Winding end processing method, winding end structure, and stator assembly

Abstract

The application provides a winding end processing method, a winding end structure and a stator assembly. The winding end processing method comprises: cutting an angle of a head of a conductor to form a welding surface; the welding surface is at an angle with an axial direction of the conductor; applying a pushing force to the conductor which protrudes out of an iron core to make the conductor bend at a root; after bending, the welding surfaces of two conductors to be connected are adjacent to form a welding line; and the two conductors to be connected are connected by laser welding at the welding surface. In this way, the winding end structure is processed by applying a pushing force to the conductor, and the head of the conductor does not need to be pulled and forced, so that the head does not leave a pulling head, the height of the winding end is reduced, and the outer envelope size is reduced. On the other hand, since the head of the conductor has a welding surface formed by cutting an angle, and then laser welding is used to connect the conductor after bending at the welding surface, the insulating layer outside the welding surface is not damaged.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a winding end processing method, winding end structure, and stator assembly. Background Technology

[0002] The drive motor in an electric vehicle is one of the core components of the entire vehicle, and its service life and reliability directly affect the overall lifespan and safety of the vehicle. Therefore, the reliability and compactness of the motor winding design are particularly important for the development of automotive drive motors. New flat wire windings significantly improve the slot fill factor of the motor and have excellent heat dissipation, resulting in a substantial improvement in both peak and continuous performance.

[0003] In particular, IPIN windings are highly convenient to manufacture, have high reliability and fault tolerance, and therefore have been widely used in China.

[0004] like Figure 1 and Figure 2 As shown, the winding end 01 of the existing IPIN winding is mainly processed using a twisting process. Generally, a tooling clamps the pull end 02 located at the head and applies a pulling force F, forming two bending points 03 and 04 for each conductor. On the one hand, due to the presence of the pull end 02 above the bending point 03, the overall height of the IPIN winding end is relatively high, resulting in significant material waste and a large outer envelope size. On the other hand, when the pulling force F is applied, the insulation layer at the bending point 03 is prone to peeling off, thus easily causing defects.

[0005] Therefore, IPIN windings have faced strong challenges from other types of flat wire motors, gradually limiting their application range. Summary of the Invention

[0006] The purpose of this invention is to provide a winding end processing method, winding end structure and stator assembly to solve the problems of large winding end envelope size and damage to the insulation layer in existing windings.

[0007] To solve the above-mentioned technical problems, the present invention provides a winding end processing method, which includes: cutting the head of the conductor to form a welding surface; the welding surface is at an angle to the axial direction of the conductor;

[0008] A pushing force is applied to the conductor that extends out after being inserted into the iron core, causing the conductor to be bent at its root; after bending, the welding surfaces of the two conductors to be connected are adjacent to form a welding line;

[0009] The two conductors to be connected are joined at the welding surface by laser welding.

[0010] Optionally, after bending, the welding surfaces of the two conductors to be connected are located on the same plane; and / or, the welding line is perpendicular to the axial direction of the iron core.

[0011] Optionally, before being inserted into the iron core, the head of the conductor undergoes a pre-processing step; the pre-processing step includes: thinning the head of the conductor in the direction of the conductor to be connected to form a connecting surface.

[0012] Optionally, the extending direction of the connecting surface is arranged at an angle to the axial direction of the iron core.

[0013] Optionally, along the extension direction of the welding line, the energy distribution of the laser welding is greater in the middle than at both ends.

[0014] Optionally, the step of applying a pushing force to the conductor extending after it has been inserted into the iron core, causing the conductor to bend at its root, includes:

[0015] A pushing force is applied to the head of the conductor, causing the conductor to bend at the root until it is formed.

[0016] Optionally, the step of applying a pushing force to the conductor extending after it has been inserted into the iron core, causing the conductor to bend at its root, includes:

[0017] A pushing force is applied to the root of the conductor, causing the conductor to bend initially at the root. Then, a pushing force is applied to the head of the conductor, causing the conductor to continue bending at the root until it is formed.

[0018] Optionally, the step of applying a pushing force to the conductor extending after it has been inserted into the iron core, causing the conductor to bend at its root, includes:

[0019] A pushing force is applied to the root of the conductor, causing the conductor to bend initially at the root. Then, the point of force application gradually moves from the root to the head. While the point of force application is moving, a pushing force is applied to the conductor, causing the conductor to continue bending at the root until it is formed.

[0020] Optionally, before applying a thrust to the root of the conductor, the winding end processing method further includes: providing an auxiliary limiting body at the root of the conductor, such that the auxiliary limiting body abuts against the conductor along the radial direction of the conductor.

[0021] Optionally, after connecting the two conductors to be connected at the welding surface by laser welding, the winding end processing method further includes:

[0022] The head of the conductor is coated or low-pressure plastic-coated to form a head coating.

[0023] Optionally, a pushing force is applied to the conductor extending out after it is inserted into the iron core, so that during the process of bending at the root of the conductor, the pushing force is applied only to the conductor to keep the conductor from forming a reverse bend relative to the bending direction at the root in the part extending out of the axial end of the iron core.

[0024] Optionally, the winding end processing method is applied to the IPIN winding, and both axial ends of the conductor of the IPIN winding are processed using the winding end processing method.

[0025] To solve the above-mentioned technical problems, the present invention also provides a winding end structure, which includes: two conductors to be connected;

[0026] The conductor is bent at the root of the iron core, and the head of the conductor has a welding surface formed by beveling before entering the iron core. The welding surface is at an angle to the axis of the conductor. The welding surfaces of the two conductors to be connected are adjacent to form a welding line. The two conductors to be connected are connected at the welding surface by laser welding.

[0027] Optionally, the head of the conductor has a connecting surface facing the other conductor to be connected; the connecting surfaces of the two conductors to be connected are fitted together.

[0028] Optionally, the connecting surface and the body of the conductor form a height difference in the direction to be connected of the conductor, with the connecting surface being lower than the body of the conductor.

[0029] Optionally, the conductor is a flat wire, the longer radial direction of the flat wire is the width direction, and the shorter radial direction is the thickness direction; the conductor is bent at its root along the width direction; the connecting surface is located in the thickness direction of the flat wire.

[0030] Optionally, the conductor, in the portion extending axially from one end of the iron core, does not have a reverse bend relative to the bending direction of the root.

[0031] Optionally, the winding end structure is applied to an IPIN winding, wherein both axial ends of the conductor of the IPIN winding are bent at the root of the conductor extending from the iron core, and the bending directions of the two axial ends of the same conductor are opposite.

[0032] Optionally, the winding end structure further includes a head coating that covers the head of the conductor; the head coating is an electrical insulator.

[0033] Optionally, the extending direction of the connecting surface is arranged at an angle to the axial direction of the iron core.

[0034] Optionally, the connecting surface includes inclined sections and / or curved sections.

[0035] To solve the above-mentioned technical problems, the present invention also provides a stator assembly, which includes: an iron core and a winding disposed on the iron core; the conductor of the winding adopts the winding end structure as described above.

[0036] Optionally, multiple conductors are circumferentially distributed around the iron core at the same radius to form a conductor group; the stator assembly includes at least two conductor groups arranged radially inside and outside the iron core; all conductors in the same conductor group have the same bending direction, and the conductors in adjacent conductor groups have opposite bending directions; the two conductors to be connected are respectively located in adjacent conductor groups.

[0037] Optionally, in different conductor groups, the conductors are circumferentially distributed in the same position; the conductors to be connected are spaced 5 other conductors apart in the circumferential distribution position.

[0038] In summary, the winding end processing method, winding end structure, and stator assembly provided by the present invention include the following: cutting the head of the conductor to form a welding surface; the welding surface is at an angle to the axial direction of the conductor; applying a pushing force to the conductor extending after being inserted into the iron core, causing the conductor to bend at its root; after bending, the welding surfaces of the two conductors to be connected are adjacent to form a welding line; and the two conductors to be connected are connected at the welding surface by laser welding.

[0039] With this configuration, the winding end structure uses a thrust method to process the conductor, eliminating the need for pulling force on the conductor head. This prevents the formation of a pulling head, reduces the winding end height, and decreases the outer envelope size. Furthermore, because the conductor head has a chamfered corner forming a welding surface, laser welding is used at the welding surface after the conductor is bent. This prevents damage to the insulation layer outside the welding surface, effectively improving the winding's reliability. Attached Figure Description

[0040] Those skilled in the art will understand that the accompanying drawings are provided to better understand the invention and do not constitute any limitation on the scope of the invention. Wherein:

[0041] Figure 1 This is an overall schematic diagram of a stator assembly manufactured using a twisting head process;

[0042] Figure 2 This is a schematic diagram of a winding end structure processed using a twisting head technique;

[0043] Figure 3 This is an overall schematic diagram of the stator assembly according to an embodiment of the present invention;

[0044] Figure 4This is a schematic diagram of the winding end structure according to an embodiment of the present invention;

[0045] Figure 5a This is a schematic diagram of a typical unit of the winding end structure according to an embodiment of the present invention, wherein the welding surfaces are located on the same plane to form a welding line;

[0046] Figure 5b This is a schematic diagram showing that a weld line cannot be formed on the welding surface in an embodiment of the present invention;

[0047] Figure 5c This is a schematic diagram of a typical unit of the winding end structure according to an embodiment of the present invention, wherein the welding surface is concave at an angle to form a welding line;

[0048] Figure 5d This is a schematic diagram of a typical unit of the winding end structure according to an embodiment of the present invention, wherein the welding surface protrudes outward at an angle to form a welding line;

[0049] Figure 5e This is a schematic diagram of the winding end structure before conductor connection according to an embodiment of the present invention;

[0050] Figure 5f This is a schematic diagram of a typical unit of the winding end structure according to an embodiment of the present invention, wherein the connecting surface is arranged at an angle to the axial direction of the iron core.

[0051] In the attached image:

[0052] 01-Winding end; 02-Pull end; 03, 04-Bending point; 10-Conductor; 11-Bending; 12-Welding surface; 13-Welding line; 14-Connecting surface; 15-Head coating; 20-Core; 21-Winding; 31-First force application point; 32-Second force application point; 33-Force application trajectory. Detailed Implementation

[0053] To make the objectives, advantages, and features of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clarify the explanation of the embodiments of this invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and may sometimes use different scales.

[0054] As used in this invention, the singular forms “a,” “an,” and “the” include plural objects; the term “or” is generally used to mean “and / or”; the term “a number” is generally used to mean “at least one”; the term “at least two” is generally used to mean “two or more”; furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined as "first," "second," and "third" may explicitly or implicitly include one or at least two of those features. The term "head" generally refers to the end of the guide body that extends out of the stator core and is away from the stator core, while the term "root" generally refers to the end of the guide body that extends out of the stator core and is close to the stator core. The terms "one end" and "the other end," as well as "proximal end" and "far end," generally refer to two corresponding parts, which include not only endpoints. The terms "installed," "connected," and "joined" should be interpreted broadly. For example, they can be fixed connections, detachable connections, or integral connections; they can be mechanical connections or electrical connections; they can be direct connections or indirect connections through an intermediate medium; they can be internal connections between two components or the interaction between two components. Furthermore, as used in this invention, the phrase "one element is disposed on another element" generally only indicates that there is a connection, coupling, cooperation, or transmission relationship between the two elements, and the connection, coupling, cooperation, or transmission between the two elements can be direct or indirect through an intermediate element. It should not be construed as indicating or implying a spatial orientation relationship between the two elements, i.e., one element can be located arbitrarily inside, outside, above, below, or to one side of the other element, unless otherwise explicitly stated. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0055] The purpose of this invention is to provide a winding end processing method, winding end structure and stator assembly to solve the problems of large winding end envelope size and damage to the insulation layer in existing windings.

[0056] The following description is in conjunction with the accompanying drawings.

[0057] The inventors discovered through research that, for example Figure 1 and Figure 2 In the winding end structure processed by the twisting process shown, the presence of the pull end 02, while not conducive to reducing the outer envelope size, objectively provides some convenience for welding due to its longer length. Specifically, when the pull end 02 is clamped and a pulling force is applied to the conductor, the conductor's insulation layer (such as enamel) is easily cracked. Generally, the conductor at the pull end 02 is the area without enamel, and the bending point 03 is the junction of the enamel and unenamel areas. Therefore, at the head of the pull end 02 (i.e., Figure 2The upper part is welded using conventional welding methods. Due to the relatively long transition at the pulling end 02, the paint below the bending point 03 will not be affected. Therefore, although the existing twisting process may cause the paint at the bending point 03 to peel off during processing, it will not have a significant impact on the paint during welding.

[0058] To reduce the height of the winding end structure, please refer to... Figures 3 to 5f This embodiment proposes processing the conductor 10 by using a pushing force on the winding end structure. The head of the conductor 10 does not require pulling force, thus eliminating the presence of a pulling head and reducing the winding end height and outer envelope size. Since there is no pulling head, the insulation layer of the conductor 10 generally extends to the head to avoid short circuits during winding formation. However, if the conductor head is welded using conventional welding methods (such as brazing or resistance welding), the insulation layer near the conductor head is easily affected, leading to defects such as paint peeling near the welding area. To address this problem, the inventors discovered that a welding surface 12 can be formed by chamfering the head of the conductor 10. After bending the conductor 10, the welding surfaces 12 of the conductors to be connected are adjacent to form a welding line 13. Laser welding is then used at the welding surfaces 12, thus avoiding damage to the insulation layer outside the welding surface 12 and effectively improving the reliability of the winding.

[0059] Based on the above research, please refer to Figures 3 to 5f This invention provides a winding end structure comprising: two conductors 10 to be connected; each conductor 10 has a bend 11 at its root extending from an iron core 20; the head of each conductor 10 has a welding surface 12 formed by chamfering before entering the iron core 20; the welding surface 12 is at an angle to the axial direction of the conductor 10; the welding surfaces 12 of the two conductors 10 to be connected are adjacent to form a welding line 13; the two conductors 10 to be connected are connected at the welding surface 12 by laser welding. Please refer to... Figure 4 Here, the two conductors 10 to be connected refer to the two conductors 10 that need to be connected according to the winding arrangement. In practice, the two conductors 10 to be connected are often conductors 10 of the same phase. Figure 5aAn example of a typical unit of the winding end structure is shown, in which the two conductors 10 are the conductors 10 to be connected after bending. It is understood that the bending directions of the two conductors 10 to be connected are opposite, so that the two conductors 10 can intersect and connect. It should also be noted that the weld line 13 refers to the adjacent and overlapping edges of the two weld surfaces 12. Specifically, the angles of the two weld surfaces 12 relative to the axial direction of their respective conductors 10 should be reasonably configured so that after bending, the adjacent edges of the two weld surfaces 12 can overlap to form the weld line 13. If the adjacent edges of the two weld surfaces 12 are at an angle to each other, such as... Figure 5b As shown, welding line 13 cannot be formed, making laser welding difficult.

[0060] To achieve the above-mentioned winding end structure processing and manufacturing, embodiments of the present invention provide a winding end processing method, which includes:

[0061] Step S1: Chamfer the head of conductor 10 to form a welding surface 12; the welding surface 12 is at an angle to the axial direction of conductor 10;

[0062] Step S2: Apply a pushing force to the conductor 10 that extends out after being inserted into the iron core, causing the conductor 10 to bend at its root 11; after bending, the welding surfaces 12 of the two conductors 10 to be connected are adjacent to form a welding line 13.

[0063] Step S3: Connect the two conductors 10 to be connected at the welding surface 12 by laser welding.

[0064] Since it is difficult to process the conductor 10 after it has been inserted into the iron core 20 and it is also difficult to control the accurate angle of the cut, it is difficult to make the welding surfaces 12 adjacent to each other to form the welding line 13. Therefore, the step of cutting the head of the conductor 10 to form the welding surface 12 is preferably performed before the conductor 10 is inserted into the iron core 20.

[0065] Preferably, after bending, the welding surfaces 12 of the two conductors 10 to be connected are located on the same plane; and / or; the welding line 13 is perpendicular to the axial direction of the core 20. In an exemplary example, such as Figure 5a As shown, after bending, the welding surfaces 12 of the two conductors 10 to be connected are located on the same plane, and the two welding surfaces 12 are adjacent to form a welding line 13. At this time, laser welding can be easily performed on the welding surfaces 12 to form a reliable electrical connection between the two conductors 10 to be connected. Furthermore, since the energy of laser welding is mainly distributed near the welding line 13, it can effectively reduce the impact on the enamel coating of the conductors 10, effectively improving the reliability of the winding. Preferably, as Figure 4As shown, the two welding surfaces 12 located on the same plane can be perpendicular to the axial direction of the iron core 20 (i.e., the vertical direction in the figure), so the welding line 13 is also perpendicular to the axial direction of the iron core 20, which facilitates laser welding. Of course, in some embodiments, the welding line 13 can also be at a certain angle to the axial direction of the iron core 20, and is not limited to being perpendicular. The welding line 13 only needs to be fully exposed to the laser welding machine.

[0066] In other embodiments, such as Figure 5c and 5d As shown, after bending, the welding surfaces 12 of the two conductors 10 to be connected are not on the same plane. The two welding surfaces 12 are inclined relative to their respective conductors 10, but the adjacent edges of the two welding surfaces 12 still overlap, forming a welding line 13. In these embodiments, laser welding can also be performed on the welding surfaces 12. It should be noted that in the examples listed above, the welding surfaces 12 are all planar. It can be understood that in some other embodiments, the welding surfaces 12 can also be curved, and the welding line 13 is not limited to a straight line, but can also be an arc. Those skilled in the art can make changes according to actual conditions, and the present invention is not limited in this regard.

[0067] Preferably, along the extension direction of the welding line 13, the energy distribution of the laser welding is greater in the middle than at both ends. The inventors have found that if the energy distribution of the laser welding is uniformly distributed along the extension direction of the welding line 13, it can easily affect the insulation layer near the ends of the welding line 13. Furthermore, in practice, the two conductors 10 to be connected do not need to be welded along the entire welding line 13. As long as reliable welding is ensured in the middle portion of the welding line 13, the reliability of the electrical connection between the two conductors 10 to be connected can be effectively guaranteed. Therefore, this embodiment proposes a laser welding energy distribution greater in the middle than at both ends, ensuring a reliable electrical connection between the two conductors 10 to be connected in the middle of the welding line 13. The ends of the welding line 13, due to the heat transferred from the middle portion, only require a small amount of laser welding energy to complete the welding. This configuration also avoids affecting the insulation layer near the ends of the welding line 13.

[0068] Optional, please continue to refer to Figure 5e The head of the conductor 10 has a connecting surface 14, which faces another conductor 10 to be connected; the connecting surfaces 14 of the two conductors 10 to be connected are fitted together. Figure 5e The diagram shows the state of the two conductors 10 to be connected before connection, with each conductor 10 having a connection surface 14 on its opposite ends. After connection, the two conductors 10 will appear as follows: Figure 5a As shown, the connecting surfaces 14 of the two conductors are fitted together, which ensures a reliable electrical connection between the two conductors 10 after welding.

[0069] Optional, please refer to Figure 5f In some embodiments, the extending direction of the connecting surface 14 is arranged at an angle to the axial direction of the iron core 20. To facilitate welding, the laser used in laser welding typically irradiates along the axial direction of the iron core 20, approximately perpendicular to the welding surface 12. The inventors have discovered that if the extending direction of the connecting surface 14 is parallel to the laser irradiation direction, it is prone to burn-through in some cases. Therefore, the extending direction of the connecting surface 14 can be configured to be at an angle to the axial direction of the iron core 20, so that the connecting surface 14 of the two conductors 10 forms an angle with the laser irradiation direction, thus preventing burn-through.

[0070] Preferably, the connecting surface 14 includes inclined sections and / or curved sections. The connection surface 14 being arranged at an angle to the axial direction of the core 20 can be implemented in various ways. Figure 5f One example is shown where the head of conductor 10 is thinned in a wedge shape, so that the heads of two opposing conductors 10 form inclined sections with the same tilt direction. Figure 5f In the example shown, the head of the conductor 10 on the right is wedge-shaped with a larger top and a smaller bottom, while the head of the conductor 10 on the left is wedge-shaped with a smaller top and a larger bottom. Understandably, the connecting surfaces 14 of the two conductors 10 are still in contact with each other, but both connecting surfaces 14 are inclined relative to the axis of the iron core 20.

[0071] In other embodiments, the connection surfaces 14 of the two opposing conductors 10 may also include mutually adaptable curved sections, such as those that are kneaded into matching wavy or arc shapes, which can reduce the possibility of solder burn-through. In other embodiments, the heads of the conductors 10 may be twisted to form connection surfaces 14 at an angle to the axial direction of the core 20; this invention is not limited to this.

[0072] For preferred options, please refer to [the provided text]. Figure 4 The conductor 10 is a flat wire, with its longer radial direction being the width direction and its shorter radial direction being the thickness direction; the conductor 10 is bent at its root along the width direction; the connecting surface 14 is located in the thickness direction of the flat wire.

[0073] For further details, please refer to... Figure 5e The connecting surface 14 and the body of the conductor 10 form a height difference in the direction in which the conductor 10 is to be connected, with the connecting surface 14 being lower than the body of the conductor 10. The direction in which the conductor 10 is to be connected is the normal direction of the connecting surface 14. Figure 5eIn the case of the flat wire shown, this refers to the thickness direction of the flat wire. In the direction to be connected of conductor 10, the connecting surface 14 and the body of conductor 10 form a step-like height difference. The connecting surface 14 being lower than the body of conductor 10 means that the distance between the connecting surface 14 and the other conductor 10 to be connected is greater than the distance between the body of conductor 10 and the other conductor 10 to be connected. With this configuration, after the two conductors 10 to be connected are joined together by the connecting surfaces 14, it is beneficial to reduce the thickness in the direction to be connected and avoid affecting the adjacent set of conductors 10 to be connected.

[0074] The processing of the connecting surface 14 is preferably performed before the conductor 10 is inserted into the iron core 20. Specifically, in the winding end processing method, before being inserted into the iron core 20, the head of the conductor 10 undergoes a pre-processing step; the pre-processing step includes: thinning the head of the conductor 10 in the direction towards the conductor 10 to be connected to form the connecting surface 14. After thinning, the connecting surface 14 is lower than the body of the conductor 10, creating a height difference in the direction to be connected.

[0075] In some embodiments, thinning can be performed not only in the direction toward the conductor 10 to be connected, but also in the direction away from the conductor 10 to be connected. In this way, the conductor 10 is universal in the thickness direction, which facilitates random selection during assembly and is not limited by the connection order of the conductors 10. That is, in the thickness direction, conductor A can be connected to conductor B, or conductor B can be connected to conductor A.

[0076] Please refer to Figure 4 The following describes, with reference to several examples, the steps of applying a pushing force to the conductor 10 that extends out after being inserted into the iron core 20, so that the conductor 10 bends at its root.

[0077] In the first example, the step of applying a pushing force to the conductor 10 extending after being inserted into the iron core 20, causing the conductor 10 to bend at its root, includes: applying a pushing force to the head of the conductor 10, causing the conductor 10 to bend at its root until it is formed. It should be noted that applying a pushing force to the head of the conductor 10 here does not narrowly refer to applying force to the very tip of the conductor 10, but should be broadly understood as applying a pushing force to a region near the head. For example, in... Figure 4 In the example shown, the point of application of the thrust at the head can be abstracted as the first force application point 31. This first force application point 31 is relatively close to the head end of the conductor 10. It can be understood that the direction of the thrust is mainly along the width direction of the conductor 10, so that the conductor 10 bends along the width direction at the root. The scheme of directly applying the thrust to the first force application point 31 at the head is simple to operate, but since the force is only applied to the first force application point 31 near the head, it is easy for the conductor 10 to bend not only at the root, but also to form a certain degree of bending as a whole.

[0078] In the second example, the step of bending the conductor 10 at its root after it extends through the iron core 20 includes: applying a pushing force to the root of the conductor 10 to induce an initial bend at the root, and then applying a pushing force to the head of the conductor 10 to continue bending at the root until it is formed. It should also be noted that applying a pushing force to the head or root of the conductor 10 here does not narrowly refer to applying force to the very tip or root of the conductor 10, but should be broadly understood as applying a pushing force to a region near the head or root. For example, in... Figure 4 In the example shown, the point of application of the thrust at the head can be abstracted as the first point of application 31, and the point of application of the thrust at the root can be abstracted as the second point of application 32. Applying the thrust to the second point of application 32 at the root first causes the conductor 10 to bend initially at the root. Then, applying the thrust to the first point of application 31 at the head causes the conductor 10 to continue bending at the root. This step-by-step bending method reduces the overall bending of the conductor 10, keeping the conductor 10 in a relatively straight shape.

[0079] In the third example, the step of bending the conductor 10 at its root after it extends through the iron core 20 includes: applying a pushing force to the root of the conductor 10 to cause an initial bend at the root; then gradually moving the point of force along the root towards the head; and simultaneously applying a pushing force to the conductor 10 to continue bending at the root until the desired shape is formed. For example, in... Figure 4 In the example shown, the point of application of the thrust at the head can be abstracted as the first point of application 31, and the point of application of the thrust at the root can be abstracted as the second point of application 32. The trajectory of the point of application moving gradually from the root to the head is the force application trajectory 33. The force application method in this example can also reduce the bending of the conductor 10 as a whole, keeping the conductor 10 in a relatively straight shape.

[0080] Preferably, for the conductor 10 extending after being inserted into the iron core 20, during the bending process at the root, only a pushing force is applied to the conductor 10 to prevent it from forming a reverse bend relative to the root bending direction in the portion extending from one axial end of the iron core 20. That is, the conductor 10 does not have a reverse bend relative to the root bending direction in the portion extending from one axial end of the iron core 20. Compared to the existing pulling-type force application method, applying only a pushing force ensures that the conductor 10 will not form a reverse bend relative to the root bending direction. It is understood that the formation of a reverse bend will increase the height of the winding end, wasting space and material. Applying only a pushing force, on the one hand, ensures that a reverse bend will not form, and on the other hand, reduces the torque required for force application, while also reducing problems such as insulation layer peeling caused by pulling-type force application.

[0081] Optionally, before applying a thrust to the root of the conductor 10, the winding end processing method further includes: providing an auxiliary limiting body (not shown) at the root of the conductor 10, such that the auxiliary limiting body abuts against the conductor 10 radially. The auxiliary limiting body may be cylindrical, which can restrict the root of the conductor 10, causing the bending of the conductor 10 to be closer to the root.

[0082] Furthermore, the winding end structure also includes a head coating 15, which covers the head of the conductor 10; the head coating 15 is an electrical insulator. It should be noted that the head of the conductor 10 here is not narrowly defined as the tip of the conductor 10, but should be broadly understood as a region near the head. For example, the head coating 15 can cover several areas such as the welding surface 12 and the back surface opposite the connecting surface 14. The head coating 15 is an electrical insulator, such as a polymer impregnating varnish or epoxy resin. The head coating 15 can be formed by coating or by low-pressure plastic coating. Based on this, after the conductors 10 to be connected are laser welded to the welding surface 12, the winding end processing method further includes: Step S4: applying a coating or low-pressure plastic coating to the head of the conductor 10 to form the head coating 15. The head coating 15 serves two purposes: firstly, it provides physical protection for the welding surface 12 at the end of the winding to prevent the conductor 10 from separating after welding; secondly, it insulates the welding surface 12 to prevent short circuits between the winding and the housing.

[0083] Please refer to Figure 3 Preferably, the winding end structure is applied to an IPIN winding, wherein both axial ends of the conductor 10 of the IPIN winding are bent at the root extending from the iron core 20, and the bending directions of the two axial ends of the same conductor 10 are opposite. Figure 3 In the example shown, the upper end of a conductor 10 extending from the iron core 20 is bent in a clockwise direction around the iron core 20, while the lower end of the conductor 10 extending from the iron core 20 is bent in a counterclockwise direction around the iron core 20. The bending directions at the two ends of the same conductor 10 along the axis are opposite.

[0084] Correspondingly, the winding end processing method is applied to IPIN windings, where both axial ends of the conductor 10 of the IPIN winding are processed using the winding end processing method. In the prior art, both axial ends of the conductor 10 of the IPIN winding are processed using a twisting process. By using the winding end processing method provided in this embodiment for both ends, the height of both ends of the winding can be reduced. It is understood that the winding end processing method and winding end structure provided in this embodiment are also applicable to HAIRPIN windings. One axial end of the HAIRPIN winding is pre-bent, and its other end also needs to be processed using a twisting process; therefore, the winding end processing method and winding end structure provided in this embodiment can also be applied.

[0085] Based on the above winding end structure, this embodiment also provides a stator assembly, which includes: an iron core 20 and a winding 21 disposed on the iron core 20; the conductor 10 of the winding 21 adopts the winding end structure described above. Please refer to the following. Figure 3 and Figure 4 This example illustrates a stator assembly.

[0086] exist Figure 3 In the illustrated example, multiple conductors 10 are circumferentially distributed around the iron core 20 at the same radius, forming a conductor group, i.e. Figure 3 A ring of conductors 10 located on the same circumference. The stator assembly includes at least two groups of conductors arranged radially inside and outside the iron core 20; all conductors 10 in the same group have the same bending direction, and the conductors 10 in adjacent groups have opposite bending directions; the two conductors 10 to be connected are located in adjacent groups. Specifically, in Figure 3 In the illustrated example, the stator assembly includes eight conductor groups. In the conductor groups arranged from the outermost to the innermost ring, all conductors 10 in the odd-numbered rings are bent clockwise after extending from the core at the upper end and counterclockwise after extending from the core at the lower end. In the conductor groups of even-numbered rings, all conductors 10 are bent counterclockwise after extending from the core at the upper end and clockwise after extending from the core at the lower end. This configuration ensures that the conductors 10 in adjacent inner and outer conductor groups bend in opposite directions, allowing them to connect to each other.

[0087] Please refer to Figure 4Preferably, in different conductor groups, the circumferential distribution positions of the conductors 10 are the same; the same circumferential distribution positions of the conductors 10 will be explained here. Each conductor 10, after being inserted into the iron core 20, has its fixed circumferential distribution position. For example, viewing a stator assembly from a top view, with the circumferential distribution position of the conductors 10 distributed at the 12 o'clock position as 0°, the circumferential distribution positions of different conductors 10 gradually increase along the clockwise direction until they circle the iron core 20. The same circumferential distribution position of the conductors 10 means that the distribution of the conductors 10 around the iron core 20 in different conductor groups is the same. For example, taking a simplified conductor group containing only 6 conductors 10 as an example, the circumferential distribution positions of the conductors 10 in a conductor group are 0°, 60°, 120°, 180°, 240°, and 300°, respectively. In other different conductor groups, the circumferential distribution positions of conductor 10 are also 0°, 60°, 120°, 180°, 240°, and 300°. This is referred to as the circumferential distribution positions of conductor 10 being the same in different conductor groups. With this configuration, the conductors 10 in different conductor groups are actually arranged radially around the center, and the conductors 10 located at the same circumferential distribution position in all conductor groups are arranged in a straight line along the radial direction of the iron core 20. It should be noted that the number of conductors 10 in the above-described conductor group is merely an example and not a limitation on the number of conductors 10. Those skilled in the art can set the number of conductors 10 in the conductor group according to actual needs.

[0088] Furthermore, the conductors 10 to be connected are spaced five circumferentially distributed positions from each other conductor 10. Preferably, the stator assembly has three phases, each phase including conductors 10 arranged in two adjacent circumferentially distributed positions, and the three phases are arranged sequentially in turn. Figure 4 As shown, conductors 10 arranged at circumferential positions sa and sb are all phase A, conductors 10 arranged at circumferential positions sc and sd are all phase B, and conductors 10 arranged at circumferential positions se and sf are all phase C, and so on in a cycle. Generally, the conductors 10 to be connected are of the same phase. Since the three phase conductors 10 are arranged in turn, there is a gap of 5 other conductors 10 circumferential positions between the circumferential positions of conductors 10 of the same phase. For example, conductor 10a in the innermost conductor group at circumferential position sa is bent counterclockwise and connected to conductor 10b in the second conductor group from the inside out at circumferential position sg. There is a gap of 5 other conductors 10 circumferential positions between conductors 10a and conductor 10b, namely circumferential positions sb, sc, sd, se, and sf.

[0089] Optionally, the stator assembly also includes lead wires, which can be connected to the conductors 10 of the winding according to conventional arrangements in the art, and will not be described in detail in this embodiment.

[0090] In summary, the winding end processing method, winding end structure, and stator assembly provided by the present invention include the following: cutting the head of the conductor to form a welding surface; the welding surface is at an angle to the axial direction of the conductor; applying a pushing force to the conductor extending after being inserted into the iron core, causing the conductor to bend at its root; after bending, the welding surfaces of the two conductors to be connected are adjacent to form a welding line; and the two conductors to be connected are connected at the welding surface by laser welding.

[0091] With this configuration, the winding end structure uses a thrust method to process the conductor, eliminating the need for pulling force on the conductor head. This prevents the formation of a pulling head, reduces the winding end height, and decreases the outer envelope size. Furthermore, because the conductor head has a chamfered corner forming a welding surface, laser welding is used at the welding surface after the conductor is bent. This prevents damage to the insulation layer outside the welding surface, effectively improving the winding's reliability.

[0092] It should be noted that the above embodiments can be combined with each other. The above description is only a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A method for processing the ends of a winding, characterized in that, include: The conductor head is chamfered to form a soldering surface; The welding surface is at an angle to the axial direction of the conductor; Before being inserted into the iron core, the head of the conductor undergoes a pretreatment step. The preprocessing steps include: thinning the head of the conductor in the direction facing the conductor to be connected and in the direction away from the conductor to be connected to form a connecting surface; thinning the head of the conductor in a wedge shape so that the heads of two opposite conductors form inclined sections in the same direction; the head of one conductor is wedge-shaped with a larger top and a smaller bottom, and the head of the other conductor is wedge-shaped with a smaller top and a larger bottom; the extension direction of the connecting surface is arranged at an angle to the axis of the iron core, and both connecting surfaces are inclined relative to the axis of the iron core. A pushing force is applied to the conductor extending from the iron core, causing the conductor to bend at its root; wherein, during the bending process at the root, the pushing force is applied only to the conductor to prevent the conductor from forming a reverse bend relative to the root bending direction in the portion extending from one end of the iron core; after bending, the welding surfaces of the two conductors to be connected are adjacent to form a welding line. The two conductors to be connected are joined at the welding surface by laser welding. After the two conductors to be connected are laser welded together at the welding surface, the heads of the conductors are coated or low-pressure plastic-coated to form a head coating.

2. The winding end processing method according to claim 1, characterized in that, After bending, the welding surfaces of the two conductors to be connected are located on the same plane; and / or the welding line is perpendicular to the axial direction of the iron core.

3. The winding end processing method according to claim 1, characterized in that, Along the extension direction of the welding line, the energy distribution of the laser welding is greater in the middle than at both ends.

4. The winding end processing method according to claim 1, characterized in that, The step of applying a pushing force to the conductor extending from the iron core, causing the conductor to bend at its root, includes: A pushing force is applied to the head of the conductor, causing the conductor to bend at the root until it is formed.

5. The winding end processing method according to claim 1, characterized in that, The step of applying a pushing force to the conductor extending from the iron core, causing the conductor to bend at its root, includes: A pushing force is applied to the root of the conductor, causing the conductor to bend initially at the root. Then, a pushing force is applied to the head of the conductor, causing the conductor to continue bending at the root until it is formed.

6. The winding end processing method according to claim 1, characterized in that, The step of applying a pushing force to the conductor extending from the iron core, causing the conductor to bend at its root, includes: A pushing force is applied to the root of the conductor, causing the conductor to bend initially at the root. Then, the point of force application gradually moves from the root to the head. While the point of force application is moving, a pushing force is applied to the conductor, causing the conductor to continue bending at the root until it is formed.

7. The winding end processing method according to any one of claims 4 to 6, characterized in that, Before applying a thrust to the root of the conductor, the winding end processing method further includes: providing an auxiliary limiting body at the root of the conductor, such that the auxiliary limiting body abuts against the conductor along the radial direction of the conductor.

8. The winding end processing method according to claim 1, characterized in that, The winding end processing method is applied to IPIN windings, and both axial ends of the conductor of the IPIN winding are processed using the winding end processing method.

9. A winding end structure formed by the winding end processing method according to any one of claims 1 to 8, characterized in that, include: The two conductors to be connected; The conductor bends at the root extending from the iron core. The head of the conductor has a welding surface formed by chamfering before entering the iron core. The welding surface is at an angle to the axis of the conductor. The welding surfaces of the two conductors to be connected are adjacent to form a welding line. The two conductors to be connected are connected by laser welding at the welding surface. The head of the conductor has a connecting surface. The head of the conductor is wedge-shaped and thinned so that the heads of the two opposing conductors form inclined sections with the same inclination direction. The head of one conductor is wedge-shaped, wider at the top and narrower at the bottom, while the head of the other conductor is wedge-shaped, narrower at the top and wider at the bottom. The extension direction of the connecting surface is arranged at an angle to the axial direction of the iron core, and both connecting surfaces are inclined relative to the axial direction of the iron core. The connecting surface faces or is away from the other conductor to be connected; the connecting surfaces of the two conductors to be connected are in close contact with each other; the connecting surface and the body of the conductor form a height difference in the direction to be connected of the conductor, and the connecting surface is lower than the body of the conductor; the conductor does not have a reverse bend relative to the bending direction of the root in the portion extending from one end of the iron core axially. The winding end structure also includes a head coating, which covers the head of the conductor; The head coating is an electrical insulator.

10. The winding end structure according to claim 9, characterized in that, The conductor is a flat wire, with its longer radial direction being the width direction and its shorter radial direction being the thickness direction; the conductor is bent at its root along the width direction; the connecting surface is located in the thickness direction of the flat wire.

11. The winding end structure according to claim 9, characterized in that, The winding end structure is applied to the IPIN winding, wherein both axial ends of the conductor of the IPIN winding are bent at the root of the conductor extending from the iron core, and the bending directions of the two axial ends of the same conductor are opposite.

12. The winding end structure according to claim 9, characterized in that, The connecting surface includes inclined sections and / or curved sections.

13. A stator assembly, characterized in that, include: An iron core and a winding disposed on the iron core; the conductor of the winding adopts the winding end structure according to any one of claims 9 to 12.

14. The stator assembly according to claim 13, characterized in that, Multiple conductors are circumferentially distributed around the iron core at the same radius to form conductor groups; the stator assembly includes at least two conductor groups arranged radially inside and outside the iron core; all conductors in the same conductor group have the same bending direction, and the conductors in adjacent conductor groups have opposite bending directions; the two conductors to be connected are respectively located in adjacent conductor groups.

15. The stator assembly according to claim 14, characterized in that, In different conductor groups, the conductors are circumferentially distributed in the same position; the conductors to be connected are spaced 5 other conductors apart in the circumferential distribution position.

Images