Rotating electric machines

Abstract

One embodiment of the rotating electrical machine of the present invention includes: a rotor centered on a central axis; a stator located radially outside the rotor; a cylindrical housing surrounding the stator from the radial outside; and a flow path arranged on at least one of a peripheral wall portion of the housing and an outer peripheral portion of the stator, and allowing refrigerant to flow inside. The flow path has a plurality of spiral flow path portions whose axial positions shift as they move circumferentially around the central axis. The plurality of flow path portions include: a first flow path portion; and a second flow path portion arranged axially with the first flow path portion. The first flow path portion has a first inlet and a first outlet arranged at both ends of the spiral formed by the first flow path portion and communicating with the outside of the flow path. The second flow path portion has a second inlet and a second outlet arranged at both ends of the spiral formed by the second flow path portion and communicating with the outside of the flow path.

Description

Technical Field

[0001] The present invention relates to a rotating electrical machine. Background Art

[0002] A rotating electrical machine includes a rotor, a stator, and a housing that holds the stator inside. In some rotating electrical machines, a cooling jacket includes a channel through which a liquid coolant flows (for example, Patent Document 1).

[0003] [Prior art literature]

[0004] [Patent Document]

[0005] [Patent Document 1] U.S. Patent Application Publication No. 2020 / 0153291

[0006] Conventional rotating electrical machines still have room for improvement in reducing the pressure loss of the refrigerant flowing in the flow path. Summary of the Invention

[0007] One object of the present invention is to provide a rotating electrical machine capable of reducing the pressure loss of a refrigerant flowing in a flow path.

[0008] One embodiment of the rotating electrical machine of the present invention includes: a rotor centered on a central axis; a stator located radially outside the rotor; a cylindrical housing surrounding the stator from the radial outside; and a flow path disposed on at least one of a peripheral wall portion of the housing and an outer peripheral portion of the stator, and allowing refrigerant to flow therein. The flow path includes a plurality of spiral flow path portions whose axial positions shift as they move circumferentially around the central axis. The plurality of flow path portions include: a first flow path portion; and a second flow path portion arranged axially with the first flow path portion. The first flow path portion includes a first inlet and a first outlet disposed at both ends of the spiral formed by the first flow path portion and communicating with the outside of the flow path. The second flow path portion includes a second inlet and a second outlet disposed at both ends of the spiral formed by the second flow path portion and communicating with the outside of the flow path.

[0009] According to the rotating electrical machine of one aspect of the present invention, it is possible to reduce the pressure loss of the refrigerant flowing through the flow path. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a cross-sectional view schematically showing a rotating electrical machine according to one embodiment.

[0011] Figure 2 This is a perspective view showing the internal space of the flow path according to one embodiment in a three-dimensional shape.

[0012] Figure 3It is a perspective view showing the internal space of the flow path of the first modification example in a three-dimensional shape.

[0013] Figure 4 It is a perspective view showing the internal space of the flow path of the second modification example in a three-dimensional shape.

[0014] Figure 5 It is a perspective view showing the internal space of the flow path of the third modification example in a three-dimensional shape.

[0015] Figure 6 This is a graph showing the relationship between flow rate and pressure loss according to the type of flow path.

[0016] Figure 7 This is a graph showing the temperature at each position in the axial direction of the stator, that is, the temperature gradient.

[0017] (Explanation of Symbols)

[0018] 10…rotating motor;

[0019] 11…housing;

[0020] 11a…peripheral wall portion;

[0021] 30…rotor;

[0022] 40… stator;

[0023] 50A, 50B, 50C, 50D... flow path;

[0024] 51…First flow path department;

[0025] 51a…first inlet;

[0026] 51b…first outflow port;

[0027] 52 ... a second flow path portion;

[0028] 52a…second inlet;

[0029] 52b…second outflow port;

[0030] 57…inflow opening;

[0031] 58…outflow opening;

[0032] J…central axis;

[0033] θ1… one side of the circumference;

[0034] θ2…the other side in the circumferential direction. DETAILED DESCRIPTION

[0035] like Figure 1As shown, in this embodiment, the direction in which the central axis J of the rotating electrical machine 10 extends is referred to as "axial direction". In this embodiment, the axial direction is, for example, a direction along the horizontal direction. The axial direction is equivalent to the X-axis direction shown in the figures. One axial side is the +X side, and the other axial side is the -X side. In addition, in this embodiment, the radial direction centered on the central axis J is referred to as "radial direction", and the circumferential direction centered on the central axis J is referred to as "circumferential direction". As shown in FIG. Figure 2 As shown, a predetermined direction in the circumferential direction is referred to as one circumferential side θ1, and a direction opposite to the one circumferential side θ1 is referred to as the other circumferential side θ2. In this embodiment, when viewing a flow path 50A described later from the other axial side (-X side) toward the one axial side (+X side), the one circumferential side θ1 corresponds to the clockwise direction about the central axis J, and the other circumferential side θ2 corresponds to the counterclockwise direction.

[0036] like Figure 1 As shown, in this embodiment, rotating electrical machine 10 forms part of drive device 100. Although not specifically shown, drive device 100 is mounted on a vehicle to rotate the axle. The vehicle equipped with drive device 100 is a hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHV), electric vehicle (EV), or other vehicle that uses a motor as its power source.

[0037] Drive device 100 includes a rotating electrical machine 10, a transmission device (not shown), a housing unit 80 (partially omitted from the illustration), and an inverter unit 90. The transmission device is connected to rotating electrical machine 10 and transmits the rotation of rotor 30 of rotating electrical machine 10 to a vehicle axle. The transmission device includes a reduction gear connected to rotating electrical machine 10 and a differential device connected to the reduction gear.

[0038] The rotating electric machine 10 includes a rotor 30 centered on a central axis J; a stator 40 located radially outside the rotor 30; a housing 11; a plurality of bearings 15 and 16; and a flow path 50A. The rotating electric machine 10 of this embodiment is an inner rotor type motor. The rotor 30 rotates relative to the stator 40 about the central axis J.

[0039] The housing 11 houses the rotor 30 and stator 40. The housing 11 is cylindrical and radially surrounds the stator 40. The housing 11 forms part of the housing unit 80. The housing unit 80 comprises the housing 11 and a gear housing 12. The gear housing 12 houses the speed reducer and differential gear of the transmission. The housing 11 may also be referred to as the motor housing.

[0040] The housing 11 extends axially with the central axis J as the center. The housing 11 has a peripheral wall portion 11a and a pair of side wall portions 11b, 11c. The peripheral wall portion 11a is cylindrical with the central axis J as the center and extends axially. The pair of side wall portions 11b, 11c are respectively plate-shaped. A pair of plate surfaces of each side wall portion 11b, 11c face the axial direction. One side wall portion 11b of the pair of side wall portions 11b, 11c is connected to the end portion on one axial side of the peripheral wall portion 11a. The other side wall portion 11c of the pair of side wall portions 11b, 11c is connected to the end portion on the other axial side of the peripheral wall portion 11a. One side wall portion 11b holds a bearing 15. The other side wall portion 11c holds a bearing 16. The plurality of bearings 15, 16 are arranged at intervals from each other in the axial direction.

[0041] The rotor 30 includes a shaft 31, a rotor core 32, and magnets 33. The shaft 31 extends axially about a central axis J. The shaft 31 has a cylindrical or cylindrical shape. The shaft 31 is supported by a plurality of bearings 15 and 16 for rotation about the central axis J. The bearings 15 and 16 are, for example, ball bearings or roller bearings.

[0042] The rotor core 32 is cylindrical and centered on the central axis J, extending axially. The outer diameter of the rotor core 32 is larger than the outer diameter of the shaft 31. The axial dimension of the rotor core 32 is smaller than the axial dimension of the shaft 31. The rotor core 32 is arranged radially outward from the shaft 31. The rotor core 32 is axially arranged between the two ends of the shaft 31. The inner circumferential surface of the rotor core 32 is fixed to the outer circumferential surface of the shaft 31 by pressing, bonding, etc. In other words, the rotor core 32 is fixed to the outer circumferential surface of the shaft 31. The rotor core 32 is axially arranged between the pair of bearings 15 and 16. The magnet 33 is fixed to the outer circumference of the rotor core 32.

[0043] The stator 40 faces the rotor 30 with a gap therebetween in the radial direction. The stator 40 surrounds the rotor 30 from the radially outer side over the entire circumference. The stator 40 includes a stator core 41 , an insulator 42 , and a coil 43 .

[0044] The stator core 41 has a cylindrical shape centered on the central axis J and extends axially. The stator core 41 surrounds the rotor 30 from the radially outer side. For example, the stator core 41 comprises a plurality of electromagnetic steel sheets stacked axially. The outer circumference of the stator core 41 contacts the inner circumference of the housing 11. The stator core 41 and the housing 11 are secured to each other, for example, by screws or a fitting mechanism.

[0045] The stator core 41 includes a core back portion 41a and a plurality of pole teeth 41b. The core back portion 41a is cylindrical, centered on the central axis J. The outer circumferential surface of the core back portion 41a contacts the inner circumferential surface of the peripheral wall portion 11a. The pole teeth 41b protrude radially inward from the inner circumferential surface of the core back portion 41a. The pole teeth 41b are plate-shaped, with a pair of plate surfaces facing the circumferential direction. The plurality of pole teeth 41b are spaced apart from each other in the circumferential direction. The radially inner side surface of each pole tooth 41b faces the outer circumferential surface of the rotor 30, separated by a gap.

[0046] The insulator 42 is attached to the stator core 41. The insulator 42 is made of an insulating material, such as resin. The insulator 42 has a portion covering at least a portion of each pole tooth 41b. The coil 43 is attached to the stator core 41 via the insulator 42. Multiple coils 43 are arranged circumferentially. Each coil 43 is attached to a respective pole tooth 41b via the insulator 42.

[0047] A refrigerant such as water flows inside flow path 50A. Flow path 50A is disposed on at least one of peripheral wall 11a of housing 11 and the outer periphery of stator 40. In this embodiment, flow path 50A is disposed on the inner periphery of peripheral wall 11a.

[0048] like Figure 1 and Figure 2 As shown, the flow path 50A has: a plurality of flow path portions 51, 52; an inlet opening portion 57 communicating with the outside of the flow path 50A; and an outlet opening portion 58 communicating with the outside of the flow path 50A. Figure 1 , the flow path 50A is schematically shown, and detailed illustrations of the flow path portions 51 and 52 are omitted. Figure 2 The interior space of flow path 50A in this embodiment is shown as a three-dimensional shape. In this embodiment, inlet opening 57 and outlet opening 58 extend radially outward from flow path portions 51 and 52, respectively. One or more inlet openings 57 are provided in flow path 50A. One or more outlet openings 58 are provided in flow path 50A.

[0049] like Figure 2 As shown, the plurality of flow path portions 51, 52 are respectively in the shape of a spiral whose axial position shifts as it shifts in the circumferential direction around the central axis J. Specifically, each flow path portion 51, 52 is respectively a continuous spiral extending in the axial direction in the prescribed direction as it shifts in the circumferential direction. Although not specifically shown in the figure, in the present embodiment, in the cross section along the central axis J, the axial dimension of each flow path portion 51, 52 is respectively greater than the radial dimension. The inner peripheral portion of each flow path portion 51, 52 is radially opposite to the core back portion 41a of the stator 40, or is arranged inside the core back portion 41a. In the present embodiment, the inner peripheral portion of each flow path portion 51, 52 is arranged on the outer peripheral surface of the core back portion 41a (refer to Figure 1 ).

[0050] like Figure 2 As shown, the plurality of flow paths 51 and 52 include a first flow path 51 and a second flow path 52 axially aligned with the first flow path 51. In this embodiment, the first and second flow paths 51 and 52 extend side by side in a double helical pattern. The flow path lengths of the first and second flow paths 51 and 52 are identical.

[0051] The first flow path portion 51 includes a first inlet 51a and a first outlet 51b, which are arranged at both ends of the spiral formed by the first flow path portion 51 and communicate with the exterior of the flow path 50A. The first flow path portion 51 has a spiral shape that extends toward one axial side (+X side) as it moves from the first inlet 51a toward the circumferential side θ1. The second flow path portion 52 includes a second inlet 52a and a second outlet 52b, which are arranged at both ends of the spiral formed by the second flow path portion 52 and communicate with the exterior of the flow path 50A. The second flow path portion 52 has a spiral shape that extends toward one axial side as it moves from the second inlet 52a toward the circumferential side θ1.

[0052] In this embodiment, the flow path 50A has multiple flow path sections 51 and 52, namely, at least a first flow path section 51 and a second flow path section 52. The first flow path section 51 and the second flow path section 52, respectively, have inlets 51a and 52a and outlets 51b and 52b that communicate with the exterior of the flow path 50A. For example, compared to a single-spiral flow path having the same overall length as the flow path 50A in this embodiment but differing from this embodiment in having only one inlet and outlet, this embodiment can shorten the flow path lengths of the first flow path section 51 and the second flow path section 52. Consequently, the pressure loss of the refrigerant flowing through each flow path section 51 and 52 can be appropriately reduced. The refrigerant flowing smoothly through the flow path 50A can efficiently cool the stator 40.

[0053] Figure 6 This is a graph showing the relationship between flow rate and pressure loss depending on the type of flow path. Figure 6 In the figure, "5 spirals (parallel)" represents the double spiral flow path 50A of the present embodiment, and "5 spirals (single)" represents a single spiral flow path, which is different from the present embodiment and has the same total length as the flow path 50A but has only one inlet and outlet, i.e., a comparative example. Figure 6 As shown, at flow rates of 3.0 to 10 L / min, the pressure loss of the "5 spirals (parallel)" flow path 50A of the present embodiment is reduced to 1 / 4 or less compared to the "5 spirals (single)" of the comparative example.

[0054] like Figure 2As shown, in this embodiment, the first inlet 51a and the second inlet 52a are arranged in the same inlet opening 57. The inlet opening 57 is arranged at the end of the flow path 50A on the other axial side (-X side). According to this embodiment, the pressure loss of the refrigerant flowing in each flow path portion 51, 52 can be reduced, and the structure of the flow path 50A can be further simplified. In addition, the pipe connection portion connecting the flow path 50A and the external pipe can be suppressed to a smaller number. However, it is not limited to this, and the first inlet 51a and the second inlet 52a can also be arranged in different inlet openings 57.

[0055] In the present embodiment, the first outflow port 51b and the second outflow port 52b are arranged in the same outflow opening portion 58. The outflow opening portion 58 is arranged at the end portion of the flow path 50A on one axial side (+X side). According to the present embodiment, the pressure loss of the refrigerant flowing in each flow path portion 51, 52 can be reduced, and the structure of the flow path 50A can be further simplified. In addition, the piping connection portion connecting the flow path 50A and the external piping can be suppressed to a smaller number. However, the present invention is not limited thereto, and the first outflow port 51b and the second outflow port 52b can also be arranged in different outflow opening portions 58.

[0056] like Figure 1 As shown, the inverter unit 90 is fixed to the housing unit 80. In the present embodiment, the inverter unit 90 is fixed to the housing 11. The inverter unit 90 includes an inverter housing 91 and an inverter (not shown) housed in the inverter housing 91. The inverter is electrically connected to each coil 43 of the stator 40. The inverter supplies power to the rotating electrical machine 10. In the present embodiment, a refrigerant supply path 95 for conveying refrigerant from a radiator (not shown) to the flow path 50A passes through the interior of the inverter unit 90. The refrigerant flowing in the refrigerant supply path 95 cools the inverter of the inverter unit 90 and then flows into the flow path 50A through the inlet opening 57.

[0057] The present invention is not limited to the above-described embodiment, and as described below, for example, structural changes and the like can be made without departing from the spirit of the present invention.

[0058] Reference Figure 3 A first modified example of the rotating electrical machine 10 of the above embodiment will be described. The rotating electrical machine 10 of the first modified example includes a flow path 50B instead of the flow path 50A. Figure 3 The internal space of the flow path 50B of the first modification is shown in a three-dimensional shape. The structure of the flow path 50B is partially different from that of the flow path 50A. In the first modification, the same structure as the above structure may be given the same name or symbol, and its description may be omitted.

[0059] like Figure 3As shown, in the flow path 50B, the first flow path portion 51 and the second flow path portion 52 extend in parallel in a double helical shape. The first flow path portion 51 has a helical shape that extends toward one axial side (+X side) as it moves from the first inlet 51a toward the circumferential side θ1. The second flow path portion 52 has a helical shape that extends toward the other axial side (-X side) as it moves from the second inlet 52a toward the circumferential side θ2.

[0060] According to the first modified example, the refrigerant flow direction along the spiral of the first flow path portion 51 and the refrigerant flow direction along the spiral of the second flow path portion 52 are opposite to each other in the circumferential direction and the axial direction, respectively. This allows the stator 40 to be cooled from both axial directions, minimizing the temperature difference, or temperature gradient, at various axial positions of the stator 40, and enabling uniform cooling of the stator 40.

[0061] Specifically, in the first flow path portion 51, the refrigerant temperature is lowest when it flows in through the first inlet 51a, and reaches its highest temperature when it flows out through the first outlet 51b due to heat exchange with the stator 40. Furthermore, in the second flow path portion 52, the refrigerant temperature is lowest when it flows in through the second inlet 52a, and reaches its highest temperature when it flows out through the second outlet 52b due to heat exchange with the stator 40. By adopting the structure of the flow path 50B of the first modified example, the sum of the temperatures of the refrigerant flowing in the first flow path portion 51 and the refrigerant flowing in the second flow path portion 52 can be maintained approximately constant in each axial portion. This ensures that the cooling effect of the flow path 50B at each axial position of the stator 40 is equalized, minimizing the temperature gradient within the stator 40.

[0062] Figure 7 Graph 50B is a graph showing the temperature at each position in the axial direction of the stator 40 when the stator 40 is cooled using the flow path 50B of the first modified example, that is, the temperature gradient. Figure 7 As shown, according to the first modification, the temperature difference at each axial position of the stator 40 can be suppressed to be small.

[0063] like Figure 3As shown, the first inlet 51a and the second inlet 52b are arranged adjacent to each other in the axial direction. In addition, the first inlet 51b and the second inlet 52a are arranged adjacent to each other in the axial direction. According to the first modified example, it is possible to collect the piping connection parts of the connecting flow path 50B and the external piping. In addition, in the first modified example, the inlet opening portion 57 configured with the first inlet 51a and the inlet opening portion 57 configured with the second inlet 52a are different from each other. That is, the inlet opening portions 57 are arranged in plurality at intervals. In addition, the outflow opening portion 58 configured with the first inlet 51b and the outflow opening portion 58 configured with the second inlet 52b are different from each other. That is, the outflow opening portions 58 are arranged in plurality at intervals. The first inlet 51b and the second inlet 52b are arranged between the first inlet 51a and the second inlet 52a in the axial direction.

[0064] Next, refer to Figure 4 A description will be given of a second modification of the rotary electric machine 10. The rotary electric machine 10 of the second modification includes a flow path 50C instead of the flow paths 50A and 50B described above. Figure 4 The internal space of the flow path 50C of the second modified example is shown as a three-dimensional shape. The structure of the flow path 50C is partially different from that of the flow paths 50A and 50B. In addition, in the second modified example, for the same structure as the above structure, the same name or symbol may be attached and its description may be omitted.

[0065] like Figure 4 As shown, in the flow path 50C, the first flow path portion 51 and the second flow path portion 52 are connected to each other to form a continuous spiral. That is, the first flow path portion 51 and the second flow path portion 52 are connected to each other in a manner that forms a single spiral. In the second modified example, the first flow path portion 51 is arranged in the axially one side (+X side) portion of the flow path 50C, and the second flow path portion 52 is arranged in the axially other side (-X side) portion of the flow path 50C. The first flow outlet 51b of the first flow path portion 51 is arranged at the end of the axially one side of the flow path 50C, and the first flow inlet 51a is arranged between the two axial ends of the flow path 50C. The second flow outlet 52b of the second flow path portion 52 is arranged at the end of the axially other side of the flow path 50C, and the second flow inlet 52a is arranged between the two axial ends of the flow path 50C.

[0066] Even when the flow path 50C is in a single spiral shape as in the second modification, the flow path lengths of the first flow path portion 51 and the second flow path portion 52 can be kept short, thereby reducing the pressure loss of the refrigerant flowing in each flow path portion 51, 52. Figure 6 In the figure, "8 spirals (parallel)" represents the flow path 50C of the second modified example, and "8 spirals (single)" represents a single spiral flow path that is the same length as the flow path 50C but has only one inlet and outlet, which is a comparative example. Figure 6As shown, at flow rates of 3.0 to 10 L / min, the pressure loss of the "8 spirals (parallel)" flow path 50C of the second modified example is reduced to less than 1 / 4 compared to the "8 spirals (single)" of the comparative example.

[0067] In the flow path 50C, the first flow path portion 51 is in the shape of a spiral extending from the first inlet 51a toward the circumferential side θ1 toward the axial side (+X side). The second flow path portion 52 is in the shape of a spiral extending from the second inlet 52a toward the circumferential side θ2 toward the axial side (-X side). According to the second modification, the flow direction of the refrigerant along the spiral of the first flow path portion 51 and the flow direction of the refrigerant along the spiral of the second flow path portion 52 are opposite to each other in the circumferential direction and the axial direction, respectively. Therefore, the temperature difference, that is, the temperature gradient, at each axial position of the stator 40 can be suppressed to a small value, thereby enabling the stator 40 to be uniformly cooled.

[0068] In the second modification, the first inlet 51a and the second inlet 52a are arranged in the same inlet opening 57. According to the second modification, the pressure loss of the refrigerant flowing through each flow path portion 51, 52 can be reduced, and the structure of the flow path 50C can be further simplified. Furthermore, the number of piping connection points connecting the flow path 50C to external piping can be reduced.

[0069] In the second modified example, the inlet opening 57 is arranged in the middle part between the two axial end parts in the flow path 50C. Specifically, the inlet opening 57 is arranged in the axial center part of the flow path 50C. That is, the first inlet 51a and the second inlet 52a are arranged axially between the first outlet 51b and the second outlet 52b. According to the second modified example, by making the refrigerant flow from the axial middle part of the stator 40 where the temperature easily rises toward the two axial end parts, the temperature gradient of the stator 40 can be suppressed to a smaller level. In addition, in the second modified example, the flow path length of the first flow path part 51 and the flow path length of the second flow path part 52 are the same. Therefore, it is easier to cool the stator 40 uniformly in the axial direction.

[0070] Next, refer to Figure 5 A description will be given of a third modification of the rotary electric machine 10. The rotary electric machine 10 of the third modification includes a flow path 50D instead of the flow paths 50A, 50B, and 50C described above. Figure 5 The internal space of flow path 50D of the third modification is shown as a three-dimensional shape. The structure of flow path 50D differs from that of flow paths 50A, 50B, and 50C in part. In the third modification, the same structures as those described above are sometimes given the same names or symbols, and their descriptions are omitted.

[0071] like Figure 5As shown, in the flow path 50D, the first flow path portion 51 and the second flow path portion 52 are interconnected to form a continuous spiral. In the third modified example, the first flow path portion 51 is arranged in the portion on the other axial side (-X side) of the flow path 50D, and the second flow path portion 52 is arranged in the portion on the one axial side (+X side) of the flow path 50D. The first inlet 51a of the first flow path portion 51 is arranged at the end on the other axial side of the flow path 50D, and the first outlet 51b is arranged between the two axial ends of the flow path 50D. The second inlet 52a of the second flow path portion 52 is arranged at the end on one axial side of the flow path 50D, and the second outlet 52b is arranged between the two axial ends of the flow path 50D.

[0072] In the third modification, the first outflow port 51b and the second outflow port 52b are provided in the same outflow opening 58. According to the third modification, the pressure loss of the refrigerant flowing through each flow path portion 51, 52 can be reduced, and the structure of the flow path 50D can be further simplified. Furthermore, the number of piping connection points connecting the flow path 50D to external piping can be reduced.

[0073] In the third modified example, the outflow opening 58 is positioned midway between the two axial ends of the flow path 50D. Specifically, the outflow opening 58 is positioned in the axial center of the flow path 50D. That is, the first outflow port 51b and the second outflow port 52b are positioned axially between the first inflow port 51a and the second inflow port 52a. According to the third modified example, the stator 40 can be cooled from both axial directions, minimizing the temperature difference, or temperature gradient, at various axial locations on the stator 40, thereby achieving uniform cooling of the stator 40.

[0074] In the above-described embodiment and various modifications, examples are given in which the flow path lengths of the first flow path portion 51 and the second flow path portion 52 are the same, but the present invention is not limited thereto. The flow path lengths of the first flow path portion 51 and the flow path lengths of the second flow path portion 52 may also be different from each other. In this case, the positions of the inlet ports 51a, 52a and the outlet ports 51b, 52b of each flow path portion 51, 52 can be appropriately changed, making it easier to meet various requirements for the rotating electrical machine 10. Furthermore, regardless of the flow path lengths of each flow path portion 51, 52, for example, by changing the temperature, type, flow velocity, flow rate, etc. of the refrigerant flowing through each flow path portion 51, 52, or by changing the flow path cross-sectional area of ​​each flow path portion 51, 52, the temperature gradient of the stator 40 can be suppressed to a small level, thereby achieving uniform cooling.

[0075] In the above embodiment and various modifications, examples are provided in which only one first flow path portion 51 and one second flow path portion 52 are provided, but the present invention is not limited thereto. Although not specifically illustrated, multiple first flow path portions 51 and multiple second flow path portions 52 may be provided in the axial direction. In this case, the stator 40 can be cooled uniformly over a wider axial range.

[0076] In the above-described embodiment and various variations, examples are provided in which the multiple flow path portions include a first flow path portion 51 and a second flow path portion 52, but the present invention is not limited thereto. Although not specifically illustrated, the multiple flow path portions may also include a first flow path portion 51, a second flow path portion 52, and a third flow path portion arranged axially alongside the first flow path portion 51. The third flow path portion includes a third inlet and a third outlet, which are arranged at both ends of the spiral formed by the third flow path portion and communicate with the exterior of the flow path. The first flow path portion 51 is axially arranged between the second flow path portion 52 and the third flow path portion. Furthermore, the first flow path portion 51 has a spiral shape that extends toward one axial side (+X side) as it moves from the first inlet 51a toward the circumferential side θ1. The second flow path portion 52 has a spiral shape that extends toward the other axial side (-X side) as it moves from the second inlet 52a toward the other circumferential side θ2. The third flow path portion has a spiral shape that extends toward the other axial side as it moves from the third inlet toward the other circumferential side θ2. That is, the direction of flow of the refrigerant along the spiral of the third flow path portion and the direction of flow of the refrigerant along the spiral of the second flow path portion 52 are the same in both the circumferential direction and the axial direction.

[0077] In detail, for example Figure 3 In the case where the structure including the third flow path portion is applied to the flow path 50B shown in the figure, the third flow path portion is arranged on the other axial side (-X side) of the first flow path portion 51, and the first flow path portion 51 is arranged axially between the second flow path portion 52 and the third flow path portion. That is, the third flow path portion, the first flow path portion 51, and the second flow path portion 52 extend in parallel in a triple spiral shape. In addition, for example, Figure 4 In the case where the structure including the third flow path section is applied to the flow path 50C shown, the third flow path section is arranged on the axial side (+X side) of the first flow path section 51, and the first flow path section 51 is arranged axially between the second flow path section 52 and the third flow path section. Furthermore, the third flow path section, the first flow path section 51, and the second flow path section 52 are connected in series to form a continuous single spiral. In addition, for example, Figure 5In the case where a structure including the above-mentioned third flow path portion is applied to the flow path 50D shown, the third flow path portion is arranged on the other axial side (-X side) of the first flow path portion 51, and the first flow path portion 51 is arranged axially between the second flow path portion 52 and the third flow path portion. In addition, the third flow path portion, the first flow path portion 51, and the second flow path portion 52 are connected in series to form a continuous single spiral. In any of the above cases, the pressure loss can be suppressed to a small level. In addition, the refrigerant flow direction along the spiral of the first flow path portion 51 located between these flow paths is opposite to the flow direction of the refrigerant along the spiral of the second flow path portion 52 and the flow direction of the refrigerant along the spiral of the third flow path portion. Therefore, the stator 40 can be cooled from both axial sides, the temperature difference, that is, the temperature gradient, at each axial position of the stator 40 can be suppressed to a small level, and the stator 40 can be cooled uniformly.

[0078] In the above embodiment and various modifications, flow paths 50A, 50B, 50C, and 50D are arranged on the inner periphery of peripheral wall portion 11a of housing 11, but the present invention is not limited thereto. Flow paths 50A, 50B, 50C, and 50D may be arranged on the outer periphery of peripheral wall portion 11a, on the outer periphery of stator 40, i.e., core back portion 41a, or on both peripheral wall portion 11a and core back portion 41a.

[0079] In the above embodiment and various modifications, the refrigerant flowing through the refrigerant supply path 95 cools the inverter (not shown) of the inverter unit 90 and then flows into the flow paths 50A, 50B, 50C, and 50D. However, the present invention is not limited to this. The refrigerant supply path 95 may not pass through the inverter unit 90. In other words, the refrigerant flowing through the refrigerant supply path 95 may flow into the flow paths 50A, 50B, 50C, and 50D without cooling the inverter.

[0080] The refrigerant flowing through the flow paths 50A, 50B, 50C, and 50D is not limited to water, and may be, for example, oil other than water.

[0081] The rotating electric machine to which the present invention is applied is not limited to motors; it may also be a generator. The application of the rotating electric machine is not particularly limited. For example, the rotating electric machine may be installed in a vehicle for purposes other than rotating an axle, or may be installed in equipment other than a vehicle. The posture in which the rotating electric machine is used is not particularly limited.

[0082] The various structures described in the above embodiments and modifications may be combined without departing from the scope of the present invention. In addition, additions, omissions, substitutions, and other changes to the structures may be made. The present invention is not limited to the above embodiments, but is limited only by the appended claims.

Claims

1. A rotating electrical machine, wherein: The rotating electrical machine comprises: a rotor centered on a central axis; a stator, the stator being located radially outside the rotor; a cylindrical housing, the housing surrounding the stator from the radial outside; and a flow path, the flow path being arranged in at least one of a peripheral wall portion of the housing and an outer peripheral portion of the stator and allowing refrigerant to flow therein, The flow path includes a plurality of spiral flow path portions whose axial positions shift as they move toward the circumference around the central axis. The plurality of flow path portions include: a first flow path portion; and a second flow path portion, wherein the second flow path portion and the first flow path portion are arranged in parallel in the axial direction; The first flow path portion has a first inlet and a first outlet arranged at both ends of the spiral formed by the first flow path portion and communicating with the outside of the flow path, and has a spiral shape extending toward one side in the axial direction as it moves from the first inlet toward one side in the circumferential direction. The second flow path portion has a second inlet and a second outlet arranged at both ends of the spiral formed by the second flow path portion and communicating with the outside of the flow path, and has a spiral shape extending toward one side or the other side in the axial direction as it moves from the second inlet toward one side or the other side in the circumferential direction. Among the plurality of flow path portions, the first flow path portion and the second flow path portion are different flow path portions.

2. The rotating electrical machine according to claim 1, wherein A plurality of at least one of the first flow path portion and the second flow path portion are arranged in the axial direction.

3. The rotating electrical machine according to claim 1 or 2, wherein: The flow path length of the first flow path portion and the flow path length of the second flow path portion are the same.

4. The rotating electrical machine according to claim 1 or 2, wherein: The flow path length of the first flow path portion and the flow path length of the second flow path portion are different from each other.

5. A rotating electrical machine, wherein: The rotating electrical machine comprises: a rotor centered on a central axis; a stator, the stator being located radially outside the rotor; a cylindrical housing, the housing surrounding the stator from the radial outside; and a flow path, the flow path being arranged in at least one of a peripheral wall portion of the housing and an outer peripheral portion of the stator and allowing refrigerant to flow therein, The flow path has an inlet opening communicating with the outside of the flow path, and has a plurality of spiral flow path portions whose axial positions shift as they go toward the circumferential direction around the central axis. The plurality of flow path portions include: a first flow path portion; and a second flow path portion, wherein the second flow path portion and the first flow path portion are arranged in parallel in the axial direction; The first flow path portion has a first inlet and a first outlet disposed at both ends of the spiral formed by the first flow path portion and communicating with the outside of the flow path. The second flow path portion has a second inlet and a second outlet disposed at both ends of the spiral formed by the second flow path portion and communicating with the outside of the flow path. The first inlet and the second inlet are arranged in the same inlet opening.

6. A rotating electrical machine, wherein: The rotating electrical machine comprises: a rotor centered on a central axis; a stator, the stator being located radially outside the rotor; a cylindrical housing, the housing surrounding the stator from the radial outside; and a flow path, the flow path being arranged in at least one of a peripheral wall portion of the housing and an outer peripheral portion of the stator and allowing refrigerant to flow therein, The flow path has an outflow opening communicating with the outside of the flow path, and has a plurality of spiral flow path portions whose axial positions shift as they go toward the circumferential direction around the central axis. The plurality of flow path portions include: a first flow path portion; and a second flow path portion, wherein the second flow path portion and the first flow path portion are arranged in parallel in the axial direction; The first flow path portion has a first inlet and a first outlet disposed at both ends of the spiral formed by the first flow path portion and communicating with the outside of the flow path. The second flow path portion has a second inlet and a second outlet disposed at both ends of the spiral formed by the second flow path portion and communicating with the outside of the flow path. The first outflow port and the second outflow port are arranged in the same outflow opening.

7. A rotating electrical machine, wherein: The rotating electrical machine comprises: a rotor centered on a central axis; a stator, the stator being located radially outside the rotor; a cylindrical housing, the housing surrounding the stator from the radial outside; and a flow path, the flow path being arranged in at least one of a peripheral wall portion of the housing and an outer peripheral portion of the stator and allowing refrigerant to flow therein, The flow path includes a plurality of spiral flow path portions whose axial positions shift as they move toward the circumference around the central axis. The plurality of flow path portions include: a first flow path portion; and a second flow path portion, wherein the second flow path portion and the first flow path portion are arranged in parallel in the axial direction; The first flow path portion has a first inlet and a first outlet disposed at both ends of a spiral formed by the first flow path portion and communicating with the outside of the flow path, and has a spiral shape extending toward one side in the axial direction as it moves from the first inlet toward one side in the circumferential direction. The second flow path portion has a second inlet and a second outlet arranged at both ends of the spiral formed by the second flow path portion and communicating with the outside of the flow path, and has a spiral shape extending toward the other axial side as it moves from the second inlet toward the other circumferential side.

8. The rotating electrical machine according to claim 7, wherein: The first inlet and the second outlet are arranged adjacent to each other in the axial direction.

9. A rotating electrical machine, wherein: The rotating electrical machine comprises: a rotor centered on a central axis; a stator, the stator being located radially outside the rotor; a cylindrical housing, the housing surrounding the stator from the radial outside; and a flow path, the flow path being arranged in at least one of a peripheral wall portion of the housing and an outer peripheral portion of the stator and allowing refrigerant to flow therein, The flow path includes a plurality of spiral flow path portions whose axial positions shift as they move toward the circumference around the central axis. The plurality of flow path portions include: First flow department; a second flow path portion, the second flow path portion being arranged side by side with the first flow path portion in the axial direction; and a third flow path portion, the third flow path portion and the first flow path portion being arranged in parallel in the axial direction; The first flow path portion is arranged between the second flow path portion and the third flow path portion in the axial direction. The first flow path portion has a first inlet and a first outlet disposed at both ends of a spiral formed by the first flow path portion and communicating with the outside of the flow path, and has a spiral shape extending toward one side in the axial direction as it moves from the first inlet toward one side in the circumferential direction. The second flow path portion has a second inlet and a second outlet arranged at both ends of the spiral formed by the second flow path portion and communicating with the outside of the flow path, and has a spiral shape extending toward the other axial side as it moves from the second inlet toward the other circumferential side. The third flow path portion includes a third inlet and a third outlet disposed at both ends of the spiral formed by the third flow path portion and communicating with the outside of the flow path. The third flow path portion has a spiral shape extending toward the other axial side as it moves from the third inlet toward the other circumferential side.

10. A rotating electrical machine, wherein: The rotating electrical machine comprises: a rotor centered on a central axis; a stator, the stator being located radially outside the rotor; a cylindrical housing, the housing surrounding the stator from the radial outside; and a flow path, the flow path being arranged in at least one of a peripheral wall portion of the housing and an outer peripheral portion of the stator and allowing refrigerant to flow therein, The flow path includes a plurality of spiral flow path portions whose axial positions shift as they move toward the circumference around the central axis. The plurality of flow path portions include: a first flow path portion; and a second flow path portion, wherein the second flow path portion and the first flow path portion are arranged in parallel in the axial direction; The first flow path portion has a first inlet and a first outlet disposed at both ends of the spiral formed by the first flow path portion and communicating with the outside of the flow path. The second flow path portion has a second inlet and a second outlet disposed at both ends of the spiral formed by the second flow path portion and communicating with the outside of the flow path. The first inlet and the second inlet are arranged between the first outflow port and the second outflow port in the axial direction.

11. A rotating electrical machine, wherein: The rotating electrical machine comprises: a rotor centered on a central axis; a stator, the stator being located radially outside the rotor; a cylindrical housing, the housing surrounding the stator from the radial outside; and a flow path, the flow path being arranged in at least one of a peripheral wall portion of the housing and an outer peripheral portion of the stator and allowing refrigerant to flow therein, The flow path includes a plurality of spiral flow path portions whose axial positions shift as they move toward the circumference around the central axis. The plurality of flow path portions include: a first flow path portion; and a second flow path portion, wherein the second flow path portion and the first flow path portion are arranged in parallel in the axial direction; The first flow path portion has a first inlet and a first outlet disposed at both ends of the spiral formed by the first flow path portion and communicating with the outside of the flow path. The second flow path portion has a second inlet and a second outlet disposed at both ends of the spiral formed by the second flow path portion and communicating with the outside of the flow path. The first outflow port and the second outflow port are arranged between the first inflow port and the second inflow port in the axial direction.

12. A rotating electrical machine, wherein: The rotating electrical machine comprises: a rotor centered on a central axis; a stator, the stator being located radially outside the rotor; a cylindrical housing, the housing surrounding the stator from the radial outside; and a flow path, the flow path being arranged in at least one of a peripheral wall portion of the housing and an outer peripheral portion of the stator and allowing refrigerant to flow therein, The flow path includes a plurality of spiral flow path portions whose axial positions shift as they move toward the circumference around the central axis. The plurality of flow path portions include: a first flow path portion; and a second flow path portion, wherein the second flow path portion and the first flow path portion are arranged in parallel in the axial direction; The first flow path portion has a first inlet and a first outlet disposed at both ends of the spiral formed by the first flow path portion and communicating with the outside of the flow path. The second flow path portion has a second inlet and a second outlet disposed at both ends of the spiral formed by the second flow path portion and communicating with the outside of the flow path. The first flow path portion and the second flow path portion extend in parallel in a double helical shape.

13. A rotating electrical machine, wherein: The rotating electrical machine comprises: a rotor centered on a central axis; a stator, the stator being located radially outside the rotor; a cylindrical housing, the housing surrounding the stator from the radial outside; and a flow path, the flow path being arranged in at least one of a peripheral wall portion of the housing and an outer peripheral portion of the stator and allowing refrigerant to flow therein, The flow path includes a plurality of spiral flow path portions whose axial positions shift as they move toward the circumference around the central axis. The plurality of flow path portions include: a first flow path portion; and a second flow path portion, wherein the second flow path portion and the first flow path portion are arranged in parallel in the axial direction; The first flow path portion has a first inlet and a first outlet disposed at both ends of the spiral formed by the first flow path portion and communicating with the outside of the flow path; The second flow path portion has a second inlet and a second outlet disposed at both ends of the spiral formed by the second flow path portion and communicating with the outside of the flow path. The first flow path portion and the second flow path portion are connected to each other to form a continuous spiral shape.

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