Rotary electrical machine

Abstract

A rotary electrical machine is provided with a stator comprising: an annular stator core in which a plurality of slots are formed; a coil having a plurality of slot insertion sections for insertion into the slots, said plurality of slot insertion sections being inserted into mutually different slots; and an insulating member disposed between the slots and each of the slot insertion sections, wherein the coil includes a coil end section protruding from an end surface of the stator core to the exterior and connecting the plurality of slot insertion sections to each other, the coil also includes a transition direction surface in contact with the insulating member, and the slots include a coil-fixing section in contact with the transition direction surface of the coil, and a space-forming section that is a space formed on a surface side on the opposite side from the transition direction surface of the coil.

Description

rotating electrical machines

[0001] The present invention relates to a rotating electric machine.

[0002] While there is a demand for improved motor output density, as current density increases, the center of the coil in the slot becomes the hottest, limiting output. To address this issue, cooling methods such as directly spraying cooling oil onto the coil in the slot are used to improve cooling. For example, Patent Document 1 below discloses a technology for cooling a motor that can be made smaller by providing cooling jackets 6 at the front and rear ends of a stator core 5, surrounding the coil ends 7A protruding from each end to form liquid-tight annular spaces, and engaging and positioning the stator core 5 side end of the cooling jacket 6 with a base plate 8.

[0003] Japanese Patent Application Laid-Open No. 2005-348594

[0004] In view of the technology described in Patent Document 1, the object of the present invention is to provide a rotating electric machine that can fix the coil while ensuring cooling path space, without relying on varnish, which is an insulating material filled in the gaps within the slots, thereby reducing the coil temperature through direct cooling of the coil and improving assembly ease.

[0005] A rotating electric machine having a stator including an annular stator core in which a plurality of slots are formed, a coil having a plurality of slot insertion portions to be inserted into the slots, the coil inserting the plurality of slot insertion portions into different slots, and an insulating member arranged between the slot and each of the slot insertion portions, wherein the coil has a coil end portion that protrudes outward from an end face of the stator core and connects the plurality of slot insertion portions, the coil has a transition direction surface that contacts the insulating member, and the insulating member has a coil fixing portion that contacts the transition direction surface of the coil and a space forming portion that is a space formed on the surface of the coil opposite to the transition direction surface.

[0006] According to the present invention, it is possible to provide a rotating electric machine that realizes a reduction in coil temperature by direct cooling of the coil and an improvement in assembly efficiency.

[0007] 1. An electric drive system for a vehicle and an example of a cooling configuration. 2. A cooling oil circulation structure in an electric drive system according to an embodiment of the present invention. 3. An assembly diagram of insulating members inserted into slots according to an embodiment of the present invention. 4. A diagram of the relationship between the coils and insulating members in the slots according to an embodiment of the present invention. 5. An arrangement diagram of the coils and insulating members in the slots according to an embodiment of the present invention. 6. Modified examples. 7. An explanatory diagram of the teeth of a stator according to an embodiment of the present invention.

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and some omissions and simplifications have been made as appropriate for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0009] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0010] (One embodiment and overall configuration) (Fig. 1) A vehicle body 1 is a vehicle that travels with tires 2 on four wheels. The vehicle body 1 has an electric drive system 6 that drives the tires 2, an oil cooler 7 that is connected to the electric drive system 6 via a cooling system 3 and exchanges heat with the circulating refrigerant, and a chiller 5 that is connected to the oil cooler 7 via a cooling system 4 and releases heat from the circulating refrigerant to the outside of the vehicle body 1. The electric drive system 6 is, for example, a system using a motor for transmitting power to the tires 2. The oil cooler 7 is water-cooled if the refrigerant is cooling water, or oil-cooled if the refrigerant is cooling oil.

[0011] (Fig. 2) The motor 8 has a stator 11, a rotor 12, and a reducer 20. The rotor 12 has a magnet. The stator 11 has a stator core and a coil 10, and between the stator core and the coil 10 are a first resin member 15 which is a bobbin and a second resin member 16 which is a cuff. The first resin member 15 and the second resin member 16 are insulating members.

[0012] The rotor 12 has a rotor core, rotor end plates, a shaft, and permanent magnets. The shaft is rotatably supported by bearings. The rotor core is formed by laminating electromagnetic steel sheets (thin sheets). The reducer 20 is a mechanical device that reduces the rotational speed of the motor 8 using gears or the like and outputs the reduced speed. The stator 11 and rotor 12 may be configured to be skewed.

[0013] The cooling oil circulating inside the motor 8 moves to a flow path outside the motor 8 via a cooling oil outlet 21, passes through an oil pan 22, an oil pump 23, and the oil cooler 7 in that order, and returns to the inside of the motor 8 via a cooling oil inlet 18 of the motor 8, thereby cooling the components of the motor 8 again. In Figure 2, the flow of the cooling oil is illustrated as a cooling oil path 24.

[0014] The cooling oil path 24 will now be described. Cooling oil discharged from the motor 8 to the oil pan 22 flows to the oil pump 23, and cooling oil pumped from the oil pump 23 is cooled by the oil cooler 7 before flowing into the motor 8 and into the coil end space flow path 19.

[0015] The coil end space flow passage 19 is a circumferentially annular space surrounded by, for example, the second resin member 16 and a housing of the stator 11. The coil end space flow passage 19 is liquid-tight except for the cooling oil inlet 18 and the opening of the second resin member 16.

[0016] The cooling oil flows from the coil end spatial flow passages 19 through the openings of the second resin member 16 into the intra-slot flow passages 17 of the stator 11. The cooling oil that flows into the slots of the stator 11 cools the stator 11 and is then discharged into the chamber of the motor 8 from the openings of the first resin member 15 that is provided on the surface of the stator 11 opposite to the surface on which the second resin member 16 is provided.

[0017] The coil end space flow passage 19 may also be provided on the coil end portion side of the stator 11 that is provided on the cooling oil outlet 21 side. Furthermore, the cooling oil path 24 in the stator 11 may be located outside the in-slot flow passage 17, and may be provided in parallel or series to the in-slot flow passage 17, for example.

[0018] (Figure 3) Figure 3(a) is a diagram showing how the first resin member 15 and the second resin member 16 are inserted into the stator 11 from opposite sides in the direction of the arrows, Figure 3(b) is a diagram showing how the coil 10 is inserted into the stator 11 into which the first resin member 15 and the second resin member 16 have been inserted in the direction of the arrows after the process of Figure 3(a), and Figure 3(c) is a diagram showing how the coil end of the coil 10 inserted into the stator 11 has been bent and the coil 10 has been welded and fixed to the stator 11 after the process of Figure 3(b).

[0019] Each first resin member 15 is inserted into a slot from one end face of the stator core of the stator 11 and positioned within the slot, so that it is positioned between the wall surface of the slot and the coil 10 to be inserted subsequently. The second resin member 16, which connects to the first resin member 15 inserted into the annular stator core having multiple slots, is inserted into the slot from the other end face of the stator core, and its outer periphery is held by a jig. The first resin member 15 and the second resin member 16 are connected to each other at the end faces of the stator core.

[0020] The first resin members 15 are individually formed and inserted into the respective slots of the stator 11, while the second resin member 16 is integrally molded in a circular shape along the end face of the stator core. The second resin member 16 connects to the ends of the first resin members 15 inserted into the respective slots of the stator 11. Cooling oil for cooling the stator 11 flows into the slots of the stator 11 from the second resin member 16 side.

[0021] The coil 10 has a plurality of slot insertion portions that are inserted into slots of the stator 11, and the plurality of slot insertion portions are inserted into different slots. The coil 10 also has coil end portions that protrude outward from the end face of the stator core and connect the plurality of slot insertion portions together.

[0022] This makes it easier to seal the liquid-tight space for pouring cooling oil into the stator 11, and prevents the cooling oil from leaking into the gap between the stator 11 and the rotor 12.

[0023] (FIGS. 4 and 5) The diagram on the left side of FIG. 4 is an explanatory diagram of the coil 10 in the slot on the opening side of the second resin member 16. The diagram on the right side of FIG. 4 shows the state of the coil 10 in the slot on the opening side of the first resin member 15.

[0024] The opening of the first resin member 15 and the opening of the second resin member 16 each have a space forming portion 27 between them and the coil 10 inserted in the slot. This ensures a cooling path space within the slot and allows the cooling oil flowing into the slot to come into direct contact with the coil 10 to cool it, thereby reducing the temperature of the coil 10.

[0025] The openings of the first resin member 15 and the second resin member 16 also have coil fixing portions 28 that fix the coil 10 to the first resin member 15 and the second resin member 16. The coil 10 is configured so that coil insertion portions connected by coil ends are inserted into predetermined slots, transitioning through multiple slots. In this case, the layers into which the pair of coil insertion portions connected by coil ends are inserted are different from each other. For example, in one slot, a coil insertion portion is inserted into the first layer, and the other coil insertion portion connected to this coil insertion portion by a coil end is inserted into the second layer of another slot. Note that the pair of coil insertion portions can rotate in opposite directions within each slot, so the coil 10 has no rotational freedom.

[0026] In the coil insertion portion, the surface that comes into contact with the first resin member 15 and the second resin member 16 is referred to as the transition direction surface 30 ( FIG. 5 ). The space forming portion 27 is formed on the surface of the coil 10 opposite the transition direction surface. The contact of the transition direction surface 30 of the coil 10 with the coil fixing portion 28 reduces the degree of freedom of the coil 10, including radial and circumferential movement, and allows the coil 10 to be fixed by restricting its rotational freedom between the predetermined slots into which the coil 10 is inserted. On the other hand, the coil fixing portion 28 alone has a degree of freedom, so it does not hinder the insertion of the coil 10, improving assembly ease.

[0027] 4, the opening cross sections of the first resin member 15 and the second resin member 16 into which the same coil 10 is inserted are different from each other. This allows the coil fixing portions 28 of the first resin member 15 and the second resin member 16 to restrict the circumferential freedom of the coil 10 and also restrict the rotational freedom of the coil 10 between the inserted slots, thereby improving the fixation of the coil 10.

[0028] 5, the coil fixing portions 28 are provided at different positions in the radial direction of the slot for each layer. In other words, the coil fixing portions 28 are in contact with opposing surfaces of the coils 10 alternately in the circumferential direction for each layer. This contributes to preventing cracking of the first resin member 15 during the bending process associated with fixing the coils 10 inserted into the stator 11.

[0029] (Modification) (FIG. 6) As a modification, the space forming portion 27 may be provided with a protrusion 31 that protrudes toward the coil 10 from the surface of the first resin member 15 that faces the coil 10. Also, the coil fixing portion 28 that contacts the transition direction surface of the coil 10 may be provided with a notch 32 that does not contact a part of the transition direction surface. This promotes turbulence in the refrigerant flowing through the slot, further improving the cooling performance of the coil 10. Note that the protrusion 31 may be provided in any layer of the slot.

[0030] (Fig. 7) The teeth formed between the multiple slots in the stator 11 are parallel teeth 33 whose slot-side surfaces are parallel to each other. This increases the cross-sectional area of ​​the cooling oil path within the slot, thereby improving the cooling performance of the coil 10.

[0031] According to the embodiment of the present invention described above, the following advantageous effects are achieved.

[0032] (1) A rotating electric machine (8) includes a stator including an annular stator core having a plurality of slots formed therein, a coil (10) having a plurality of slot insertion portions inserted into the slots, the plurality of slot insertion portions being inserted into different slots from each other, and insulating members disposed between the slots and the respective slot insertion portions, wherein the coil (10) has coil end portions that protrude outward from an end face of the stator core and connect the plurality of slot insertion portions to each other. The coil (10) has a transition direction surface (30) that contacts the insulating member. The insulating member has a coil fixing portion (28) that contacts the transition direction surface of the coil, and a space forming portion (27) that is a space formed on the surface of the coil opposite the transition direction surface (30). This configuration provides a rotating electric machine (8) that achieves reduced coil temperature through direct cooling of the coil and improved assembly.

[0033] (2) The insulating members include a first insulating member 15 inserted into the slot from one end face of the stator core and a second insulating member 16 inserted into the slot from the other end face of the stator core, and the first insulating member 15 and the second insulating member 16 are connected to each other at the end faces of the stator core. This configuration can prevent refrigerant oil from leaking into the gap.

[0034] (3) The slots have coil fixing portions 28, and the coil fixing portions 28 are provided at different positions in the radial direction of the slots for each layer of the stator 11. This prevents cracking of the first resin member 15 during the bending process of the coil 10.

[0035] (4) The coil fixing portion 28 has a notch 32 that does not contact a part of the transition direction surface 30, and the space forming portion 27 has a protrusion 31 that extends from the insulating member toward the coil 10. This configuration contributes to improving the cooling performance within the slot.

[0036] (5) The teeth formed between the plurality of slots are parallel teeth 33 whose slot-side surfaces are parallel to each other. This contributes to improving the cooling performance within the slots.

[0037] (6) The second insulating member 16 is integrally formed circumferentially along the end face of the stator core, and allows the cooling oil to flow into the slots. This configuration prevents the cooling oil from leaking into the gaps.

[0038] The present invention is not limited to the above-described embodiments, and various modifications and combinations of other configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to those having all of the configurations described in the above-described embodiments, and includes those in which some of the configurations are omitted.

[0039] REFERENCE SIGNS LIST 1 Vehicle body 2 Tire 3 Cooling system of electric drive system 4 Vehicle cooling system 5 Chiller 6 Electric drive system 7 Oil cooler 8 Motor 10 Coil 11 Stator 12 Rotor 13 Shaft 14 Magnet 15 First resin member 16 Second resin member 17 In-slot flow path 18 Cooling oil inlet 19 Coil end space flow path 20 Reducer 21 Cooling oil outlet 22 Oil pan 23 Oil pump 24 Cooling oil path 25 Welding 26 Coil bending 27 Space forming portion 28 Coil fixing portion 30 Transition direction surface 31 Protrusion 32 Notch 33 Parallel teeth

Claims

1. A rotating electric machine having a stator including: an annular stator core in which a plurality of slots are formed; a coil having a plurality of slot insertion portions to be inserted into the slots, the plurality of slot insertion portions being inserted into different slots; and insulating members arranged between the slots and each of the slot insertion portions, wherein the coil has a coil end portion that protrudes outward from an end face of the stator core and connects the plurality of slot insertion portions to each other, the coil has a transition direction surface in contact with the insulating member, and the insulating member has a coil fixing portion in contact with the transition direction surface of the coil, and a space forming portion that is a space formed on the surface side of the coil opposite to the transition direction surface.

2. A rotating electric machine as described in claim 1, wherein the insulating members include a first insulating member inserted into the slot from one end face of the stator core and a second insulating member inserted into the slot from the other end face of the stator core, and the first insulating member and the second insulating member are connected to each other at the end faces of the stator core.

3. A rotating electric machine according to claim 1, wherein the slot has the coil fixing portion, and the coil fixing portion is provided at a different position in the radial direction of the slot for each layer of the stator.

4. A rotating electric machine as claimed in claim 1, wherein the coil fixing portion has a cutout portion that does not contact any part of the transition direction surface, and the space forming portion has a protrusion that extends from the insulating member towards the coil.

5. A rotating electric machine according to claim 1, wherein the teeth formed between the plurality of slots are parallel teeth whose surfaces facing the slots are formed parallel to each other.

6. A rotating electric machine according to claim 2, wherein the second insulating member is integrally formed in a circumferential shape along the end face of the stator core, and allows cooling oil to flow into the slots.

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