stata

Abstract

This invention provides a technology that enables the proper mounting of segment coils to the stator core. [Solution] A stator for a motor comprising a cylindrical stator core and a plurality of coils wound around the stator core. The stator core comprises a plurality of slots arranged along the circumferential direction. The coil comprises a plurality of segment coils connected within the plurality of slots. Each of the plurality of segment coils comprises a first leg inserted into one of the plurality of slots, a second leg inserted into another of the plurality of slots, which is spaced circumferentially apart from the slot in which the first leg is inserted by one or more slots, and a coil end portion connecting the first leg and the second leg and protruding from the end face of the stator core. The coil end portion has a parallel portion extending substantially parallel to the end face in the vicinity of the slot in which the first leg is inserted.

Description

Technical Field

[0001] The technology disclosed in the present specification relates to a stator. In particular, it relates to a stator for a motor.

Background Art

[0002] Patent Document 1 discloses a segment coil that is inserted into a slot of a stator core. This segment coil has two accommodating portions each accommodated in a separate slot, and a coil end portion that connects the two accommodating portions and protrudes from an end face of the stator core. The coil end portion has a substantially V-shape with two inclined portions.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In this type of stator, the segment coil is fixed to the stator core by pressing the coil end portion to press-fit the accommodating portions into the slots. In the segment coil of Patent Document 1, the inclined portions of the coil end portion are pressed to press-fit the accommodating portions into the slots. Since the inclined portions are inclined relative to the end face of the stator core, it is difficult to accurately apply a force in the axial direction of the stator (that is, the extending direction of the slots). For example, if there is a difference in rigidity between the two accommodating portions due to manufacturing tolerances or the like, a force may be applied to the accommodating portions in an unintended direction during press-fitting, and the accommodating portions may deform. As a result, the insertion length of the accommodating portions into the slots varies, which may affect the performance of the motor. The present specification provides a technology that allows the segment coil to be properly mounted to the stator core.

Means for Solving the Problems

[0005] The technology disclosed herein is embodied in a stator for a motor. The stator comprises a stator core having a cylindrical shape and a plurality of coils wound around the stator core. The stator core comprises a plurality of slots arranged circumferentially. The coils comprise a plurality of segment coils connected within the plurality of slots. Each of the plurality of segment coils comprises a first leg inserted into one of the plurality of slots, a second leg inserted into another of the plurality of slots which is circumferentially spaced apart from the slot in which the first leg is inserted by one or more slots, and a coil end portion connecting the first leg and the second leg and protruding from the end face of the stator core. The coil end portion has a parallel portion extending substantially parallel to the end face in the vicinity of the slot in which the first leg is inserted.

[0006] In this stator, the coil end portion has a parallel portion that extends substantially parallel to the end face of the stator core. When inserting the segment coil into the slot, the parallel portion of the segment coil is pressed in the axial direction of the stator, thereby allowing force to be applied precisely in the insertion direction of the first leg (i.e., the direction of extension of the slot). Furthermore, the parallel portion is located near the slot into which the first leg is inserted. Because the position where force is applied to the coil end portion is close to the position of the slot into which the first leg is inserted, it is possible to suppress the application of force to the first leg in an unintended direction. [Brief explanation of the drawing]

[0007] [Figure 1] A perspective view showing the configuration of the stator core. [Figure 2] Enlarged perspective view of the stator as seen from the radially inner side. [Figure 3] A diagram showing how segment coils are connected to other segment coils. [Figure 4] A circumferentially enlarged plan view showing the arrangement of multiple segment coils as seen from the radially inward side. [Modes for carrying out the invention]

[0008] In one embodiment of this technology, the connection between the first leg and the parallel portion may be located on the side of the slot into which the first leg is inserted, rather than on the side of the slot adjacent to the slot into which the first leg is inserted in the circumferential direction.

[0009] In the above configuration, the connection point is located near the slot into which the first leg is inserted. Therefore, when inserting the segment coil into the slot, the circumferential distance between the position where force is applied to the coil end (i.e., the position of the parallel section) and the position of the slot into which the first leg is inserted is small, allowing for appropriate axial force to be applied to the first leg. Consequently, variations in the insertion length of the first leg can be further suppressed.

[0010] In one embodiment of this technology, the parallel portion may be a first parallel portion. The coil end portion may further include a second parallel portion connected to the first parallel portion, provided at a greater distance from the end face than the first parallel portion, and extending substantially parallel to the end face. The second parallel portion may overlap with another first parallel portion of the plurality of segment coils when the stator is viewed from the axial direction.

[0011] In coils wound around a stator core, a structure is sometimes adopted in which one segment coil intersects with other segment coils in a three-dimensional manner. In such cases, multiple segment coils are arranged on the stator core in a three-dimensional intersecting state, and the multiple segment coils are inserted together into the slot. In the above configuration, when the stator is viewed from the axial direction, the second parallel portion of one segment coil is arranged to overlap with the first parallel portion of another segment coil. Therefore, when the first parallel portion of one segment coil is pressed in the axial direction while multiple segment coils are arranged on the stator core in a three-dimensional intersecting state, the second parallel portion of one segment coil presses against the first parallel portion of the other segment coils. Both the first and second parallel portions extend approximately parallel to the end face of the stator core. Therefore, when the first parallel portion of one segment coil is pressed, the second parallel portion presses against the first parallel portion of the other segment coils. This allows force to be accurately applied in the axial direction to the other segment coils as well. Consequently, the other segment coils can be properly inserted into the slot.

[0012] In one embodiment of this technology, the plurality of segment coils may include a plurality of first segment coils inserted into the plurality of slots from one axial side and a plurality of second segment coils inserted into the plurality of slots from the other axial side. Each of the first and second legs of the plurality of first segment coils may be connected to either the first or second leg of the plurality of second segment coils within the plurality of slots via a cylindrical connecting member.

[0013] Each segment coil is connected to one another within the slot to form a plurality of coils. In the technology disclosed herein, variations in the insertion length of the legs into the slot are suppressed, so that in the above configuration, the first segment coil and the second segment coil can be suitably connected via a connecting member.

[0014] (Examples) The stator 10 of the embodiment will be described with reference to the drawings. The stator 10, in combination with the rotor, constitutes a motor. Although not particularly limited, the motor can be used in electric vehicles as a prime mover to drive the wheels. Electric vehicles include, for example, battery electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, and fuel cell electric vehicles.

[0015] As shown in Figures 1 to 3, the stator 10 comprises a stator core 12 and a plurality of coils 18. In Figure 1, for clarity, only one segment coil 30 of the coils 18 is shown. The stator core 12 is made of a soft magnetic material. As an example, the stator core 12 of this embodiment has a structure in which a plurality of electromagnetic steel sheets are laminated. As shown in Figure 1, the stator core 12 has a core back 14 that extends cylindrically along the axial direction and a plurality of teeth 16 provided on the inner circumferential surface 14a of the core back 14. As shown in Figure 1, the plurality of teeth 16 are arranged at equal intervals along the circumferential direction. Each tooth 16 protrudes radially inward from the inner circumferential surface 14a of the core back 14. Between each of two circumferentially adjacent teeth 16, a groove-shaped slot 17 is formed, which is a space in which a part of the coil 18 is housed. Each slot 17 extends radially along the stator core 12. Multiple slots 17 are arranged at equal intervals along the circumferential direction.

[0016] The coil 18 is wound around the teeth 16 of the stator core 12. As shown in Figure 2, the coil 18 has multiple segment coils 30. The coil 18 is formed by connecting multiple segment coils 30. As shown in Figures 1 and 3, the segment coil 30 is a conductor 32 made of a metal or alloy material, and is covered with a coil film 34 made of an insulating material, except for its ends. In the following, to distinguish between one segment coil 30 and other segment coils 30, the reference numbers of the segment coils 30 and each element constituting the segment coils 30 may be denoted by the subscripts "A", "B", and "C".

[0017] As shown in Figure 1, the segment coil 30 is inserted into the slot 17 from one axial end of the stator core 12. As shown in Figure 3, the segment coil 30A is electrically connected to another segment coil 30B, which is inserted into the slot 17 from the other axial end of the stator core 12, via a connecting member 50. The connecting member 50 is conductive and is a cylindrical member that electrically connects the two segment coils 30 within the slot 17. The conductor 32A of one segment coil 30A is fitted into one end of the connecting member 50, and the conductor 32B of the other segment coil 30B is fitted into the other end of the connecting member 50, thereby electrically connecting the two segment coils 30.

[0018] As shown in Figures 1 and 4, each segment coil 30 comprises a first leg portion 36, a second leg portion 38, and a coil end portion 40. Each leg portion 36, 38 is arranged to extend axially within the slot 17. As shown in Figure 2, the legs 36, 38 of multiple segment coils 30 are arranged in layers within a single slot 17. While not particularly limited, for example, a coil 18 has a structure in which the segment coils 30 are wound in six layers. Within a single slot 17, up to six legs 36, 38 are arranged radially.

[0019] As shown in Figure 4, the first leg portion 36 and the second leg portion 38 of one segment coil 30 are respectively inserted into separate slots 17 that are spaced apart in the circumferential direction with a plurality of slots 17 interposed therebetween. For example, in the present embodiment, as shown in Figure 4, the segment coil 30A, which is one of the segment coils 30 disposed at the innermost side in the radial direction of the stator core 12, has the first leg portion 36A and the second leg portion 38A inserted into separate slots 17 that are spaced apart in the circumferential direction with six slots 17 interposed therebetween. Note that in Figure 4, for the sake of clarity of the drawing, only two segment coils 30A and 30B among the plurality of segment coils 30 are illustrated.

[0020] The coil end portion 40 connects the first leg portion 36 and the second leg portion 38. As shown in Figure 2 and Figure 4, the coil end portion 40A protrudes from the end face 12a of the stator core 12 in a state where the segment coil 30A is inserted into the slot 17. As shown in Figure 2, the coil end portion 40 connects the first leg portion 36 and the second leg portion 38 while three-dimensionally intersecting with the coil end portions 40 of other segment coils 30.

[0021] The coil end portion 40 includes a first parallel portion 42 and a second parallel portion 44. The first parallel portion 42 is connected to the first leg portion 36 via the connection portion 39. The connection portion 39 is located closer to the slot 17 in which the first leg portion 36 is inserted than to the slot 17 adjacent in the circumferential direction to the slot 17 in which the first leg portion 36 is inserted. In the present embodiment, as shown in Figure 4, the connection portion 39 of each segment coil 30 extends outward along the axial direction from the slot 17 in which the first leg portion 36 is inserted. The connection portion 39 extends outward along the axial direction from the end face 12a of the stator core 12. The first parallel portion 42 extends from the end of the connection portion 39 substantially parallel to the end face 12a of the stator core 12.

[0022] The second parallel portion 44 is connected to the first parallel portion 42. As shown in FIG. 4, the second parallel portion 44 is provided at a greater distance from the end face 12a of the stator core 12 than the first parallel portion 42. The second parallel portion 44 extends substantially parallel to the end face 12a of the stator core 12.

[0023] As shown in FIG. 2 and FIG. 4, the second parallel portion 44A of the segment coil 30A is arranged so as to overlap with the first parallel portion 42C of another one segment coil 30C when viewed in the axial direction.

[0024] When inserting each segment coil 30 into the slot 17, each segment coil 30 is disposed relative to the stator core 12 in a state of being three-dimensionally crossed. Then, by pressing the coil end portion 40, all the segment coils 30 are collectively inserted into the slots 17. In the stator 10 of the present embodiment, the coil end portion 40 has the first parallel portion 42 extending substantially parallel to the end face 12a of the stator core 12. When inserting the segment coil 30 into the slot 17, by pressing the first parallel portion 42 in the axial direction of the stator 10, a force can be accurately applied in the insertion direction of the first leg portion 36 (that is, the extending direction of the slot 17). Further, the first parallel portion 42 is located in the vicinity of the slot 17 into which the first leg portion 36 is inserted. In particular, in the present embodiment, the connection portion 39 that connects the first leg portion 36 and the first parallel portion 42 extends outward along the axial direction from the slot 17 into which the first leg portion 36 is inserted. That is, the circumferential positions of the slot 17 into which the first leg portion 36 is inserted and the connection portion 39 are substantially equal. For this reason, when a force is applied to the coil end portion 40, it is possible to suppress the force from being applied to the first leg portion 36 in an unintended direction. Thereby, variation in the insertion length of the first leg portion 36 is suppressed, and the segment coil 30 can be appropriately attached to the stator core 12.

[0025] Furthermore, in this embodiment, when the stator 10 is viewed from the axial direction, the second parallel portion 44A of one segment coil 30A is arranged to overlap with the first parallel portion 42C of another segment coil 30C. Therefore, when the first parallel portion 42A of one segment coil 30A is pressed in the axial direction with each segment coil 30 arranged in a three-dimensional crossing manner relative to the stator core 12, the second parallel portion 44A of one segment coil 30A presses against the first parallel portion 42C of the other segment coil 30C. Both the first parallel portion 42 and the second parallel portion 44 extend substantially parallel to the end face 12a of the stator core 12. Therefore, when the first parallel portion 42A is pressed, the second parallel portion 44A presses against the first parallel portion 42C of the other segment coil 30C. This allows force to be accurately applied in the axial direction to the other segment coils 30C as well. Consequently, the other segment coils 30C can be properly inserted into the slot 17. When inserting each segment coil 30 into the slot 17, the first parallel portion 42C of the other segment coils 30C may be pressed in addition to the first parallel portion 42A of the segment coil 30A.

[0026] Furthermore, in this embodiment, as shown in Figure 3, the segment coil 30 is connected to other segment coils 30 within the slot 17 to form a plurality of coils 18. As described above, in this embodiment, variations in the insertion length of the legs 36 and 38 into the slot 17 are suppressed, so that the segment coil 30A and the segment coil 30B can be suitably connected via the connecting member 50.

[0027] In the above-described embodiment, the connecting portion 39 may be located on the side of the slot 17 adjacent to the slot 17 in the circumferential direction with respect to the slot 17 into which the first leg portion 36 is inserted. Also, the connecting portion 39 may extend inclined with respect to the axial direction. Furthermore, the segment coil 30 does not necessarily have a second parallel portion 44.

[0028] The specific examples of the technologies disclosed herein have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples described above. Furthermore, the technical elements described herein or in the drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies illustrated herein or in the drawings achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself. [Explanation of symbols]

[0029] 10: Stator, 12: Stator core, 12a: End face, 14: Core back, 16: Teeth, 17: Slot, 18: Coil, 30: Segment coil, 36: First leg, 38: Second leg, 39: Connection, 40: Coil end, 42: First parallel section, 44: Second parallel section, 50: Connecting member

Claims

1. A stator for a motor, A stator core having a cylindrical shape, Multiple coils wound around the stator core, Equipped with, The stator core comprises a plurality of slots arranged along the circumferential direction, The coil comprises a plurality of segment coils connected within the plurality of slots, Each of the above-mentioned plurality of segment coils is A first leg portion is inserted into one of the aforementioned multiple slots, A second leg is inserted into one of the aforementioned plurality of slots, which is spaced circumferentially apart from the slot into which the first leg is inserted, with one or more slots in between. It comprises a coil end portion that connects the first leg portion and the second leg portion and protrudes from the end face of the stator core, The coil end portion has a parallel portion that extends substantially parallel to the end face in the vicinity of the slot into which the first leg portion is inserted. stata.

2. The stator according to claim 1, wherein the connection portion between the first leg and the parallel portion is located on the side of the slot into which the first leg is inserted, more so than any slot adjacent to the slot in the circumferential direction with respect to the slot into which the first leg is inserted.

3. The aforementioned parallel portion is the first parallel portion, The coil end portion is connected to the first parallel portion and further comprises a second parallel portion which is spaced further apart from the end face than the first parallel portion and extends substantially parallel to the end face. The stator according to claim 1 or 2, wherein the second parallel portion overlaps with one of the first parallel portions of the plurality of segment coils when the stator is viewed from the axial direction.

4. The plurality of segment coils include a plurality of first segment coils inserted into the plurality of slots from one side in the axial direction, and a plurality of second segment coils inserted into the plurality of slots from the other side in the axial direction. The stator according to claim 1, wherein each of the first leg and the second leg of the plurality of first segment coils is connected to either the first leg or the second leg of the plurality of second segment coils within the plurality of slots via a cylindrical connecting member.

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