JP2014100040A - Stator of rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stator, of a rotary electric machine, that has favorable insulating properties.SOLUTION: A stator includes: a stator core having a plurality of slots; and stator coils that are provided in the respective slots. Each slot is provided with N segment conductors 28 (N is a positive even number). The stator coils are formed by connecting the segment conductors 28 together through welds provided at respective conductor ends 28E of the segment conductors 28. At a first axial coil end 62, the conductor ends 28E are arranged annularly in a circumferential direction so as to form N annular lines. At the first axial coil end 62, an insulating member is annularly interposed between at least a pair of annular lines. The stator coils are wholly and approximately uniformly covered only with resin 601 that contains 5 to 40 wt.% of inorganic filler with an average particle diameter of 3 to 7 μm.

Description

  The present invention relates to a stator for a rotating electrical machine.

  In response to the recent global warming, rotating electrical machines are required to have a small size and high output. As such a rotating electrical machine, for example, it has a stator core having a large number of slots that are open on the inner peripheral side, and a plurality of substantially U-shaped segment conductors are inserted into each slot to improve the space factor. In order to increase the output by improving the cooling performance, it is known.

  Then, in order to improve the insulation performance, the first resin member is thinly attached to the second coil end group in which a plurality of joint portions formed by joining the first coil end group in which the turn portion is formed and the tip portion are disposed. In addition, there is a vehicle alternator stator in which the second resin member is thickly attached only in the vicinity of the joint portion of the second coil end group (see, for example, Patent Document 1).

  There is also an electric device that defines the material of the second resin member used for the joint (see, for example, Patent Document 2).

Japanese Patent No. 3770263 JP 2012-90433 A

  In the technique of Patent Document 1, it is necessary to use two types of resin members, and the second resin member is thickly attached only in the vicinity of the joint portion of the second coil end group. In the insulation design, the thickness of the resin member at the coil end may be substantially uniform, and there is no necessity to increase the thickness only in the vicinity of the joint. By using two types of resin members, a double production facility is required for adhesion and drying of the resin members, and more material is required than the resin members required for dielectric strength by increasing the thickness of only the joints. There was a problem.

  The technology of Patent Document 2 is an alternative to the second resin member (powder epoxy varnish) used in Patent Document 1 and the like, and dust is prevented by using a liquid resin at the joint. . However, the above-mentioned problem remains because it is intended only for the joint portion and uses two types of resin members.

  In order to solve the above problems, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above-described problems. For example, the present application includes a stator core provided with a plurality of slots and a stator coil provided in the slots. N slot conductors (where N is a positive even number) are provided in the slot, and the stator coil is connected to a plurality of the segment conductors via welds provided at the conductor ends of the segment conductors. Are connected, and the conductor end portions are annularly arranged in the circumferential direction at one coil end in the axial direction, constitute an N-row annular row, and at least a pair of the coil ends at the one axial coil end. In a stator of a rotating electrical machine in which an insulating member is interposed between annular rings, the entire stator coil is almost uniformly covered only with a resin containing 5 to 40 wt% of inorganic filler having an average particle diameter of 3 to 7 μm. And said that you are.

  ADVANTAGE OF THE INVENTION According to this invention, the stator of the rotary electric machine excellent in insulation can be provided. Problems, configurations, and effects other than those described above will become apparent from the description of the following examples.

Sectional drawing which shows the whole structure of the rotary electric machine apparatus containing the stator by the Example of this invention. The perspective view which shows the structure of the stator to which this invention is applied. It is a figure explaining the segment conductor of a stator coil, (a) is a figure which shows one segment conductor, (b) is a figure explaining the coil formation by a segment conductor, (c) is arrangement | positioning of the segment conductor in a slot FIG. The perspective view which shows the stator coil of a U phase. The cross-sectional perspective view which shows the welding side coil end part of the stator coil in the rotary electric machine before varnish application | coating. The cross-sectional perspective view which shows the non-welding side coil end part of the stator coil in the rotary electric machine before varnish application. The top view of the welding side coil end part of a stator coil. The top view of the non-welding side coil end part of a stator coil. The block diagram which shows the structure of the vehicle carrying the rotary electric machine by this invention.

Embodiments of the present invention will be described below with reference to the drawings.
In the following description, an electric motor used in a hybrid vehicle is used as an example of a rotating electric machine. In the following description, “axial direction” refers to a direction along the rotation axis of the rotating electrical machine. The circumferential direction refers to the direction along the rotational direction of the rotating electrical machine. The “radial direction” refers to a radial direction (radial direction) when the rotational axis of the rotating electrical machine is the center. “Inner circumference side” refers to the radially inner side (inner diameter side), and “outer circumference side” refers to the opposite direction, that is, the radially outer side (outer diameter side).

  FIG. 1 is a cross-sectional view showing a rotating electrical machine including a stator according to the present invention. The rotating electrical machine 10 includes a housing 50, a stator 20, a stator core 21, a stator coil 60, and a rotor 11.

  The stator 20 is fixed to the inner peripheral side of the housing 50. The rotor 11 is rotatably supported on the inner peripheral side of the stator 20. The housing 50 constitutes an outer casing of an electric motor that is formed into a cylindrical shape by cutting an iron-based material such as carbon steel, casting of cast steel or aluminum alloy, or pressing. The housing 50 is also referred to as a frame or a frame.

  A liquid cooling jacket 130 is fixed to the outer peripheral side of the housing 50. The inner peripheral wall of the liquid cooling jacket 130 and the outer peripheral wall of the housing 50 constitute a refrigerant passage 153 for a liquid refrigerant RF such as oil, and the refrigerant passage 153 is formed so as not to leak. The liquid cooling jacket 130 houses the bearings 144 and 145 and is also called a bearing bracket.

  In the case of direct liquid cooling, the refrigerant RF passes through the refrigerant passage 153 and flows out from the refrigerant outlets 154 and 155 toward the stator 20 to cool the stator 20.

  The stator 20 includes a stator core 21 and a stator coil 60. The stator core 21 is made by laminating thin sheets of silicon steel plates. The stator coil 60 is wound around a plurality of slots 15 provided in the inner peripheral portion of the stator core 21. Heat generated from the stator coil 60 is transferred to the liquid cooling jacket 130 via the stator core 21 and is radiated by the refrigerant RF flowing through the liquid cooling jacket 130.

  The rotor 11 includes a rotor iron core 12 and a rotating shaft 13. The rotor core 12 is made by laminating thin sheets of silicon steel plates. The rotating shaft 13 is fixed to the center of the rotor core 12. The rotating shaft 13 is rotatably held by bearings 144 and 145 attached to the liquid cooling jacket 130 and rotates at a predetermined position in the stator 20 at a position facing the stator 20. The rotor 11 is provided with a permanent magnet 18 and an end ring (not shown).

  In assembling the rotating electrical machine, the stator 20 is inserted into the housing 50 in advance and attached to the inner peripheral wall of the housing 50, and then the rotor 11 is inserted into the stator 20. Next, the rotating shaft 13 is assembled to the liquid cooling jacket 130 so that the bearings 144 and 145 are fitted.

  A detailed configuration of the main part of the stator 20 used in the rotating electrical machine 10 according to the present embodiment will be described with reference to FIG. The stator 20 includes a stator core 21 and a stator coil 60 wound around a plurality of slots 15 provided on the inner peripheral portion of the stator core. The stator coil 60 uses a conductor (copper wire in this embodiment) having a substantially rectangular cross section to improve the space factor in the slot, thereby improving the efficiency of the rotating electrical machine.

  The stator core 21 is formed with, for example, 72 slots 15 that open to the inner diameter side in the circumferential direction. A slot liner 302 is disposed in each slot 15 to ensure electrical insulation between the stator core 21 and the stator coil 60.

  The slot liner 302 is formed in a B shape or an S shape so as to wrap a copper wire.

  The winding method of the stator coil 60 will be briefly described with reference to FIG. A copper wire insulated by enamel or the like having a substantially rectangular cross section is formed into a substantially U-shaped segment conductor 28 having the anti-welding side coil end apex 28C as a turning point as shown in FIG. . At this time, the non-welding side coil end apex 28 </ b> C may be any shape that wraps around the conductor in a substantially U shape. That is, the shape is not limited to a shape in which the anti-welding side coil end apex 28C and the anti-welding side anti-welding side coil end conductor skew portion 28F form a substantially triangular shape when viewed from the radial direction as shown in FIG. For example, in a part of the anti-welding side coil end apex 28C, the conductor is substantially parallel to the end face of the stator core 21 (when viewed from the radial direction, the anti-welding side coil end apex 28C and the anti-welding side coil end The conductor slant portion 28F may have a substantially trapezoidal shape).

  The segment conductor 28 is inserted into the status lot from the axial direction. Connection is made as shown in FIG. 3B at another segment conductor 28 inserted at a predetermined slot away from the conductor end 28E (for example, by welding). At this time, the segment conductor 28 is formed with a conductor straight line portion 28S that is a portion inserted into the slot and a conductor skew portion 28D that is a portion inclined toward the conductor end portion 28E of the segment conductor to be connected. The 2, 4, 6... (Multiple of 2) segment conductors are inserted into the slots. FIG. 3C shows an example in which four segment conductors are inserted in one slot. However, since the cross section is a substantially rectangular conductor, the space factor in the slot can be improved, and the efficiency of the rotating electrical machine can be improved. improves.

  FIG. 4 is a diagram when the coil 40 for one phase (for example, U phase) is formed by repeating the connection operation of FIG. The coil 40 for one phase is configured such that the conductor end 28E gathers in one axial direction, and forms a welding side coil end 62 and an anti-welding side coil end 61 where the conductor end 28E gathers. In the coil 40 for one phase, a terminal for each phase (U-phase terminal 42U in the example of FIG. 4) is formed at one end, and a neutral wire 41 is formed at the other end.

  The detailed configuration of the welded portion (welding side coil end 62) of the stator 20 used in the rotating electrical machine 10 will be described with reference to FIG. The stator 20 includes a stator core 21 and a stator coil 60 wound around a plurality of slots 15 provided on the inner peripheral portion of the stator core. The stator coil 60 uses a coil having a substantially rectangular cross section, improves the space factor in the slot, and improves the efficiency of the rotating electrical machine. Insulating paper 300 is annularly arranged for insulation between the coils. Insulating paper 301 is annularly arranged for insulation between the welds.

  After the insulating paper is disposed, the entire stator coil is almost uniformly covered only with the epoxy resin 601 containing 5 to 40 wt% of inorganic filler (for example, calcium carbonate) having an average particle diameter of 3 to 7 μm.

  The detailed structure of the anti-welding part (anti-welding side coil end 61) of the stator 20 will be described with reference to FIG. The stator 20 includes a stator core 21 and a stator coil 60 wound around a plurality of slots 15 provided on the inner peripheral portion of the stator core. The stator coil 60 uses a coil having a substantially rectangular cross section, thereby improving the space factor in the slot and improving the efficiency of the rotating electrical machine. Insulating paper 301 is annularly arranged for insulation between the coils.

  Similarly to the welding side coil end 62, the anti-welding side coil end 61 is covered with the epoxy resin 601 only substantially uniformly after the insulating paper is disposed. Here, the epoxy resin 601 is the same material (epoxy resin containing 5 to 40 wt% of inorganic filler (for example, calcium carbonate) having an average particle diameter of 3 to 7 μm) that covers the welding side coil end 62.

  FIG. 7 is an enlarged view of the vicinity of the conductor end 28 </ b> E of the welding side coil end 62. The segment conductor 28 is an exposed conductor in which the insulating coating 29A (the portion shown by shading in FIG. 7) covered with an insulating coating such as an enamel coating and the conductive coating (copper wire) are exposed by peeling off the insulating coating. Part 29B. The conductor exposed portion 29B is provided at the conductor end portion 28E. This conductor portion is exposed for welding. Further, the entire segment conductor 28 including the insulating coating portion 29A and the conductor exposed portion 29B is almost uniformly covered only with an epoxy resin 601 containing 5 to 40 wt% of an inorganic filler (for example, calcium carbonate) of 3 to 7 μm. Yes. Since the second resin member used in the prior art is not used and the thickness is uniform, a double production facility is not required for adhesion and drying of the resin member, and the resin member necessary for insulation withstand voltage There is an effect that the above materials are unnecessary. Furthermore, by providing the annular insulating paper 300, 301 shown in FIG. 5, it is possible to take countermeasures when voids or the like are generated in the epoxy resin 601 and insulation failure occurs.

  FIG. 8 is an enlarged view of the vicinity of the anti-welding side coil end apex 28 </ b> C of the anti-welding side coil end 61. In the non-welding side coil end 61, an insulation coating portion 29 </ b> A is formed over the entire circumference of the segment conductor 28. Further, the segment conductor 28 is almost uniformly covered only with the epoxy resin 601 containing 5 to 40 wt% of inorganic filler (for example, calcium carbonate) having an average particle diameter of 3 to 7 μm so as to cover the insulating coating portion 29A. Since the second resin member used in the prior art is not used and the thickness is uniform, a double production facility is not required for adhesion and drying of the resin member, and the resin member necessary for insulation withstand voltage There is an effect that the above materials are unnecessary. Furthermore, by providing the annular insulating paper 301 shown in FIG. 6, it is possible to take a countermeasure when a void or the like is generated in the epoxy resin 601 and an insulation failure occurs.

  With this configuration, the entire stator coil is almost uniformly covered only with an epoxy resin 601 containing 5 to 40 wt% of an inorganic filler (for example, calcium carbonate) having an average particle diameter of 3 to 7 μm. It is possible to obtain a rotating electric machine that is covered by the second resin member and that satisfies the insulating properties required for an electric vehicle or a hybrid electric vehicle by arranging the annular insulating resins 300 and 301 for reinforcing the insulation. Become.

  In the above, the resin used for forming the insulating film is an epoxy resin from the viewpoint of heat resistance. As the epoxy resin, both a solvent type in which the resin is diluted with a solvent and a solventless type in which the resin is not diluted with a solvent can be used. More preferred.

  Solvent-free epoxy resins are not particularly limited, such as acid anhydride-cured epoxy resins, dicyandiamide-cured epoxy resins, and single-cured epoxy resins with a catalyst such as imidazole. From an easy point, an acid anhydride curable epoxy resin is more preferable.

  Examples of the solvent-free acid anhydride cured epoxy resin include KE-573D manufactured by Hitachi Chemical Co., Ltd., TVB2643 manufactured by Kyocera Chemical Co., Ltd., K-8841 manufactured by Somaar Co., Ltd., and E-530. It is not limited to.

  The inorganic filler to be added is not particularly limited, such as silicon oxide, aluminum oxide, aluminum hydroxide, talc, and calcium carbonate. However, calcium carbonate is preferable because it is inexpensive. The inorganic filler is preferably surface-treated with a carboxylic acid, a silane coupling agent or the like from the viewpoint of improving the wettability with respect to the resin.

  The average particle size of the inorganic filler is preferably 3 to 7 μm because it is easily available, easily obtains a viscosity preferable for forming an insulating coating, and inexpensive.

  Examples of calcium carbonate as an inorganic filler include Shiroishi Calcium Co., Ltd. Whiteon (registered trademark) B, Takehara Chemical Industry Co., Ltd. Sunlite SL-100, White Seal WS-K, etc. It is not limited. The addition amount of the inorganic filler is preferably 5 to 40 wt% from the viewpoint of being thin and uniform covering the whole, but when a further preferable value was searched for, it was found to be 20 to 35 wt%.

  Although the epoxy resin 601 is desirably covered almost uniformly, the boundary surface with the insulating paper 300 and 301 and the complicated shape portion of the coil may adhere unevenly. The term “substantially uniform” as used herein means that the thickness is not intentionally increased as in the prior art (for example, Patent Document 1).

  Further, “only” in the description that it is almost uniformly covered only by the epoxy resin 601 does not exclude the presence of an insulating coating formed on a conductor in advance, such as an enamel coating. The term “only” used here means that the insulating resin applied for reinforcing the insulation after the segment conductor 28 is molded is only the epoxy resin 601 and does not use the second resin member in the prior art. ing.

  In the above, a permanent magnet type rotating electrical machine has been described, but since the feature of the present invention relates to the coil insulation of the stator, the rotor is not a permanent magnet type, but an induction type, synchronous reluctance, It can be applied to a claw magnetic pole type. In addition, the winding method is a wave winding method, but any winding method having similar characteristics can be applied. Next, the explanation is made with the inner rotation type, but the same applies to the outer rotation type.

  The configuration of the vehicle on which the rotating electrical machine 10 according to this embodiment is mounted will be described with reference to FIG. FIG. 9 is a powertrain of a hybrid vehicle on the premise of four-wheel drive. An engine and a rotating electrical machine 10 are provided as main power on the front wheel side. The power generated by the engine and the rotating electrical machine 10 is shifted by the transmission and transmitted to the front wheel drive wheels. In driving the rear wheel, the rotating electrical machine 10 disposed on the rear wheel side and the rear wheel side driving wheel are mechanically connected to transmit power.

  The rotating electrical machine 10 starts the engine and switches between generation of driving force and generation of electric power for recovering energy at the time of vehicle deceleration as electric energy according to the running state of the vehicle. The driving and power generation operation of the rotating electrical machine 10 are controlled by the power converter so that the torque and the rotational speed are optimized in accordance with the driving situation of the vehicle. Electric power necessary for driving the rotating electrical machine 10 is supplied from the battery via the power converter. Further, when the rotating electrical machine 10 is in a power generation operation, the battery is charged with electrical energy via the power conversion device.

  Here, the rotating electrical machine 10 that is the power source on the front wheel side is disposed between the engine and the transmission, and has the configuration described with reference to FIGS. As the rotating electrical machine 10 that is a driving force source on the rear wheel side, the same one can be used, or a rotating electrical machine having another general configuration can be used. Of course, the present invention can also be applied to a hybrid system other than the four-wheel drive system.

  As described above, according to the present invention, it is possible to provide a stator for a rotating electrical machine that is excellent in cooling performance despite its small size and high output.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. In addition, it is possible to add, delete, and replace other configurations for a part of the configuration of the embodiment.

DESCRIPTION OF SYMBOLS 10 Rotating electrical machine 11 Rotor 12 Rotor core 13 Rotating shaft 15 Slot 18 Permanent magnet 20 Stator 21 Stator iron core 28A Segment conductor 28B Segment conductor 28C Anti-welding side coil end vertex 28D Conductor skew part 28E Conductor end part 28F Conductor skew Row portion 28S Conductor linear portion 50 Housing 60 Stator coil 61 Anti-welding side coil end 62 Welding side coil end 130 Liquid cooling jacket 144 Bearing 145 Bearing 150 Refrigerant (oil) storage space 153 Refrigerant passage 154 Refrigerant outlet 155 Refrigerant outlet 300 Annular insulation Paper 301 Annular insulating paper 302 Slot liner 400 Coolant passage 401 Coolant pool 601 Resin member RF refrigerant

Claims (3)

A stator core provided with a plurality of slots;
A stator coil provided in the slot,
Each of the slots is provided with N (where N is a positive even number) segment conductors;
The stator coil is configured by connecting a plurality of the segment conductors via a welded portion provided at a conductor end of each segment conductor,
The conductor end portions are annularly arranged in the circumferential direction at one coil end in the axial direction, and constitute an N-row annular row,
In the stator of the rotating electrical machine in which an insulating member is annularly interposed between at least a pair of the annular rows at one coil end in the axial direction,
The stator of a rotating electrical machine, wherein the entire stator coil is substantially uniformly covered only with a resin containing 5 to 40 wt% of an inorganic filler having an average particle diameter of 3 to 7 µm. The stator of the rotating electrical machine according to claim 1,
The stator of a rotating electrical machine, wherein the resin contains 20 to 35 wt% of the inorganic filler.   The rotary electric machine provided with the stator of the rotary electric machine of Claim 1 or 2.