Motor stator and motor

Abstract

The utility model provides a motor stator and a motor. The motor stator comprises a stator core and a stator winding which are assembled together. The stator iron core is provided with a plurality of grooves which are distributed in the circumferential direction of the motor stator at intervals, and the stator winding is installed on the stator iron core. The stator winding comprises a plurality of hairpin units, each hairpin unit is inserted into two different grooves, the different hairpin units are welded together to enable the stator winding to form a preset electrical loop, and all welding portions of the stator winding are located on the two axial sides of the stator iron core. The electric distance between adjacent welding parts can be increased through a relatively simple structure, and corresponding cost is saved. In addition, the electrical distance between the welding parts of the stator winding is increased, so that the electrical safety performance of the motor comprising the motor stator can be fully improved.

Description

Technical Field

[0001] This application relates to the field of electric motors, and particularly to electric motor stators and electric motors including such stators. Background Technology

[0002] Today, electric motors are widely used in pure electric vehicles and hybrid vehicles as a power source to drive the vehicle. An electric motor typically consists of a stator and a rotor that can rotate relative to the stator. The stator includes a stator core and stator windings assembled together. For example... Figure 1A and Figure 1B As shown, in a typical configuration of the stator winding 10, multiple hairpin units (also known as U-pins) 10a are welded together. In this winding configuration, the welded joints of different hairpin units 10a inserted into the slots 20c of the stator core are located on the same side of the stator core along the axial direction A of the motor stator. As the performance requirements of motors become increasingly stringent, the number of conductor layers in each slot 20c of the stator core (i.e., the number of hairpin units 10a inserted into each slot 20c) is increasing, potentially reaching up to ten layers per slot 20c. This results in a very large number of welded joints where the hairpin units 10a of the motor winding are welded together, leading to a smaller electrical distance between adjacent welded joints. However, with the voltage of motors used in pure electric vehicles and hybrid vehicles reaching 800V or higher, this reduced electrical distance cannot meet the electrical safety requirements of the motor.

[0003] To improve the electrical safety performance of motors, one existing solution involves applying or potting insulating materials to the welded areas for additional insulation. However, this complicates the motor manufacturing process, increases costs, makes it difficult to guarantee motor quality, and the materials used for insulation may pollute the environment. Another existing solution, such as the international patent application WO2024 / 045795A1 entitled "A Motor, Powertrain, and Vehicle," uses insulating covers to cover the electrical connections and leads of the windings, increasing the electrical clearance and creepage distance between adjacent components and improving the motor's insulation safety. However, this only increases the electrical distance between the welded areas of a portion of the motor's components, offering limited improvement to the motor's electrical safety. Utility Model Content

[0004] To overcome or at least mitigate the shortcomings of the prior art, one object of this application is to provide a motor stator that can increase the electrical distance between all adjacent welded parts of a hairpin motor winding with a relatively simple construction. Another object of this application is to provide a motor including the above-described motor stator, which can significantly improve the electrical safety performance of the motor.

[0005] To achieve the above objectives, this application adopts the following technical solution.

[0006] This application provides a motor stator, including a stator core and a stator winding. The stator core has a plurality of slots spaced apart circumferentially on the motor stator, and the stator winding is mounted on the stator core.

[0007] The stator winding includes multiple hairpin units, each of which is inserted into two different slots. The different hairpin units are welded together to form a predetermined electrical circuit. All the welded parts of the hairpin units of the stator winding are located on both sides of the axial direction of the stator core.

[0008] In one alternative, the welding points corresponding to two hairpin units inserted into adjacent layers of the same slot are located on opposite sides of the stator core.

[0009] In another alternative embodiment, the stator winding includes a multi-phase winding, wherein the welding portions corresponding to the hairpin units constituting each phase winding are located on both axial sides of the stator core.

[0010] In another alternative embodiment, all the welded portions located on one axial side of the stator core are electrically equidistant from adjacent welded portions in the circumferential direction of the motor stator; and

[0011] All the welded parts located on the other side of the stator core in the axial direction are electrically equidistant from each other in the circumferential direction of the motor stator.

[0012] In another alternative, the number of welded portions located on one axial side of the stator core is equal to the number of welded portions located on the other axial side of the stator core.

[0013] In another alternative, the number of welding points corresponding to the slot is half the number of hairpin units in the slot, and these welding points are evenly distributed on both sides of the stator core.

[0014] In another alternative embodiment, at one axial end of the stator core, a non-welded portion of the hairpin unit is sandwiched between two radially adjacent welded portions, and a non-welded portion of the hairpin unit is sandwiched between two circumferentially adjacent welded portions.

[0015] In another alternative embodiment, the hairpin unit includes a first arm, a second arm, a crown-side end, a first torsion-side end, and a second torsion-side end.

[0016] The first arm and the second arm are inserted into different slots, and one end of the first arm and one end of the second arm are connected to the crown-side end.

[0017] The first twisted end is connected to the other end of the first arm and can be used for welding with other hairpin units, and the second twisted end is connected to the other end of the second arm and can be used for welding with other hairpin units.

[0018] In another alternative embodiment, for the same hairpin unit, the crown-side end and the first torsion-side end and the second torsion-side end are located on opposite sides of the stator core along its axial direction.

[0019] This application also provides a motor including the motor stator described in any of the above technical solutions.

[0020] By adopting the above technical solution, this application provides a motor stator and a motor including the motor stator. The motor stator includes a stator core and a stator winding assembled together. The stator core has multiple slots spaced apart circumferentially on the motor stator, and the stator winding is mounted on the stator core. Further, the stator winding includes multiple hairpin units, each hairpin unit inserted into two different slots, and different hairpin units are welded together so that the stator winding forms a predetermined electrical circuit. All welded portions of the stator winding are located on both axial sides of the stator core.

[0021] In this way, since all the welded joints of the stator winding hairpin units are positioned on both sides of the stator core axially, compared to a scheme where all welded joints are positioned on the same side of the stator core axially, the electrical distance between adjacent welded joints can be increased with a relatively simple structure. Furthermore, this scheme eliminates the need for additional insulation treatment of the welded joints using coating or potting insulating materials, as is done in the prior art, thus saving corresponding costs. In addition, the increased electrical distance between the welded joints of the stator winding significantly improves the electrical safety performance of the motor including the aforementioned motor stator. Attached Figure Description

[0022] Figure 1A This is a circumferentially unfolded schematic diagram showing a portion of the winding structure of a single-phase winding of an existing motor stator, where black dots represent the welding points between hairpin units.

[0023] Figure 1B It shows Figure 1AA partial schematic diagram of the motor stator is shown, in which rows of black rectangles represent the arms of the hairpin units inserted into each slot, black dots represent the welding points between the hairpin units, and the numbers above the black rectangles represent the slot numbers in the stator core.

[0024] Figure 2A This is a circumferentially unfolded schematic diagram showing the winding method of a portion of the first phase winding of a motor stator according to an embodiment of this application, wherein the black dots represent the welding parts between the hairpin units.

[0025] Figure 2B This is a circumferentially unfolded schematic diagram showing the winding method of a portion of the second phase winding of a motor stator according to an embodiment of this application, wherein the black dots represent the welding parts between the hairpin units.

[0026] Figure 2C This is a circumferentially unfolded schematic diagram showing the winding method of a portion of the third phase winding of an electric motor stator according to an embodiment of this application, wherein the black dots represent the welding parts between the hairpin units.

[0027] Figure 2D It shows Figures 2A to 2C The diagram shows a partial view of the motor stator, where rows of black rectangles represent the insertion points of the card-cutting units into their respective slots, black dots represent the welding points between the card-cutting units, and the numbers above the black rectangles represent the slot numbers in the stator core.

[0028] Figure 3 It shows Figures 2A to 2C A schematic diagram of the stator winding hairpin unit of the motor stator.

[0029] Explanation of reference numerals in the attached figures

[0030] 10 stator windings; 10a hairpin unit; 20c slot;

[0031] 1. Stator winding; 1a. Hairpin unit; 11. First arm; 12. Second arm; 13. Crown-side end; 14. First torsional-side end; 15. Second torsional-side end; 2c. Slot;

[0032] A. Axial direction; C. Circumferential direction Detailed Implementation

[0033] Exemplary embodiments of this application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are for teaching those skilled in the art how to implement this application only, and are not intended to exhaust all possible methods of this application, nor to limit the scope of this application.

[0034] In this application, "axial," "radial," and "circumferential" refer to the axial, radial, and circumferential directions of the motor stator (stator core), respectively. "One side of the axial direction" and "the other side of the axial direction" refer to opposite sides in the axial direction; otherwise, no special limitations are imposed on "one side of the axial direction" and "the other side of the axial direction." In the accompanying drawings of this application, "one side of the axial direction" can be... Figure 1A , Figure 2A , Figure 2B , Figure 2C The upper side of the middle, the other side of the axis can be Figure 1A , Figure 2A , Figure 2B , Figure 2C The lower side of the middle.

[0035] The structure of the motor stator according to this application will be described below with reference to the accompanying drawings.

[0036] According to one embodiment of this application, the motor stator can be used, for example, in a three-phase motor (i.e., the number of phases of current in the windings of the motor stator is three). Specifically, the motor stator includes a stator core and a stator winding 1 assembled together.

[0037] In this embodiment, the stator core can be formed by stacking silicon steel sheets. For example... Figures 2A to 2D As shown, the stator core has a plurality of slots 2c evenly distributed at intervals C along the circumferential direction. In this embodiment, the number of slots 2c is 48. Figures 2A to 2C The diagram shows a schematic representation of these 48 slots 2c unfolded along the circumferential direction C. It can be understood that... Figures 2A to 2C In the diagram, two parallel line segments marked with Arabic numerals represent slots 2c with different serial numbers, in order to facilitate the explanation of the technical solution of this application. Figure 2D The diagram shows the radial arrangement of the arms (flat lines) of the hairpin units 1a in different slots 2c, with four layers of arms (flat lines) of hairpin units 1a arranged radially in each slot 2c.

[0038] In this embodiment, the stator winding 1 is connected via a card issuing unit 1a (see...). Figure 3 A hairpin winding that is inserted into a slot in the stator core and twisted into shape, and then electrically connected, for example, by welding.

[0039] Specifically, stator winding 1 includes three-phase windings, and each phase winding may include multiple (e.g., two) sub-windings connected in series or in parallel, such as... Figures 2A to 2C As shown, each sub-winding is composed of multiple hairpin units 1a. Specifically, as... Figure 3As shown, each hairpin unit 1a includes an integrally formed first arm 11, a second arm 12, a crown-side end 13, a first torsional-side end 14, and a second torsional-side end 15. The first arm 11 and the second arm 12 both extend linearly along the axial direction A of the stator core. The first arm 11 and the second arm 12 of the same hairpin unit 1a are located in different slots 2c and in different layers within the slots 2c. For example, as... Figure 1A As shown, the first arm 11 of a card-spinning unit 1a can be located in the first layer of the first slot 2c, and the second arm 12 can be located in the second layer of the seventh slot 2c. Further, let the number of slots 2c spanned by the first arm 11 and the second arm 12 of the card-spinning unit 1a be the pitch. In this embodiment, the pitch of the card-spinning units 1a in each phase winding can be the same. Additionally, as... Figure 3 As shown, the crown-side end 13 has a bent shape, and one end of the first arm 11 and one end of the second arm 12 are connected to the crown-side end 13. The first torsional end 14 is connected to the other end of the first arm 11 for electrical connection with other hairpin units 1a by welding; the second torsional end 15 is connected to the other end of the second arm 12 for electrical connection with other hairpin units 1a by welding. In this way, by electrically connecting the hairpin units 1a together, the phase windings realize a predetermined electrical circuit.

[0040] Furthermore, Figures 2A to 2C The diagram shows a portion of the circumferential winding structure of the first phase (which can be the U phase), the second phase (which can be the V phase), and the third phase (which can be the W phase) winding in a three-phase system (U phase, V phase, W phase, also known as A phase, B phase, and C phase). 48 slots 2c are deployed circumferentially along the C direction. Each phase winding can include two sub-windings. The winding pattern of each phase winding is the same, except that the starting slots 2c of each phase winding are different, resulting in each phase winding using different slots 2c.

[0041] like Figure 2A As shown, for a sub-winding of the first phase winding, the two arms of a hairpin unit 1a are inserted into the stator core from slots 1 and 7, respectively. The two arms of the hairpin unit 1a adjacent to this hairpin unit 1a in the circumferential direction C are inserted from slots 13 and 19, respectively. Similarly, the two arms of the next hairpin unit 1a are inserted from slots 25 and 31, and the two arms of the next hairpin unit 1a are inserted from slots 37 and 43. The arms of these hairpin units 1a can be located in the first and second layers of each slot 2c. Figure 2A As shown, the three welding points of the above-mentioned hairpin unit 1a, corresponding to a sub-winding of the first phase winding, can be located at... Figure 2AOn the lower side (the other side of the axial direction) of the first phase winding. In another sub-winding of the first phase winding, the two arms of a hairpin unit 1a are inserted into the stator core from slots 2 and 8, respectively. The two arms of the hairpin unit 1a adjacent to this hairpin unit 1a in the circumferential direction C are inserted from slots 14 and 20, respectively. And so on, the two arms of the next hairpin unit 1a are inserted from slots 26 and 32, and the two arms of the next hairpin unit 1a are inserted from slots 38 and 44. The arms of these hairpin units 1a can be located in the first and second layers of each slot 2c. Figure 2A As shown, the three welding points of the aforementioned hairpin unit 1a, corresponding to the other sub-winding of the first phase winding, are all located at... Figure 2A The upper side (axial side) of the middle. Further, as... Figure 2B and Figure 2C As shown, the winding method of the second phase winding and the third phase winding is the same as that of the first phase winding, except that the slot 2c of the initial winding of each phase winding is different, so that each phase winding uses a different slot 2c. Moreover, the distribution of the welding parts between the hairpin units 1a of the second phase winding and the third phase winding is the same as that between the hairpin units 1a of the first phase winding.

[0042] Thus, in this embodiment, all welding points of the hairpin unit 1a corresponding to each phase winding are evenly distributed on both axial sides, such that the number of welding points on one axial side of the stator core is equal to the number of welding points on the other axial side of the stator core (considering that the torsional end of some hairpin units 1a will be used as the wiring terminal for connecting the winding to, for example, a motor controller, this equality includes approximately equalness). The number of welding points corresponding to the same slot 2c is half the number of hairpin units 1a in that slot 2c, and these welding points are evenly distributed on both axial sides of the stator core. Moreover, see... Figure 2D At one axial end of the stator core, a non-welded portion of hairpin unit 1a (corresponding to the hollow circle in the figure) is sandwiched between two radially adjacent welded portions, and a non-welded portion of hairpin unit 1a (corresponding to the hollow circle in the figure) is sandwiched between two circumferentially adjacent welded portions. All welded portions on one axial side of the stator core have equal electrical distances between adjacent welded portions in the circumferential direction C (the influence of the unwelded torsional end is not considered here); and all welded portions on the other axial side of the stator core have equal electrical distances between adjacent welded portions in the circumferential direction C (the influence of the unwelded torsional end is not considered here). Further, as... Figure 1B and Figure 2D The motor stator according to this application adopts the above-described scheme. Figure 2D ), which is the same as the existing motor stator except for the distribution of the welding parts. Figure 1B Compared to the previous method, the electrical distance between the welded parts of the motor stator in this application is significantly increased, thus enabling a relatively simple structure to increase the electrical distance between adjacent welded parts. Furthermore, the solution of this application eliminates the need for additional insulation treatment of the welded parts using coating or potting insulating materials, as is done in the prior art, thereby saving corresponding costs.

[0043] It should be understood that the above embodiments are merely exemplary and are not intended to limit this application. Those skilled in the art can make various modifications and changes to the above embodiments under the teachings of this application without departing from the scope of this application. The technical solutions of this application are further described below.

[0044] i. This application also provides a motor including the above-described motor stator. Since the electrical distance between the welded parts of the stator winding 1 of the motor stator according to this application is increased, the electrical safety performance of the motor including the above-described motor stator can be significantly improved.

[0045] ii. The conductors of the windings according to this application are flat wires, more preferably flat copper wires. Flat wires enable the stator core slots 2c to achieve a filling rate of 60% or more. In this application, the sub-windings of each phase winding can be connected in series, in parallel, or in a mixed connection (series and parallel). The three-phase windings can be connected in a delta configuration or in a star configuration.

[0046] iii. It is understood that in the technical solution of this application, this application does not limit the number of layers of stator winding 1 arranged in slot 2c. The number of layers of stator winding 1 assembled on the stator core and arranged radially in each slot 2c can be 2N, where N is a positive integer. For the same card issuing unit 1a, the first arm 11 can be located in the Mth layer and the second arm 12 can be located in the M+1th layer, where M is a positive integer and is an odd number.

[0047] iv. It is understood that the technical concept of this application is that each hairpin unit 1a of the stator winding 1 is inserted into two different slots 2c, and the different hairpin units 1a are welded together to form a predetermined electrical circuit in the stator winding 1. All the welded parts of the stator winding 1 are located on both sides of the stator core along the axial direction. It is understood that various schemes can be adopted to increase the electrical distance between adjacent welded parts, and are not limited to a certain specific scheme.

[0048] Under the premise of satisfying the above technical concept, in a more preferred embodiment, the welding positions corresponding to the hairpin unit 1a inserted into one slot 2c and the welding positions corresponding to the hairpin unit 1a of the adjacent layer inserted into the same slot 2c are respectively located on both sides of the axial direction of the stator core (taking four layers of hairpin units in the same slot 2c as an example, the welding positions corresponding to the hairpin unit 1a of the first layer inserted into the same slot 2c are located on one side of the axial direction of the stator core, the welding positions corresponding to the hairpin unit 1a of the second layer inserted into the same slot 2c are located on the other side of the axial direction of the stator core, the welding positions corresponding to the hairpin unit 1a of the third layer inserted into the same slot 2c are located on one side of the axial direction of the stator core, and the welding positions corresponding to the hairpin unit 1a of the fourth layer inserted into the same slot 2c are located on the other side of the axial direction of the stator core), and the welding positions corresponding to the hairpin unit 1a constituting a sub-winding are respectively located on both sides of the axial direction of the stator core. Thus, the effect of adopting the above embodiment is illustrated using a motor stator with 48 slots and four layers of conductors in each slot 2c as an example. In this preferred embodiment, viewed axially from the stator, every two conductor layers (the arm of the hairpin unit 1a) correspond to one welding position of the hairpin unit 1a, and four conductor layers correspond to two welding positions. Viewed radially from the stator, each slot 2c corresponds to welding positions located on both sides of the axial direction. Thus, compared to an embodiment where all welding positions are located on the same side of the stator core, for each phase winding, the welding positions corresponding to each slot 2c are located on both sides of the axial direction. Therefore, the electrical distance between adjacent welding positions in the circumferential direction can be twice the pitch, and the electrical distance between adjacent welding positions in the radial direction can be the height of four conductor layers. Consequently, the electrical distance is approximately doubled compared to the prior art, both circumferentially and radially. This increased electrical distance also facilitates welding operations.

Claims

1. A motor stator, characterized in that, It includes a stator core and a stator winding. The stator core has multiple slots spaced apart circumferentially on the motor stator. The stator winding is mounted on the stator core. The stator winding includes multiple hairpin units, each of which is inserted into two different slots. The different hairpin units are welded together to form a predetermined electrical circuit. All the welded parts of the hairpin units of the stator winding are located on both sides of the axial direction of the stator core.

2. The motor stator according to claim 1, characterized in that, The welding points corresponding to the two hairpin units inserted into the same slot in adjacent layers are located on both sides of the axial direction of the stator core.

3. The motor stator according to claim 1, characterized in that, The stator winding includes a multi-phase winding, and the welding parts corresponding to the hairpin units constituting each phase winding are respectively located on both sides of the stator core along the axial direction.

4. The motor stator according to any one of claims 1 to 3, characterized in that, All the welded portions located on one axial side of the stator core are electrically equidistant from each other in the circumferential direction of the motor stator; and All the welded parts located on the other side of the stator core in the axial direction are electrically equidistant from each other in the circumferential direction of the motor stator.

5. The motor stator according to claim 4, characterized in that, The number of welded portions located on one axial side of the stator core is equal to the number of welded portions located on the other axial side of the stator core.

6. The motor stator according to any one of claims 1 to 3, characterized in that, The number of welding points corresponding to the slot is half the number of hairpin units in the slot, and these welding points are evenly distributed on both sides of the stator core.

7. The motor stator according to any one of claims 1 to 3, characterized in that, At one axial end of the stator core, a non-welded part of the hairpin unit is sandwiched between two radially adjacent welded parts, and a non-welded part of the hairpin unit is sandwiched between two circumferentially adjacent welded parts.

8. The motor stator according to any one of claims 1 to 3, characterized in that, The hairpin unit includes a first arm, a second arm, a crown-side end, a first torsion-side end, and a second torsion-side end. The first arm and the second arm are inserted into different slots, and one end of the first arm and one end of the second arm are connected to the crown-side end. The first twisted end is connected to the other end of the first arm and can be used for welding with other hairpin units, and the second twisted end is connected to the other end of the second arm and can be used for welding with other hairpin units.

9. The motor stator according to claim 8, characterized in that, For the same hairpin unit, the crown-side end and the first torsion-side end and the second torsion-side end are located on opposite sides of the stator core along the axial direction.

10. An electric motor, characterized in that, The motor stator includes any one of claims 1 to 9.

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