Rotary electric machine

Abstract

To improve cooling performance in a configuration in which a refrigerant is caused to flow through a coil end part of a rotary electric machine to release heat of a coil.SOLUTION: A rotary electric machine 1 according to the present invention includes: a stationary core 21 including a plurality of teeth 21a around which a coil 22a is wound; a housing 23 supporting the stationary core 21; and a refrigerant flow passage 25a formed by the housing 23 and the stator core 21 so as to surround a coil end part 22a2 of the coil 22a. The rotary electric machine 1 has a rectifying member 26A disposed on an inner- peripheral side of the coil end part 22a2, and the rectifying member 26A protrudes from the coil end part 22a2 on at least one side in a radial direction Zc.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a rotating electric machine. [Background technology]

[0002] Patent Document 1 describes a stator including a stator core having a plurality of teeth arranged in the circumferential direction, and a plurality of coils wound in a concentrated winding manner around each of the teeth (Abstract and Paragraph 0017). Each of the coils includes a coil body portion formed by winding a coated conductor around the teeth, a first lead-out portion led from the coil body portion to one axial side of the stator core, and a second lead-out portion led from the coil body portion to the other axial side of the stator core (Abstract). Furthermore, the stator of Patent Document 1 includes a heat transfer member at an end portion on the other axial side of the stator core (Paragraph 0031). The heat transfer member faces the side surface opposite to the surface facing the teeth in the coil end portion (second lead-out portion), and a part of the heat of the coil is transferred to the stator core via the heat transfer member, and the heat transferred to the stator core is released to the outside of the motor via the housing (Paragraph 0034). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-178242 Summary of the Invention [Problem to be solved by the invention]

[0004] In the stator of Patent Document 1, part of the heat from the coil is transferred to the stator core via a heat transfer member and then released to the outside of the motor via the housing, and no consideration is given to a configuration for flowing a refrigerant through the coil end portion to release the heat from the coil.

[0005] An object of the present invention is to improve the cooling performance in a configuration in which a coolant is caused to flow through the coil end portion of a rotating electrical machine to release heat from the coil. [Means for solving the problem]

[0006] In order to achieve the above object, a rotating electric machine according to the present invention comprises: a stator core having a plurality of teeth around which coils are wound; a housing supporting the stator core; a coolant passage formed by the housing and the stator core so as to surround a coil end portion of the coil, a straightening member disposed on the inner circumferential side of the coil end portion, The flow rectifying member protrudes beyond the coil end portion at least on one side in a radial direction. Effect of the Invention

[0007] According to the present invention, in a configuration in which a coolant is caused to flow through a coil end portion of a rotating electrical machine to release heat from the coil, it is possible to improve the cooling performance. Problems, configurations and effects other than those described above will become apparent from the following description of the preferred embodiment of the invention. [Brief description of the drawings]

[0008] [Figure 1] 1 is an exploded perspective view of a rotating electric machine according to an embodiment of the present invention; [Diagram 2] FIG. 1 is a schematic diagram showing concentrated winding in which two coils are arranged in one slot formed between two adjacent teeth. [Diagram 3] FIG. 11 is a schematic diagram showing concentrated winding in which a coil is wound around every other tooth. [Figure 4] 1 is a perspective view showing a cooling structure according to an embodiment of the present invention, partially in section; [Diagram 5] FIG. 2 is a perspective view showing a configuration of a stator winding according to an embodiment of the present invention. [Figure 6]1 is a plan view, viewed from the axial direction, showing a state in which a stator winding according to an embodiment of the present invention is assembled to a stator core. [Figure 7] 1 is a perspective view showing a state in which a bobbin according to an embodiment of the present invention is assembled to a stator core. [Figure 8] FIG. 8 is a perspective view showing a state in which a coil is assembled to the bobbin in FIG. 7. [Figure 9] 2A and 2B are schematic diagrams of a coil end portion according to an embodiment of the present invention as viewed from a radial direction (upper diagram) and an axial direction (lower diagram). [Figure 10] 13 is an example of an analysis of the flow of coolant around a coil end portion. [Figure 11] 1A and 1B are schematic diagrams (upper diagram) and (lower diagram) of a coil end portion viewed from the radial direction and the axial direction when a coil inner circumference side straightening member and an inter-coil straightening member are used. [Figure 12] 13 is an example of an analysis of the flow of coolant around a coil end portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In the following description, the configuration according to the present invention and the configuration according to a comparative example will be described, but the same reference numerals will be used to designate similar configurations to avoid duplication of similar descriptions. Furthermore, when there are differences between the configurations to which the same reference numerals are used, the differences will be described.

[0010] A rotating electric machine 1 according to an embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is an exploded perspective view of the rotating electric machine 1 according to an embodiment of the present invention.

[0011] The rotating electric machine 1 includes, as its components, a stator 2, a rotor 3, end brackets 4, and a power conversion device 5. The stator 2 has a stator core 21, and the rotor 3 has a rotor core 31. In this embodiment, the rotor core 31 is disposed on the inner peripheral side of the stator core 21 such that its outer peripheral surface faces the inner peripheral surface of the stator core 21. The stator core 21 is supported by and housed in the housing 23, and the outer peripheral surface of the stator core 21 is covered by the housing 23.

[0012] The stator 2 and the rotor 3 may be configured to be disposed such that the inner peripheral surface of the rotor core 31 faces the outer peripheral surface of the stator core 21 .

[0013] The power converter 5 performs switching operations to convert DC power supplied from a battery (not shown) into three-phase AC power. This three-phase AC power is supplied to the stator windings of the stator 2, and a rotating magnetic field is generated in the stator 2. The rotating magnetic field generated in the stator 2 drives the rotor 3 to rotate.

[0014] Although not shown in Fig. 1, the rotor 3 is provided with a rotating shaft. The dashed line 1a in Fig. 1 represents the axis of the rotating shaft and its extension line. In the following explanation, the direction along the axis of the rotating shaft will be referred to as the "axial direction." Furthermore, the "circumferential direction" and "radial direction" refer to the "circumferential direction" and "radial direction" of the rotating electric machine (stator core, rotor core) unless otherwise specified.

[0015] Here, the form of the coil used in the rotating electric machine 1 according to one embodiment of the present invention will be described with reference to Figs. 2 and 3. In this embodiment, a stator winding 22 wound by concentrated winding will be described. The present invention is also applicable to stator windings other than concentrated winding. A concentrated winding stator winding has a high space factor and a wide coil end side surface, and is one of the configurations that maximizes the effect of the present invention. In particular, Figs. 2 and 3 will describe an example in which the stator winding is configured by an edgewise coil in which a rectangular wire is wound so that its short side is on the inner periphery side. However, the stator winding 22 of the present invention is not limited to an edgewise coil, and may be configured by a wire material in which multiple wires with round cross sections are twisted together.

[0016] Fig. 2 is a schematic diagram showing concentrated winding in which two coils 22a are arranged in one slot 21b formed between two adjacent teeth 21a. In Fig. 2, Za represents the axial direction, Zb represents the circumferential direction, and Zc represents the radial direction. The same applies below.

[0017] 2 shows the teeth 21a and the coils 22a wound around the teeth 21a as viewed from the center side in the radial direction Zc. When the coils 22a are wound around one tooth 21a, the slot insertion portions 22a1 are inserted into two slots 21b formed on both sides of the tooth 21a in the circumferential direction Zb. That is, the coils 22a have two slot insertion portions 22a1. The two slot insertion portions 22a1 are connected by two coil end portions 22a2. One of the two coil end portions 22a2 is drawn out from one end face 21c11 of the stator core 21 to the outside of the stator core 21 (slot 21b), and the other coil end portion 22a2 is drawn out from the other end face 21c2 of the stator core 21 to the outside of the stator core 21 (slot 21b).

[0018] In this example, one of the slot insertion portions 22a1 of two adjacent coils 22a is inserted into one slot 21b. The current directions of the two adjacent coils 22a are set to be opposite to each other, and the currents flowing through the two slot insertion portions 22a1 inserted into the same slot 21b flow in the same direction in the axial direction Za. As a result, N poles and S poles are alternately arranged on the multiple teeth 21a arranged in the circumferential direction Zb.

[0019] FIG. 3 is a schematic diagram showing concentrated winding in which coil 22a is wound around every other tooth 21a. 3 shows the teeth 21a and the coils 22a wound around the teeth 21a as viewed from the radial center, and when the coils 22a are wound around one tooth 21a, the slot insertion portions 22a1 are inserted into two slots 21b formed on both sides of the tooth 21a in the circumferential direction Zb. The coils 22a have two slot insertion portions 22a1, and the two slot insertion portions 22a1 are connected by two coil end portions 22a2. One of the two coil end portions 22a2 is drawn out from one end face 21c1 of the stator core 21 to the outside of the stator core 21 (slot 21b), and the other coil end portion 22a2 is drawn out from the other end face 21c2 of the stator core 21 to the outside of the stator core 21 (slot 21b).

[0020] In this example, the coils 22a are wound around every other tooth 21a1, and one of the slot insertion portions 22a1 of each coil 22a is inserted into each slot 21b. Therefore, in this example, the teeth (first teeth) 21a1 around which the coils 22a are wound and the teeth (second teeth) 21a2 around which the coils 22a are not wound are arranged alternately in the circumferential direction Zb. In this example, by passing currents in the same direction through the coils 22a wound around every other tooth 21a1, the N poles and S poles are arranged alternately on the multiple teeth 21a arranged in the circumferential direction Zb.

[0021] That is, in the rotating electric machine 1 of this embodiment, The stator core 21 has a plurality of first teeth 21a1 around which the coils 22a are wound and a plurality of second teeth 21a2 around which the coils 22a are not wound, The first teeth 21a1 and the second teeth 21a2 are arranged alternately in the circumferential direction Zb of the stator core 21.

[0022] In this case, the dead space in the slot 21b becomes smaller, improving the space factor. Since the dead space becomes a stagnation area of ​​the coolant and reduces the amount of heat dissipated through the coolant, it is better to have no dead space.

[0023] 3, the teeth 21a1 on which the coil 22a is provided have both side surfaces 21a11, 21a12 extending in parallel from the outer periphery side toward the inner periphery side of the stator core 21. Teeth with both side surfaces 21a11, 21a12 extending in parallel are called "parallel teeth." That is, in the rotating electric machine 1 of this embodiment, the first teeth 21a1 are parallel teeth in which both side surfaces 21a11, 21a12 facing the circumferential direction are formed in parallel.

[0024] On the other hand, the second teeth 21a2 are formed so that their width increases from the inner periphery side to the outer periphery side of the stator core 21. Therefore, both side surfaces 21a11, 21a12 of the teeth 21a2 are not parallel. The teeth 21a2 are called "trapezoidal teeth."

[0025] When the coil 22a is used to form a continuous coil 22X (see FIG. 5) and the pre-wound continuous coil 22X is inserted into the first tooth 21a1, a gap is generated between the trapezoidal tooth and the coil 22a, resulting in a poor space factor. The stator core 21 of this embodiment improves the space factor by forming the first tooth 21a1 as a parallel tooth. The improved space factor brings the wires of the coil 22a into close contact with each other, improving the heat dissipation effect from the coil 22a to the stator core 21 and reducing the amount of heat generated. Furthermore, the structure in which the pre-wound coil 22a is inserted into the tooth 21a is easy to disassemble, making it easy to recycle.

[0026] Both the concentrated winding coil 22a shown in Fig. 2 and the concentrated winding coil 22a shown in Fig. 3 can be used as the stator winding 22 according to the present invention. Below, a configuration employing the concentrated winding coil 22a shown in Fig. 3 will be described. The following description of the concentrated winding coil 22a also applies to the configuration employing the concentrated winding coil 22a shown in Fig. 2.

[0027] A cooling structure according to an embodiment of the present invention will be described with reference to Fig. 4. Fig. 4 is a perspective view, partly in cross section, showing the cooling structure according to an embodiment of the present invention.

[0028] A cooling structure (cooling section) 25 of the coil 22a is provided in the coil end portion 22a2. The cooling section 25 has a refrigerant flow path 25a through which a refrigerant flows. The refrigerant flow path 25a is formed by the housing 23 and the end faces 21c1, 21c2 of the stator core 21. The housing 23 has a radial step surface 23a facing the end faces 21c1, 21c2 of the stator core 21, and a recess 23b recessed in the axial direction Za from the radial step surface 23a. The recess 23b has an outer peripheral surface 23b1, an inner peripheral surface 23b2, and a bottom surface 23b3 connecting the outer peripheral surface 23b1 and the inner peripheral surface 23b2.

[0029] The refrigerant flow path 25a is formed by the recess 23b of the housing 23 and the end faces 21c1, 21c2 of the stator core 21 facing the recess 23b, which form flow path surfaces. The recess 23b accommodates the coil end portion 22a2 so as to surround the outer circumferential surface 22a21 of the coil end portion 22a2, the side surface 22a22 facing inward in the radial direction Zc, and the side surface 22a23 facing outward in the radial direction Zc, and further forms a space for flowing the amount of refrigerant required for cooling the coil 22a.

[0030] In this case, the side surface 22a22 is the innermost side surface of the coil end portion 22a2, and the side surface 22a23 is the outermost side surface of the coil end portion 22a2. Hereinafter, the side surface 22a22 may be referred to as the "inner peripheral side surface" and the side surface 22a23 may be referred to as the "outer peripheral side surface". The width W1 of the refrigerant flow path 25a formed between the side surface (outer peripheral side surface) 22a23 of the coil end portion 22a2 and the outer peripheral surface 23b1 of the housing 23 is larger than the width W2 of the refrigerant flow path 25a formed between the side surface (inner peripheral side surface) 22a22 of the coil end portion 22a2 and the inner peripheral surface 23b2 of the housing 23. Therefore, the cross-sectional area of ​​the refrigerant flow path 25a formed on the outer peripheral side with respect to the coil end portion 22a2 is larger than the cross-sectional area of ​​the refrigerant flow path 25a formed on the inner peripheral side with respect to the coil end portion 22a2.

[0031] In a configuration in which the housing 23 abuts against the inner side surface 22a22 of the coil end portion 22a2 to restrict radially inward movement of the coil end portion 22a2, the width W2 of the refrigerant flow path 25a formed between the inner side surface 22a22 of the coil end portion 22a2 and the housing 23 is essentially zero, and the refrigerant flow path 25a is formed on the side of the outer side surface 22a23 of the two side surfaces 22a22, 22a23 of the coil end portion 22a2.

[0032] The coil 22a is cooled by dissipating heat from the coil end portion 22a2 to the coolant flowing through the coolant flow passage 25a. The coolant flow passage 25a is provided on both end faces 21c1, 21c2 of the stator core 21 in the same manner.

[0033] A bobbin 24 is provided on the tooth 21a, and the coil 22a is wound around the bobbin 24. The coil 22a is provided on the tooth 21a of the stator core 21 so that the bobbin 24 is interposed between the coil 22a and the tooth 21a. The wire of the coil 22a is provided with an electrically insulating coating, and the bobbin 24 is used as a member for ensuring electrical insulation between the coil 22a and the stator core 21.

[0034] The configuration of the stator winding 22 according to one embodiment of the present invention will be specifically described with reference to Figs. 5 is a perspective view showing the configuration of a stator winding 22 according to an embodiment of the present invention. The stator winding 22 is produced by forming four coils 22A, 22B, 22C, and 22D into an integrated coil component using a continuous material (strand), and connecting the multiple coil components. Hereinafter, each of the four coils 22A, 22B, 22C, and 22D will be referred to as a "coil 22a," and the coil component formed by the four coils 22A, 22B, 22C, and 22D will be referred to as a "continuous coil 22X" to distinguish them. In this specification, the continuous coil 22X will be described as the stator winding 22.

[0035] The continuous coil 22X has four coils 22A, 22B, 22C, and 22D and a crossover wire 22b connecting the four coils 22A, 22B, 22C, and 22D. The continuous coil 22X is wound in advance and assembled to a bobbin 24 integrated with the teeth 21a1 and 21a2 of the stator core 21. The number of coils 22a constituting the continuous coil 22X is not limited to four.

[0036] The continuous coil 22X is made of a continuous conductor without any connection portion for connecting the coils 22a. This makes it possible to eliminate the welding process for connection and the process of applying an insulating coating after welding. As a result, the assembly process of the rotating electric machine 1 is simplified.

[0037] A bobbin 24 around which the coil 22a is wound is provided on the stator core 21. The bobbin 24 is interposed between the coil 22a and the teeth 21a, and has a rectifying member (rectifying portion) 26A. That is, the rotating electric machine 1 of this embodiment has the following features: A bobbin 24 is provided between the coil 22a and the teeth 21a. The current rectifying member 26A is formed integrally with the bobbin around which the coil 22a is wound. The flow rectifying member 26A is provided on the inner periphery side of the coil end portion 22a2. The flow rectifying member 26A is in contact with the coil end portion 22a2 to improve the heat transfer from the coil 22a to the stator core 21. The flow rectifying member 26A may be referred to as a "coil end inner periphery flow rectifying member" in the following description.

[0038] The flow straightening member 26A is disposed on the inner periphery side of the coil end portion 22a2, and is a member that straightens the flow of the refrigerant flowing through the refrigerant flow passage 25a. For this reason, the flow straightening member 26A may be referred to as the "coil inner periphery side flow straightening member" or the "first flow straightening member." The function of the flow straightening member 26A will be described in detail later. In this embodiment, the flow straightening member 26A is configured integrally with the bobbin 24 as a part of the bobbin 24. The flow straightening member 26A may also be provided separately from the bobbin 24 as a separate member.

[0039] The bobbin 24 is attached to the stator core 21. In this embodiment, the bobbin 24 is fixed to the stator core 21 and integrated with the stator core 21. This facilitates the assembly work of the stator core 21, the bobbin 24, and the continuous coil 22X.

[0040] In order to integrate the stator core 21 and the bobbin 24, the electromagnetic steel sheet that constitutes the stator core 21 may be placed in a mold, and resin may be injected into the mold to form the bobbin 24. In this case, the rectifying member 26A and the bobbin 24 are made of resin, and are molded to be integrated with the stator core 21. This improves the heat transfer from the coil 22a to the stator core 21. In addition, the effect of reducing the amount of heat generated by improving the space factor and improving positioning accuracy can be obtained. The adhesion between the coil 22a, the rectifying member 26A, and the stator core 1 is improved, improving the heat transfer, and the improved space factor improves the efficiency of the rotating electric machine 1. Furthermore, by configuring the rectifying member 26A to contact the inner circumference of the coil 22a, the positioning accuracy of the coil 22a is improved, leading to a reduction in the axial length (miniaturization) of the coil 22a.

[0041] 6 is a plan view seen from the axial direction, showing a state in which a stator winding 22 according to an embodiment of the present invention is assembled to a stator core 21. The continuous coil 22X is fitted to the stator core 21 by inserting four coils 22A, 22B, 22C, and 22D into every other tooth 21a1.

[0042] In a state where the continuous coil 22X is fitted in the stator core 21, the rectifying member 26A is provided so as to protrude in the radial direction Zc beyond the coil end portion. In this case, the rectifying member 26A protrudes in the radial direction Zc beyond both side surfaces 22a22, 22a23 of the coil end portion 22a2 in the radial direction Zc. In FIG. 6, the rectifying member 26A protrudes by a magnitude of δ1 outward in the radial direction Zc beyond the side surface 22a23 on the outer periphery side of the coil end portion 22a2. Also, the rectifying member 26A protrudes by a magnitude of δ2 inward in the radial direction Zc beyond the side surface 22a22 on the inner periphery side of the coil end portion 22a2.

[0043] The rectifying member 26A does not need to protrude in the radial direction Zc from both side surfaces 22a22, 22a23 of the coil end portion 22a2, but only needs to protrude from the coil end portion 22a2 on at least one side in the radial direction Zc. As described in FIG. 4, in a configuration in which the cross-sectional area of ​​the refrigerant flow path 25a formed on the outer circumferential side of the coil end portion 22a2 is larger than the cross-sectional area of ​​the refrigerant flow path 25a formed on the inner circumferential side of the coil end portion 22a2, it is preferable that the rectifying member 26A protrudes in the radial direction Zc from at least the outer circumferential side surface 22a23 of the coil end portion 22a2. This can improve the rectifying effect of the refrigerant in a larger refrigerant flow path.

[0044] As described above, the rotating electric machine 1 of this embodiment has the following features: A stator core 21 having a plurality of teeth 21a around which coils 22a are wound; a housing 23 supporting the stator core 21; A rotating electric machine (1) including a coolant passage (25a) formed by a housing (23) and a stator core (21) so as to surround a coil end portion (22a2) of a coil (22a), The coil end portion 22a2 has an airflow rectifying member 26A disposed on the inner circumferential side thereof. The flow straightening member 26A protrudes beyond the coil end portion 22a2 at least on one side in the radial direction Ac.

[0045] Further, the rotating electric machine 1 of this embodiment is The refrigerant flow path 25a has an outer circumferential surface 23b1 and an inner circumferential surface 23b2 formed by the housing 23, A gap W1 formed between the outer peripheral surface 23b1 and the coil end portion 22a2 is larger than a gap W2 formed between the inner peripheral surface 23b2 and the coil end portion 22a2, The flow straightening member 26A protrudes radially outward beyond the coil end portion 22a2.

[0046] 7 is a perspective view showing a state in which a bobbin 24 according to an embodiment of the present invention is assembled to a stator core 21. The bobbin 24 has a straightening member 26A, and is molded integrally with the stator core 21 using a resin material.

[0047] The bobbin 24 has a first covering portion 24a covering the side surface of the slot 21b facing the radial direction Zc, a second covering portion 24b covering the side surface of the slot 21b facing the circumferential direction Zb, and a third covering portion 24c covering the side surface of the slot 21b facing the circumferential direction Zb.

[0048] The first covering portion 24a is provided at the innermost portion of the slot 21b and constitutes a slot inner side covering portion. The second covering portion 24b is a covering portion (first tooth covering portion) that covers the side surface of the first tooth 21a1 facing the circumferential direction Zb, and is provided on both side surfaces of the first tooth 21a1 facing the circumferential direction Zb. The third covering portion 24c is a covering portion (second tooth covering portion) that covers the side surface of the second tooth 21a2 facing the circumferential direction Zb. One third covering portion 24c is provided for each of the two second teeth 21a2 adjacent to one first tooth 21a1.

[0049] Therefore, one bobbin 24 has two slot deep side covering portions 24a, two first tooth covering portions 24b, and two second tooth covering portions 24c. A slot 21b into which the coil 22a is inserted is formed in a space surrounded on three sides by the slot deep side covering portions 24a, the first tooth covering portions 24b, and the second tooth covering portions 24c. The slot deep side covering portions 24a, the first tooth covering portions 24b, and the second tooth covering portions 24c prevent the coil 22a from directly contacting the stator core 21, improving electrical insulation in the stator 2.

[0050] The first tooth covering portion 24b extends radially inward from one circumferential end of one of the slot deep side covering portions 24a. The second tooth covering portion 24c extends radially inward from the other circumferential end of one of the slot deep side covering portions 24a. The first tooth covering portion 24b and the second tooth covering portion 24c are connected by the slot deep side covering portion 24a. The two first tooth covering portions 24b are connected by a connecting portion 24d provided on one end face side of the stator core 21. The connecting portion 24d constitutes a fourth covering portion that covers the end face of the first tooth 21a1 on the one end face side of the stator core 21.

[0051] The flow straightening member 26A is provided on the connection portion (fourth covered portion) 24d. The flow straightening member 26A is provided so as to protrude from the connection portion 24d in the axial direction Za and extend in the radial direction Zc. The flow straightening member 26A is formed to have a length L24 such that both ends in the radial direction Zc match both ends of the bobbin 24 in the radial direction Zc. The flow straightening member 26A, the first teeth covered portion 24b and the second teeth covered portion 24c are formed so that the tip portions 21a3 of the first teeth 21a1 and the second teeth 21a2 have a length L24 exposed from the resin forming the bobbin 24 by δ3.

[0052] Fig. 8 is a perspective view showing a state in which coil 22a is assembled to bobbin 24 in Fig. 7. Crossover wire 22b (see Fig. 5) is provided on one end surface side of stator core 21, and Fig. 8 is a view seen from the other end surface side of stator core 21 where crossover wire 22b is not provided.

[0053] In this embodiment, the configuration described in Fig. 4 is adopted in which the housing 23 abuts against the inner peripheral side surface 22a22 of the coil end portion 22a2 to restrict the radially inward movement of the coil end portion 22a2. In this case, the width W2 (see Fig. 4) of the refrigerant flow path 25a formed between the inner peripheral side surface 22a22 of the coil end portion 22a2 and the housing 23 is substantially zero, and the refrigerant flow path 25a is formed on the outer peripheral side surface 22a23 side of the both side surfaces 22a22, 22a23 of the coil end portion 22a2.

[0054] Further, a tip 24c1 (end on the gap side with the stator core 21) of the second teeth covering portion 24c and an inner circumferential side surface 22a22 of the coil end portion 22a2 are disposed at the same position in the radial direction Zc. That is, a distance δ4 in the radial direction Zc between the tip 24c1 of the second teeth covering portion 24c and the inner circumferential side surface 22a22 of the coil end portion 22a2 is zero (δ4=0). Note that a tip of the first teeth covering portion 24b is disposed at the same position as the tip 24c1 of the second teeth covering portion 24c in the radial direction Zc.

[0055] In this embodiment, the straightening member 26A protrudes radially outward by a size of δ1 beyond the outer peripheral side surface 22a23 of the coil end portion 22a2, and is arranged in the refrigerant flow path 25a, in a refrigerant flow path portion formed on the inner peripheral side of the coil end portion 22a2, and in a refrigerant flow path portion formed on the side of the outer peripheral side surface 22a23 of the coil end portion 22a2.

[0056] The rectifying member 26A is made of resin, and in this case, the surface of the rectifying member 26A facing the coil 22a is made of an electrical insulator. This allows the coil 22a to come into contact with the rectifying member 26A, improving the heat transfer from the coil 22a to the stator core 21. This configuration also means that the rectifying member 26A may be made of a conductive material separate from the bobbin 24, and an electrical insulator may be provided on the surface facing the coil 22a. In this case, the rectifying member 26A separate from the bobbin 24 is attached to the bobbin 24. Alternatively, the rectifying member 26A is integrated with the bobbin 24 when the bobbin 24 is molded.

[0057] The effects of this embodiment will be described with reference to Figures 9 and 10. Figure 9 is a schematic diagram (upper diagram) of the coil end portion 22a2 in one embodiment of the present invention as viewed from the radial direction and the axial direction (lower diagram). Figure 10 is an example of an analysis of the flow of refrigerant around the coil end portion 22a2.

[0058] FIG. 10(a) shows an example of analysis of the refrigerant flow when the flow straightening member 26A of this embodiment is not used, and it can be seen that a stagnation portion of the refrigerant occurs on the inner circumferential side of the coil end portion 22a2.

[0059] For xEV drive motors, improved heat dissipation performance is required to achieve higher power density. In low-speed, high-torque motors, the proportion of heat generated is large due to coil copper loss, and development of a direct oil-cooling structure that cools the coils in a concentrated manner is being promoted. When pumping refrigerant (cooling oil) to the coil end flow passages in a concentrated winding with skipping one coil, the following issues arise:

[0060] The outer periphery of the coil end portion 22a2 has a high heat transfer coefficient (heat flux) because the refrigerant flows quickly and vortexes are easily generated by cavity flow. On the other hand, the inner periphery of the coil end portion 22a2 does not flow and remains there, resulting in a low heat transfer coefficient and poor heat dissipation efficiency, as well as a localized rise in the temperature of the refrigerant. To improve heat dissipation, it is important to improve the heat dissipation performance of the inner periphery and side surfaces of the coil end portion 22a2.

[0061] 10(b) shows an example of an analysis of the refrigerant flow when the flow straightening member 26A is arranged on the inner circumferential side of the coil end portion 22a2. By arranging the flow straightening member 26A on the inner circumferential side of the coil end portion 22a2, it is possible to prevent or suppress the occurrence of a stagnation area of ​​the refrigerant on the inner circumferential side of the coil end portion 22a2.

[0062] As described above, the stagnation of the coolant generated on the inner circumferential side of the coil end portion 22a2 reduces the heat dissipation efficiency of the coil end portion 22a2 through the coolant. In this embodiment, the rectifying member 26A is disposed on the inner circumferential side of the coil end portion 22a2, and the rectifying member 26A is protruded in the radial direction Ac from the coil end portion 22a2, so that the flow rate of the coolant on the side surface of the coil end portion 22a2 can be increased and the heat transfer rate of the part can be improved, as shown in FIG. 9. In addition, a part of the heat generated in the coil end portion 22a2 is dissipated to the coolant through the rectifying member 26A, thereby improving the amount of heat dissipation. As a result, a high output density can be realized in the rotating electric machine 1, and the rotating electric machine 1 can be made smaller and lighter, and its power consumption can be improved.

[0063] In a configuration in which the first teeth 21a1 around which the coil 22a is wound and the second teeth 21a2 around which the coil 22a is not wound are arranged alternately in the circumferential direction Zb of the stator core 21 (the configuration in FIG. 3), the side surface of the coil end portion 22a2 becomes wider, thereby enhancing the above-mentioned effect.

[0064] In a low-speed, high-torque motor, copper loss is dominant, and the coil 22a reaches the highest temperature. Resins used in the rectifying member 26A have a higher thermal conductivity than the cooling oil (refrigerant). For example, when PPS resin is used in the rectifying member 26A, the thermal conductivity of PPS resin is 1 to 5 W / mK, whereas the thermal conductivity of ATF (automatic transmission fluid) used as the cooling oil is 0.1 W / mK. This results in a high thermal conductivity from the coil 22a to the stator core 21.

[0065] Regardless of whether or not a straightening member 26A is arranged on the inner circumferential side of the coil end portion 22a2, a refrigerant stagnation area A is generated between three circumferentially adjacent coil end portions 22a2, as shown in Figures 10(a) and (b).

[0066] A configuration for suppressing the generation of stagnation portion A will be described with reference to Figures 11 and 12. Figure 11 is a schematic diagram (upper diagram) of coil end portion 22a2 viewed from the radial direction and a schematic diagram (lower diagram) viewed from the axial direction when coil inner circumference side flow straightening member 26A and inter-coil flow straightening member 26B are used. Figure 12 is an example of analysis of the flow of refrigerant around coil end portion 22a2.

[0067] 11 and 12(b), a current rectifying member 26B is disposed between two circumferentially adjacent coil end portions 22a2. The current rectifying member 26B may be referred to as an "inter-coil current rectifying member" or a "second current rectifying member."

[0068] Figure 12(a) shows an example of an analysis of the refrigerant flow when neither the coil inner circumference side straightening member 26A nor the inter-coil straightening member 26B is used, and Figure 12(b) shows an example of an analysis of the refrigerant flow when both the coil inner circumference side straightening member 26A and the inter-coil straightening member 26B are used. In Figure 12(a), it can be seen that a refrigerant stagnation area A is generated between two circumferentially adjacent coil end portions 22a2.

[0069] While the portion between two circumferentially adjacent coil end portions 22a2 exhibits cavity flow, the refrigerant tends to stagnate near the stator core 21. By disposing inter-coil flow straightening member 26B in refrigerant stagnation portion A, the flow rate of the refrigerant between the two coil end portions 22a2 is improved, and the heat transfer coefficient from coil end portion 22a2 is improved.

[0070] Coil inner circumference side flow rectifying member 26A is disposed on first tooth 21a1 around which coil 22a is wound, whereas inter-coil flow rectifying member 26B is disposed on second tooth 21a2 around which coil 22a is not wound. Similar to coil inner circumference side flow rectifying member 26A, inter-coil flow rectifying member 26B can be molded integrally with bobbin 24 from resin when bobbin 24 is molded.

[0071] The inter-coil current member 26B is lower than the portion of the coil end portion 22a2 that protrudes highest from the axial end face 21c1 (or 21c2) of the stator core 21. That is, a height dimension H26B in the axial direction Za of the inter-coil current member 26B is smaller than a protruding dimension H22a2 of the coil end portion 22a2 from the axial end face 21c1 (or 21c2) of the stator core 21. Also, the inter-coil current member 26B is disposed so as not to protrude radially outward (toward the outer circumferential surface 23b1 of the housing 23) beyond the side surface 22a23 of the coil end portion 22a2.

[0072] As described above, the rotating electric machine 1 of this embodiment has the following features: An inter-coil current rectifying member 26B is provided between the coil end portions 22a2 of two coils 22a adjacent to each other in the circumferential direction, The inter-coil current member 26B is provided at a position corresponding to the second tooth 21a2 in the circumferential direction Zb, The inter-coil current member 26B is lower than the highest portion of the coil end portion 22a2 protruding from the axial end face 21c1 (or 21c2) of the stator core 21 in the axial direction Za. Furthermore, the inter-coil flow straightening member 26B is disposed so as not to protrude beyond the coil end portion 22a2 on the side where the flow straightening member 26A protrudes beyond the coil end portion 22a2 in the radial direction Zc.

[0073] In addition, the rotating electric machine 1 of this embodiment has The refrigerant flow path 25a has an outer peripheral wall 23b1 and an inner peripheral wall 23b2 formed by the housing 23, A gap W1 formed between the outer peripheral wall 23b1 and the coil end portion 22a2 is larger than a gap W2 formed between the inner peripheral wall 23b2 and the coil end portion 22a2, The flow straightening member 26A protrudes radially outward beyond the coil end portion 22a2, The inter-coil current member 26B is disposed radially outward from the coil end portion 22a2 so as not to protrude from the coil end portion.

[0074] The inter-coil flow straightening member 26B can be used alone, or it is also possible to use both the coil inner circumference side flow straightening member 26A and the inter-coil flow straightening member 26B. By using both, it is possible to further improve the heat transfer coefficient from the coil end portion 22a2 to the refrigerant compared to a configuration including only the coil inner circumference side flow straightening member 26A.

[0075] The present invention is not limited to the above-described embodiments, but includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the configurations. In addition, it is possible to add, delete, or replace part of the configuration of the embodiments with other configurations. [Explanation of symbols]

[0076] 1... rotating electric machine, 22X... continuous coil, 22a... coil, 22b... jumper wire, 21... stator core, 21a1... teeth around which the coil is wound, 21b... slot, 21a2... teeth around which the coil is not wound.

Claims

1. a stator core having a plurality of teeth around which coils are wound; a housing supporting the stator core; a coolant passage formed by the housing and the stator core so as to surround a coil end portion of the coil, a straightening member disposed on the inner circumferential side of the coil end portion, The rectifying member protrudes beyond the coil end portion at least on one side in a radial direction.

2. 2. The rotating electric machine according to claim 1, the stator core has a plurality of first teeth around which the coil is wound and a plurality of second teeth around which the coil is not wound, A rotating electric machine in which the first teeth and the second teeth are arranged alternately in the circumferential direction of the stator core.

3. 3. The rotating electric machine according to claim 2, The first teeth are parallel teeth having both circumferentially facing side surfaces formed parallel to each other.

4. 2. The rotating electric machine according to claim 1, The rectifying member has a surface facing the coil, the surface being made of an electrical insulator.

5. 2. The rotating electric machine according to claim 1, A bobbin is provided between the coil and the teeth, The rectifying member is integrally formed with a bobbin around which the coil is wound.

6. 6. A rotating electric machine according to claim 5, The straightening member and the bobbin are made of resin and are molded integrally with the stator core.

7. 2. The rotating electric machine according to claim 1, The refrigerant flow path has an outer circumferential surface and an inner circumferential surface defined by the housing, a gap formed between the outer circumferential surface and the coil end portion is larger than a gap formed between the inner circumferential surface and the coil end portion, The straightening member protrudes radially outward beyond the coil end portion.

8. 3. The rotating electric machine according to claim 2, an inter-coil current rectifying member is provided between coil end portions of two coils adjacent to each other in the circumferential direction; the inter-coil current member is provided at a position corresponding to the second tooth in a circumferential direction, the inter-coil current member is lower than a portion where the coil end portion protrudes most highly from an axial end face of the stator core in the axial direction, Furthermore, the inter-coil current rectifying member is disposed so as not to protrude beyond the coil end portion on the radial side where the current rectifying member protrudes beyond the coil end portion.

9. 9. A rotating electric machine according to claim 8, The refrigerant flow path has an outer peripheral wall and an inner peripheral wall formed by the housing, a gap formed between the outer circumferential wall and the coil end portion is larger than a gap formed between the inner circumferential wall and the coil end portion, The flow rectifying member protrudes radially outward beyond the coil end portion, The inter-coil current member is disposed radially outward from the coil end portion so as not to protrude beyond the coil end portion.

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