Rotating electrical machines and vehicles

Abstract

The present invention aims to provide a highly efficient and reliable rotating electric machine. The rotating electric machine comprises a stator wound with a plurality of coils and a rotor rotatably supported with respect to the stator with a predetermined gap therebetween, wherein the coil has at least one connection portion per turn in a slot of the stator, the connected conductors have steps with each other in the connection portion, and are engaged with other conductors in a manner of mutually filling the steps, the steps have contact surfaces that are in contact with each other and electrically conductive in the slot, and a heat expandable sheet that can pressurize the coil in the radial direction of the stator is arranged in the slot.

Description

Technical Field

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

[0002] For variable speed driven rotating motors installed in railway vehicles, automobiles, construction machinery, etc., the driving speed is constantly increasing in order to achieve miniaturization. This is because the motor output is proportional to the product of torque and speed, so by increasing the speed to reduce torque, an attempt is made to obtain the same output with a small motor. However, as the speed increases, the power supply frequency increases, so the AC copper loss of the stator coil increases, resulting in reduced efficiency and increased heat generation. AC copper loss is the loss caused by the deviation of current distribution in the coil conductor due to the magnetic flux in the cross-slot, and the larger the current, frequency, and conductor cross-sectional area, the greater the increase.

[0003] As background art in this technical field, there are the following prior arts: Patent Document 1 (Japanese Patent Laid-Open No. 11-285217) describes a stator for a vehicle AC generator in which a plurality of conductor segments provided on a stator core form two or more pairs of layers in slots and are arranged in only one row.

[0004] In addition, patent document 2 (Japanese Patent Laid-Open No. 2015-023771) describes a rotating electric machine stator, characterized in that it comprises: a stator core having a plurality of slots; and a stator coil, comprising a conductor segment on one side of a first leg and a second leg inserted into the first and second slots from one axial end side of the stator core, a first conductor segment on the other side of the first leg inserted into the first slot from the other axial end side of the stator core, and a second conductor segment on the other side of the second leg inserted into the second slot from the other axial end side of the stator core, wherein the legs opposite to each other in each slot are joined to each other, and a plurality of conductor segments on one side and conductor segments on the other side are joined in sequence to form.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Laid-Open No. 11-285217

[0008] Patent Document 2: Japanese Patent Application Publication No. 2015-023771 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] In the case of distributed winding stators widely used in automobile drive motors, in order to achieve mass production, a manufacturing method is adopted in which the number of coil turns is reduced to a few turns, and the coils adjacent to each other at the axial ends of the stator are connected by welding (for example, refer to Patent Document 1). In order to reduce the AC copper loss in this structure, it is necessary to take measures such as using multiple sections of flat square wire to form a coil conductor with one turn. However, when the coil conductor becomes multiple sections, the number of welding points at the connection part of the coil end increases, and there is a disadvantage that the manufacturing becomes complicated. In addition, in the method of welding the coil end, in the coil pulling process or welding process when forming the connection part, it is easy to cause damage to the insulation coating or poor welding, and ensuring the reliability of the motor becomes a problem.

[0011] As a prior art for solving this problem, there is a method of forming a fitting structure in the stator slot to join the coil conductor, as described in Patent Document 2. However, in the technology described in Patent Document 2, the compromise between fitting workability and long-term reliability cannot be solved. Specifically, in order to fit the multiple conductors constituting the stator coil, it is hoped that the gap of the fitting part can be increased to facilitate fitting and improve workability. However, if the gap of the fitting part is increased, in addition to the fitting part being easy to fall off after assembly, the deviation of the contact resistance becomes larger, so it is difficult to ensure the reliability of the motor. On the other hand, if the gap of the fitting part is reduced, in addition to the situation that fitting becomes difficult and electrical conduction cannot be ensured, since it is necessary to apply force in the fitting direction during fitting, there is a possibility that the fitting part is deformed and electrical conduction cannot be ensured. In this way, it is difficult to ensure reliability in any case. In addition, even if the tolerance can be managed in a way that it is easy to embed and difficult to pull out, the production management cost required for tolerance management becomes large, so the product price rises.

[0012] An object of the present invention is to provide a highly efficient and highly reliable rotating electrical machine and a vehicle equipped with the rotating electrical machine.

[0013] Technical means of solving problems

[0014] In order to achieve the above-mentioned purpose, the present invention includes various embodiments. For example, in a rotating electric machine having a stator around which a plurality of coils are wound and a rotor supported so as to be rotatable relative to the stator with a predetermined gap therebetween, the coil has at least one connection portion per turn in a slot of the stator, the connected conductors have steps with each other in the connection portions, and are engaged with other conductors in a manner that fills the steps with each other, the steps have contact surfaces that are in contact with each other and electrically conductive in the slots, and a heat-expandable sheet that can pressurize the coil in the radial direction of the stator is arranged in the slots.

[0015] Effects of the Invention

[0016] According to the present invention, a highly efficient and highly reliable rotating electrical machine and a vehicle equipped with the rotating electrical machine can be provided. Other problems, configurations, and effects than those described above will become apparent from the following description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a figure which shows the coil structure in the 1st Example of this invention.

[0018] Figure 2 It is a diagram showing a method of connecting coil conductors in the first embodiment of the present invention.

[0019] Figure 3 It is a cross-sectional view of the coil in the first embodiment of the present invention.

[0020] Figure 4 It is a diagram showing a method of fixing the connection portion of the coil in the first embodiment of the present invention.

[0021] Figure 5 This is an external view of the stator coil in the first embodiment of the present invention.

[0022] Figure 6 It is a diagram showing a coil connection method in the second embodiment of the present invention.

[0023] Figure 7 It is a cross-sectional view of a coil in the third embodiment of the present invention.

[0024] Figure 8 It is a diagram showing a vehicle in a fourth embodiment of the present invention.

[0025] Fig. 9 It is the magnetic flux line diagram of the stator slot cross section when the motor is energized.

[0026] Fig.10 This is a diagram showing the structure of a coil having one turn. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same components are denoted by the same reference numerals. Their names and functions are the same, and repeated descriptions are avoided. In the present invention, the definition of "coil" is set to one turn of a hexagonal winding or one cycle of a wave winding. Therefore, for example, in a configuration in which a coil is wound with 4 turns, it is represented as a coil with 4 turns. In addition, the definition of "a configuration in which a coil has a connection portion inside a stator core" is set to Fig.10 (a) or Fig.10The structure shown in (b). In addition, when a coil of one turn is composed of multiple conductors, unless otherwise specified, the multiple conductors are collectively referred to as coil conductors. In addition, in the following description, rotating motors driven at variable speeds in automobiles, railway vehicles, etc. are exemplified, but the rotating motors to which the present invention is applied are not limited to these, and can be applied to all rotating motors including rotating motors driven at constant speeds. In addition, the rotating motor to which the present invention is applied may be an induction motor, a permanent magnet synchronous motor, a winding type synchronous motor, or a synchronous reluctance rotating motor. In addition, in the following description, an internally-transformed rotating motor is exemplified, but the present invention can also be applied to an externally-transformed rotating motor. In addition, the material of the coil conductor constituting the rotating motor to which the present invention is applied may be copper, aluminum, or other conductive materials.

[0028] <Example 1>

[0029] Below, use Figures 1 to 5 A first embodiment of the present invention will be described. Figure 1 It is a diagram showing the configuration of a coil in the first embodiment of the present invention. Figure 2 It is a diagram showing a method of connecting coil conductors in the first embodiment of the present invention. Figure 3 It is a cross-sectional view of the coil in the first embodiment of the present invention. Figure 4 It is a diagram showing a method of fixing the connection portion of the coil in the first embodiment of the present invention. Figure 5 This is an external view of the stator coil in the first embodiment of the present invention.

[0030] use Figure 1 and Figure 2 The overall structure of the stator coil of this embodiment is described. Figure 1 In the embodiment, the stator 101 has an inward-turning rotor (not shown), which is supported on the radial inner side so as to be rotatable in the circumferential direction via a gap. The stator 101 has a plurality of slots in the circumferential direction, and coil conductors are inserted into the slots. In order to ensure insulation between the coils, the coil conductors are coated with an insulating film such as epoxy resin. Figure 1 1 slot of the stator 101 and four turns of coils 201, 211, 221, 231 inserted into the slot are shown. For example, in the case of automobile drive motors, in order to facilitate mass production, one conductor is often used to form a coil with one turn. However, since the AC copper loss increases during high-speed rotation, it is known that a method of using multiple sections of flat square wires to form a coil with one turn can reduce the AC copper loss. Fig. 9 The configuration for reducing AC copper loss in the above configuration will be described.

[0031] Fig. 9 It is the magnetic flux line diagram of the stator slot cross section when the motor is powered. Figure 1 Similarly, four turns of coils 201 , 211 , 221 , and 231 are inserted into one slot. Fig. 9(a) shows a case where a coil with one turn is formed by one conductor. Fig. 9 (b) shows a case where two flat conductors form a coil of one turn. When current is passed through the conductors, a magnetic flux φ (in Fig. 9 6 in the example above). Due to the influence of the magnetic resistance distribution of the slot, the closer to the slot opening (i.e., the gap between the stator 101 and the rotor), the denser the magnetic flux lines. If the current flowing through the coil of one turn is equal, the distribution of the magnetic flux lines is similar to Fig. 9 (a) and (b) are the same. Since the current flowing through the coil undergoes an alternating change when the motor is driven, the magnetic flux φ also undergoes an alternating change. According to the law of electromagnetic induction, an electromotive force U and an eddy current I in the conductor are generated in the direction that cancels out the change Δφ of the magnetic flux every tiny time Δt, thereby generating an AC copper loss Pac. The resistance of the path through which the eddy current I flows in the conductor is usually called the AC resistance Rac. The following relationship holds for each physical quantity (~ is a symbol indicating a ratio).

[0032] U~-Δφ / Δt

[0033] I~U / Rac

[0034] Pac~Rac×(I squared)

[0035] Therefore, Pac can be expressed as follows.

[0036] Pac~(square of Δφ) / Rac

[0037] Now, if we set Fig. 9 If the AC copper loss generated in coil 201 of (a) is 1 pu, then the AC copper loss of coil 211 is also 1 pu. The number of magnetic fluxes φ passing through coil 221 is twice that of coil 201, that is, 2 fluxes. The AC copper loss is proportional to the square, so it is 4 pu. Similarly, the AC copper loss of coil 231 is also 4 pu, and the total AC copper loss of the four coils is 10 pu. On the other hand, if Fig. 9 As shown in (b), if two conductors are used to form each coil, the magnetic flux passing through each conductor becomes half, and the conductor cross-sectional area becomes 1 / 2, so the resistance Rac of the path through which the eddy current flows in the conductor becomes 2 times. Therefore, the AC copper loss generated on the two conductors of coil 201 is 1 / 8 pu respectively, and the total is 1 / 4 pu. Similarly, the AC copper loss of coil 211 is 1 / 4 pu, the AC copper loss of coil 221 is 1 pu, and the AC copper loss of coil 231 is 1 pu. The total AC copper loss of the four coils is 2.5 pu. Fig. 9 The AC copper loss of (b) is Fig. 9 The size of (a) is 1 / 4 of that of (a). Thus, by forming the structure with a flat conductor, the AC copper loss can be greatly reduced.

[0038] From the above, we can see that Figure 1 In order to reduce the AC copper loss, two conductors are used to form a coil with one turn. However, in the prior art, when such a structure is adopted, there is a disadvantage that the number of welding points at the connection part of the coil end increases, and the production of the coil becomes complicated. In addition, as another method, there is a method of forming a chimeric structure in the stator slot and joining the coil conductor in this part, but there is a disadvantage that it cannot solve the compromise between chimeric workability and long-term reliability. The present invention is used to solve these problems. Figure 2 Explain its specific solution and principle.

[0039] Figure 2 is focused on Figure 1 An enlarged view of the connection of the one-turn coils 201 and 202 is shown. Figure 2 (b) and Figure 1 Indicates the state where the coils are connected identically.

[0040] like Figure 2 As shown in (a), the one-turn coils 201 and 202 are divided into upper and lower parts in the axial center, and the upper part is composed of a flat conductor 201a and a conductor 201b, and similarly, the lower part is composed of a flat conductor 202a and a conductor 202b. The conductor 202 is covered with a heat-expandable sheet 401, and is pre-set in a stator slot in a state where the conductor 202 and the heat-expandable sheet 401 are combined, and the conductor 201 is inserted into the slot from above. The conductor 201 in the upper part and the conductor 202 in the lower part are configured in a manner having an L-shaped step shape that can contact each other on the side, as shown in FIG. Figure 2 As shown in (b), the conductors 201 and 202 are fitted in the groove in a manner of step combination. In addition, the connecting portion of the conductor 201 and the conductor 202 is subjected to a conductive surface treatment (for example, covered with a conductive plating layer), as shown in FIG. Figure 2 As shown in (b), the conductive plated portion 301a of the conductor 201a is opposite to the conductive plated portion 301b of the conductor 201b, and is opposite to the conductive plated portion 302a of the conductor 202a. Moreover, the conductive plated portion 302a of the conductor 202a is also opposite to the conductive plated portion 302b of the conductor 202b. The conductive surface treatment of the connecting portion between the conductors may not be conductive plating, but may use nanoparticle bonding or conductive paste.

[0041] In this state, if the stator coil is overheated, the heat-expandable sheet 401 expands. Figure 2As shown in (c), a force is generated to make the conductive plated portions of the conductor 201a and the conductor 201b closely contact each other, and similarly, the conductive plated portions of the conductor 201a and the conductor 202a closely contact each other, and the conductive plated portions of the conductor 202a and the conductor 202b closely contact each other. As a result, the conductive plated portions are in contact with each other in the radial direction, and the electrical conduction of the conductors 201a, 201b, 202a, and 202b formed separately is ensured.

[0042] According to this method, in the stage of inserting the coil into the stator slot, since it is before the expansion of the heating expansion sheet, the interlocking gap between the coils can be fully ensured, and the coil insertion operation can be carried out extremely easily. In addition, since it is only necessary to implement conductive plating treatment on the connecting portion, high-precision tolerance management is not required, and the production cost can be suppressed. In addition, since subsequent processes such as stretching, bending or welding after the coil is inserted are not required, and force does not need to be applied in the interlocking direction, the coil will not be deformed, which can improve the product reliability. In addition, through the expansion pressure of the heat-expandable sheet, the conductors constituting the coil are pressurized to each other, so that they are pressed, and the surface contact of the connecting portion is stably maintained. Therefore, even for long-term electromagnetic vibration, the displacement and falling off of the connecting portion can be suppressed, and high reliability can be ensured.

[0043] In addition, in the illustrated embodiment, the coils 201, 202, etc. are covered with the heat expandable sheet 401, but the heat expandable sheet 401 may not cover the entire circumference of the coils 201, 202 as long as the heat expandable sheet 401 is set at a position where the conductive plated portions of the conductors constituting the coils are pressed against each other.

[0044] The heat-expandable sheet is obtained, for example, by mixing an expandable filler such as liquefied carbon dioxide into a resin that develops adhesive properties when heated, such as an epoxy resin, and forming the sheet. The sheet may be in any form as long as it is configured to apply expansion pressure to each coil turn, and is not limited to Figure 2 The form of Figure 3 As shown in (a), a bobbin 499 having the same shape as the slot may be provided, and a partition plate may be provided for each coil. Figure 3 In (a), the heat expandable sheet 401 and the like are provided inside each space of the bobbin 499, but the bobbin 499 may be formed of a heat expandable sheet.

[0045] In addition, since it is possible to achieve Figure 2The state of (b) is sufficient, so it is not limited to the above connection sequence. For example, it can also be a sequence of inserting the conductor 201 and the conductor 202 separately in a state where the heat-expandable sheet 401 is set in the stator slot in advance. When the above-mentioned winding tube 499 is used, by adopting this step, the insertion operation can be simplified. In addition, in the early stage of the connection operation, the conductor 201a and the conductor 201b can be fixed at at least one position using an adhesive to form an integral structure, which can simplify the insertion operation.

[0046] As a method for making a conductive plated portion, although the process of stripping the insulating film of the conductor and performing electroplating is simple, it is not limited to this process as long as the electrical conduction of the connecting portion and the electrical insulation of the other parts can be ensured. In addition, by making the film thickness of the conductive plated portion greater than the thickness of the insulating film, the conductive surface can be slightly protruded from the side of the conductor, so that the conductive surface can be reliably in surface contact. In addition, it is also possible to perform processing to make the metal constituting the coil protrude slightly from the side of the conductor on the conductive surface (for example, processing to pressurize perpendicularly to the protruding direction).

[0047] The step shape of the connection part of the conductor 201 and the conductor 202 is as follows: Figure 2 As shown, the flat conductors 201a and 201b may be overlapped to form an L-shaped step shape, but even if the conductors 201 and 202 are each formed of one conductor, if the AC copper loss is sufficiently small, the connection portion of the conductors 201 and 202 may be processed into an L-shape to form a conductive surface.

[0048] The structure and principle of a rotating electrical machine capable of reducing AC copper loss and achieving high efficiency and high reliability have been described above through the first embodiment of the present invention.

[0049] for Figure 1 The conductors 211 and 212, the conductors 221 and 222, and the conductors 232 and 231 are also Figure 2 The conductors 201 and 202 shown are constructed in the same combination. Figure 1 As shown, it is preferred that the heat-expandable sheets 401, 411, 421, 431 protrude axially outward from the axial end surface of the stator slot. This is because the edge of the axial end surface of the stator slot rubs against the insulation coating of the coil, which may damage the insulation coating of the coil. In order to protect the insulation coating from friction with the edge, the heat-expandable sheet is effectively used. Figure 1 In order to simplify the description, the coil end is shown as extending linearly in the axial direction, but the coil end is usually folded back in the circumferential direction at the axial end surface to reduce the winding resistance. Therefore, in such a structure, edge protection using a heat expandable sheet is also useful.

[0050] In addition, if dust or moisture is mixed into the connection parts 301, 311, 321, 331 in the stator slots, poor insulation or poor conduction may occur, so it is preferred to seal the axial end surface parts 601, 602 of the slots to fill the gaps between the conductor and the slots and between the conductor and the thermal expansion sheet. By setting such a structure, dust can be suppressed from mixing into the slots, and long-term reliability can be improved.

[0051] here, Figure 1 The conductive plated portions of the connecting portions 301, 311, 321, 331 shown are charged to a voltage equivalent to the motor terminal voltage. The following describes the operation of this portion as an electrode at this time. With respect to the axial direction of the stator 101, sufficient withstand voltage can be ensured by the surface insulation of the heat expandable sheet. With respect to the circumferential surface, since the inner wall of the stator slot (electromagnetic steel sheet) is generally at ground potential, a potential difference is generated, but this can also be ensured by the through-layer insulation of the heat expandable sheet to ensure sufficient withstand voltage. With respect to the radial surface of the conductive plated portion, it is necessary to ensure the surface insulation distance with the inner wall of the stator slot (electromagnetic steel sheet), but as Figure 3 As shown in (b), by providing the overlapping portion 431a of the heat expandable sheet, a sufficient withstand voltage can be ensured.

[0052] Figure 4 This shows a method of fixing the conductors 201 and 202 more firmly. Figure 4 In the embodiment, recesses 501 and 502 are provided on the side surfaces of the conductors 201 and 202 in the stator slots. The recesses 501 and 502 may be provided at a predetermined distance relative to the connection portions 301 and 302, or may be provided at a predetermined distance relative to the end of the heat-expandable sheet. With such a configuration, the heat-expandable sheet sinks into the recesses 501 and 502, thereby suppressing the conductors 201 and 202 from being offset or falling out of the stator slots due to electromagnetic vibration, and suppressing dust from mixing into the connection portions, thereby improving long-term reliability.

[0053] In addition, Figure 4 In the embodiment, the recesses 501 and 502 are provided on the radial side surfaces of the conductor, but recesses may be provided on other side surfaces (for example, the entire periphery of the portion).

[0054] As described above, according to the first embodiment, Figure 5 As shown, the welding portion at the coil end can be eliminated, so the axial length of the motor can be shortened, and further miniaturization can be achieved.

[0055] <Example 2>

[0056] use Figure 6 A second embodiment of the present invention will be described. Figure 6 It is a diagram showing a coil connection method in the second embodiment of the present invention.

[0057] Figure 6 The composition shown is Figure 2 The difference in the structure shown is that the one-turn coils 201 and 202 are divided into upper and lower parts at the axial center, and the upper part is composed of flat conductors 201a, 201b, and 201c, and the lower part is also composed of flat conductors 202a, 202b, and 202c. In this way, by forming a one-turn coil with three conductors in the upper and lower parts, the one-turn coil can be formed with a flatter conductor, so that the AC copper loss can be further reduced, and a high-efficiency rotating electric machine can be obtained.

[0058] <Example 3>

[0059] use Figure 7 A third embodiment of the present invention will be described. Figure 7 It is a cross-sectional view of a coil in the third embodiment of the present invention.

[0060] Figure 7 The composition shown in (a) is Figure 3 The difference between the structures shown is that, regarding the number of conductors n (n is a natural number) constituting one turn of the coil, the number of conductors n0 of the coil farthest from the gap and the number of conductors n3 of the coil closest to the gap are in the relationship of n0<n3. The AC copper loss increases as it approaches the slot opening (the gap between the stator and the rotor). Therefore, Fig. 9 As shown, by increasing the number of conductors of the coil close to the gap and making one conductor flatter, the AC copper loss can be further reduced.

[0061] In addition, Figure 7 In the embodiment shown in (a), the thickness t of the four coils is set to 2t0=2t1=3t2=3t3, but even if it is set to 2t0=2t1<3t2=3t3, the number of conductors can be n0<n3.

[0062] On the other hand, Figure 7 In (b), the number of conductors constituting one turn of the coils in the slots is the same, and the radial thickness t of the conductors is configured such that the radial thickness t0 of the conductor farthest from the gap and the radial thickness t3 of the conductor closest to the gap satisfy t0>t3. In this way, by making the coil conductors close to the gap flatter, the AC copper loss can be further reduced.

[0063] <Example 4>

[0064] use Figure 8 A fourth embodiment of the present invention will be described. Figure 8 It is a diagram showing a vehicle in a fourth embodiment of the present invention.

[0065] The present invention is applicable to Figure 8 The rotating motors 751, 752 in the vehicle 700 are shown. Figure 8 As shown, vehicle 700 is, for example, a hybrid vehicle or a plug-in hybrid vehicle, and is equipped with an engine 760 , rotating electrical machines 751 , 752 , and a battery 780 .

[0066] When driving the rotating electrical machines 751 and 752, the battery 780 supplies DC power to the driving power conversion device (inverter device) 770. The power conversion device 770 converts the DC power from the battery 780 into AC power and supplies it to the rotating electrical machines 751 and 752, respectively.

[0067] During regenerative driving, AC power generated by rotating electric machines 751 and 752 based on the kinetic energy of the vehicle is supplied to power converter 770. Power converter 770 converts the AC power from rotating electric machines 751 and 752 into DC power and supplies the DC power to battery 780.

[0068] The rotation torque generated by the engine 760 and the rotary electric machines 751 , 752 is transmitted to the wheels 710 via the transmission 740 , the differential gear 730 , and the axle 720 .

[0069] Generally, a car requires a wide range of motion performance, such as low speed and high torque when starting on a slope, high speed and low torque on a highway, and medium speed and medium torque on the street. In such a wide range of motion performance, the rotary motors 751 and 752 to which the present invention is applied can operate efficiently. Furthermore, since heat loss is reduced, the safety of the vehicle 700 can be improved and the life can be extended. In addition, the cruising distance of the vehicle 700 can be extended.

[0070] In addition, in an electric vehicle that does not include the engine 760 and is driven only by the power of the rotating electric machine, the same effect can be obtained by applying the rotating electric machine of the present invention.

[0071] Furthermore, in an electric vehicle that does not include a transmission 740 but directly couples the shaft of a rotating electric machine to a wheel 710 , that is, a so-called in-wheel motor, the same effect can be obtained by applying the rotating electric machine of the present invention.

[0072] As described above, according to the embodiment of the present invention, in a rotating electric machine having a stator 101 around which a plurality of coils 201, 211, 221, 231 are wound, and a rotor (not shown) rotatably supported with respect to the stator 101 via a predetermined gap, the coils 201, 202, etc. have at least one connection portion per turn in the slots of the stator 101, the connected conductors 201a, 201b, etc. have steps at the connection portions, and are fitted with other conductors 202a, 202b, etc. in a manner of filling the steps, the steps have contact surfaces (conductive plated portions 301a, etc.) that are in contact with each other in the radial direction in the slots and are electrically conductive, and the heat expandable sheets 401, etc. that can pressurize the coils 201, 202, etc. in the radial direction of the stator 101 are arranged in the slots, so that since the coils 201, 202, etc. are covered by the heat expandable sheets 401, etc., reliable contact of the contact portions can be maintained, fitting workability and long-term reliability can be achieved, and a rotating electric machine with high efficiency and high reliability can be provided.

[0073] In addition, regarding the number n of conductors constituting one turn of the coil, by making the number n3 of conductors of the coil closest to the gap larger than the number n0 of conductors of the coil farthest from the gap, the conductor of the coil closest to the gap is made flat, thereby reducing AC copper loss.

[0074] In addition, regarding the radial thickness t of the conductor, the radial thickness t3 of the conductor closest to the gap is made smaller than the radial thickness t0 of the conductor farthest from the gap, so that the AC copper loss can be reduced.

[0075] Furthermore, since the contact surfaces of the conductors 201a, 201b, etc., which are in contact with each other, are covered with the conductive plated portions 301a, 301b, 302a, 302b, etc., it is possible to suppress poor conduction at the contact surfaces due to deterioration.

[0076] Furthermore, since the side surfaces of the conductors 201a and 201b other than the contact surfaces are covered with the insulating film, insulation between adjacent conductors can be ensured.

[0077] Furthermore, since the contact surface protrudes beyond the portion covered by the insulating film, the contact surfaces can be reliably brought into contact with each other.

[0078] In addition, since the conductors 201a, 201b, 202a, 202b, etc. have recesses 501a, 501b, 502a, 502b in the slots into which the heat-expandable sheets 401, etc. can be sunk, the conductors 201a, 201b, 202a, 202b can be prevented from shifting or falling out of the stator slots due to electromagnetic vibration, and dust can be prevented from mixing into the connecting portions, thereby improving long-term reliability.

[0079] In addition, since the heat-expandable sheet 401 and the like protrude axially outward further than the axial end surfaces 601 and 602 of the slot, damage to the insulating coating of the coil caused by friction between the edge of the axial end surface of the stator slot and the insulating coating of the coil can be suppressed, thereby improving long-term reliability.

[0080] Furthermore, since the thermally expandable sheet 401 or the like fills the gap between the conductor and the slot in the axial end surface portions 601 and 602 of the slot, it is possible to suppress the intrusion of dust into the slot, thereby improving long-term reliability.

[0081] In addition, since the rotating motors 751 and 752 of this embodiment, the battery 780, and the power conversion device 770 that converts the DC power of the battery into AC power and supplies the above-mentioned AC power to the above-mentioned rotating motors are provided, a vehicle equipped with a highly efficient and reliable rotating motor can be provided.

[0082] In addition, the present invention is not limited to the above-mentioned embodiments, and includes various variations and equivalent structures within the purpose of the attached technical solutions. For example, the above-mentioned embodiments are described in detail in order to explain the present invention in an easy-to-understand manner, and the present invention is not limited to the situation where all the structures described must be present. In addition, a part of the structure of a certain embodiment can be replaced with the structure of other embodiments. In addition, the structure of other embodiments can be added to the structure of a certain embodiment. In addition, for a part of the structure of each embodiment, other structures can be added, deleted, or replaced.

[0083] Explanation of symbols

[0084] 1: Vehicle

[0085] 101: Stator

[0086] 201, 202, 211, 212, 221, 222, 231, 232: Coil conductors

[0087] 301, 302, 311, 312, 321, 322, 331, 332: connection part

[0088] 401, 411, 421, 431: Thermal expansion sheet

[0089] 501, 502: concave part

[0090] 601, 602: Axial end surface of the groove

[0091] 700: Vehicles

[0092] 710: Wheels

[0093] 720: Axle

[0094] 730: Differential gear

[0095] 740: Transmission

[0096] 751, 752: Rotating electrical machines

[0097] 760: Engine

[0098] 770: Power conversion device

[0099] 780: Battery.

Claims

1. A rotating electric machine comprising a stator around which a plurality of coils are wound and a rotor rotatably supported with respect to the stator via a predetermined gap, wherein: Each turn of the coil is composed of two conductors, and each turn of the coil has at least one connection portion in a slot of the stator. The two conductors have L-shaped steps formed by being staggered in the axial direction of the slot at the connection portion, and are fitted with other conductors in a manner that the L-shaped steps are filled with each other. The L-shaped step has a contact surface that contacts and electrically conducts with the other conductor in the radial direction of the stator in the slot. The coil covering one turn is arranged in the slot, and a heat expandable sheet capable of pressurizing the coil in the radial direction of the stator is provided. The conductor is provided with a recessed portion in the groove at a predetermined distance from the connecting portion, into which the thermally expandable sheet can be sunk.

2. The rotating electrical machine according to claim 1, characterized in that: Regarding the number of conductors constituting one turn of the coil, the number of conductors of the coil closest to the gap is greater than the number of conductors of the coil farthest from the gap.

3. The rotating electrical machine according to claim 1, characterized in that: Regarding the thickness of the conductors in the radial direction of the stator, the thickness of the conductor closest to the gap is smaller than the thickness of the conductor farthest from the gap.

4. The rotating electrical machine according to claim 1, characterized in that: In the connection portion, contact surfaces where the conductors contact each other are covered with a conductive plating layer.

5. The rotating electrical machine according to claim 1, characterized in that: The side surfaces of the conductor other than the contact surface are covered with an insulating film.

6. The rotating electrical machine according to claim 5, characterized in that The contact surface protrudes beyond a portion covered by the insulating film.

7. The rotating electrical machine according to claim 1, characterized in that The thermally expandable sheet protrudes outward from the axial end surface of the groove.

8. The rotating electrical machine according to claim 1, characterized in that The thermally expandable sheet fills a gap between the conductor and the slot at an axial end surface of the slot.

9. A vehicle, characterized in that: include: The rotating electrical machine according to any one of claims 1 to 8; Battery; as well as A power conversion device converts the DC power of the battery into AC power and supplies the AC power to the rotating electric machine.

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