The number of linear conductors (7) is twice the number of phases of the motor. Each linear conductor (7) is placed in a series of stator slots (61) in the same sector area on the stator core (6), and each linear conductor (7) is located in the same radial layer within the corresponding stator slot (61). The flat wire windings correspond to the output terminals and neutral point (4) of each phase of the motor, which are all located in the fan-shaped area where multiple straight conductors (7) are placed.
2. The compact flat wire motor stator according to claim 1, characterized in that, The number of stator slots (61) is an integer multiple of the number of motor phases.
3. The compact flat wire motor stator according to claim 2, characterized in that, The flat wire winding also includes multiple cross coils, each cross coil having two legs and a transition section connecting the two legs. The two legs of the cross coil extend from one end of the stator core (6) through two different stator slots (61) to the other end of the stator core (6), and the spacing between the two stator slots (61) corresponding to the two legs of each cross coil is equal.
4. The compact flat wire motor stator according to claim 3, characterized in that, The stator slot (61) is divided into four radial layers along the stator core (6): layer a, layer b, layer c and layer d. Layer a is located at the end of the stator slot (61) away from the central axis of the stator core (6), and each straight conductor (7) is located in layer d of the stator slot (61).
5. The compact flat wire motor stator according to claim 4, characterized in that, The cross coils include same-layer cross coils (8) and different-layer cross coils. The two legs of the same-layer cross coils (8) are located in the same radial layer of different stator slots (61); the two legs of the different-layer cross coils are located in different radial layers of different stator slots (61). The number of same-layer cross coils (8) is equal to the number of phases of the motor.
6. The compact flat wire motor stator according to claim 5, characterized in that, The two legs of the cross coil (8) in the same layer are located in the a layer of the nth stator slot (61) and the (n+Y)th stator slot (61) after Y positions in the clockwise direction, respectively. n and Y are both positive integers, and Y is the number of phases of the motor. Each cross coil (8) in the same layer is arranged sequentially and occupies multiple adjacent stator slots (61). Each stator slot (61) in the area occupied by each cross coil (8) in the same layer has only one support foot. If the stator slot (61) occupied by the foremost support foot in the clockwise direction of each cross coil (8) is l, then the stator slot (61) occupied by the straight conductor (7) at the foremost point in the clockwise direction is l+Y.
7. The compact flat wire motor stator according to claim 6, characterized in that, The cross-layer coils include a first cross-layer coil (9), a second cross-layer coil (10), and a third cross-layer coil (11), which together occupy the radial layers in each stator slot (61) that are not occupied by the straight conductor (7) and the same-layer cross-layer coil (8). The cross-layer connection method of the first cross-layer coil (9), the second cross-layer coil (10), and the third cross-layer coil (11) is as follows: The two ends of the first cross-coil (9) are located in layer b of stator slot m (61) and layer c of stator slot m+Y after extending clockwise Y positions, where m is a positive integer; The two legs of the second cross coil (10) are located in layer a of stator slot m (61) and layer b of stator slot m+Y after extending clockwise Y positions; The two ends of the third cross-coil (11) are located in the d layer of the mth stator slot (61) and the c layer of the m+Yth stator slot (61) after Y positions clockwise.
8. The compact flat wire motor stator according to claim 7, characterized in that, The number of phases Y of the motor is 3. The output terminals corresponding to each phase number include the U-phase output terminal (1), the V-phase output terminal (2), and the W-phase output terminal (3).