Cooling structure for an electric rotary machine

Abstract

A cooling structure for an electric rotary machine, comprising: a plurality of coils (12040) with rectangular wire (12050) wound in multiple layers around an insulating part (12021) circumferentially covering a core (12000), wherein in each of the plurality of coils a gap is provided between the insulating part (12021) and the rectangular wire (12050) and a support portion (12013) is provided therein for determining the position of the wire (12050) with respect to the insulating part (12021), and a supply section to supply a cooling medium so that it flows through the gap.

Description

Technical area

[0001] The present invention relates to a structure for a rotary electric machine mounted on a vehicle, and more particularly to a structure for a rotary electric machine having an edge-wound coil formed from a rectangular wire. State of the art

[0002] During operation of an electric rotating machine, the wire in a coil generates heat, which causes the temperature to rise. It is known that failure to adequately cool the wire reduces the output power of the electric rotating machine and impairs the service life and aging resistance of the wire.

[0003] A rectangular wire is sometimes used for the stator winding of such a rotating electrical machine to form a coil with edge alignment. With such a rectangular wire, the coil has a larger cross-sectional area than with a conventional round wire, resulting in reduced DC resistance, improved frequency response, and the like. Accordingly, the coil can be reduced in size and improved in performance.

[0004] However, the rectangular wire exhibits a large radius of curvature when bending, where there is a likelihood of the wire leaving gaps from a tooth of a stator (iron core) of the rotating electrical machine. Specifically, when winding the rectangular wire around a winding section with a rectangular cross-section of an insulating member covering the iron core, it is difficult to wind the wire in a precise rectangular shape.

[0005] It is inevitable that the wire is lifted from the sides of the rectangle while in contact with the corners, resulting in gaps between the wire and the sides of the rectangle. These gaps act as thermal insulation, causing the problem that the heat generated by the wire is less likely to be transferred through the insulation material to the iron core, resulting in impaired cooling performance of the wire, even when the iron core is cooled.

[0006] In view of such a disadvantage, Japanese Patent Laid-Open No. 2004-343877 (Patent Document 1) discloses coils of a rotary electric machine whose wires can be efficiently cooled with a simple structure. Each coil of the rotary electric machine has a wire wound in multiple layers around a winding portion of an insulating member covering the iron core, and is characterized in that gaps between the winding portion of the insulating member and the wire are filled with a thermally conductive material supplied via a channel formed in the insulating member.

[0007] In the coils of the rotary electric machine, in which the spaces provided between the winding portion of the insulating member covering the iron core and the wire wound around the winding portion are filled with a thermally conductive material supplied through the channel formed in the insulating member, the transfer of heat from the wire to the iron core via the thermally conductive member and the insulating member allows for effective heat dissipation to cool the wire. Furthermore, there is no need to provide a coolant, a pump for bypassing the coolant, and the like, thus contributing to reduced costs.

[0008] However, the coil of the rotary electric machine disclosed in the above-mentioned Patent Document 1 is not directly cooled, but only indirectly cooled by transferring a large amount of heat from the coil (wire) to the iron core. This may result in insufficient cooling of the rectangular wire.

[0009] In the closest prior art document US 1 506 746 A, cooling channels are provided between a coil and a pole section. An insulating layer is provided adjacent to the contact area between the coil and the pole section.

[0010] Document DE 10 87 258 A relates to an arrangement for cooling the rotor winding of electrical machines, in which a winding 4 of the pole coil 5 is centered on a pole core 7 by insulating rods, so that eight radial channels are formed.

[0011] Document DE 14 63 852 B shows a rotor winding with a cooling element consisting of at least two branches, with adjacent branches being flowed through in countercurrent. Object of the invention

[0012] The present invention was made to solve the above-described problem. It is an object of the present invention to provide a cooling structure for a rotary electric machine that allows efficient cooling of the rotary electric machine having an edge-aligned coil formed from a rectangular wire. Disclosure of the invention

[0013] This object is solved by the subject matter of claim 1. Further aspects are defined in the subclaims.

[0014] A cooling structure for a rotary electric machine according to a first aspect is provided for cooling a rotary electric machine having a plurality of coils with a rectangular wire wound in multiple layers around an insulating member circumferentially covering an iron core. The cooling structure has a gap in each of the coils between the insulating member and the rectangular wire, which is provided at the bends due to a large radius of curvature of the rectangular wire, and has a supply device for supplying a cooling medium to flow through the gap.

[0015] According to the first aspect, the plurality of coils are formed according to the number of poles of the rotating electric machine. The coils are each formed by winding the rectangular wire in multiple layers around the insulating member covering the iron core in the circumferential direction. Due to a large radius of curvature of the rectangular wire at the bends, it is difficult to wind the rectangular wire around the insulating member covering the rectangular iron core (tooth) in the circumferential direction without gaps between them (to wind the rectangular wire with a rectangular cross-section into a rectangle without gaps between them), which inevitably results in a gap between the insulating member and the rectangular wire. The supply device supplies a cooling medium via the gap, so that the gap serves as a channel for the cooling medium.Unlike the conventional method of accommodating a thermally conductive element in the gap to indirectly improve cooling efficiency, supplying the cooling medium through the gap allows for direct cooling of the iron core. As a result, a cooling structure of a rotating electric machine can be improved, allowing efficient cooling of the rotating electric machine with an edge-aligned coil formed from a rectangular wire.

[0016] In a cooling structure for an electric rotary machine according to a second aspect, in addition to the structure according to the first aspect, the cooling medium flows from one of the coils to the other.

[0017] According to the second aspect, when the rotating shaft of the electric rotary machine is arranged horizontally, for example, a coolant is supplied to an uppermost stator coil. The cooling medium flows to an adjacent coil due to gravity. This flow continues sequentially, so that the plurality of coils can be cooled.

[0018] A cooling structure for an electric rotary machine according to a third aspect further comprises, in addition to the structure according to the first or second aspect, an insulating material that reduces a cross-sectional area of ​​the gap.

[0019] According to the third aspect, a reduction in the cross-sectional area of ​​the gap increases the flow rate of the cooling medium (here, liquid). This further promotes heat exchange, thereby achieving improved cooling efficiency.

[0020] In a cooling structure for an electric rotary machine according to a fourth aspect, in addition to the structure according to any one of the first and second aspects, the supply means includes a passage that supplies the cooling medium to a hole communicating with the gap, and a pump that causes the cooling medium to flow through the passage.

[0021] According to the fourth aspect, the coolant is supplied through the coil gap of the rotating electric machine by means of the pump, and the coolant having absorbed heat is supplied to a cooler. The rotating electric machine can thereby be efficiently cooled. Short description of the drawings Fig. 1 is an overall control block diagram of a hybrid vehicle with motor generators according to an embodiment of the present invention. Fig. 2 shows a power sharing mechanism. Fig. 3 is an overall structural diagram of a cooling system of a hybrid vehicle. Fig. 4 is a sectional view of a motor generator according to an embodiment of the present invention. Fig. 5 is a perspective view of the motor generator according to an embodiment of the present invention. Fig. 6 is a partially enlarged view according to Fig. 5. Fig. 7 is a sectional view corresponding Fig. 6. Fig. 8 is a side view of a motor generator (provided with cooling tubes) according to an embodiment of the present invention. Fig. 9 is a perspective view of the motor generator provided with the cooling pipes according to Fig. 8 is provided. Fig. 10A shows a stator coil end 12010 seen from the top of a motor generator 140, illustrating a (first) manner in which the cooling water flows. Fig. 10B is a sectional view along the line XB-XB in Fig. 10A. Fig. 11A shows a stator coil end 12010 viewed from the top of the motor generator 140 and illustrates a (second) manner in which the cooling water flows. Fig. 11B is a sectional view along line XIB-XIB in Fig. 11A. Fig. 12 is a partially cutaway perspective view of a motor generator according to a modification of the embodiment of the present invention. Best modes for carrying out the invention

[0022] Embodiments of the present invention will be described below with reference to the drawings. In the following description, similar parts are designated by similar reference numerals and have the same name and function. Therefore, the detailed description thereof will not be repeated. It should be noted that the size ratios and the like may vary between the drawings. It is intended to show that the present invention is not applied to a motor generator limited to a specific size ratio.

[0023] With reference to Fig. 1, a description of an overall control block diagram of a hybrid vehicle with the motor generators having a cooling structure according to an embodiment of the present invention is presented. It should be noted that the present invention is not limited to the Fig. 1. The present invention can be applied to a vehicle having an internal combustion engine as a power source, such as a gasoline engine (hereinafter referred to as an internal combustion engine), serving as both a drive source for driving the vehicle and a drive source of a generator. Alternatively, the present invention can be applied to a vehicle powered by the internal combustion engine and a motor generator, which can travel by means of the power of the motor generator (either with the engine turned off or without the engine turned off), or a hybrid vehicle having another mode in which a battery is mounted for driving (not limited to hybrid vehicles of so-called series or parallel connection, but limited to vehicles that support EV traveling orElectric vehicle driving after system activation). The battery can be implemented by, for example, a nickel-metal hydride battery or a lithium-ion battery, and the type of these is not particularly limited. Alternatively, the battery can be replaced by a capacitor. The motor generator with the cooling structure according to the embodiment of the present invention can also be applied to an electric vehicle on which no internal combustion engine is mounted.

[0024] The hybrid vehicle includes an internal combustion engine 120 and a motor generator (MG) 140. For convenience, the motor generator 140 will be referred to below as a motor generator 140A (or MG(2) 140A) and a motor generator 140B (or MG(1) 140B). However, depending on the driving state of the hybrid vehicle, the motor generator 140A may function as a generator and the motor generator 140B may function as a motor. When the motor generator functions as a generator, regenerative braking is performed. When the motor generator functions as a generator, the vehicle's kinetic energy is converted into electrical energy, resulting in vehicle deceleration.

[0025] The hybrid vehicle also includes a speed reduction device 180 for transmitting the power generated by the engine 120 and / or the motor generator 140 to a driven wheel 160 and for transmitting the driving of the driven wheel 160 to the engine 120 and the motor generator 140, a power splitting mechanism (for example, a planetary gear mechanism described below) 200 that distributes the power generated by the engine 120 to two paths for driving the driven wheel 160 and the motor generator 140B (MG(1) 140B), a drive battery 220 for collecting electric power for driving the motor generator 140, an inverter 240 for performing current control while switching between a direct current for driving the battery 220 and an alternating current of the motor generator 140A (MG(2) 140A). and the motor generator 140B (MG(1) 140B),a battery control unit (hereinafter referred to as a battery ECU (Electronic Control Unit)) 260 for managing and controlling the state of charge or discharge (e.g., SOC) of the driving battery 220; an engine ECU 280 for controlling the operating condition of the engine 120; an MG ECU 300 for controlling the motor generator 140, a battery ECU 260, an inverter 240, and the like according to the state of the hybrid vehicle; an HV ECU 320 or hybrid vehicle ECU 320 for managing and controlling the battery ECU 260, the engine ECU 280, the MG ECU 300, and the like in an interactive manner to control the entire hybrid system so that the hybrid vehicle can run at optimal efficiency, and the like.

[0026] In the present embodiment, a boost converter 242 is provided between the traction battery 220 and the inverter 240. Since the rated voltage of the traction battery 220 is lower than that of the motor generator 140A (MG(2) 140A) and the motor generator 140B (MG(1) 140B), the boost converter 242 boosts the electric power before supplying the electric power from the traction battery 220 to the motor generator 140A (MG(2) 140A) and the motor generator 140B (MG(1) 140B).

[0027] Although the respective ECU or electronic control units in Fig. 1 are provided separately, two or more ECUs may be integrated into one ECU, for example, the MG-ECU 300 and AV-ECU 320 may be integrated into one ECU, as shown by dashed lines in Fig. 1 is shown.

[0028] The power split mechanism 200 is implemented by a planetary gear mechanism (planetary gear) to distribute the power of the engine 120 to both the driven wheels 160 and the motor generator 140B (MG(1) 140B). By controlling the number of revolutions of the motor generator 140B (MG(1) 140B), the power split mechanism 200 also serves as a continuously variable transmission. The rotational power of the engine 120 is received by a carrier (C) to be transmitted to the motor generator 140B (MG(1) 140B) through a sun gear (S) and to the motor generator 140A (MG(2) 140A) and to an output shaft (on the driven wheel 160 side) through a ring gear (R).To stop the rotation of the engine 120, the kinetic energy of the rotation of the rotating engine 120 is converted into electrical energy at the motor generator 140B (MG (1) 140B) to reduce the rotational speed of the engine 120.

[0029] In a hybrid vehicle equipped with a hybrid system such as this one in Fig. 1, when conditions predetermined regarding the state of the vehicle are met, the AV-ECU 320 controls the engine 120 via the motor generator 140A (MG(2) 140A) and the engine ECU 280 so that the hybrid vehicle runs only by means of the motor generator 140A (MG(2) 140A) of the motor generator 140. For example, the predetermined conditions include a condition that the driving battery 220 has an SOC of a predetermined value or above. With such control, the hybrid vehicle can be driven only by means of the motor generator 140A (MG(2) 140A) even if the engine 120 is operated at low efficiency at the start of driving, during low-speed traveling, or the like.As a result, the SOC of the drive battery 220 can be reduced (the drive battery 220 can be charged at a subsequent stop of the vehicle).

[0030] In a normal driving state, the power of the engine 120 is split into two paths by the power split mechanism 200, so that the driven wheel 160 is directly driven while the motor generator 140B (MG(1) 140B) is driven for power generation. At this stage, the motor generator 140A (MG(2) 140A) is driven by the generated electric power to assist in driving the wheel 160. During high-speed driving, the electric power from the traction battery 220 is further supplied to the motor generator 140A (MG(2) 140A) to increase the power output of the motor generator 140A (MG(2) 140A), thus applying additional driving force to the driven wheels.During deceleration, the motor generator 140A (MG(2) 140A), driven following the driven wheels 160, serves as a generator to perform regeneration, and the regenerated electric power is stored in the traction battery 220. When the traction battery 220 has a reduced amount of charge and charging is specifically required, the output of the engine 120 is increased to increase the amount of power generation of the motor generator 140B (MG(1) 140B), thereby increasing the amount of charge of the traction battery 220.

[0031] Furthermore, a state of charge (SOC) of the traction battery 220 is usually set to approximately 60 percent so that energy can be recovered each time regeneration is performed. To prevent the traction battery 220 from deteriorating, the upper and lower limits of the SOC are set to 80 percent and 30 percent, respectively. The HV-ECU 320, via the MG-ECU 300, controls the power generation and regeneration by the motor generator 140, as well as the engine output, so that the SOC does not exceed the upper limit and falls below the lower limit. The values ​​mentioned here are merely examples and are not intended to be limiting values.

[0032] With reference to Fig. 2, the power split mechanism 200 is further described. The power split mechanism 200 is implemented by a planetary gear train having a sun gear (S) 202 (hereinafter referred to briefly as sun gear 202), a pinion gear 204, a carrier gear (C) 206 (hereinafter referred to as carrier gear 206), and a ring gear (R) 208 (hereinafter referred to briefly as ring gear 208).

[0033] The pinion gear 204 meshes with the sun gear 202 and the ring gear 208. The carrier 206 rotatably supports the pinion gear 204. The sun gear 202 is coupled to the rotation shaft of the MG (1) 140B. The carrier 206 is coupled to the crankshaft of the engine 120. The ring gear 208 is coupled to the rotation shaft of the MG (2) 140A and the speed reduction device 180.

[0034] Coupling the engine 120, MG (1) 140B and MG (2) 140A together by means of the power split mechanism 200 implemented by the planetary gear train brings the engine 120, MG (1) 140B and MG (2) 140A into a relationship in which their rotational speeds are connected with a straight line in a nomogram representation.

[0035] With reference to Fig. 3, the overall structure of a hybrid cooling system with a motor generator 140 having the cooling structure according to the embodiment of the present invention will now be described. As shown in Fig. 3, this hybrid cooling system (hereinafter also referred to as a cooling system) is a system in which the cooling water (LLC (Long Life Coolant) as a cooling medium) flows as a liquid coolant from / to the motor generator 140 and from / to a PCU 2200 to / from an HV cooler 2330 by way of an HV water pump 2310 to cool the motor generator 140 and the PCU 2200.

[0036] In addition to the above-mentioned HV water pump 2310 and the above-mentioned HV cooler 2330, the cooling system includes an HV cooler-dedicated pipe 2320 for supplying high-temperature cooling water with absorbed heat to the motor generator 140 and the PCU 2200, an HV cooler return pipe 2340 for returning cooling water, whose temperature has dropped due to heat exchange at the HV cooler 2330, from the HV cooler 2330, and a receiving tank 2300.

[0037] The storage tank 2300 serves as an auxiliary tank for the cooling water and is provided to accommodate changes in the temperature of the cooling water in the pipes of this cooling system and changes in the capacity of the pipes caused by the bypassing of the cooling water. Specifically, in the case where the storage tank 2300 is not provided, an insufficient volume of cooling water relative to the capacity of the cooling pipes causes air to enter the cooling pipes. In such a case, air entering the pipes of the cooling system is admitted to the HV water pump 2310, causing the HV water pump 2310 to remain airtight. Then, the cooling water can no longer circulate. To avoid such a situation, the storage tank 2300 is provided.

[0038] In the Fig. 3, the cooling water is circulated via the HV cooler 2330, the PCU 2200, the storage tank 2300, the HV water pump 2310, and the motor generator 140 in that order. The PCU 2200 has an IPM for driving the motor generator 140 and is therefore located near the motor generator 140, as shown in Fig. 3. Accordingly, when the engine 120 is mounted at the front of the vehicle, the motor generator 140 and the PCU 2200 are located near the engine 120.

[0039] It should be noted that the position of the motor generator 140 and the PCU 2200 is not limited to that described above. Although the cooling system is described as being separate from the cooling system of the engine 120, the cooling system controlled by the control device according to the present invention is not limited to that described above. Specifically, the cooling system may share cooling pipes with the cooling system of the engine 120. Alternatively, one radiator may be shared while providing pipes independently (in other words, the radiator of the engine 120 also serves as the HV radiator), or any other sharing mode may be adopted (for example, sharing only one cooling fan between the radiators).

[0040] With reference to Fig. 4, the internal structure of the motor generator 140 with the cooling structure according to the embodiment of the present invention will now be described. The motor generator 140 is mounted on the hybrid vehicle described above, with the rotation shaft horizontal or substantially horizontal as shown in Fig. 4 is shown.

[0041] Fig. 4 is a cross-sectional view of such a motor generator 140. This motor generator includes a rotor portion including a rotor 11010 rotatably supported by two bearings 11020, and a stator portion including a stator core 12000 disposed on the periphery of the rotor 11010. The rotor 11010 is supported by bearings 11020 and rotates about a rotating shaft 11000 to transmit rotational torque to the vehicle's drivetrain (the power split mechanism 200 described above).

[0042] The stator core 12000 is located opposite the rotor 11010, leaving a narrow gap between them. The stator core 12000 has slots extending therethrough in a direction parallel to the rotating shaft, and a coil is wound along the slots. A current flows through the coil to cause the stator core 12000 to generate a magnetic field for rotating the rotor 11010.

[0043] Ends of the stator coil wound around the stator core 12000 form stator coil ends 12010. The stator coil is wound in such a manner that it runs along the slots of the stator core 12000, with an insulating paper 12021 interposed between them. Teeth are provided between the slots.

[0044] It should be noted that the rotor 11010 can be formed from a stack of a plurality of electromagnetic steel plates (thin plates approximately 0.3 mm to 0.5 mm thick) or be a single-piece unit. The components, including the rotating shaft 11000, the rotor 11010, the layer 11020, the stator core 12000, and the stator coil ends 12010, are enclosed in a housing 13000.

[0045] The stator coil 12040, which is wound around the stator core 12000 and in Fig. 4 is formed from a rectangular wire to form an edge-aligned coil, or an edge-wound coil, or an edge-oriented coil. This rectangular wire has a larger radius of curvature when bending than a round wire, resulting in a larger gap from the tooth of the stator (iron core) of the rotating electric machine. A primary feature of the cooling system according to the present embodiment is the use of the gap as the channel for the cooling medium (cooling water or cooling oil).

[0046] Fig. 5 is a perspective view of a motor generator 140 with the cooling system according to the embodiment of the present invention. Insulating plates (insulators) covering the stator core ends 12010 are provided with cooling water inlets 12011 leading to gaps. The mode of the starter coil ends 12010 changes depending on the number of poles of the motor generator 140, for example. In the present embodiment, a group of two inlets is provided for each insulating plate.

[0047] Fig. 6 is an enlarged view of a section with a coil with edge orientation corresponding to a pole. Fig. 7 is a sectional view showing Fig. 6. As stated in the Fig. 6 and Fig. 7, a rectangular wire 12050 is wound around the tooth 12018 to form an edge-aligned coil. As shown in Fig. 7, it is difficult to wind a rectangular wire 12050 around the rectangular tooth 12018 without leaving gaps between them (it is difficult to wind the rectangular wire 12050 with a rectangular cross section exactly as a rectangle without gaps between them). However, as shown in Fig. 7, support portions 12013 are provided for determining the position of the edge-aligned coil with respect to the tooth 12018. This provides a cooling water channel 12012 between the edge-aligned coil formed of the rectangular wire 12050 and the tooth 12018 (more precisely, with insulating materials (insulators) interposed therebetween).

[0048] Cooling water inlets 12011, which are Fig. 6 are shown, correspond in position to the cooling water channel 12012, which is shown in Fig. 7. Accordingly, supplying cooling water (LLC) to cooling water inlets 12011 (from the external side of the motor generator 140 toward the rotating shaft (toward the inner or central side)) allows cooling water to flow through the cooling water channel 12012. This allows the coil to be directly cooled with edge alignment with the cooling water.

[0049] With reference to the Fig. 8 and Fig. 9, the supply of cooling water to the motor generator 140 is now described. As described in the Fig. 8 and Fig. 9 are cooling water inlets 12011, which are in Fig. 5 are provided along the entire circumference of the stator coil ends 12010 of the motor generator 140. Cooling water supply pipes 12014 are provided along the entire circumference of the stator coil ends 12010 in such a way that the cooling water inlets 12011 provided along the entire circumference are covered. Cooling water supply pipes 12014 have outlets that correspond in position to the cooling water inlets 12011. As indicated by arrows in Fig. 8, cooling water discharged through the outlets passes through cooling water inlets 12011 to flow into the cooling water passage 12012. Since the cooling water flows from the top to the bottom of the motor generator 140 by gravity, the outlets can be provided only at the top of the cooling water supply pipes 12014.

[0050] As mentioned above with reference to Fig. 3, the present hybrid cooling system is configured to circulate the cooling water by means of the HV water pump 2310 to dissipate the heat absorbed at the motor generator 140 to the HV cooler 2330. Accordingly, the cooling water flows through the cooling water channel 12012 extending from the outer side to the middle side of the motor generator 140, shown in Fig. 4, opens, via a drain hole (not shown) located at the bottom of the motor generator 140, and flows via the HV cooler-destined pipe 2320 to be directed into the HV cooler 2330.

[0051] With reference to the Fig. 10A and Fig. 10B describes the flow of cooling water. Fig. 10A is a diagram of the stator coil end 12010 as viewed from the top of the motor generator 140, showing cooling water inlets 12011 provided in the insulating plates.

[0052] Fig. 10B is a sectional view along the line XB-XB in Fig. 10A. As it is in Fig. As shown in Figure 10B, a plurality of edge-aligned coils 12015 (stator coil ends 12010) are provided for each pole. Cooling water flowing into the cooling water channels 20000, 20010, 20020, and 20030 formed by insulators 12016 and 12017 exchanges heat with the stator coils to reduce the temperature of the stator coils.

[0053] With reference to the Fig. 11A and Fig. 11B, the flow of cooling water is described when an edge-oriented coil 22015 has an insulator 22017 with a different shape relative to the insulator 12017. In a similar manner to Fig. 10A is Fig. 11A is a diagram of a stator coil end 12010 as viewed from the top of the motor generator 140, showing the cooling water inlets 12011 provided in the insulating plates. Fig. 11B is a sectional view along line XIB-XIB in Fig. 11A.

[0054] For the edge-aligned coil 22015 (stator coil ends 12010), the insulator 22017 is shorter than the insulator 12017 used in the Fig. 10A and Fig. 10B. Therefore, the cooling water flowing into a cooling water channel 30000 through one of a group of two cooling water inlets 12011 flows into a cooling water channel 30010 communicating with the other cooling water channel 12011. Further, the cooling water discharged from the cooling water channel 30010 flows into a cooling water channel 30020 through one of the cooling water inlets 12011 of another edge-directed coil located downward to flow into a cooling water channel 30030 communicating with the other of the cooling water inlets 12011. Further, the cooling water discharged from the cooling water channel 30030 flows into the other edge-directed coil located downward. Furthermore, the cooling water flowing sequentially into the cooling water channels 30000, 30010, 30020 and 30030, each formed by insulators 22016 and 22017, exchanges heat with the stator coils to reduce the temperature of the stator coils.

[0055] As described above, the motor generator with the cooling structure according to the present embodiment is configured so that cooling water flows through the gaps resulting from a large radius of curvature when the edge-aligned coil is formed from the rectangular wire with a large radius of curvature at the bends. This allows for direct cooling of the stator coils to achieve improved thermal characteristics of the motor generator. Modifications

[0056] With reference to Fig. 12, a modification of the motor generator having the cooling structure according to the embodiment of the present invention will be described.

[0057] Fig. 12 corresponds to Fig. 7 (although the orientation is different). A difference from the one in Fig.7 is that instead of the support portions 12013, an insulator 40002 is added to an insulator 40000 and a support portion 40010 is provided thereon.

[0058] Specifically, a cooling water channel 40030 that is narrower than the cooling water channel 12012 is obtained. A rectangular wire element 40020 is arranged to surround the cooling water channel 40030. Such a narrower cooling water channel results in a higher flow rate of the cooling water. This achieves improved heat exchange efficiency, resulting in higher cooling performance.

[0059] It should be understood that the embodiments disclosed herein are illustrative but not limiting in all respects. The scope of the present invention is intended to be defined by the claims rather than by the foregoing description, and to include all modifications and variations equivalent in meaning and scope to the claims.

Claims

[1] A cooling structure for an electric rotary machine, comprising: a plurality of coils (12040) with rectangular wire (12050) wound in multiple layers around an insulating part (12021) circumferentially covering a core (12000), wherein in each of the plurality of coils a gap is provided between the insulating part (12021) and the rectangular wire (12050) and a support portion (12013) is provided therein for determining the position of the wire (12050) with respect to the insulating part (12021), and a supply section to supply a cooling medium so that it flows through the gap. [2] The cooling structure for an electric rotating machine according to claim 1, wherein the cooling medium flows from one of the plurality of coils to the other coil. [3] The cooling structure for an electric rotary machine according to claim 1, further comprising an insulating material (40002) reducing a cross-sectional area of ​​the gap. [4] The cooling structure for an electric rotary machine according to claim 1, wherein the supply section comprises: a channel (12012) which supplies the cooling medium to a hole communicating with the gap, and a pump (10P) that causes the cooling medium to flow through the channel. [5] The cooling structure for an electric rotary machine according to claim 4, wherein the channel (12012) has an outer peripheral surface with a contour corresponding to a curved inner peripheral surface of the rectangular wire (12050). [6] The cooling structure for an electric rotary machine according to claim 1, wherein the cooling medium comprises liquid.

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