Rotating electric machines

Abstract

To realize suitable cooling by a rotary electric machine even while simplifying a configuration.SOLUTION: A rotary electric machine 10 comprises: a stator 30 having stator windings 31; a rotor 20 which is arranged opposite to the stator 31; and a housing 60 which houses the stator 30 and the rotor 20. A coolant supply unit 70 which supplies liquid coolant to the inside of the housing 60 is provided at a position to be an upper part in a vertical direction of the stator 30 and the rotor 20 in an installation state of the rotary electric machine 10 in the housing 60. In addition, the rotary electric machine 10 is provided with a guide unit which guides the coolant to be supplied from the coolant supply unit 70 to an air gap between the stator 30 and the rotor 20 in the housing 60.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The disclosure in this specification relates to rotating electrical machines. [Background technology]

[0002] Various configurations for cooling the stator and rotor of a rotating electric machine have been proposed. For example, Patent Document 1 describes a cooling structure for a rotating electric machine that includes a first oil passage provided vertically above the stator, a second oil passage formed inside the rotor, and a third oil passage provided along a wall portion at one axial end of the rotating electric machine and connecting the first oil passage and the second oil passage. In this cooling structure, oil in the first oil passage is discharged from a discharge hole toward the stator, and oil is circulated through the second oil passage inside the rotor, thereby cooling not only the stator but also the rotor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-22344 Summary of the Invention [Problem to be solved by the invention]

[0004] In the cooling structure of Patent Document 1, the oil passage for supplying oil to the second oil passage is partially shared with the oil passage for supplying oil to the first oil passage, which is supposed to prevent the oil passage configuration from becoming complicated. However, this configuration requires oil passages that pass through the stator and rotor, and each oil passage requires multiple discharge holes, which still leads to a complicated structure.

[0005] The present invention has been made in view of the above circumstances, and has an object to realize suitable cooling in a rotating electrical machine while simplifying the configuration. [Means for solving the problem]

[0006] The various aspects disclosed in this specification employ different technical means to achieve their respective objectives. The objectives, features, and advantages disclosed in this specification will become more apparent by referring to the following detailed description and the accompanying drawings.

[0007] Method 1 is: a stator having a stator winding; a rotor disposed opposite the stator; a housing that accommodates the stator and the rotor, a refrigerant supply unit that is provided in the housing at a position vertically above the stator and the rotor when the rotating electric machine is installed, and that supplies a liquid refrigerant into the housing; a guide portion in the housing that guides the coolant supplied from the coolant supply portion to an air gap between the stator and the rotor; The present invention is characterized by comprising:

[0008] The refrigerant supply unit that supplies liquid refrigerant is located in the housing vertically above the stator and rotor when the rotating electric machine is installed, and the refrigerant supplied from the refrigerant supply unit is guided into the air gap between the stator and rotor by a guide unit within the housing. In this case, the refrigerant guided into the air gap is diffused circumferentially by the rotation of the rotor, and the refrigerant simultaneously cools the stator and rotor. As a result, the rotating electric machine can be optimally cooled while maintaining a simplified configuration.

[0009] In means 2, a rotating electric machine as in means 1 has an outer rotor structure in which the rotor is arranged radially outside the stator, and is used in an orientation in which the axial direction is horizontal or approximately horizontal, and a winding bend portion bent radially outward is provided at the axial end of the stator winding, and the winding bend portion is the guide portion.

[0010] In an outer rotor rotating electric machine used with the axial direction oriented horizontally or nearly horizontally, when the axial ends of the stator winding are bent radially outward, the winding bends extend vertically or nearly vertically, and face the axial end face of the rotor. In this case, by making the winding bends function as guides, the refrigerant can be effectively guided from the axial ends of the stator winding toward the air gap.

[0011] Means 3 provides a rotating electric machine as in Means 1, which has an outer rotor structure in which the rotor is disposed radially outside the stator, and is used with the axial direction in a horizontal or approximately horizontal direction, wherein the stator winding has a plurality of partial windings for each of the multi-phase phase windings, and the partial windings have a pair of intermediate conductor portions and a crossover portion provided on one axial end side and the other axial end side, connecting the pair of intermediate conductor portions in a ring shape, and one of the pair of intermediate conductor portions of the partial winding of another phase is disposed between the pair of intermediate conductor portions, so that the intermediate conductor portions of each phase are arranged in a predetermined order in the circumferential direction, and at least one of the crossover portions of the partial windings that overlap each other at the axial end of the stator winding is bent radially outward, and the winding bend portion bent radially outward at the crossover portion is the guide portion.

[0012] In a stator winding having multiple partial windings, it is assumed that one of a pair of intermediate conductor portions of a partial winding of another phase is disposed between a pair of intermediate conductor portions of the partial winding, so that the intermediate conductor portions of each phase are arranged in a predetermined order in the circumferential direction. In this case, at least one of the crossover portions of the partial windings that overlap each other at the axial end of the stator winding is bent radially outward, thereby suppressing interference between the circumferentially arranged partial windings. Furthermore, by making the winding bends bent radially outward at the crossover portions of the partial windings function as guide portions, it becomes possible to guide the refrigerant from the axial end of the stator winding toward the air gap.

[0013] In means 4, in means 2 or 3, the axial end faces of the rotor and the winding bends face each other in the axial direction, and an annular refrigerant passage is formed between the axial end faces of the rotor and the winding bends, extending circumferentially along the winding bends.

[0014] In a configuration in which the axial end face of the rotor and the winding bends at the axial end of the stator winding face each other in the axial direction, a groove-like space is formed between the axial end face of the rotor and the winding bends of the stator winding. This groove-like space serves as an annular refrigerant passage through which the refrigerant passes, so that as the refrigerant passes through the annular refrigerant passage, the refrigerant can come into contact with the winding bends and cool the axial end of the stator winding. This improves cooling efficiency.

[0015] In a fifth aspect of the present invention, in the fourth aspect, the stator winding has protrusions that protrude in the axial direction from the winding bend in the annular refrigerant passage and are provided at predetermined intervals in the circumferential direction.

[0016] In the configuration in which the annular refrigerant passage is formed between the axial end face of the rotor and the winding bend portion of the stator winding as described above, protrusions are provided at predetermined circumferential intervals that protrude in the axial direction from the winding bend portion. In this case, when the refrigerant passes through the annular refrigerant passage, the protrusions that extend in the axial direction from the winding bend portion guide the refrigerant toward the rotor, i.e., toward the air gap. This further improves cooling efficiency.

[0017] Means 6 is a rotating electric machine as in means 1, which has an outer rotor structure in which the rotor is arranged radially outside the stator, and is used with the axial direction in a horizontal or approximately horizontal direction, and in which an annular wall portion facing the axial end face of the rotor is provided at a position axially outside the rotor at the axial end of the stator core on which the stator winding is wound, and the annular wall portion is the guide portion.

[0018] The stator core has an annular wall portion facing the axial end face of the rotor at a position axially outward of the rotor at the axial end of the stator core. With this configuration, the annular wall portion functions as a guide portion, thereby making it possible to effectively guide the refrigerant from the axial end of the stator core toward the air gap.

[0019] In means 7, in any of means 2 to 6, the rotor has a magnet portion and a magnet holding member that holds the magnet portion, and the magnet holding member has a cylindrical portion to which the magnet portion is assembled and an end plate portion provided on one axial side of the cylindrical portion, the guide portion is provided on one of both axial sides of the stator winding, on the side opposite the end plate portion of the magnet holding member, and a through hole that penetrates radially is provided in the magnet holding member between the magnet portion and the end plate portion.

[0020] In a rotor for a rotating electric machine, if the magnet holding member has a cylindrical portion to which the magnet portion is attached and an end plate portion provided on one axial side of the cylindrical portion, and a guide portion is provided on one of the axial sides of the stator winding opposite the end plate portion of the magnet holding member, it is possible that the refrigerant that enters the air gap from the guide portion side of the stator winding on the axial side thereof may pass through to the opposite side of the guide portion (i.e., the end plate side of the magnet holding member). In this case, by providing a through hole that penetrates radially between the magnet portion and the end plate portion in the magnet holding member, the refrigerant is discharged from the through hole as the rotor rotates. Furthermore, the discharge of the refrigerant from the through hole promotes the flow of the refrigerant into the air gap. Therefore, refrigeration by the refrigerant in the air gap can be effectively achieved.

[0021] In Means 8, in any of Means 1 to 7, the refrigerant supply section has a refrigerant passage formed along the wall of the housing and a refrigerant supply hole through which the refrigerant falls from the refrigerant passage, and the refrigerant passage is provided with a force dissipation section that attenuates the momentum of the refrigerant flow.

[0022] When a coolant is supplied from the coolant supply unit of the housing to a predetermined position in the stator winding, if the coolant flow velocity in the coolant passage of the coolant supply unit is too strong, the coolant may splash in unexpected directions as it falls from the coolant supply hole, resulting in an unintended reduction in the amount of coolant supplied to the desired air gap. In this regard, by providing a force dissipator in the coolant passage of the coolant supply unit that attenuates the flow velocity of the coolant, splashing of the coolant as it falls from the coolant supply hole can be suppressed, allowing the coolant to be optimally supplied to the desired air gap. In this case, it is no longer necessary to increase the coolant flow rate in advance to account for splashing, thereby enabling efficient cooling of the stator, etc. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a cross-sectional view showing the overall structure of a rotating electric machine. [Figure 2] FIG. 2 is a cross-sectional view showing a rotor, a stator, and a stator holder in a rotating electric machine. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 10 is a perspective view showing the state in which two partial windings are combined. [Figure 6] FIG. 3 is a cross-sectional view showing the configuration of the axial end portions of the rotor and the stator. [Figure 7] FIG. 4 is a plan view showing the configuration of a refrigerant supply unit. [Figure 8] FIG. 2 is a diagram showing the flow of a refrigerant in a vertical cross section of the rotating electric machine. [Figure 9] FIG. 4 is a diagram showing the flow of a refrigerant in a plan view of the stator viewed from the vertical direction. [Figure 10] FIG. 4 is a diagram showing the flow of a refrigerant in a plan view of the stator viewed from the vertical direction. [Figure 11] FIG. 3 is a cross-sectional view showing a rotor, a stator, and a stator holder. [Figure 12] FIG. 10 is a diagram showing another configuration of partial windings. [Figure 13] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment of a rotating electric machine according to the present invention will be described with reference to the drawings. In the following embodiments and modifications, identical or equivalent parts are designated by the same reference numerals in the drawings, and the same explanations are incorporated herein by reference. The rotating electric machine of this embodiment is used, for example, as a generator or motor for a vehicle.

[0025] FIG. 1 is a cross-sectional view showing the overall structure of a rotating electric machine 10 according to this embodiment. FIG. 2 is a cross-sectional view showing a rotor 20, a stator 30, and a stator holder 50 in the rotating electric machine 10. FIG. 3 is a perspective view of the rotor 20, and FIG. 4 is a perspective view of the stator 30. In the following description, the direction of the central axis of rotation of the rotating electric machine 10 is referred to as the axial direction, the direction extending radially from the center of rotation as the radial direction, and the direction extending circumferentially around the central axis of rotation as the circumferential direction. The rotating electric machine 10 is an outer rotor, surface magnet, three-phase rotating electric machine, and is primarily composed of a rotor 20, a stator 30, a stator holder 50, and a housing 60 that accommodates the rotor 20, the stator 30, and the stator holder 50. The rotating electric machine 10 is mounted on a vehicle with its axial direction oriented horizontally or approximately horizontally. Therefore, in FIG. 1, the left-right direction is the horizontal direction, and the up-down direction is the vertical direction.

[0026] As shown in Figures 2 and 3, the rotor 20 has a rotating shaft 21, a rotor carrier 22 integrally provided on the rotating shaft 21, and an annular magnet unit 23 fixed to the rotor carrier 22. The rotor carrier 22 has an outer cylindrical portion 25 and an inner cylindrical portion 26 provided coaxially with the rotating shaft 21, and end plate portions 27 provided on one axial end side of the outer cylindrical portion 25 and the inner cylindrical portion 26, and the magnet unit 23 is assembled in an annular shape to the radial inside of the outer cylindrical portion 25. The other axial end side of the rotor carrier 22 is open. The rotor carrier 22 corresponds to the "magnet holding member," and the outer cylindrical portion 25 corresponds to the "cylindrical portion." The end plate portion 27 is substantially disc-shaped, and the rotating shaft 21 extending toward the open end side of the rotor carrier 22 is fixed to its center.

[0027] The magnet unit 23 is composed of a plurality of permanent magnets 28 arranged with alternating polarities along the circumferential direction of the rotor 20. The magnet unit 23 has a plurality of magnetic poles in the circumferential direction due to the plurality of permanent magnets 28 arranged in the circumferential direction. The magnet unit 23 corresponds to the "magnet section." Each permanent magnet 28 is a polar anisotropic magnet, and generates magnetic flux concentrated in an area near the d-axis on the magnetic flux action surface on the radially inner side (stator 30 side) of both radial faces. Specifically, the permanent magnets 28 are configured so that an arc-shaped magnetic flux path is formed along the direction of the easy axis of magnetization, and the direction of the easy axis of magnetization is more parallel to the d-axis on the side of the d-axis, which is the magnetic pole center, than on the side of the q-axis, which is the magnetic pole boundary.

[0028] The magnet unit 23 has recesses 23a, 23b on its radially outer and radially inner circumferential surfaces according to the orientation of each permanent magnet 28, and the recesses 23a, 23b are formed at predetermined intervals when viewed in the circumferential direction. That is, the magnet unit 23 has two permanent magnets 28 for each magnetic pole, and in each permanent magnet 28, the magnetic flux path is inclined obliquely with respect to the radial direction, thereby shortening the magnetic flux path length near two diagonal corners of the permanent magnet 28. Therefore, the recesses 23a, 23b are formed at each corner where the magnetic flux path length is shortened. More specifically, the recess 23a is formed at the d-axis position on the radially outer outer circumferential surface of the magnet unit 23 (i.e., the circumferential surface opposite the stator), and the recess 23b is formed at the q-axis position on the radially inner inner circumferential surface (i.e., the circumferential surface facing the stator).

[0029] Next, the configuration of the stator 30 will be described.

[0030] As shown in Figures 2 and 4, the stator 30 is an armature with a teethless structure, and has a stator winding 31 and a stator core 32. In the stator 30, the stator winding 31 has three phase windings, and each phase winding is composed of a plurality of partial windings 41. The partial windings 41 are provided according to the number of poles of the rotating electric machine 10, and a plurality of partial windings 41 are connected in parallel or series for each phase. In this embodiment, the number of magnetic poles is 16, but the number can be any number. The stator core 32 is cylindrical and composed of laminated steel sheets in which electromagnetic steel sheets are stacked in the axial direction.

[0031] The stator winding 31 has, in the axial direction, a portion corresponding to the coil side CS that faces the stator core 32 in the radial direction, and a portion corresponding to the coil end CE that is axially outside the coil side CS. The coil side CS is also a portion that faces the magnet unit 23 of the rotor 20 in the radial direction. The partial winding 41 is assembled to the radial outside of the stator core 32. In this case, the partial winding 41 is assembled with both axial end portions thereof protruding axially outward beyond the stator core 32 (i.e., toward the coil end CE).

[0032] Each partial winding 41 has one axial end bent radially and the other not bent radially. Of all the partial windings 41, partial windings 41A (half) have one axial end (left end in FIG. 4) bent and bent radially outward at that bent side. The remaining partial windings 41B have the other axial end (right end in FIG. 4) bent and bent radially inward at that bent side.

[0033] The configuration of the winding sections 41A and 41B will be described below. Fig. 5 is a perspective view showing the state in which the winding sections 41A and 41B are combined together.

[0034] Each of the partial windings 41A, 41B has a pair of linear intermediate conductor portions 42 that are parallel to each other, and a pair of transition portions 43, 44 that connect the pair of intermediate conductor portions 42 at both axial ends. The pair of intermediate conductor portions 42 and the pair of transition portions 43, 44 form a ring shape. The pair of intermediate conductor portions 42 are spaced a predetermined coil pitch apart, so that an intermediate conductor portion 42 of the partial winding 41 of another phase can be arranged between the pair of intermediate conductor portions 42 in the circumferential direction. In this embodiment, the pair of intermediate conductor portions 42 are spaced two coil pitches apart, so that one intermediate conductor portion 42 of the partial windings 41 of the other two phases is arranged between the pair of intermediate conductor portions 42. When the partial windings 41A, 41B are arranged side by side in the circumferential direction, the intermediate conductor portions 42 of the different partial windings 41A, 41B are arranged side by side in close proximity to each other in the circumferential direction. Each of the winding sections 41A and 41B is formed by winding a conductive wire in multiple layers.

[0035] The crossover portions 43, 44 on both axial sides are provided as portions corresponding to the coil ends CE, and one of the crossover portions 43, 44 is bent radially, while the other is not bent radially. This gives the winding sections 41A, 41B a generally L-shape when viewed from the side. The crossover portion 43 of the winding section 41A is bent radially outward, while the crossover portion 43 of the winding section 41B is bent radially inward.

[0036] Assuming that the partial windings 41A, 41B are arranged side by side in the circumferential direction, the planar shapes (radial planar shapes) of the transition portions 43 of the partial windings 41A, 41B may be different from each other, with the transition portion 43 of the partial winding 41A having a wider circumferential width toward its tip, and the transition portion 43 of the partial winding 41B having a narrower circumferential width toward its tip. Although not shown, each intermediate conductor portion 42 of the partial windings 41A, 41B may be covered with a sheet-like insulating coating.

[0037] Each of the partial windings 41A, 41B is formed by multiple windings of a conductive wire, and winding end portions 45, which are the start and end of the winding, are provided at one axial end. The winding end portions 45 are provided to extend in the axial direction, and a wiring module 35 is connected to each of the winding end portions 45 (see FIG. 2). The wiring module 35 is a winding connecting member that is electrically connected to each of the partial windings 41A, 41B in the stator winding 31, and this wiring module 35 connects the partial windings 41 of each phase in parallel or in series, and also connects the phase windings of each phase to a neutral point.

[0038] The wiring module 35 has an annular shape and includes a power line bus bar for each phase as wiring for each phase, and a neutral point bus bar as wiring for the neutral point. The wiring module 35 is provided on one of both axial ends of the stator 30, specifically, on the open end side of the rotor carrier 22.

[0039] In this embodiment, as shown in Fig. 2, the portion of the stator winding 31 that is axially outward from the stator core 32 is the coil end CE. However, when the axial end face X of the rotor 20 (the axial end face of the magnet unit 23) is taken as the reference, the portion of the stator winding 31 that is axially outward from the axial end face X of the rotor 20 includes the coil end CE and part of the coil side CS. In this case, as shown in Fig. 6, the portion of the stator winding 31 at the axial end that is axially outward from the rotor 20 is bent in an L-shape and includes a first portion A1 extending in the axial direction and a second portion A2 extending in the radial direction. Of these, the second portion A2 corresponds to the winding bent portion that is bent radially outward at the axial end of the stator winding 31.

[0040] When the end position of the stator core 32 and the end position of the rotor 20 coincide in the axial direction, the coil end CE coincides with a portion of the axial end of the stator winding 31 that is axially outward of the rotor 20. The second portion A2 of the stator winding 31 may be perpendicular to the first portion A1 or may be non-perpendicular, and for example, the angle formed between the second portion A2 and the first portion A1 may be an obtuse angle.

[0041] Next, the configuration of the stator holder 50 will be described. As shown in Fig. 2, the stator holder 50 is a stator holding member that holds the stator 30, and includes a first holder member 51 that is assembled to the radially inner side of the stator core 32, and a second holder member 52 that is assembled to the radially inner side of the first holder member 51. The second holder member 52 includes a cylindrical portion 52a and a flange portion 52b that is provided on one axial end side of the cylindrical portion 52a. The axial length of the cylindrical portion 52a is longer than that of the first holder member 51, and the first holder member 51 and the wiring module 35 are fixed to the cylindrical portion 52a.

[0042] Furthermore, the inner diameter dimension of the cylindrical portion 52a of the second holder member 52 is larger than the outer diameter dimension of the inner cylindrical portion 26 of the rotor carrier 22 of the rotor 20, and bearings 36 are provided at two axial positions between the cylindrical portion 52a of the second holder member 52 and the inner cylindrical portion 26 of the rotor carrier 22. This allows the rotor 20 to rotate freely relative to the integrated body of the stator 30 and the stator holder 50.

[0043] In the configuration shown in Fig. 2, an annular space is formed between the outer cylindrical portion 25 and the inner cylindrical portion 26 of the rotor carrier 22, and the magnet unit 23 of the rotor 20, the stator 30, and the stator holder 50 are provided in this annular space, overlapping radially. Here, an air gap, which is a gap with a predetermined distance, is formed between the magnet unit 23 of the rotor 20 and the stator winding 31 (partial winding 41) of the stator 30. In the configuration of Fig. 2, the axial length of the magnet unit 23 is smaller than the axial length of the stator core 32. However, these lengths may be equal to each other.

[0044] Next, the configuration of the housing 60 will be described. As shown in FIG. 1, the housing 60 is provided so as to radially and axially surround the rotor 20, the stator 30, and the stator holder 50. The housing 60 has a cylindrical first housing member 61 with a bottom, and a second housing member 62 fixed to the open end of the first housing member 61 with bolts or the like. The first housing member 61 has a cylindrical portion 63 and an end plate portion 64. A flange portion 52b of the second holder member 52 of the stator holder 50 is fixed to the end plate portion 64 of the first housing member 61. In this way, the stator 30 and the stator holder 50 are assembled to the housing 60.

[0045] A through-hole 64a is formed in the center of the end plate portion 64 of the first housing member 61, and a substantially cylindrical tubular body 65 is fixed to the through-hole 64a. The second housing member 62 has a through-hole 62a formed in the center. At one axial end of the rotor 20, the tip end of the rotating shaft 21 is rotatably inserted into the tubular body 65, and at the other axial end, the boss portion 22a of the rotor carrier 22 is rotatably inserted into the through-hole 62a of the second housing member 62. In this way, the rotor 20 is rotatably held in the housing 60.

[0046] Next, a description will be given of the cooling structure of the rotating electrical machine 10. In this embodiment, an oil-cooled structure is adopted in which cooling oil is used as a refrigerant to cool the rotor 20 and the stator 30. However, the refrigerant may be any liquid refrigerant, and a water-cooled structure using cooling water may also be adopted.

[0047] The housing 60 is provided with a refrigerant supply unit 70 that supplies a refrigerant (cooling oil). The refrigerant supply unit 70 is disposed on the vertically upper side of the cylindrical portion 63 of the housing 60, i.e., at a position that is vertically above the stator 30 and the rotor 20 when the rotating electric machine 10 is installed in the housing 60, and has an inlet portion 71 formed by a nipple or the like, a refrigerant passage 72 extending axially from the inlet portion 71, and a refrigerant supply hole 73 provided at the downstream end of the refrigerant passage 72. The refrigerant passage 72 is formed by closing a groove formed in the cylindrical portion 63 with a cover plate 74. The refrigerant supply hole 73 is provided in a position (directly above in the vertical direction) directly above the coil end CE on one axial side of the stator winding 31.

[0048] The positional relationship between the refrigerant supply hole 73 and the axial end of the stator winding 31 will be explained further below. As described with reference to FIG. 6, the axial end of the stator winding 31, located axially outward from the rotor 20, includes a first portion A1 extending in the axial direction and a second portion A2 (winding bend portion) extending in the radial direction. The refrigerant supply hole 73 is provided directly above the first portion A1. In this case, it is preferable that the positions of the refrigerant supply hole 73 and the first portion A1 overlap in the axial direction, and that the length between the axial end face of the rotor 20 and the second portion A2 in the first portion A1 approximately coincide with the diameter of the refrigerant supply hole 73. In FIG. 6, the axial position of the refrigerant supply hole 73 is indicated by W. Note that the diameter of the refrigerant supply hole 73 may be shorter than the length between the axial end face X of the rotor 20 and the second portion A2. In FIG. 6, the area sandwiched between the second portion A2 of the stator winding 31 and the axial end face of the rotor 20 forms an annular refrigerant passage A3 that extends circumferentially along the first portion A1 and the second portion A2.

[0049] The refrigerant flowing through the refrigerant passage 72 flows down vertically from the refrigerant supply hole 73 and falls on the first portion A1 of the stator winding 31. However, in this case, if the refrigerant flow in the refrigerant passage 72 is too strong, there is a concern that the refrigerant may splash in multiple directions as it flows down from the refrigerant supply hole 73. Therefore, in this embodiment, the refrigerant supply unit 70 is provided with a splash prevention mechanism that prevents the refrigerant from splashing, and the configuration of the splash prevention mechanism will be described below.

[0050] FIG. 7 is a plan view showing the configuration of the refrigerant supply unit 70. Note that FIG. 7 shows the refrigerant supply unit 70 with the cover plate 74 removed. As shown in FIG. 7, the refrigerant supply unit 70 has a narrow portion 75 that locally narrows the refrigerant passage 72, and a wall portion 76 that is provided downstream of the narrow portion 75 and upstream of the refrigerant supply hole 73. The wall portion 76 is a deceleration wall that attenuates the momentum of the refrigerant by changing the direction of the refrigerant flow in the refrigerant passage 72. In this embodiment, the wall portion 76 is configured to distribute the refrigerant in two directions. However, the configuration of the wall portion 76 can be changed, such as distributing the refrigerant in more directions or forming a maze structure using multiple wall portions 76.

[0051] According to the above configuration, the refrigerant flowing through the refrigerant passage 72 reaches the refrigerant supply hole 73 after colliding with the wall portion 76 and losing momentum. This prevents the refrigerant from splashing when it flows down from the refrigerant supply hole 73.

[0052] 1, a refrigerant recovery section 77 that recovers refrigerant inside the housing 60 is provided at a vertically lower position in the cylindrical section 63 of the housing 60. The refrigerant recovery section 77 is, for example, an oil pan attached to an opening formed at the vertically lower side of the cylindrical section 63. The refrigerant recovery section 77 is provided with an outlet section 78 formed by a nipple or the like.

[0053] Although not shown, a circulation path for circulating the refrigerant is connected to the inlet portion 71 and the outlet portion 78. The circulation path is provided with, for example, an electric pump and a heat dissipation device such as a radiator, and the refrigerant circulates through the circulation path and the refrigerant path inside the rotating electrical machine 10 as the pump is driven.

[0054] Regarding the cooling structure configured as described above, the flow of the refrigerant in the rotating electrical machine 10 will be described in more detail. Fig. 8 is a diagram showing the flow of the refrigerant in a vertical cross section of the rotating electrical machine 10, and Fig. 9 is a diagram showing the flow of the refrigerant in a plan view of the stator 30 viewed from the vertical direction.

[0055] As the pump operates, the refrigerant flows in through inlet 71, flows through refrigerant passage 72 in refrigerant supply unit 70, is decelerated by wall 76, and then falls from refrigerant supply hole 73. In this case, the refrigerant falls from above in the vertical direction toward the axial end of stator winding 31. More specifically, first portion A1 of stator winding 31 is located directly below refrigerant supply hole 73, and the refrigerant falling from refrigerant supply hole 73 is supplied directly to first portion A1 of stator winding 31 without scattering in multiple directions due to the deceleration effect of refrigerant supply unit 70.

[0056] The refrigerant then flows through the annular refrigerant passage A3 between the second portion A2 (winding bend portion) of the stator winding 31 and the axial end surface X of the rotor 20, enters the air gap between the stator winding 31 (partial winding 41) and the magnet unit 23 of the rotor 20, and is further diffused circumferentially within the air gap as the rotor 20 rotates. At this time, because the axial end of the stator winding 31 is bent into an L-shape and the second portion A2 extends radially, the refrigerant in the annular refrigerant passage A3 is guided toward the air gap. In other words, since the annular refrigerant passage A3 has the second portion A2 on one of the axial ends opposite the rotor, the outflow of the refrigerant toward the opposite rotor side is restricted, and the refrigerant easily flows toward the rotor 20 (air gap). Furthermore, as described with reference to FIG. 3 , the recess 23b is provided on the inner circumferential surface of the magnet unit 23, which also facilitates the refrigerant flow toward the air gap. The refrigerant that has entered the air gap simultaneously cools the stator 30 and the rotor 20.

[0057] The refrigerant diffuses throughout the air gap as rotor 20 rotates, and is then collected in refrigerant collection section 77 and discharged from outlet section 78. The refrigerant then flows through the circulation path and into refrigerant supply section 70 from inlet section 71, and is used again to cool rotor 20 and stator 30.

[0058] The partial winding 41 may be impregnated with varnish or the like to maintain the L-shape of the transition portion 43. Alternatively, the partial winding 41 may have a shape-maintaining component attached to the transition portion 43.

[0059] According to the present embodiment described above in detail, the following excellent effects can be obtained.

[0060] A refrigerant supply unit 70 that supplies liquid refrigerant is provided at a position vertically above the stator 30 and the rotor 20, and within the housing 60, the refrigerant supplied from the refrigerant supply unit 70 is guided to the air gap between the stator 30 and the rotor 20 by the winding bends of the stator winding 31 (the bridge portions 43 of the partial winding 41) that serve as guides. In this case, the refrigerant guided to the air gap is diffused circumferentially by the rotation of the rotor 20, and the stator 30 and the rotor 20 are cooled simultaneously by this refrigerant. As a result, the rotating electric machine 10 can be appropriately cooled while the configuration is simplified.

[0061] In the outer rotor type rotating electric machine 10 used with the axial direction oriented horizontally or approximately horizontally, when the axial end of the stator winding 31 is bent radially outward, the second portion A2, which is the winding bend, extends vertically or approximately vertically, and the second portion A2 faces the axial end face of the rotor 20. In this case, by making the second portion A2 function as a guide, the refrigerant can be suitably guided from the axial end of the stator winding 31 toward the air gap.

[0062] In the stator winding 31 having a plurality of partial windings 41, one of a pair of intermediate conductor portions 42 in a partial winding 41 of another phase is disposed between a pair of intermediate conductor portions 42 of the partial windings 41, so that the intermediate conductor portions 42 of each phase are arranged in a predetermined order in the circumferential direction. In this case, one of the crossover portions 43, 44 of the partial windings 41 that overlap each other at the axial end of the stator winding 31 is bent radially outward, thereby suppressing interference between the partial windings 41 arranged in the circumferential direction. In addition, the second portion A2 bent radially outward in the crossover portion 43 of the partial winding 41 functions as a guide portion, thereby making it possible to appropriately guide the refrigerant from the axial end of the stator winding 31 toward the air gap.

[0063] In a configuration in which the axial end face of the rotor 20 and the second portion A2 (winding bend portion) at the axial end of the stator winding 31 face each other in the axial direction, a groove-like space is formed between the axial end face of the rotor 20 and the second portion A2 of the stator winding 31. This groove-like space serves as an annular refrigerant passage A3 through which the refrigerant passes, so that when the refrigerant passes through the annular refrigerant passage A3, the axial end of the stator winding 31 can be cooled while coming into contact with the second portion A2, thereby improving cooling efficiency.

[0064] The wall portion 76 is provided in the refrigerant passage 72 of the refrigerant supply portion 70 as a force dissipator that attenuates the momentum of the refrigerant flow, which can prevent the refrigerant from splashing when it drops from the refrigerant supply hole 73, thereby enabling the refrigerant to be suitably supplied to the desired air gap. In this case, it is no longer necessary to increase the refrigerant flow rate in advance to account for the amount of refrigerant that will splash, allowing for efficient cooling of the stator 30, etc.

[0065] (Other embodiments) The above embodiment may be modified as follows, for example.

[0066] Fig. 10 is a diagram showing the flow of refrigerant in a plan view of the stator 30 viewed from the vertical direction. As shown in Fig. 10, the stator winding 31 may have protrusions 81 that protrude axially from the second portion A2 (winding bend portion) in the annular refrigerant passage A3. The protrusions 81 are provided at predetermined intervals in the circumferential direction, and may be provided, for example, at positions between the winding sections 41. In this case, the protrusions 81 may be provided between the winding sections 41A or between the winding sections 41B.

[0067] 10, when the refrigerant passes through the annular refrigerant passage A3, the protrusion 81 extending axially from the second portion A2 guides the refrigerant toward the rotor 20, i.e., toward the air gap, thereby further improving the cooling efficiency.

[0068] 11 is a cross-sectional view showing the rotor 20, the stator 30, and the stator holder 50. As shown in this Fig. 11, a configuration may be adopted in which a plurality of through holes 82 that penetrate in the radial direction are provided in the outer cylindrical portion 25 of the rotor carrier 22 between the magnet unit 23 and the end plate portion 27.

[0069] In the configuration shown in FIG. 11 , a second portion A2 (winding bend portion) serving as a guide portion is provided on one of the axial sides of the stator winding 31, opposite the end plate portion 27 of the rotor carrier 22. The refrigerant that enters the air gap from the second portion A2 side of the axial side of the stator winding 31 may pass through to the opposite side of the second portion A2 (i.e., the end plate portion 27 side). In this case, the rotor carrier 22 is provided with through-holes 82 that penetrate radially between the magnet unit 23 and the end plate portion 27, and the refrigerant is discharged from the through-holes 82 as the rotor 20 rotates. Furthermore, as the refrigerant is discharged from the through-holes 82, a negative pressure is created in the inner space of the rotor carrier 22, promoting the inflow of the refrigerant into the air gap. This allows for optimal cooling by the refrigerant in the air gap.

[0070] The configuration of the partial windings 41 of the stator winding 31 may be changed as follows. In the configuration shown in FIG. 12(a), the crossover portions on both axial sides of each partial winding 41 are bent radially in opposite directions. All partial windings 41 have the same shape in side view and are assembled to the stator core 32 with their axial assembly positions offset from one another. In the configuration shown in FIG. 12(b), all partial windings 41 are roughly C-shaped in side view and are assembled radially in opposite directions. That is, in one partial winding 41A, each crossover portion on both axial sides is bent toward the stator core 32, and in the other partial winding 41B, each crossover portion on both axial sides is bent away from the stator core 32. In the configuration shown in FIG. 12(b), the rotor 20 may be assembled to the outer periphery of the stator in a divided state.

[0071] In either configuration shown in Figure 12(a) or (b), the winding bend portion bent radially outward at the crossover portion of the partial winding 41 is used as a guide portion that guides the refrigerant to the air gap between the stator 30 and the rotor 20, thereby making it possible to effectively cool the stator 30 and the rotor 20.

[0072] The stator winding 31 may have a winding structure that does not use partial windings 41. For example, the stator core 32 may be provided with teeth and slots, and a conductor wire may be wound in the slots by wave winding or the like. In this configuration, the stator winding 31 may have a winding bent portion at the axial end that is bent radially outward.

[0073] 13, an annular wall portion 83 facing the axial end face of the rotor 20 may be provided at a portion of the axial end of the stator core 32 that is axially outward of the rotor 20, and the annular wall portion 83 may function as a "guide portion." In FIG. 13, the stator winding 31 is wound in the slots 32a of the stator core 32, and the annular wall portion 83 extending in the circumferential direction is provided on the outer circumferential surface of the stator core 32.

[0074] In this case, the refrigerant is supplied to the axial end of the stator core 32 from above in the vertical direction, and then enters the air gap between the stator 30 and the rotor 20, thereby cooling the stator 30 and the rotor 20 simultaneously.

[0075] 13, the annular wall 83 may be provided with protrusions 84 that protrude in the axial direction from the annular wall 83. The protrusions 84 may be provided at predetermined intervals in the circumferential direction. With this configuration, when the refrigerant passes through the annular refrigerant passage between the axial end face of the rotor 20 and the annular wall 83, the protrusions 84 extending in the axial direction from the annular wall 83 guide the refrigerant toward the rotor 20, i.e., toward the air gap. This further improves cooling efficiency.

[0076] In the above embodiment, the rotating electric machine 10 is used with its axial direction horizontal or approximately horizontal. However, this may be changed. For example, the rotating electric machine 10 may be used with its axial direction vertical or approximately vertical. In this case, if the end plate portion 64 of the first housing member 61 of the housing 60 is located on the vertically upper side, the refrigerant supply portion 70 may be provided on the end plate portion 64, and a guide portion that guides the refrigerant into the air gap between the stator 30 and the rotor 20 may be provided vertically below the refrigerant supply portion 70. For example, if the stator has a slot winding structure, the coil ends of the stator winding may face the rotor, and the coil ends may serve as guide portions to guide the refrigerant into the air gap.

[0077] The rotating electric machine 10 may have a configuration different from that of a surface permanent magnet type rotating electric machine. For example, the rotating electric machine 10 may be an interior permanent magnet type rotating electric machine. [Explanation of symbols]

[0078] 10... rotating electric machine, 20... rotor, 30... stator, 60... housing, 70... refrigerant supply section

Claims

1. a stator (30) having a stator winding (31); a rotor (20) disposed opposite the stator; a housing (60) that accommodates the stator and the rotor, has an outer rotor structure in which the rotor is disposed radially outside the stator, and is used with its axial direction in a horizontal or substantially horizontal direction, a refrigerant supply unit (70) provided in the housing at a position vertically above the stator and the rotor when the rotating electric machine is installed, the refrigerant supply unit supplying a liquid refrigerant into the housing; a guide portion (A2) in the housing that guides the refrigerant supplied from the refrigerant supply portion to an air gap between the stator and the rotor; Equipped with A rotating electric machine in which a winding bent portion (A2) bent radially outward is provided at an axial end of the stator winding, and the winding bent portion serves as the guide portion.

2. a stator (30) having a stator winding (31); a rotor (20) disposed opposite the stator; a housing (60) that accommodates the stator and the rotor, has an outer rotor structure in which the rotor is disposed radially outside the stator, and is used with its axial direction in a horizontal or substantially horizontal direction, a refrigerant supply unit (70) provided in the housing at a position vertically above the stator and the rotor when the rotating electric machine is installed, the refrigerant supply unit supplying a liquid refrigerant into the housing; a guide portion (A2) in the housing that guides the refrigerant supplied from the refrigerant supply portion to an air gap between the stator and the rotor; Equipped with The stator winding has a plurality of partial windings (41) for each of the multi-phase windings, The partial winding has a pair of intermediate conductor portions (42) and transition portions (43, 44) provided at one and the other axial ends thereof and annularly connecting the pair of intermediate conductor portions, and one of the pair of intermediate conductor portions of the partial winding of another phase is disposed between the pair of intermediate conductor portions, so that the intermediate conductor portions of each phase are arranged in a predetermined order in the circumferential direction, and at least one of the transition portions of the partial windings that overlap each other at the axial end of the stator winding is bent radially outward, The rotating electric machine, wherein the winding bent portion (A2) bent radially outward at the transition portion serves as the guide portion.

3. 3. The rotating electric machine according to claim 1, wherein an axial end face of the rotor and the winding bend portion are opposed to each other in the axial direction, and an annular refrigerant passage (A3) is formed between the axial end face of the rotor and the winding bend portion, extending circumferentially along the winding bend portion.

4. 4. The rotating electric machine according to claim 3, wherein the stator winding has protrusions (81) that protrude in the axial direction from the winding bend portion in the annular refrigerant passage and are provided at predetermined intervals in the circumferential direction.

5. a stator (30) having a stator winding (31); a rotor (20) disposed opposite the stator; a housing (60) that accommodates the stator and the rotor, has an outer rotor structure in which the rotor is disposed radially outside the stator, and is used with its axial direction in a horizontal or substantially horizontal direction, a refrigerant supply unit (70) provided in the housing at a position vertically above the stator and the rotor when the rotating electric machine is installed, the refrigerant supply unit supplying a liquid refrigerant into the housing; a guide portion (83) in the housing for guiding the coolant supplied from the coolant supply portion to the air gap between the stator and the rotor; Equipped with an annular wall portion (83) facing an axial end face of the rotor is provided at a portion of the stator core (32) on which the stator winding is wound, the portion being axially outward of the rotor; The rotating electric machine, wherein the annular wall portion is the guide portion.

6. The rotor has a magnet portion (23) and a magnet holding member (22) that holds the magnet portion, The magnet holding member has a cylindrical portion (25) to which the magnet portion is assembled, and an end plate portion (27) provided on one axial side of the cylindrical portion, the guide portion is provided on one of both axial sides of the stator winding, opposite the end plate portion of the magnet holding member, The rotating electric machine according to any one of claims 1 to 5, wherein a through hole (82) that penetrates radially is provided between the magnet portion and the end plate portion in the magnet holding member.

7. The refrigerant supply portion has a refrigerant passage (72) formed along the wall portion of the housing and a refrigerant supply hole (73) through which the refrigerant drops from the refrigerant passage, 7. The rotating electric machine according to claim 1, wherein the refrigerant passage is provided with an energy dissipator (76) that attenuates the momentum of the refrigerant flow.

8. a stator (30) having a stator winding (31); a rotor (20) disposed opposite the stator; A rotating electric machine (10) comprising: a housing (60) that accommodates the stator and the rotor, a refrigerant supply unit (70) provided in the housing at a position vertically above the stator and the rotor when the rotating electric machine is installed, the refrigerant supply unit supplying a liquid refrigerant into the housing; a guide portion (A2, 83) in the housing that guides the refrigerant supplied from the refrigerant supply portion to an air gap between the stator and the rotor; Equipped with The refrigerant supply portion has a refrigerant passage (72) formed along the wall portion of the housing and a refrigerant supply hole (73) through which the refrigerant drops from the refrigerant passage, The rotating electric machine has an energy dissipation section (76) provided in the refrigerant passage for attenuating the momentum of the refrigerant flow.

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