Rotating electric machine and electric vehicle

Abstract

A rotary electric motor (100) includes: a housing (3); a stator (10) having a stator core (11) fixed to the housing (3) and a coil (12) wound around the stator core (11); and a rotor (20) rotatably supported on the housing (3) and having a rotor core (21) and a shaft (22), wherein at least one of the rotor (20) and the housing (3) has a coolant flow path (20P, 31P) for supplying coolant (C) to a coil edge end (12E) of the coil, and the diameter of a spray hole (21H, 31H) for spraying coolant (C) from the coolant flow path (20P, 31P) into a space inside the housing is smaller than the diameter of the coolant flow path (20P, 31P).

Description

Technical Field

[0001] This disclosure relates to a rotary electric motor and an electric vehicle. Background Technology

[0002] In the past, in rotating electrical machines such as motors and generators, a cooling method was proposed to cool the coil wound around the stator core by bringing the coolant into contact with the stator core or the coil edge (see, for example, Patent Document 1). Patent Document 1 discloses a technique in which cooling oil is discharged from the housing toward the stator core and the coil edge to cool the coil edge, and then the cooling oil that is dispersed by contact with the rotating rotor adheres to the coil edge, thereby providing an additional cooling effect.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Publication No. 2023-518387 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] In Patent Document 1, in addition to allowing the cooling oil to flow directly to the coil edge as described above, a method is proposed to improve the cooling performance of the coil edge by utilizing oil that scatters from the rotating rotor toward the coil edge located on its outside. However, in Patent Document 1, under the driving conditions of the rotating motor coil being at high temperature, low speed, and high torque, the coolant in contact with the rotor does not scatter but flows down under gravity. Therefore, there is a technical problem that it is not possible to uniformly provide additional cooling effect to the coil edge.

[0008] Furthermore, in the method of directly spouting cooling oil to the coil edge, the flexibility of configuration is limited because the outlet needs to be adjusted towards the coil edge. Additionally, there is a technical problem: changes in the driving conditions cause variations in the viscosity and flow rate of the cooling oil, or changes in the airflow generated by the rotor's rotation, causing the discharged coolant to deviate from the coil edge, thus reducing cooling efficiency.

[0009] This disclosure discloses a technology for solving the above-mentioned technical problems, with the aim of providing a rotary motor capable of efficiently and uniformly cooling the coil edge ends and having a high degree of freedom in the configuration of the cooling path, as well as an electric vehicle including the rotary motor.

[0010] Technical solutions adopted to solve technical problems

[0011] The rotary electric motor disclosed herein includes: shell; A stator having a stator core fixed to the housing and a coil wound around the stator core; and A rotor, rotatably supported on the housing, having a rotor core and a shaft. At least one of the rotor and the housing has a coolant flow path that supplies coolant to the coil edge end of the coil. The diameter of the injection hole that sprays the coolant from the coolant flow path into the space inside the housing is smaller than the diameter of the coolant flow path.

[0012] In addition, the electric vehicles disclosed herein include: A refrigerant circulation system that utilizes at least a portion of the coolant from a rotating electric motor as a refrigerant.

[0013] Invention Effects

[0014] According to the rotary motor and electric vehicle disclosed herein, it is possible to provide a rotary motor and an electric vehicle including the rotary motor that can efficiently and uniformly cool the coil edge ends and have a high degree of freedom in the configuration of the cooling path. Attached Figure Description

[0015] Figure 1 This is a cross-sectional view of the rotary motor of Embodiment 1 cut by a plane including the central axis of the shaft, and it is a diagram showing the flow path of the coolant in the rotary motor.

[0016] Figure 2 This is a cross-sectional view of the injection hole in Embodiment 1.

[0017] Figure 3 It is a cross-sectional view of the outer casing cylindrical portion of Embodiment 1 cut along a direction perpendicular to the axial direction, and is a cross-sectional view of the portion where the injection holes are located.

[0018] Figure 4 This is a cross-sectional view of a rotary electric motor showing an example of an internal flow path provided in the housing end plate of Embodiment 1.

[0019] Figure 5 This is a cross-sectional view of the rotor of Embodiment 1 after being cut with a plane including the axis of the shaft.

[0020] Figure 6 This is a cross-sectional view showing a modified example of the coolant flow path of Embodiment 1.

[0021] Figure 7 This is a cross-sectional view of the injection hole in Embodiment 2.

[0022] Figure 8 This is a cross-sectional view of a modified example of the injection hole in Embodiment 2.

[0023] Figure 9 This is a cross-sectional view of a modified example of the injection hole in Embodiment 2.

[0024] Figure 10 This is a cross-sectional view of the rotor of Embodiment 3 after being cut with a plane including the central axis of the shaft.

[0025] Figure 11 yes Figure 10 The DD line sectional view is a view showing only the cross-section of the outer casing cylindrical portion and the coil edge end.

[0026] Figure 12 This is a cross-sectional view showing a modified example of the outer casing cylindrical portion of Embodiment 3.

[0027] Figure 13 This is a cross-sectional view showing a modified example of the outer casing cylindrical portion and protrusion of Embodiment 3, and is a partial cross-sectional view perpendicular to the axial direction.

[0028] Figure 14 This is a top view of the end plate of the rotor in Embodiment 4, and is a view taken from the axial outside.

[0029] Figure 15 This is a cross-sectional view of the rotor core and permanent magnet of Embodiment 4, perpendicular to the axial direction.

[0030] Figure 16 This is a cross-sectional view of the hollow flow path portion of the shaft and the main portion of the end plate in Embodiment 4.

[0031] Figure 17 yes Figure 16 EE line section view.

[0032] Figure 18 This is a block diagram illustrating an example of the cooling circuit of the electric vehicle according to Embodiment 5.

[0033] Figure 19 This is a block diagram illustrating another example of the cooling circuit of the electric vehicle according to Embodiment 5. Detailed Implementation

[0034] Implementation method 1.

[0035] Hereinafter, the rotary motor of Embodiment 1 will be described using the accompanying drawings.

[0036] In this specification, unless otherwise specified, "axial," "circumferential," "radial," "inner circumferential side," "outer circumferential side," "inner circumferential surface," and "outer circumferential surface" refer to the rotor's "axial," "circumferential," "radial," "inner circumferential side," "outer circumferential side," "inner circumferential surface," and "outer circumferential surface," respectively. Additionally, unless otherwise specified, "upper" and "lower" refer to, in the context of the mentioned location, an imaginary surface perpendicular to the axial direction, with the side containing the rotor's center point defined as "lower," and the opposite side as "upper."

[0037] Figure 1 It is a cross-sectional view of the rotary motor 100 after being cut by a plane including the central axis O of the shaft 22, and it is a diagram showing the coolant flow path of the coolant C of the rotary motor 100.

[0038] like Figure 1 As shown, the rotary motor 100 includes a housing 3, a stator 10, and a rotor 20. The housing 3 includes an annular housing cylindrical portion 31 and two housing end plates 32 that close the openings on both sides of the housing cylindrical portion 31 in the axial Z direction.

[0039] The stator 10 is fixed to the inner side of the cylindrical portion 31 of the outer casing. The stator 10 is composed of a stator core 11 and a coil 12. The stator core 11 is composed of stacked electromagnetic steel plates, and the coil 12 is wound around the stator core 11.

[0040] A rotor 20 is disposed inside the stator 10. The rotor 20 consists of a rotor core 21, permanent magnets (not shown), and a shaft 22. The rotor core 21 is made of stacked electromagnetic steel plates, and the permanent magnets are housed in multiple permanent magnet insertion holes within the rotor core 21. The shaft 22 transmits rotational power. The rotor 20 is configured to be supported by bearings 5 ​​fitted in the center of the two outer casing end plates 32, enabling the outer circumferential surface of the rotor 20 to rotate relative to the inner circumferential surface of the stator 10.

[0041] In addition, Figure 1 In the example described, an inner rotor type is used, in which the rotor 20 is arranged inside the stator 10. However, it can also be an outer rotor type, in which the rotor is arranged outside the stator, or an axial clearance type, in which the stator and rotor are arranged facing each other in the axial direction, or other configurations.

[0042] The cooling performance of a rotating electrical machine, specifically the motor, has a significant impact on its continuous operation performance and durability. For example, during continuous operation, coil degradation can be accelerated when the coil reaches high temperatures due to copper losses. In particular, the exposed coil edges on the axial upper side of the stator core cannot dissipate heat to the stator core; therefore, it is preferable to allow coolant contact to efficiently dissipate heat.

[0043] To this end, the outer casing cylindrical portion 31 of the rotary motor 100 includes an inner casing flow path 31P (coolant flow path) that allows coolant C to diffuse from the multiple injection holes 31H provided in the inner casing flow path 31P toward the interior of the rotary motor 100 to a range larger than the orifice diameter of the injection holes 31H. Details will be explained in detail later, but a characteristic structure is provided in the inner casing flow path 31P, for example, on the injection holes 31H and their upstream side, as a means to diffuse coolant C to a range larger than the orifice diameter of the injection holes 31H. As a result, coolant C floats at a higher density in the space R within the casing where the coil edge end 12E is exposed, thus adhering to the surface of the coil edge end 12E throughout the entire range, enabling uniform cooling of the coil edge end 12E.

[0044] Similarly, if the rotary motor 100 operates continuously at high temperatures, irreversible demagnetization of the permanent magnets may occur, potentially reducing the maximum torque. Therefore, if... Figure 1 As shown, a rotor coolant flow path 20P is also provided in the rotor 20. The rotor coolant flow path 20P is composed of an in-shaft flow path 22P formed hollowly within the shaft 22 and a rotor core in-core flow path 21P formed within the rotor core 21. Alternatively, there are cases where end plates are provided on both sides of the rotor core 21 along the axial direction Z, and a portion of the rotor coolant flow path 20P is formed on the end plate itself or between the end plate and the laminated steel plates of the rotor core 21.

[0045] When the coolant C used to cool the permanent magnet is injected from the injection hole 21H at the axial Z end of the rotor core 21 into the space R inside the housing 3, the coolant is diffused to a greater extent than the orifice diameter of the injection hole 21H, similar to the injection hole 31H on the housing cylindrical portion 31. As a result, the proportion of coolant C floating in the space R inside the housing 3 is further increased, and the cooling effect on the coil edge end 12E is improved.

[0046] Conventionally, centrifugal spraying, utilizing the rotational force of the rotor, has been proposed as a method to disperse coolant from the rotor toward the coil edge. However, centrifugal spraying suffers from the following technical problem: under low-speed, high-torque driving conditions where the coil generates significant heat, the coolant is not sprayed but flows down under gravity, thus making it unsuitable for cooling the coil edge. In this embodiment 1, the coolant C sprayed from the rotor 20 can become tiny droplets unaffected by the rotational speed and float within the space R. Therefore, the coolant C can also be supplied to the coil edge 12E portion located above and laterally to the rotor 20 relative to the plumb bob.

[0047] Furthermore, as a side effect, the proportion of coolant C floating in the space R within the housing 3 is increased, allowing coolant C to adhere to and wet the bearing 5 within the same space R. Thus, given that coolant C possesses properties as a lubricant for the bearing 5 and electrical insulation, it can function as an insulating coating that inhibits electro-corrosion of the bearing 5.

[0048] Furthermore, the distribution of the supply of coolant C to the stator 10 and the supply of coolant C to the rotor 20 can be adjusted by changing the pressure loss by creating a difference in the inner diameter of the flow path 31P inside the housing and the coolant flow path 20P inside the rotor.

[0049] Figure 2 These are cross-sectional views of injection holes 31H and 21H.

[0050] The nozzles 31H and 21H, located at the outlets of the flow path 31P inside the housing and the flow path 21P inside the rotor core, have diameters smaller than those of the flow path 31P inside the housing and the flow path 21P inside the rotor core. That is, the nozzles 31H and 21H are formed as conical structures with diameters gradually decreasing towards the outlet direction. As a result, the pressure of the coolant C after injection is lower than before injection, but the flow rate is higher. Furthermore, surrounding air is forcefully drawn into the discharged coolant C, thus allowing the coolant C to diffuse over a larger area than the diameter of the nozzles 31H and 21H, enabling the coolant C to float. Figure 1 The space R inside the outer shell 3 shown.

[0051] Furthermore, by increasing the degree to which the cross-sectional area of ​​the conical structure becomes smaller, or by increasing the supply flow rate and supply pressure of the coolant C per unit cross-sectional area at the outlet, the droplets of coolant C ejected from the injection holes 31H and 21H can be made finer. When adjusted to disperse such fine droplets in a mist, the coolant C can float at a higher density in the space R within the outer casing 3 described above. Furthermore, the coolant C can adhere to the surface of the coil edge 12E throughout its entire range, enabling more uniform cooling of the coil edge 12E.

[0052] Figure 3 It is a cross-sectional view of the outer casing cylindrical portion 31 after being cut along a direction perpendicular to the axial direction Z, and is a cross-sectional view of the portion where the injection hole 31H is located.

[0053] The outer cylindrical portion 31 includes an annular internal flow path 31P extending throughout its circumference. The internal flow path 31P has a plurality of injection holes 31H, which open radially (X) toward the space R within the outer casing 3 and are spaced apart circumferentially (Y). By setting the injection holes 31H as... Figure 2The conical structure shown increases the pressure loss at the outlet, and the flow rate of coolant C injected per unit time from a single injection hole 31H is less than the flow rate of coolant hanging from the outer casing to the coil edge.

[0054] Therefore, to achieve the desired cooling effect at the coil edge 12E, multiple injection holes 31H are provided to supply a sufficient amount of coolant C. Additionally, in Figure 3 The injection holes 31H are uniformly arranged in the circumferential Y direction, but can also be offset if the supply of coolant C is sufficient. Furthermore, the sprayed coolant C floats within the space R, thus eliminating the need for the injection holes 31H to be aligned with the coil edge 12E. As a result, the flexibility in the arrangement of the flow path 31P within the housing and the injection holes 31H is increased, enabling reductions in manufacturing costs and miniaturization of the motor 100 through space-saving design of the flow path 31P within the housing.

[0055] Figure 4 This is a cross-sectional view of a rotary electric motor showing an example of an internal flow path 32P provided in the housing end plate 32.

[0056] Alternatively, the internal flow path 32P and the injection hole 32H can be provided only on one side of the housing end plate 32 of the housing 3, so that the internal flow path 32P of the housing can be formed into a shorter and simpler design.

[0057] Figure 5 This is a cross-sectional view of the rotor 20 of Embodiment 1 after being cut with a plane including the central axis O of shaft 22.

[0058] The rotor coolant flow path 20P includes: an internal shaft flow path 22P, which extends axially from one end of the shaft 22 along the Z direction and further extends radially to the outside; a plurality of end plate internal flow paths 23P, which are connected to the internal shaft flow path 22P and extend radially to the outside in the end plate 23 located at the axial Z end of the rotor core 21; and a plurality of rotor core internal flow paths 21P, which are connected to each end plate internal flow path 23P and extend axially along the permanent magnet M inside the rotor core 21.

[0059] Furthermore, the outer end of the flow path 23P inside the end plate is connected to the injection hole 21H1 that passes through the end plate 23 and opens along the axial direction Z, and the other end of the flow path 21P inside the rotor core along the axial direction Z is connected to the injection hole 21H2 that passes through the end plate 24 and opens. The coolant C flowing in from the flow path 22P inside the shaft is divided into: a flow path that is injected from the injection hole 21H1 of one end plate 23 into the space R inside the housing 3; and a flow path that flows along the side of the permanent magnet M along the axial direction Z and is then injected from the injection hole 21H2 of the end plate 24 on the opposite side into the space R inside the housing 3.

[0060] Furthermore, the flow rate of the coolant C, which branches off within the rotor 20, can be largely distributed to the permanent magnet M side. Figure 1 If the cooling of the coil edge 12E on the right side shown is insufficient, it can be adjusted... Figure 4 The arrangement of the injection holes 32H on the outer casing end plate 32 shown is used to supplement the insufficient supply of coolant C. Thus, the amount of coolant C required to suppress irreversible demagnetization of the permanent magnet M caused by heat can be supplied.

[0061] Furthermore, similar to the outer casing 3, the injection holes 21H1 and 21H2 included in the end plates 23 and 24 are configured as follows: Figure 2 The conical structure shown enables the coolant C to be sprayed into the space R inside the housing 3 in the form of tiny droplets, even when the rotor 20 is not rotating.

[0062] Figure 6 This is a cross-sectional view showing a modified example of the rotor coolant flow path 20P.

[0063] like Figure 6 As shown, in the rotor 20 without end plates, the internal flow path 22P can also be extended to the center of the rotor core 21 along the axial direction Z, and the internal flow path 21P of the rotor core is positioned to the outer side facing the radial direction X to connect with it, and branches off along both sides of the permanent magnet M along the axial direction Z on the inner side of the permanent magnet M. In this case, for example, the aperture of the internal flow path 21P of the rotor core can be reduced in the stacked steel plates at both ends of the axial direction Z to form the injection hole 21H, thereby increasing the flow rate of the coolant C after injection.

[0064] Furthermore, to ensure the extensive diffusion of coolant C from the two injection holes 21H, it is preferable to maintain a high pressure and high flow rate of coolant C flowing in the rotor coolant flow path 20P. For this purpose, it is possible to consider... Figure 5 as well as Figure 6 In the rotor core 21 shown, the gaps (between layers) of the stacked electromagnetic steel plates are filled with resin such as adhesive to improve the airtightness of the coolant flow path. Furthermore, when flow paths are provided in the end plates 23 and 24, resin can also be filled between the end plates 23 and 24 and the stacked steel plates.

[0065] In this embodiment 1, the coolant C is a fluid with electrical insulation and rust-preventing effects (e.g., ATF: Automatic Transmission Fluid, automatic transmission oil, etc.). Alternatively, while ensuring insulation around the coil 12, a non-insulating fluid such as water can be used. Furthermore, a gas-liquid mixed-phase refrigerant used in air conditioning or similar applications can also be used. When water or a refrigerant is used as the coolant C, when the coolant C comes into contact with the coil edge 12E, heat is absorbed from the coil edge 12E through the latent heat of vaporization generated by the phase change from liquid to gas, thereby expecting to improve cooling efficiency.

[0066] Furthermore, when the coolant C vaporizes upon contact with the heated coil 12, it is possible to prevent the coolant C from remaining in the coil. Figure 4 The gap G between the stator core 11 and the rotor core 21 shown can also be used to reduce the drag torque.

[0067] The rotary motor according to embodiment 1 includes: shell; Stator, the stator having a stator core fixed to the housing and a coil wound around the stator core; and A rotor, rotatably supported on the housing, having a rotor core and a shaft. At least one of the rotor or the housing has a coolant flow path that supplies coolant to the coil edge end of the coil. The diameter of the injection hole for spraying coolant from the coolant flow path into the space inside the housing is smaller than the diameter of the coolant flow path. Therefore, by setting the sprayed coolant to a mist that floats even under gravity, the coolant can be distributed in all directions even at low rotor speeds, and the coil edges can be cooled evenly.

[0068] also, The injection hole is conical in shape. Because the outlet of the coolant flow path is relatively small, the sprayed coolant flows at a faster speed, forcefully entraining the surrounding air. Therefore, it can spread the coolant over a larger area than the diameter of the spray nozzle.

[0069] also, The rotor core includes an internal flow path, in which the coolant flows along a permanent magnet housed within the rotor core. Therefore, the coolant used to dissipate heat generated in the permanent magnet can be reused to cool the coil.

[0070] also, The rotor core is composed of multiple stacked steel plates, or multiple stacked steel plates and end plates. The spaces between the laminated steel plates and between the laminated steel plates and the end plates are filled with resin. Therefore, it is possible to seal the coolant flow path inside the rotor, maintaining a faster flow rate and higher pressure of the coolant before it reaches the injection hole.

[0071] Implementation method 2.

[0072] Hereinafter, the rotary motor of Embodiment 2 will be described, focusing on the parts that differ from Embodiment 1.

[0073] In this embodiment, another form of the structure in the coolant flow path described in Embodiment 1, which allows the coolant C to diffuse to a range larger than the flow path diameter, is described to illustrate the structure of the injection hole that improves cooling effect and productivity.

[0074] Figure 7 These are cross-sectional views of injection holes 231H and 221H.

[0075] The inner flow path 31P of the outer casing and the inner flow path 21P of the rotor core have a throttling orifice OF, an intake port IN, and a mixing chamber RM near the injection holes 231H and 221H. The throttling orifice OF is located near the injection holes 231H and 221H, and the inner diameter of the inner flow path 31P of the outer casing and the inner flow path 21P of the rotor core (coolant flow path) within the throttling orifice OF is smaller than the inner diameter of the inner flow path 31P of the outer casing and the inner flow path 21P of the rotor core (coolant flow path) before and after the throttling orifice OF. The coolant C after passing through the throttling orifice OF utilizes the phenomenon of increased flow velocity and decreased pressure to set the orifice diameter of the throttling orifice OF so that the pressure in the mixing chamber RM is lower than the gas pressure (atmospheric pressure) in the outer casing 3.

[0076] Therefore, the flow potential of the coolant C after passing through the throttling orifice OF and the flow potential of the air drawn in from the intake port IN cause the coolant C to form tiny droplets in the mixing chamber RM. This, in conjunction with the mixing of the coolant C and air after injection, further contributes to the process. Figure 2 Compared to the injection holes 31H and 21H, in Figure 7 In the spray holes 231H and 221H shown, the coolant C diffuses more easily over a larger area than the aperture of the spray holes 231H and 221H. Therefore, it is possible to form droplets into a finer mist and disperse them.

[0077] Figure 8This is a cross-sectional view of the injection hole 221H2 in a modified example of Embodiment 2. A swirling chamber RM2 is located near the injection hole 221H2 within the rotor core flow path 21P (and similarly for other coolant flow paths). Within the swirling chamber RM2, the coolant C flows in a spiral pattern along the inner wall of the swirling chamber RM2, thus widely distributing the coolant C within the space R of the outer casing 3 in a manner that expands from the injection hole 221H2.

[0078] Figure 9 This is a cross-sectional view of the nozzle component PA having the injection hole 221H3 of the modified embodiment 2. The front end of the coolant flow path is divided into the nozzle component PA, and the nozzle component PA has Figure 2 , Figure 7 , Figure 8 The injection holes and threaded portions S2 shown are for connection with threaded portions S1 provided on the rotor core 21 or the housing end plate 32. This allows for easy molding of the nozzle component PA via demolding, and improves mass production capabilities.

[0079] in addition, Figure 9 The nozzle component PA shown can also be a nozzle of a spray device (atomizer). As long as the nozzle component has the function of spraying coolant C in a mist, it can be of any shape, and can also adopt a structure that includes various atomizers with spraying function at the front end of the coolant flow path (as a spraying principle, there are spray nozzle type, electrostatic nozzle type, ultrasonic spray type, etc.).

[0080] Additionally, as described in Implementation 1 Figure 2 And this embodiment 2 Figures 7-9 The conical structure shown is a straight conical shape, but it can also be a curved conical shape, or a stepped diameter reduction structure that combines different apertures.

[0081] According to the rotary motor of embodiment 2, The coolant flow path near the injection orifice includes: a throttling orifice, the inner diameter of which is smaller than the inner diameter of the coolant flow path before and after the throttling orifice; an intake port for drawing gas from the space; and a mixing chamber for mixing the coolant with the gas. Therefore, the coolant flow rate increases and the pressure decreases as it passes through the throttling orifice. As a result, the air pressure in the mixing chamber can be reduced to below atmospheric pressure. By mixing the coolant with air in the mixing chamber and then spraying it from the injection orifice, the coolant can be diffused over a wider area.

[0082] also, The coolant flow path includes a swirling chamber near the injection orifice, the swirling chamber generating a swirling flow along its inner wall. Therefore, the coolant flowing into the vortex chamber becomes a spiral flow along the inner wall of the vortex chamber, which enables the coolant to be distributed into the space inside the outer casing in a manner that expands from the injection holes.

[0083] also, The spray hole is the nozzle of the spray device. Therefore, a spray device can be used to distribute the coolant in a finer mist, thereby uniformly cooling the inside of the casing.

[0084] Implementation method 3.

[0085] Hereinafter, the rotary motor of Embodiment 3 will be described, focusing on the parts that differ from Embodiment 1. Figure 10 This is a sectional view of the rotary motor 300 after being cut by a plane including the central axis O of shaft 22.

[0086] Figure 11 yes Figure 10 The DD-line sectional view is a view showing only the cross-section of the outer casing cylindrical portion 331 and the coil edge end 12E.

[0087] When a certain amount of coolant C floats in the space R inside the housing 303, a portion of the coolant C also adheres to the inner wall of the housing 3, which has almost no effect on the cooling of the coil edge 12E.

[0088] Therefore, for the coil edge end 12E of the rotary motor 300, the coolant C adhering to the inner wall of the housing 3 is collected and dripped onto the coil edge end 12E. For this purpose, a protrusion 331D protruding downwards from the plumb bob is provided on the inner wall of the housing cylindrical portion 331 and above the plumb bob of the coil edge end 12E when the rotary motor 300 is in operation.

[0089] Furthermore, by configuring the inner flow path 31P of the housing on the outer side of the radial X of the protrusion 331D, the temperature of the inner wall surface of the housing 303 near the protrusion 331D is reduced. Therefore, when water or refrigerant is used as the coolant C, the phase-change gas is more likely to condense on the inner wall surface of the housing 303 near the protrusion 331D than on other inner wall surfaces, which can increase the amount of coolant C dripping to the coil edge end 12E.

[0090] Alternatively, the coolant C can be guided to the protrusion 331D by using an inclination towards the protrusion 331D on the inner wall of the outer casing cylindrical portion 331, or by using a capillary effect achieved by providing a finer groove, thereby increasing the amount of liquid dripping to the coil edge end 12E.

[0091] Figure 12 This is a modified example of the outer cylindrical portion 331, which is equivalent to Figure 11 The image.

[0092] Relative to the coil edge end 12E, except Figure 12 In addition to the protrusion 331D1 positioned above the plumb bob (at the 12 o'clock position), protrusions 331D2 and 331D3 are also positioned at the 2 o'clock and 10 o'clock positions, respectively. By arranging protrusions 331D2 and 331D3, the coolant C flowing down the annular inner wall of the outer casing cylindrical portion 331 can be collected, increasing the amount of liquid dripping to the coil edge end 12E. Furthermore, by dispersing the dripping position to the coil edge end 12E in the circumferential Y direction, an additional cooling effect can be uniformly imparted in the circumferential Y direction.

[0093] Figure 13 This is a cross-sectional view showing a modified example of the outer casing cylindrical portion 331 and the protrusion 331D, and is a partial cross-sectional view perpendicular to the Z-axis. When the outer casing cylindrical portion 331 is formed by die casting, a technical problem arises where the presence of a portion with varying wall thickness, such as the protrusion, leads to internal porosity and reduced strength. Therefore, the outer casing cylindrical portion 331 and the protrusion 331D are formed separately, for example, as shown below. Figure 13 As shown, the protrusion 331D is inserted axially from the Z direction for post-installation using the slit SL provided in the cylindrical portion 331 of the outer casing, thereby preventing a reduction in strength. Furthermore, the above description of the protrusion 331D does not limit its shape, position, or number; these can be freely changed as needed.

[0094] According to the rotary motor of embodiment 3, On the inner wall of the housing, and above the plumb bob at the end of the coil in the operating state, there is a protrusion that protrudes downward toward the plumb bob. Therefore, the droplets are collected at the protrusion located directly above the edge of the coil. By dripping it onto the edge of the coil, an additional cooling effect can be achieved.

[0095] Implementation method 4.

[0096] Hereinafter, the rotary motor of Embodiment 4 will be described, in particular the structure that stabilizes the flow rate of the coolant injected from the rotor 20.

[0097] Figure 14 This is a top view of the end plate 423 of the rotor 20 in this embodiment 4, and is a view viewed from the outside of the Z-axis.

[0098] Figure 15 This is a cross-sectional view of the rotor core 21 and the permanent magnet M in this embodiment, perpendicular to the axis Z.

[0099] Figure 16This is a cross-sectional view of the hollow flow path portion of the shaft 422 and the main portion of the end plate 423 in Embodiment 4. It is a view after the shaft 422 and the end plate 423 are cut by a plane including the central axis O of the shaft 422.

[0100] Figure 17 yes Figure 16 EE line section view.

[0101] As mentioned earlier, in order to allow the coolant C injected from the rotor 20 into the space R inside the housing 3 to diffuse over a range larger than the orifice diameter of the injection hole 21H, the following method is used: Figure 2 , Figures 7-9 In the case of a structure with a narrowed cross-sectional area at the flow path outlet, when the rotor 20 rotates at high speed, the coolant C is pressed against the inner wall of the flow path 21P inside the rotor core due to centrifugal force, and the amount of coolant injected from the injection hole 21H may be reduced.

[0102] Depending on the rotor speed, the flow rate of the coolant can be adjusted by means of electrical control or by means of structural features.

[0103] However, controlling the flow path switching may lead to problems such as increased control logic, increased costs due to the addition of electrical components, and worsened electricity costs due to power consumption. Therefore, in this embodiment 4, an adjustment method implemented by structural features that utilizes the rotation of the rotor 20 itself is used.

[0104] The end plate 423 is equipped with: Figure 2 , Figures 7-9 There are two types of injection holes: one with a smaller orifice diameter, 21H; and another with a non-conical structure and a larger orifice diameter, 421H. When the rotor 20 is driven at low speed, coolant C is mainly distributed from the smaller orifice diameter, 21H. When the rotor 20 is driven at high speed, coolant C is mainly distributed from the larger orifice diameter, 421H. Furthermore, the orifice diameter, 421H, can also be slightly conical, as long as it is larger than that of the orifice diameter, 21H.

[0105] On both sides of the permanent magnet M in the circumferential Y direction, along the rotor core internal flow path 21P arranged in the axial Z direction of the permanent magnet M and Figure 14 The end plate 423 described herein is connected to the injection hole 21H. In addition, at the center of the circumferential Y direction of the permanent magnet M and inside the radial X direction, the rotor core internal flow path 421P provided along the axial Z direction of the permanent magnet M is connected to the injection hole 421H.

[0106] The internal flow path 422P extending axially in the Z direction from one end of the shaft 422 includes a cylindrical branch pipe 422Q at the end opposite to the inlet of the internal flow path 422P. The branch pipe 422Q has the same axis as the central axis O of the internal flow path 422P and has a first flow port IN1 with a smaller diameter than the internal flow path 422P.

[0107] The inlet of the branch pipe 422Q, i.e., the first flow path IN1, is connected to a plurality of first end-plate internal flow paths 423P1 extending radially outward within the end plate 423, and is also connected to the rotor core internal flow path 21P (first coolant flow path system). Furthermore, the second flow path IN2, formed between the outer peripheral surface of the branch pipe 422Q and the inner peripheral surface of the internal flow path 422P, is connected to a plurality of second end-plate internal flow paths 423P2 extending radially outward within the end plate 423, and is then connected to the rotor core internal flow path 421P (second coolant flow path system). Here, the cross-sectional area obtained by cutting the first flow path IN1 in a direction perpendicular to the axial direction Z is sufficiently larger than the cross-sectional area obtained by cutting the second flow path IN2 in a direction perpendicular to the axial direction Z.

[0108] Alternatively, the diameter of each injection hole of the end plate 423 located on the side connected to the internal flow path 422P can be set to be smaller than the diameter of each injection hole of the end plate located on the opposite side of the axial direction Z, thereby adjusting the amount of coolant C distributed from both end plates to be equal.

[0109] In addition, the number of flow paths 423P1 in the first end plate and 423P2 in the second end plate can be reduced by connecting multiple flow paths in the circumferential direction inside the end plate.

[0110] According to the rotary motor of embodiment 4, The rotor includes multiple coolant flow path systems formed by the coolant flow paths, which can adjust the flow rate of the coolant flowing in each coolant flow path system according to the rotational speed of the rotor. Therefore, a certain amount of coolant can be supplied to the space inside the casing regardless of the rotational speed.

[0111] also, The rotor shaft includes an internal flow path that extends axially from one end of the shaft. The axial flow path includes a branch pipe at its end opposite to the inlet of the axial flow path. The branch pipe has the same axis as the axial flow path and has a first flow outlet with a smaller diameter than the axial flow path. The first flow port is connected to a first coolant flow path system, which is one of the plurality of coolant flow path systems. The second flow path, formed between the outer peripheral surface of the bifurcation pipe and the inner peripheral surface of the shaft flow path, is connected to a second coolant flow path system, which is one of the plurality of coolant flow path systems. Therefore, when the drive rotor 20 rotates at low speed, the internal flow path 422P of the shaft 422 is filled with coolant. Based on the ratio of the cross-sectional areas of the first flow path IN1 to the second flow path IN2, a large amount of coolant C flows into the first coolant flow path system through the first flow path IN1. On the other hand, when the drive rotor 20 rotates at high speed, the coolant C, due to centrifugal force, forms an annular flow adhering to the inner wall of the internal flow path 422P. Therefore, a large amount of coolant C flows into the second coolant flow path system from the outer peripheral side of the second flow path IN2. Thus, without the need for electrical control to switch the flow path, the coolant flow path can be adjusted according to the rotor speed.

[0112] also, The cross-sectional area obtained by cutting the first flow path along a direction perpendicular to the axial direction is greater than the cross-sectional area obtained by cutting the second flow path along a direction perpendicular to the axial direction. Therefore, at low speeds, a large amount of coolant can be injected through the large-diameter first flow path port located in the center of the shaft flow path.

[0113] also, The diameter of the injection orifice in the second coolant flow path system is larger than the diameter of the injection orifice in the first coolant flow path system. Therefore, when rotating at high speed, coolant can be distributed into the space inside the casing from the injection holes with a large diameter.

[0114] Implementation method 5.

[0115] The electric vehicle of Embodiment 5 will now be described.

[0116] In the above embodiments 1 to 4, a structure was described in which the space R inside the housing of the rotary motor is filled with a distributed coolant C, and the coil edge 12E is cooled uniformly.

[0117] In this embodiment 5, an electric vehicle including an electromechanical integrated vehicle drive system and a refrigerant circulation system will be described, wherein the refrigerant circulation system utilizes a portion of the refrigerant used for automotive air conditioning on the drive system side for cooling the motor, inverter, battery, and lubrication of gears.

[0118] Figure 18 This is a block diagram illustrating an example of the cooling circuit of an electric vehicle 50.

[0119] Figure 18 Arrow AR1 in the diagram indicates the flow path of the liquid refrigerant C1.

[0120] Figure 18 Arrow AR2 in the diagram indicates the flow path of refrigerant C1, which is a gas-liquid mixture and at a low temperature.

[0121] Figure 18 Arrow AR3 in the diagram indicates the flow path of refrigerant C1, which is a gas-liquid mixture and at a high temperature.

[0122] Typically, the refrigerant C1 in the automotive air conditioning system CA circulates through the condenser 51, receiver 52, expansion valve 53, evaporator 54, and compressor 55, and then returns to the condenser 51.

[0123] In this embodiment 5, a portion of the low-temperature, low-pressure gas-liquid mixed-phase refrigerant C1 injected from the expansion valve 53 of the automotive air conditioner CA is supplied to the inverter 71 and the battery 80, thereby releasing the heat generated in the inverter 71 and the battery 80. It can be assumed that the refrigerant C1 after passing through the inverter 71 heats up to approximately 60°C to 80°C, but sufficient cooling can be achieved for the coil 12 and permanent magnet M, which reach temperatures above 100°C within the motor 100. The temperature of the refrigerant C1 (coolant C) increases from the upstream side to the downstream side in this order.

[0124] The gas-liquid mixture of refrigerant C1 supplied to motor 100 originates from a source having Figure 2 , Figures 7-9 The injection holes 21H and 31H of the front end structure shown are widely distributed inside the housing 3 of the motor 100, floating in the internal space R with a high density. Therefore, they contact the coil edge end 12E throughout the entire range and bring a uniform cooling effect.

[0125] At this time, when the gas-liquid mixed refrigerant C1 is injected into the space R inside the housing 3 of the motor 100, it easily becomes a state of finer droplets than a single-phase liquid. In addition, the heat generated at the coil end 12E causes a portion of the refrigerant C1 to change from a liquid to a gaseous phase, thereby expecting a greater heat absorption effect due to the latent heat of vaporization.

[0126] The refrigerant, which becomes a high-temperature gas-liquid two-phase state within the motor 100, is then supplied to the gearbox 72 and acts as a lubricant for the gears. After completing its cooling and lubrication functions in the drive system, the refrigerant C1 is supplied to the compressor 55 and returns to the automotive air conditioning CA circulation system.

[0127] Figure 19 This is a block diagram illustrating another example of the cooling circuit of an electric vehicle 50, a variation of embodiment 5.

[0128] Figure 19 Arrow AR4 in the diagram indicates the flow path of the low-temperature refrigerant C2.

[0129] Figure 19 Arrow AR5 in the diagram indicates the flow path of refrigerant C2 at high temperatures.

[0130] Preferably, the refrigerant C2 used in the motor 100, inverter 71, and battery 80 has rust-preventing and insulating properties; for example, cooling oil such as ATF is preferred. Therefore, the system is configured to use both refrigerant C1 for automotive air conditioning (CA) and refrigerant C2 for drive, and the refrigerant C2 is cooled by refrigerant C1 via heat exchanger 60.

[0131] Since the drive side uses the same refrigerant C2, the number of components such as liquid pumps, heat exchangers, and refrigerant storage tanks can be reduced, achieving cost reduction and weight reduction. Especially in the case of an electromechanical integrated structure, the motor 100, inverter 71, and gearbox 72 are integrated into a single housing 70. By using the same refrigerant C2, the refrigerant flow path included in the housing 70 can be simplified.

[0132] As described above, heat exchange occurs between the refrigerant C1 used in various structures within the electric vehicle 50, such as the automotive air conditioning CA, and the refrigerant C2 used to cool the motor 100, inverter 71, and battery 80 that constitute the vehicle drive system, through the heat exchanger 60. This allows for mutual utilization of the cooling circuits composed of each refrigerant, even when the refrigerants themselves are not shared. By selecting the most suitable type of refrigerant for each structure of the electric vehicle 50 as a whole, a cooling mechanism that can move thermally as a whole can be constructed, thereby optimizing the cooling mechanism to a high degree.

[0133] In addition, in use Figure 19 In the illustrated examples, with the use Figure 18 Similarly, in the example illustrating this, the refrigerant C1 used in the automotive air conditioning CA within the electric vehicle 50, which is a relatively low-temperature refrigerant, and the refrigerant C2 used for cooling the inverter 71, which is used for cooling the motor 100 and the gearbox 72, share the commonality that their temperatures relatively increase as they move downstream. By employing the above structure, as previously described, a systematized cooling method that optimizes the temperature of each structure being cooled can be implemented, thereby achieving efficient cooling.

[0134] In addition, in use Figure 18 as well as Figure 19 In the illustrated example, the refrigerant supplied to the mechatronic structure circulates in the order of inverter 71, motor 100, and gearbox 72, but other circulation paths are also possible.

[0135] Furthermore, regarding the motor applicable to this embodiment, a rotary motor that includes a refrigerant diffusion unit in the refrigerant flow path described in embodiments 1 to 4 can be combined with a cooling circuit that uses the refrigerant for cooling the rotary motor and for cooling and lubricating the various structures of the electric vehicle. This achieves a cooling system that reduces the overall number of components in the electric vehicle and optimizes the cooling mechanism. However, it is not limited to rotary motors that include a refrigerant diffusion unit; it can also be combined with a general rotary motor that uses refrigerant for cooling the rotary motor.

[0136] Even when combining such a general rotating electric motor, the refrigerant circulation system described in this embodiment can be used to mutually utilize the refrigerant used to cool the rotating electric motor and the cooling circuit used to cool the various structures of the electric vehicle and lubricate them, so that the basic effects previously described in this embodiment can be obtained together.

[0137] According to the electric vehicle of embodiment 5, This includes a refrigerant circulation system that uses at least a portion of the coolant from the rotating electric motor as a refrigerant. Therefore, by supplying a portion of the coolant from the rotating motor to other components installed in the vehicle, such as the coolant pump, heat exchanger, and coolant reservoir, multiple components can share the same components, thus enabling the reduction of the cost and the lightweighting of electric vehicles.

[0138] also, Includes an inverter, battery, and gears that drive the rotating electric motor. The coolant of the rotating electric motor is used as a refrigerant in at least one of the cooling of the inverter, the cooling of the battery, and the lubrication of the gears. Therefore, the rotating motor, inverter, battery, and gears are mostly located close together, thus reducing the number of components by sharing the system that supplies coolant to them. Furthermore, this is also effective for mechatronics, which integrates the motor, inverter, and gears into a single housing.

[0139] Furthermore, the coolant used in automotive air conditioning systems is employed as the coolant for the rotating electric motor. Therefore, refrigerants used in air conditioning systems with a gas-liquid mixture have a greater heat absorption effect due to the latent heat of vaporization generated during the phase change from liquid to gas, making them excellent as coolants for motors as well.

[0140] In addition, this includes: rotary electric motors; and

[0141] A refrigerant circulation system utilizing at least a portion of the coolant, The refrigerant used in the automotive air conditioning system, the refrigerant used to cool the inverter that drives and controls the rotary motor, and the coolant of the rotary motor are arranged and circulated sequentially from upstream to downstream. The temperatures of the refrigerant and the coolant increase sequentially from upstream to downstream. Therefore, electric vehicles can obtain the temperature of each structural component that is the object to be cooled as a whole vehicle, and integrate an ideal cooling system to achieve efficient cooling.

[0142] Furthermore, a refrigerant circulation system is included, in which the cooling circuit for the refrigerant used in the automotive air conditioning system and the cooling circuit for cooling the inverter that drives and controls the rotary motor can exchange heat via a heat exchanger. Therefore, by selecting the most suitable type of refrigerant for each structural component in an electric vehicle and constructing a cooling mechanism that allows for thermal movement as a whole, the cooling mechanism of an electric vehicle can be optimized at a high level.

[0143] This disclosure describes various exemplary embodiments and examples, but the various features, methods and functions described in one or more embodiments are not limited to specific embodiments and can be applied to embodiments individually or in various combinations.

[0144] Therefore, numerous variations not illustrated are contemplated within the scope of the technology disclosed in this application. These include variations, additions, or omissions of at least one constituent element, as well as the extraction of at least one constituent element and its combination with constituent elements of other embodiments.

[0145] Symbol Explanation

[0146] 100, 300 Rotary motor; 10 Stator; 11 Stator core; 12 Coil; 12E Coil edge end; 20 Rotor; 20P Rotor coolant flow path; 21 Rotor core; 21H, 21H1, 21H2, 221H, 221H2, 221H3, 421H Injection holes; 21P, 421P Internal flow path of rotor core; OF Throttling orifice; 22, 422 Shaft; 22P, 422P Internal flow path of shaft; 422Q Branch piping; 23, 423, 24 End plates; 23P Internal flow path of end plate; 423P1 Internal flow path of first end plate; 423P2 Internal flow path of second end plate; 3, 303 Housing; 31, 331 Cylindrical portion of housing; 31P, 32P Internal flow path of housing; 32 Casing end plate; 31H, 231H injection holes; 331D, 331D1, 331D2, 331D3 protrusions; 5 bearing; 50 electric vehicle; 51 condenser; 52 receiver; 53 expansion valve; 54 evaporator; 55 compressor; 60 heat exchanger; 70 housing; 71 inverter; 72 gearbox; 80 battery; AR1, AR2, AR3, AR4, AR5 arrows; C coolant; C1, C2 refrigerant; CA automotive air conditioning; G clearance; IN intake port; IN1 first flow path; IN2 second flow path; M permanent magnet; O central axis; PA nozzle assembly; R space; RM mixing chamber; RM2 vortex chamber; SL slit; X radial; Y circumferential; Z axial.

Claims

1. A rotary electric motor, characterized in that, include: shell; A stator having a stator core fixed to the housing and a coil wound around the stator core; as well as A rotor, rotatably supported on the housing, having a rotor core and a shaft. At least one of the rotor and the housing has a coolant flow path that supplies coolant to the coil edge end of the coil. The diameter of the injection hole that sprays the coolant from the coolant flow path into the space inside the housing is smaller than the diameter of the coolant flow path.

2. The rotary motor according to claim 1, characterized in that, The injection hole has a tapering shape at the front end.

3. The rotary motor according to claim 1 or 2, characterized in that, The spray hole is the nozzle of the spray device.

4. The rotary motor according to claim 1 or 2, characterized in that, The coolant flow path near the injection orifice includes: a throttling orifice, the inner diameter of which is smaller than the inner diameter of the coolant flow path before and after the throttling orifice; an intake port that draws in gas from the space; and a mixing chamber that mixes the coolant with the gas.

5. The rotary motor according to claim 1 or 2, characterized in that, The coolant flow path includes a swirling chamber near the injection orifice, the swirling chamber generating a swirling flow along its inner wall.

6. The rotary electric motor according to any one of claims 1 to 5, characterized in that, The inner wall of the housing, and in the operating state, has a protrusion that protrudes downward toward the bottom of the plumb bob at the end of the coil edge.

7. The rotary electric motor according to any one of claims 1 to 6, characterized in that, The rotor includes multiple coolant flow path systems formed by the coolant flow path, which can adjust the flow rate of the coolant flowing in each coolant flow path system according to the rotation speed of the rotor.

8. The rotary electric motor according to claim 7, characterized in that, The rotor shaft includes an internal flow path that extends axially from one end of the shaft. The axial flow path includes a branch pipe at its end opposite to the inlet of the axial flow path. The branch pipe has the same axis as the axial flow path and has a first flow outlet with a smaller diameter than the axial flow path. The first flow port is connected to a first coolant flow path system, which is one of the plurality of coolant flow path systems. The second flow path, formed between the outer peripheral surface of the bifurcation pipe and the inner peripheral surface of the shaft flow path, is connected to a second coolant flow path system, which is one of the plurality of coolant flow path systems.

9. The rotary electric motor according to claim 8, characterized in that, The cross-sectional area obtained by cutting the first flow path along a direction perpendicular to the axial direction is greater than the cross-sectional area obtained by cutting the second flow path along a direction perpendicular to the axial direction.

10. The rotary electric motor according to claim 8 or 9, characterized in that, The diameter of the injection hole in the second coolant flow path system is larger than the diameter of the injection hole in the first coolant flow path system.

11. The rotary electric motor according to any one of claims 1 to 10, characterized in that, The rotor core includes an internal flow path for the coolant to flow along a permanent magnet housed within the rotor core.

12. The rotary electric motor according to any one of claims 1 to 11, characterized in that, The rotor core is composed of multiple stacked steel plates, or multiple stacked steel plates and end plates. The spaces between the layers of the laminated steel plates and between the laminated steel plates and the end plate are filled with resin.

13. An electric vehicle, characterized in that, The electric vehicle includes a refrigerant circulation system that uses at least a portion of the coolant of the rotary motor according to any one of claims 1 to 12 as a refrigerant.

14. The electric vehicle according to claim 13, characterized in that, Includes an inverter, battery, and gears that drive the rotating electric motor. The coolant of the rotating electric motor is used as a refrigerant in at least one of the cooling of the inverter, the cooling of the battery, and the lubrication of the gears.

15. An electric vehicle, characterized in that, The refrigerant used in automotive air conditioning is used as the coolant in the rotary motor according to any one of claims 1 to 12.

16. An electric vehicle, characterized in that, include: The rotary motor according to any one of claims 1 to 12; as well as A refrigerant circulation system utilizing at least a portion of the coolant, The refrigerant used in the automotive air conditioning system, the refrigerant used to cool the inverter that drives and controls the rotary motor, and the coolant of the rotary motor are arranged and circulated in sequence from upstream to downstream. The temperatures of the refrigerant and the coolant increase sequentially from the upstream side to the downstream side.

17. An electric vehicle, characterized in that, The electric vehicle includes a refrigerant circulation system, wherein the refrigerant circulation system includes a cooling circuit for the refrigerant used in the automotive air conditioning system of claim 15 and a cooling circuit for cooling the inverter that drives and controls the rotating motor, which can be thermally moved via a heat exchanger.

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