Rotating Electric Machine

Abstract

To provide a rotary electric machine which reduces a leak current of a coolant and improve a heat extraction effect as a whole.SOLUTION: A rotary electric machine 100 includes: an inner housing 13 that houses a stator 11 and a rotator 12; and an outer housing 14 that covers an outer periphery of the inner housing 13. Main flow channels C1 to C3 making a coolant circulate comprise a double-structured housing formed between the inner housing 13 and the outer housing 14. In the rotary electric machine 100, leak flow channels L12 and L23 making the coolant leak between the adjacent main flow channels C1 to C3 are formed when by the inner housing 13 and the outer housing 14 form the main flow channels C1 to C3. Then, at least part of the leak flow channels L12 and L23 includes a bent shape for bending a circulation direction of the coolant circulated in the leak flow channels L12 and L23.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a rotating electric machine including a housing having a flow passage through which a coolant flows. [Background technology]

[0002] Patent Document 1 describes a rotating electrical machine in which a cylindrical inner housing is provided inside a cylindrical outer housing, and a coolant flow path is formed between them. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 213052 Summary of the Invention [Problem to be solved by the invention]

[0004] When a flow path through which a coolant or other refrigerant flows is formed between the inner housing and the outer housing, this flow path is, in principle, made watertight and / or airtight by the abutment of the inner housing and the outer housing.

[0005] However, the inner housing and the outer housing have dimensional tolerances as an assembly margin. Therefore, it is inevitable that a gap will be generated between the inner housing and the outer housing due to the dimensional tolerance. As a result, it is virtually inevitable that a leak flow will occur, in which the refrigerant leaks between the flow paths, due to the gap between the inner housing and the outer housing caused by the dimensional tolerance. If such a leak flow occurs, the heat removal effect of the entire flow path may be reduced.

[0006] Therefore, an object of the present invention is to provide a rotating electric machine which reduces the leakage flow of coolant and improves the overall heat removal effect even if gaps occur between the inner housing and the outer housing due to dimensional tolerances, etc. [Means for solving the problem]

[0007] One aspect of the present invention is a rotating electric machine having a double-structure housing including an inner housing that houses a stator and a rotor, and an outer housing that covers the outer periphery of the inner housing, and a main flow path through which a refrigerant flows is formed between the inner housing and the outer housing. In this rotating electric machine, when the main flow path is formed by the inner housing and the outer housing, a leak flow path that causes the refrigerant to leak is formed between adjacent main flow paths. At least a part of the leak flow path has a bent shape that bends the flow direction of the refrigerant flowing through the leak flow path. The inner housing has an outer peripheral surface formed with ridges separating adjacent main flow paths, the inner housing has an inner peripheral surface formed with steps adjacent to the ridges and protruding toward the inner housing, and the bent shape of the leak flow path is formed by the ridges and the steps. There are a plurality of ridges and steps along the direction of the rotor's rotation axis, and the height of the ridges decreases and the height of the steps increases along the direction of the rotor's rotation axis. Effect of the Invention

[0008] According to the present invention, even if a gap occurs between the inner housing and the outer housing due to dimensional tolerances, etc., a rotating electric machine can be provided in which the leakage flow of coolant is reduced and the overall heat dissipation effect is improved. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective cross-sectional view showing a schematic structure of a rotating electric machine. [Diagram 2] FIG. 2 is a perspective view of the inner housing. [Diagram 3] FIG. 3 is a perspective view of the outer housing. [Figure 4] FIG. 4 is a schematic cross-sectional view showing a detailed structure of the refrigerant flow path. [Diagram 5] FIG. 5 is a schematic cross-sectional view showing the structure of a refrigerant flow path of a comparative example. [Figure 6] FIG. 6 is an explanatory diagram showing the distribution of heat transfer coefficients in a refrigerant flow path of the embodiment. [Figure 7] FIG. 7 is an explanatory diagram showing the distribution of heat transfer coefficients in the refrigerant flow path of the comparative example. [Figure 8] FIG. 8 is a histogram showing the amount of heat dissipation in this embodiment and the comparative example. [Figure 9] FIG. 9 is a schematic cross-sectional view showing the structure of the refrigerant flow path of the second embodiment. [Figure 10] FIG. 10 is a graph showing the flow velocity of the main stream. [Figure 11] FIG. 11 is an explanatory diagram showing the positions where steps are provided in a spiral refrigerant flow path. [Figure 12] FIG. 12 is an explanatory diagram showing positions where steps are provided in a meandering refrigerant flow path. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] [First embodiment] 1 is a perspective cross-sectional view showing a schematic configuration of a rotating electric machine 100. The rotating electric machine 100 is a motor, a generator, or a motor-generator that operates as a motor and a generator. The rotating electric machine 100 according to this embodiment is used as a motor for driving a vehicle and / or a generator for generating electric power for driving a vehicle.

[0012] As shown in Fig. 1, a rotating electric machine 100 includes a stator 11 and a rotor 12 inside a housing. The housing of the rotating electric machine 100 has a double structure formed by an inner housing 13 that houses the stator 11 and the rotor 12, and an outer housing 14 that covers the outer periphery of the inner housing 13. A flow path (hereinafter referred to as a refrigerant flow path 15) for circulating a refrigerant (not shown) is formed between the inner housing 13 and the outer housing 14. The refrigerant cools the stator 11, the rotor 12, etc. by flowing through the refrigerant flow path 15. The refrigerant is a fluid such as a liquid or gas used for cooling, and is, for example, water or other cooling liquid, air, etc.

[0013] The refrigerant flow path 15 is composed of one or more flow paths. That is, the refrigerant flow path 15 is one flow path formed in series, or the total of two or more flow paths in which the refrigerant does not flow between each other in principle. In addition, the refrigerant flow path 15 is formed to cool a part or all of the stator 11, etc., which is the object to be cooled, by going around, turning back, or meandering, etc., in order to cool the stator 11, etc. For this reason, at least a part of the refrigerant flow path 15 is adjacent to itself. In this embodiment, the refrigerant flow path 15 is one flow path formed in series, and is formed in a spiral shape that goes around the stator 11, etc. A certain part of the refrigerant flow path 15 is adjacent to the refrigerant flow path 15 after going around. Therefore, in the cross section shown in FIG. 1, three or four refrigerant flow paths 15 are adjacent to each other in the direction of the rotation axis 16 of the rotor 12.

[0014] The refrigerant flow passage 15 is formed by the contact between the outer peripheral surface 21 (see FIG. 2) of the inner housing 13 and the inner peripheral surface 34 (see FIG. 3) of the outer housing 14. In principle, the contact between the inner housing 13 and the outer housing 14 makes the refrigerant flow passage 15 watertight and / or airtight. However, the dimensional tolerances of the inner housing 13 and the outer housing 14 are determined in advance to allow for a margin during assembly. Therefore, even after the inner housing 13 and the outer housing 14 are assembled and the housing of the rotating electric machine 100 is formed, a gap may be generated between the inner housing 13 and the outer housing 14 due to the dimensional tolerance. Therefore, in practice, the watertightness and / or airtightness of the refrigerant flow passage 15 is broken depending on the degree of the gap due to the dimensional tolerance. As a result, the refrigerant may leak between adjacent refrigerant flow passages 15.

[0015] The space between the inner housing 13 and the outer housing 14 is sealed by sealing members 17 such as O-rings provided on both ends of the area where the refrigerant flow path 15 is provided. Therefore, regardless of the dimensional tolerances of the inner housing 13 and the outer housing 14, the refrigerant does not leak outside the area where the refrigerant flow path 15 is provided.

[0016] Hereinafter, the direction parallel to the rotation axis 16 of the rotor 12 is defined as the Z direction, and the direction perpendicular to the Z direction in the cross section shown in Fig. 1 is defined as the Y direction. The X direction is defined to form a right-handed system together with the Y direction and the Z direction.

[0017] Fig. 2 is a perspective view of the inner housing 13. As shown in Fig. 2, the inner housing 13 is formed in a cylindrical shape so as to accommodate the stator 11 and the rotor 12. In this embodiment, the inner housing 13 is formed in a roughly cylindrical shape, and a recess 22 is formed in an outer circumferential surface 21 thereof.

[0018] The recess 22 is provided in a predetermined range 23 of the outer circumferential surface 21. The predetermined range 23 is a range that includes at least the range where the stator 11 abuts against the inner circumferential surface 24.

[0019] The recesses 22 form the refrigerant flow passage 15 by contacting the outer peripheral surface 21 with the inner peripheral surface 34 of the outer housing 14. The two-dot chain arrow indicates the flow direction of the refrigerant. In this embodiment, the recesses 22 are formed in a spiral shape around the outer peripheral surface 21 from a refrigerant inlet point 25 communicating with a refrigerant inlet 31 (see FIG. 3) to the rotating electric machine 100 to a refrigerant outlet point 26 communicating with a refrigerant outlet 32 ​​(see FIG. 3) from the rotating electric machine 100. The spiral structure separates adjacent recesses 22 by ridges 27. That is, the outer peripheral surface 21 of the inner housing 13 has ridges 27 formed thereon, which separate adjacent refrigerant flow passages 15.

[0020] In this embodiment, since the recess 22 is formed in a spiral shape, the ridge 27 is formed in a continuous spiral shape around the outer circumferential surface 21. In addition, when viewed along the spiral of the ridge 27 from the refrigerant inlet point 25 side to the refrigerant outlet point 26 side, the height of the ridge 27 from the bottom surface 43 (see FIG. 4) of the recess 22 is formed to be lower in stages or gradually and smoothly. Therefore, when viewed linearly along the direction of the rotation shaft 16 of the rotor 12, there are multiple ridges 27, but when comparing these ridges 27 along the direction of the rotation shaft 16 of the rotor 12 (Z direction), the height of the ridges decreases toward the positive side of the Z direction. As a result, the ridges 27 correspond to a step shape 35 (see FIG. 3, etc.) formed on the outer housing 14 described later. In addition, with this configuration, even if the ridges 27 and the step shape 35 are provided, the inner housing 13 and the outer housing 14 can be easily assembled by sliding or screwing them together.

[0021] FIG. 3 is a perspective view of the outer housing 14. As shown in FIG. 3, the outer housing 14 is formed into a cylindrical shape according to the outer shape of the inner housing 13. In this embodiment, since the inner housing 13 is formed into a generally cylindrical shape, the outer housing 14 is also formed into a generally cylindrical shape. The outer housing 14 has a refrigerant inlet 31 to the rotating electric machine 100 and a refrigerant outlet 32 ​​from the rotating electric machine 100. The refrigerant inlet 31 and outlet 32 ​​are through holes that penetrate from the outer peripheral surface 33 to the inner peripheral surface 34 of the outer housing 14. The refrigerant inlet 31 is provided at a position corresponding to the refrigerant inlet point 25 of the inner housing 13, and the refrigerant outlet 32 ​​is provided at a position corresponding to the refrigerant outlet point 26 of the inner housing 13.

[0022] The inner circumferential surface 34 of the outer housing 14 is provided with a step shape 35. The step shape 35 is a shape that generates a height difference on the inner circumferential surface 34 of the outer housing 14 by a step-like step, a slope, or other shape. In this embodiment, the step shape 35 is formed by a step-like step in which the inner circumferential surface 34 of the outer housing 14 is bent by approximately 90 degrees.

[0023] The step shape 35 is provided at a position adjacent to the protrusion 27 of the inner housing 13 when the outer housing 14 is assembled to the inner housing 13. The position adjacent to the protrusion 27 refers to the position where the side surface (YZ surface) of the step shape 35 abuts against the side surface (YZ surface) of the protrusion 27 in an ideal state where there is no gap due to dimensional tolerances.

[0024] Further, the stepped shape 35 is provided so as to protrude towards the inner housing 13. In other words, the stepped shape 35 is formed so that the inner peripheral surface 34 of the outer housing 14 protrudes towards the inner housing 13, based on the top surface of the convex strip 27 that abuts against the inner peripheral surface 34 of the outer housing 14 in an ideal state without any gap due to dimensional tolerance.

[0025] In this embodiment, the step shape 35 is formed in a continuous spiral shape that goes around along the inner circumferential surface 34 of the outer housing 14, corresponding to the recess 22 of the inner housing 13 being formed in a spiral shape. Also, when viewed along the spiral of the step shape 35 from the inlet 31 to the outlet 32 ​​of the refrigerant, the height of the step shape 35 is formed to increase stepwise or gradually and smoothly. Therefore, when viewed linearly along the direction of the rotation shaft 16 of the rotor 12 (Z direction), there are multiple step shapes 35, but when comparing these step shapes 35 along the direction of the rotation shaft 16 of the rotor 12, the height of the step shapes 35 increases toward the positive side of the Z direction. The height of the step shape 35 refers to the amount of protrusion of the inner circumferential surface 34 toward the inner housing 13.

[0026] Fig. 4 is a schematic cross-sectional view showing a detailed structure of the refrigerant flow path 15. As shown in Fig. 4, when viewed in a cross section including the rotation axis 16 of the rotor 12, the refrigerant flow path 15 is composed of, for example, adjacent main flow paths C1 to C3. The main flow paths C1 to C3 are flow paths through which the refrigerant flows when there is no gap between the inner housing 13 and the outer housing 14 due to dimensional tolerances, and are original refrigerant flow paths. In other words, the main flow paths C1 to C3 are a formal division of the refrigerant flow path 15 made for convenience of explanation, and the entire main flow paths C1 to C3 are the refrigerant flow path 15 itself.

[0027] The refrigerant that has flowed through main flow path C1 circulates around the stator 11, etc., and then flows into main flow path C2. The refrigerant that has flowed through main flow path C2 further circulates around the stator 11, etc., and then flows into main flow path C3. The flows of the refrigerant that flow through main flow paths C1 to C3 (hereinafter referred to as main flows V1 to V3) are all directed from the front of the page in FIG. 4 to the back of the page.

[0028] In this embodiment, for simplicity, the widths (lengths in the Z direction) W1 to W3 of the main flow paths C1 to C3 are assumed to be equal. 12 and the width T of the protrusion separating the main flow path C2 and the main flow path C3. 23 are considered to be equal.

[0029] When there are no gaps due to dimensional tolerances between the inner housing 13 and the outer housing 14, the main flow paths C1 to C3 that constitute the refrigerant flow path 15 are isolated by the ridges 27 and the step shape 35. For this reason, the refrigerant flows along these main flow paths C1 to C3, and there are no other flow paths for the refrigerant.

[0030] However, in reality, gaps occur between the inner housing 13 and the outer housing 14 due to dimensional tolerances. For example, in the Y direction, there is a gap D1 between the inner housing 13 and the outer housing 14 due to dimensional tolerances. Similarly, in the Z direction, there is a gap D2 between the inner housing 13 and the outer housing 14 due to dimensional tolerances. These gaps D1 and D2 form a leak flow path L through which the refrigerant leaks between the adjacent main flow paths C1 and C2. 12 Similarly, the gaps D1 and D2 form a leak flow path L through which the refrigerant leaks between the adjacent main flow paths C2 and C3. 23 That is, when the main flow paths C1 to C3 are formed by the inner housing 13 and the outer housing 14, the gaps D1 and D2 due to the dimensional tolerances cause leakage flow paths L2 through which the refrigerant leaks between the adjacent main flow paths. 12 ,L 23 is formed.

[0031] A leak path L formed between the main flow path C1 and the main flow path C2 12 The leak flow path L has a bent shape. 12 The bent shape of the leak flow path L 12 The flow direction of the refrigerant passing through the refrigerant passage is bent.

[0032] Specifically, the first flow passage 41a is formed by the gap D1 in the Y direction, and the second flow passage 41b is formed by the gap D2 in the Z direction. The first flow passage 41a is formed by the top surface of the protrusion 27 and the inner circumferential surface 34 of the outer housing 14. Therefore, the first flow passage 41a is a flow passage extending in the Z direction. On the other hand, the second flow passage 42b is formed by the side surface of the protrusion 27 on the main flow passage C2 side and the side surface of the inner circumferential surface 34 by the step shape 35. Therefore, the second flow passage 41b is a flow passage extending in the Y direction. Therefore, the first flow passage 41a and the second flow passage 41b intersect at an angle according to the protrusion 27 and the step shape 35.

[0033] In particular, in the step shape 35 of this embodiment, the inner circumferential surface 34 is bent at about 90 degrees, so that the first flow path 41a and the second flow path 41b intersect at an angle of about 90 degrees. 12 The bending angle is about 90 degrees.

[0034] In addition, the leak path L 12 The flow of the refrigerant through the 12 The leak flow V may occur from the main flow path C1 to the main flow path C2, or from the main flow path C2 to the main flow path C1, depending on the specific structures of the main flow paths C1 and C2, the flow rate of the refrigerant, and other conditions. 12 is generated from the main flow path C1 to the main flow path C2. That is, the leak flow V 12 The leak flow path L is a path in which a part of the main flow V1 flows into the first flow path 41a, and then flows into the second flow path 41b, where it is bent and merges with the main flow V2. 12 The bent shape of the leak current V 12This bends the flow direction of the

[0035] Leak flow path L 23 The leak flow path L is the same as the leak flow path L described above, except that it is formed between the main flow paths C2 and C3. 12 That is, the leak flow path L 23 The leak flow path L is formed by a first flow path 42a formed by a gap D1 in the Y direction and a second flow path 42b formed by a gap D2 in the Z direction. 23 The leak passage L23 has a bent shape that bends the flow direction of the coolant flowing through the leak passage L23. 23 The flow of the refrigerant through the 23 ) occurs from the main flow path C2 toward the main flow path C3.

[0036] The bottom surfaces 43 of the refrigerant flow paths 15 are aligned as shown by the line L1. That is, in the adjacent main flow paths C1 to C3, the distance between the stator 11 and the bottom surface 43, which is the inner surface on the stator 11 side, is substantially constant. This is because the step shape 35 and the like prevent the leakage flow path L 12 ,L 23 Even when the main flow paths C1 to C3 are bent, the main flow paths C1 to C3 are as close as possible to the stator 11 and other components to be cooled, so that the stator 11 and other components can be effectively cooled by the coolant flowing through the main flow paths C1 to C3.

[0037] As described above, the leak flow path L formed between the adjacent main flow paths C1 to C3 12 ,L 23 is the leakage current V 12 ,V 23 However, the leak flow path L 12 ,L 23 As shown above, the leakage current V 12 ,V 23 Therefore, compared with the case where a leak flow path that does not have a bent shape is formed between the adjacent main flow paths C1 to C3, the leak flow V 12 ,V 23Therefore, according to the present embodiment, the leak flow path L is prevented from being generated due to the dimensional tolerances of the inner housing 13 and the outer housing 14. 12 ,L 23 Even if a leak current V flows through these, 12 ,V 23 As a result, in the rotating electrical machine 100 of this embodiment, the cooling performance of the refrigerant passage 15 as a whole is high.

[0038] More specifically, the leak path L 12 Leak current V 12 Three types of pressure loss occur in the first flow path 41a. f1 and the bending pressure loss P due to bending from the first flow path 41a to the second flow path 41b. k and the friction pressure loss P due to friction in the second flow path 41b. f2 Therefore, the leakage current V 12 The total pressure loss P 12 , P 12 =P f1 +P k +P f2 This is the leak flow path L 23 The same applies to.

[0039] In contrast, Fig. 5 is a schematic cross-sectional view showing the structure of a refrigerant flow path 55 according to a comparative example. As shown in Fig. 5, in the comparative example, the step shape 35 is not provided on the inner circumferential surface 34 of the outer housing 14, and the protrusions 27 of the inner housing 13 are all provided at the same height. Therefore, in the refrigerant flow path 55 of the comparative example, the leak flow path L of the main flow path C1 and the main flow path C2 is 12 The first flow path 41a is formed only by the first flow path 41a and does not have a bent shape. Similarly, in the refrigerant flow path 55 of the comparative example, the leak flow path L of the main flow path C2 and the main flow path C3 23 The second flow path 42a is formed only by the first flow path 42a and does not have a bent shape. The rest of the structure is the same as that of this embodiment.

[0040] Therefore, in the refrigerant flow path 55 of the comparative example, the leak flow path L 12 Leak current V 12Friction pressure loss P due to friction in the first flow path 41a f1 That is, in the case of the refrigerant flow passage 55 of the comparative example, the total pressure loss P 12 ′ is P 12 ′=P f1 It is.

[0041] Therefore, when comparing this embodiment with the comparative example, the leakage flow V 12 The total pressure loss P 12 is the bending pressure loss P k and friction pressure loss P f2 In the comparative example, the leakage flow V 12 The total pressure loss P 12 ' is larger than the leak current V 23 The same applies to the pressure loss occurring in the refrigerant flow passage 15 of the present embodiment. 12 ,V 23 can be suppressed.

[0042] Fig. 6 is an explanatory diagram showing the distribution of heat transfer coefficients in the refrigerant flow path 15 of this embodiment, and Fig. 7 is an explanatory diagram showing the distribution of heat transfer coefficients in the refrigerant flow path 55 of a comparative example. In Figs. 6 and 7, the heat transfer coefficient of the refrigerant is represented by density (color), and the higher the density, the higher the heat transfer coefficient.

[0043] In the refrigerant flow path 15 of this embodiment, the leak flow path L 12 ,L 23 The bent shape of the leak current V 12 ,V 23 6, in the refrigerant flow path 15 of this embodiment, the distribution of the heat transfer coefficient values ​​is narrow, the heat transfer coefficient is generally uniform throughout the refrigerant flow path 15, and is generally concentrated at a high value.

[0044] On the other hand, in the refrigerant flow path 55 of the comparative example, the leak flow path L 12 ,L 23 Since the shape of the leakage current V 12 ,V 23Therefore, as shown in FIG. 7, in the refrigerant flow path 55 of the comparative example, the leak flow path L 12 ,L 23 The heat transfer coefficient is high in the ridges 27 having the grooves, and low in the main flow paths C1 to C3. As a result, in the refrigerant flow path 55 of the comparative example, the distribution of the heat transfer coefficient values ​​is wide, and the distribution within the refrigerant flow path 55 is non-uniform.

[0045] Fig. 8 is a histogram showing the amount of heat dissipation in this embodiment and the comparative example. In Fig. 8, the histogram shown by the solid line shows the amount of heat dissipation when the refrigerant flow path 15 of this embodiment is used, and the histogram shown by the dashed line shows the amount of heat dissipation when the refrigerant flow path 55 of the comparative example is used. In Fig. 8, the amount of heat dissipation is a value calculated using the heat transfer coefficients in Figs. 6 and 7. The area ratio on the vertical axis shows the area of ​​a region having a certain amount of heat dissipation relative to the surface area of ​​the inner housing 13 in Figs. 6 and 7.

[0046] As shown in FIG. 8, the average value A1 of the amount of heat removed in the refrigerant flow path 15 of this embodiment is higher than the average value A2 of the amount of heat removed in the refrigerant flow path 55 of the comparative example.

[0047] Moreover, in the refrigerant flow path 55 of the comparative example, there are many parts where the amount of heat removal is lower than the average value A2. Therefore, in the refrigerant flow path 55 of the comparative example, the desired amount of heat removal is not reached, and there are parts where heat is not actually removed.

[0048] In contrast, in the refrigerant flow path 15 of this embodiment, the portion where the amount of heat dissipation is lower than the average value A1 is greatly reduced, and the portion where the amount of heat dissipation is about the average value A1 is greatly increased. Also, the refrigerant flow path 15 of this embodiment has an averaging effect where the amount of heat dissipation approaches the average value, compared to the refrigerant flow path 55 of the comparative example. Therefore, in the refrigerant flow path 15 of this embodiment, there are almost no portions where the desired amount of heat dissipation is not reached and heat is not actually dissipated.

[0049] As is clear from these, the coolant flow path 15 according to this embodiment has a leak flow path L 12 ,L 23By making the shape of the refrigerant passage 55 bent, the leakage flow V 12 ,V 23 Therefore, the heat removal effect of the refrigerant passage 15 as a whole can be improved.

[0050] In the first embodiment, the cross section of the leak flow path L 12 ,L 23 The entire portion of the leakage path L has a bent shape formed by the step shape 35 or the like. 12 ,L 23 If a part of the portion where the leakage current V is generated has a bent shape formed by a step shape 35 or the like, the leakage current V 12 ,V 23 Therefore, at least a part of the leak flow paths L12 and L23 is reduced. 12 ,L 23 It is sufficient that the shape of the bent portion bends the flow direction of the refrigerant flowing through the bent portion.

[0051] As described above, the rotating electric machine 100 according to this embodiment includes an inner housing 13 that houses the stator 11 and the rotor 12, and an outer housing 14 that covers the outer periphery of the inner housing 13, and is provided with a housing having a double structure in which main flow paths C1 to C3, which are refrigerant flow paths 15 through which a refrigerant flows, are formed between the inner housing 13 and the outer housing 14. In this rotating electric machine 100, when the main flow paths C1 to C3 are formed by the inner housing 13 and the outer housing 14, a leak flow path L that causes the refrigerant to leak between adjacent main flow paths C1 to C3 is formed. 12 ,L 23 Then, the leak flow path L 12 ,L 23 At least a part of the leak flow path L 12 ,L 23 The refrigerant passage has a bent shape that bends the flow direction of the refrigerant passing through the refrigerant passage.

[0052] The rotating electric machine 100 according to the first embodiment has the above-mentioned configuration, 12 ,L23 The leak path L 12 ,L 23 For the refrigerant flowing through the bend, the pressure loss P k As a result, the leak path L 12 ,L 23 Even if a leak path L 12 ,L 23 Leak current flowing through V 12 ,V 23 Therefore, the rotating electric machine 100 according to the first embodiment is prevented from having gaps D1 and D2 due to the dimensional tolerances of the inner housing 13 and the outer housing 14, and thus prevents the leakage flow path L 12 ,L 23 Even if a leak current V 12 ,V 23 is reduced, and the overall heat removal effect is improved.

[0053] In the rotating electric machine 100 of the first embodiment, the leakage flow path L 12 ,L 23 However, the leak paths L12 and L23 may be formed due to factors other than the dimensional tolerance. 12 ,L 23 Even when the leak flow paths L12, L23 are formed in a bent shape by the step shape 35 or the like, the same effects as those of the first embodiment can be obtained.

[0054] In the rotating electric machine 100 according to the first embodiment, a protruding strip 27 is formed on the outer peripheral surface 21 of the inner housing 13 to separate adjacent main flow paths C1 to C3. A step shape 35 that protrudes toward the inner housing 13 side is formed on the inner peripheral surface 34 of the outer housing 14 adjacent to the protruding strip 27. That is, in the rotating electric machine 100, the bent shapes of the leak flow paths L12, L23 are formed by the protruding strip 27 of the inner housing 13 and the step shape 35 of the outer housing 14. In this way, the protruding strip 27 and the step shape 35 allow the refrigerant flow path 15 to obtain a high heat removal effect as a whole, while also reducing the leakage flow paths L12, L23. 12 ,L 23 It is easy to form it into a curved shape.

[0055] The rotating electric machine 100 according to the first embodiment has a structure in which, when there are a plurality of ridges 27 and step shapes 35 along the direction of the rotation shaft 16 of the rotor 12 (Z direction), the height of the ridges 27 decreases and the height of the step shapes 35 increases along the direction of the rotation shaft 16 of the rotor 12. With this configuration, even if the ridges 27 and step shapes 35 are formed at the abutting portions of the inner housing 13 and the outer housing 14, it is particularly easy to assemble the inner housing 13 and the outer housing 14.

[0056] In the rotating electric machine 100 of the first embodiment, the adjacent main flow paths C1 to C3 have a substantially constant distance between the stator 11 and the bottom surface 43, which is the inner surface on the stator 11 side. With this configuration, even if the protruding strip 27 and the step shape 35 are provided, the main flow paths C1 to C3 can particularly effectively cool the stator 11 and other objects to be cooled.

[0057] (Leak flow path bending angle) In the rotating electric machine 100 of the first embodiment, the leak flow path L 12 ,L 23 The leak path L is bent at about 90 degrees. 12 ,L 23 If the pipe is bent even slightly, the pressure loss P k Therefore, the leakage current V 12 ,V 23is reduced. And since the difficulty of manufacturing and assembling the inner housing 13 and the outer housing 14 increases, the leak flow path L 12 ,L 23 , except for the case where it is bent at an acute angle, the bending pressure loss P k is maximized when the leak flow path L 12 ,L 23 is bent by about 90 degrees. For this reason, like the rotating electrical machine 100, if the bending shape of the leak flow path L 12 ,L 23 is a bending shape that bends the leak flow V 12 ,V 23 by about 90 degrees, in particular, the leak flow V 12 ,V 23 can be suppressed. As a result, as a whole of the refrigerant flow path 15, in particular, the heat extraction effect is improved. Note that the bending angle at which the generally maximum bending pressure loss P k occurs in the vicinity of 90 degrees is included in the range of "about 90 degrees" mentioned here.

[0058] [Second Embodiment] In the first embodiment, for simplicity, the widths W1 to W3 of the main flow paths C1 to C3 constituting the refrigerant flow path 15 are made equal, but the widths W1 to W3 of the main flow paths C1 to C3 may be different from each other.

[0059] FIG. 9 is a schematic cross-sectional view showing the structure of the refrigerant flow path 60 of the second embodiment. The refrigerant flow path 60 of the second embodiment is formed in a series in a spiral shape in the same manner as the refrigerant flow path 15 of the first embodiment, and as shown in FIG. 9, is constituted by the main flow paths C1 to C3 in a certain YZ cross-section. However, in the refrigerant flow path 60 of the second embodiment, the widths W1 to W3 of the main flow paths C1 to C3 are different from each other. Specifically, the main flow paths C1 to C3 are formed such that the widths W1 to W3 have a relationship of W1 < W2 < W3.

[0060] That is, in the refrigerant flow path 60, the main flow paths C1 to C3 are formed such that, when comparing adjacent main flow paths, one main flow path whose height is reduced by the step shape 35 has a larger width than the other main flow path whose height is higher. For example, when comparing adjacent main flow paths C1 and C2, the height H2 of the main flow path C2 is lower than the height H1 of the main flow path C1 due to the presence of the step shape 35. Instead, the width W2 of the main flow path C2 is larger than the width W1 of the main flow path C1. Similarly, when comparing adjacent main flow paths C2 and C3, the height H3 of the main flow path C3 is lower than the height H2 of the main flow path C2 due to the presence of the step shape 35. Instead, the width W3 of the main flow path C3 is larger than the width W2 of the main flow path C2.

[0061] In this way, by forming the main flow passage having a relatively lower height to have a longer width by providing the step shape 35 compared to two adjacent main flow passages, the change in the cross-sectional area of ​​the main flow passages C1 to C3 can be suppressed. If the cross-sectional area of ​​the main flow passages C1 to C3 is reduced by providing the step shape 35, the cooling capacity may decrease in the vicinity of the main flow passage with the reduced cross-sectional area. In contrast, by reducing the change in the cross-sectional area of ​​the main flow passages C1 to C3 as described above, it is easy to maintain the cooling performance even when the step shape 35 is provided.

[0062] In particular, it is preferable that the widths W1 to W3 are determined so that the cross-sectional areas of the main flow paths C1 to C3 are substantially constant. In this case, even if the step shape 35 is provided, a decrease in cooling capacity due to the provision of the step shape 35 is likely to be suppressed.

[0063] Fig. 10 is a graph showing the flow velocities of the main flow paths V1 to V3. When the widths W1 to W3 are determined so that the cross-sectional areas of the main flow paths C1 to C3 are substantially constant, the main flow paths V1 to V3 are also substantially constant, as shown in Fig. 10. Therefore, the pressure loss P loss1 , pressure loss P in the main flow path C2 loss2 , and the pressure loss P in the main flow path C3 loss3 are almost equal, and P loss1 =P loss2 =P loss3As a result, for example, by providing the step shape 35 while keeping the widths W1 to W3 constant, the head capacity required of a pump (not shown) to circulate the refrigerant is reduced compared to the case where the pressure loss increases from the main flow path C1 to the main flow path C3.

[0064] As described above, in the rotating electric machine including the refrigerant flow passage 60 of the second embodiment, when comparing the adjacent main flow passages C1 to C3, one of the main flow passages (e.g., main flow passage C2) whose height is reduced by the step shape 35 is formed to have a larger width than the other main flow passage (e.g., main flow passage C1) whose height is higher. As a result, the leak flow passage L 12 ,L 23 Even when the step shape 35 is provided to make the refrigerant have a bent shape, the cooling capacity is easily maintained, and the head capacity required for the pump that circulates the refrigerant is also reduced.

[0065] This effect is particularly noticeable when the cross-sectional areas of the main flow paths C1 to C3 are made constant.

[0066] (Overall shape of the refrigerant flow path) In the above first and second embodiments, the refrigerant flow path 15 and the refrigerant flow path 60 are arranged in a spiral shape, but the specific shape of the refrigerant flow path is arbitrary as long as at least a part of the leak flow path formed by dimensional tolerances, etc. is formed to have a curved shape.

[0067] FIG. 11 is an explanatory diagram showing the position where the step shape 35 is provided in the spiral refrigerant flow path 15. In FIG. 11, the refrigerant flow path 15 of the first embodiment is represented by the angle around the stator 11, starting from the refrigerant inflow point 25 and the refrigerant outflow point 26. Since the refrigerant flow path 15 is formed continuously in a spiral shape, the step shape 35 is provided at the position shown by the dashed line, as shown in FIG. 11. In other words, when the main flow paths C1 to C3 are formed in a spiral shape going around the stator 11, as in the refrigerant flow path 15, the step shape 35 can be formed without interruption between the adjacent main flow paths C1 to C3. For this reason, the leak flow path L 12 ,L 23The pressure loss P k As a result, the leakage flow V of the refrigerant in the entire refrigerant flow path 15 is 12 ,V 23 Therefore, the configuration in which the main flow paths C1 to C3 are formed in a spiral shape going around the stator 11, like the refrigerant flow path 15, is one of the most preferable configurations of the refrigerant flow path 15.

[0068] Fig. 12 is an explanatory diagram showing the positions at which step shapes 35 are provided in a serpentine refrigerant flow channel 70. In Fig. 12, the shape of the refrigerant flow channel 70 is represented by angles around the stator 11, starting from the refrigerant inlet point 25 and the refrigerant outlet point 26. In the serpentine refrigerant flow channel 70, the ridges 27 are formed in a comb shape, and as shown in Fig. 12, in this refrigerant flow channel 70, the ridges 27 are provided at positions shown by dashed lines with respect to each ridge 27. Here, the serpentine refrigerant flow channel 70 is given as an example of a shape other than the spiral refrigerant flow channel 15, but the same applies to refrigerant flow channels of other shapes.

[0069] (Step height) The leak flow path L in each of the above embodiments 12 ,L 23 is formed in a bent shape by the protrusion 27 and the step shape 35, but the leak flow path L 12 ,L 23 The degree of bending of the leak flow path L 12 ,L 23 is the leakage current V 12 ,V 23 For the bend pressure loss P k As long as the leakage flow path L is bent to such an extent that additional pressure loss such as the above occurs, the effects of the above embodiments can be obtained. 12 ,L 23 The height of the step shape 35 that forms the step shape can be set arbitrarily.

[0070] For example, in the refrigerant flow path 60 of the second embodiment, the distance between the top surface of the protrusion 27 between the main flow paths C1 and C2 and the inner circumferential surface 34 of the outer housing 14 is the distance of the gap D1 generated due to the dimensional tolerance. 12 The height h of the step shape 35 formed to make the bent shape 12 (see FIG. 9) is larger than this gap D1. That is, the leak flow path L 12 The height h12 of the step shape 35 that bends the <h 12 Similarly, the distance between the top surface of the protrusion 27 between the main flow passages C2 and C3 and the inner circumferential surface 34 of the outer housing 14 is the distance of the gap D1, and the leak flow passage L 23 The height h of the step shape 35 for forming the bent shape is 23 (see FIG. 9) is larger than this gap D1. That is, the leak flow path L 23 The height of the step shape 35 that bends 23 D1 <h 23 Meet the following.

[0071] In this way, the height h of the step shape 35 12 ,h 23 is larger than the distance between the protrusion 27 and the outer housing 14, i.e., the gap D1, the leak flow path L 12 ,L 23 In the structure, the second flow paths 41b and 42b are clearly formed. 12 ,V 23 In particular, the effect of reducing the heat dissipation amount and the effect of improving the heat dissipation performance as a whole are easily obtained.

[0072] On the other hand, the height h of the step shape 35 12 ,h 23 is equal to or less than the distance (gap D1) between the protrusion 27 and the outer housing 14, the leak flow path L 12 ,L 23 However, even if it is only a small step shape 35 is formed, and its height h 12 ,h 23 Unless it is less than or equal to zero, the height h of the step shape 35 12 ,h 23Even if the gap is less than D1, the leakage current V 12 ,V 23 is the bending pressure loss P k Or a corresponding pressure loss occurs. Therefore, the height h of the step shape 35 12 ,h 23 Even if is greater than zero and smaller than the gap D1, the leak path L 12 ,L 23 As a result, the height h of the step shape 35 is 12 ,h 23 Even if the gap is less than D1, the leakage current V 12 ,V 23 and an effect of improving the overall heat removal performance can be obtained.

[0073] However, the magnitude of the friction pressure loss is generally proportional to the friction coefficient and the flow path length, and inversely proportional to the flow path width (flow path cross-sectional area). 12 ,h 23 The larger the friction pressure loss P f2 Also, the bending pressure loss P k The magnitude of the leak flow path L is generally proportional to the coefficient that increases with the bending angle, but this is the case when there is a clear bending in the structure. 12 ,L 23 If the bending angle is predetermined, the height h of the step shape 35 is 12 ,h 23 It is preferable that the height h of the step shape 35 is larger than the gap D1, and the second flow paths 41b and 42b are clearly formed in the structure. 12 ,h 23 It is particularly preferable that the distance between the ridge 27 and the outer housing 14, that is, the gap D1, be larger than this distance.

[0074] Although the embodiments of the present invention have been described above, the configurations described in the above embodiments and the respective modified examples merely represent some of the application examples of the present invention and are not intended to limit the technical scope of the present invention.

[0075] For example, in the above-mentioned embodiment, the refrigerant flows through the refrigerant flow passages 15, etc. in the order of main flow passage C1, main flow passage C2, and main flow passage C3, corresponding to the refrigerant inlet 31 and outlet 32. However, the direction in which the refrigerant flows through the refrigerant flow passages 15, etc. is arbitrary. Therefore, contrary to the above-mentioned embodiment, the refrigerant may be caused to flow from a location corresponding to the outlet 32, so that the refrigerant flows through the refrigerant flow passages 15, etc. in the order of main flow passage C3, main flow passage C2, and main flow passage C1. In this case, the same effects as those of the above-mentioned embodiment are also achieved.

[0076] In addition, as can be seen from the relationship with the flow direction of the refrigerant with respect to the refrigerant flow passage 15 in the above example, the leak flow passage L 12 ,L 23 That is, in the above-described embodiment and the like, the leak flow path formed between the upstream side and the downstream side of the coolant is bent on the downstream side, but the present invention is not limited to this.

[0077] For example, in the above embodiment, the leak flow path L is formed between the upstream main flow path C1 and the downstream main flow path C2 in the flow direction of the refrigerant. 12 In the embodiment, the second flow passage 41b is bent with respect to the first flow passage 41a parallel to the rotation axis 16 of the rotor 12 and is formed on the main flow passage C2 side. However, the second flow passage 41b may be formed on the upstream side of the first flow passage 41a (i.e., on the main flow passage C1 side). 12 The effects of the above-mentioned embodiment are obtained by creating an additional pressure loss in the leak flow path L. Therefore, even when the second flow path 41b is formed on the main flow path C1 side in this way, the same effects as those of the above-mentioned embodiment are obtained. 23 The same applies to.

[0078] In addition, the leak path L 12 ,L 23 The leak flow path L is located on both the upstream and downstream sides in the flow direction of the refrigerant. 12 ,L 23In this case, the same effects as those of the above embodiment can be obtained.

[0079] These leak paths L 12 ,L 23 When modifying this form, the specific position, size, range, etc. of the step shape 35 can be appropriately adjusted following the above embodiment. [Explanation of symbols]

[0080] 11: stator, 12: rotor, 13: inner housing, 14: outer housing, 15: refrigerant flow path, 21: outer peripheral surface, 22: recess, 27: ridge, 34: inner peripheral surface, 43: bottom surface, 100: rotating electric machine, C1 to C3: main flow path, D1: gap, D2: gap, V1 to V3: main flow path, L 12 :Leak flow path, L 23 :Leak flow path, V 12 : Leak current, V 23 :Leak flow

Claims

1. A rotating electric machine having a housing with a double structure, the housing having an inner housing that houses a stator and a rotor, and an outer housing that covers an outer periphery of the inner housing, the main flow path through which a refrigerant flows being formed between the inner housing and the outer housing, When the main flow passage is formed by the inner housing and the outer housing, a leak flow passage that causes the refrigerant to leak is formed between adjacent main flow passages, At least a portion of the leak flow path has a bent shape that bends a flow direction of the coolant flowing through the leak flow path, A protrusion is formed on an outer circumferential surface of the inner housing to separate adjacent main flow passages, A step shape is formed on the inner circumferential surface of the outer housing adjacent to the protrusion and protruding toward the inner housing, The bent shape of the leak flow path is formed by the protrusion and the step shape, a structure in which the protrusions and the step shapes are provided in a plurality of positions along the direction of the rotation axis of the rotor, and the height of the protrusions decreases and the height of the step shapes increases along the direction of the rotation axis of the rotor; Rotating electric motor.

2. The rotating electric machine according to any one of claims 1 to 5, The distance between the stator and the bottom surface, which is the inner surface on the stator side, of the adjacent main flow paths is constant. Rotating electric motor.

3. 3. A rotating electric machine according to claim 1, The leak flow path is bent by 90 degrees. Rotating electric motor.

4. 2. The rotating electric machine according to claim 1, When comparing adjacent main flow paths, one of the main flow paths having a lower height due to the step shape has a larger width than the other of the main flow paths having a higher height. Rotating electric motor.

5. 5. The rotating electric machine according to claim 4, The main flow path has a constant cross-sectional area. Rotating electric motor.

6. A rotating electric machine according to any one of claims 1 to 5, The main flow path is formed in a spiral shape that goes around the stator. Rotating electric motor.

7. 2. The rotating electric machine according to claim 1, The height of the step shape is greater than the distance between the protrusion and the outer housing. Rotating electric motor.

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