JP2014057462A - Stator of rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stator of a rotary electric machine which decreases an eddy current loss while maintaining processability of a winding and improving a space factor of a coil winding within a slot.SOLUTION: A stator 10 of a rotary electric machine comprises: a plurality of slots 18 which are arranged in a circumferential direction of a stator core 12; and a coil body 20 which is formed by winding a coil 22 and the like consisting of one conductor disposed in the circumferential direction of a slot 18 in the radial direction of the slot 18 multiple turns. The coil body 20 includes: a square conductor part 40 in the slot 18; a magnetic material layer 42 arranged around the square conductor part 40; and an insulation coat 44 arranged around the magnetic material layer 42. The coil body 20 includes coils 22, 24, 26, and 28 including the square conductor part 40 and the insulation coat 44 arranged around the square conductor part 40, at coil ends 30 and 32 protruding into both endpoints of the slot 18.

Description

  The present invention relates to a stator of a rotating electric machine, and more particularly to a stator of a rotating electric machine in which a coil winding is wound in a slot.

  In order to reduce the size and increase the performance of a rotating electrical machine, it is necessary to increase the efficiency of coil winding and reduce losses such as copper loss and iron loss. In Patent Document 1, as a stator winding of a rotating electrical machine, a rectangular wire having a concave portion and a convex portion is used, and adjacent rectangular wire coils are arranged in a slot so that the concave portion and the convex portion are fitted to each other, It is disclosed to improve the space factor in the slot of the coil.

  Patent Document 2 describes that as a wire used for a coil of an electromagnet, an attractive force as an electromagnet is increased by providing a magnetic layer on a surface layer of a conductor. In the embodiment in which this wire is used as a winding of a distributed winding coil of a stator of a rotating electric machine, a plurality of wires having a circular cross section are accommodated in one slot.

  Patent Document 3 discloses that the thickness of the insulating layer or the insulating material coated on the flat coil conductor is different between the coil end portion and the slot portion in order to reduce the size of the rotating electrical machine. In addition, a conductive polymer layer or a layer of epoxy resin mixed with a conductive or semiconductive filler is provided on the surface of the coil conductor or the insulating layer as an electric field relaxation layer for reducing the steep surge voltage of the inverter. It is also stated.

JP 2009-232607 A JP 2011-210638 A JP 2008-236924 A

  Although the space factor is improved by using a rectangular wire having a concave portion and a convex portion, the resistance value of the conductor is lowered and current flows easily, so that eddy current loss due to leakage magnetic flux may increase. Although the eddy current loss can be reduced by providing the magnetic layer on the surface layer of the conductor, the space factor is reduced by the thickness of the magnetic layer, and the miniaturization is also impaired. Further, the bending workability of the winding is reduced by the presence of the magnetic layer. An object of the present invention is to provide a stator of a rotating electrical machine that can reduce eddy current loss while improving the space factor of the coil winding in the slot while maintaining the workability of the winding. is there.

  The stator of the rotating electric machine according to the present invention includes a plurality of slots arranged along the circumferential direction of the stator core, and a coil arranged with one conductor in the circumferential direction in the slot. A coil body formed by winding, and the coil body includes a flat rectangular conductor portion, a magnetic layer provided around the flat rectangular conductor portion, and an insulating coating provided around the magnetic layer in the slot. And a coil end projecting from both ends of the slot, and including a coil having a flat conductor portion and an insulating film provided around the flat conductor portion.

  With the above configuration, the leakage magnetic flux passing through the slot in the stator of the rotating electrical machine passes through the magnetic layer provided around the rectangular conductor portion and does not pass through the rectangular conductor portion, so that eddy current loss in the rectangular conductor portion can be reduced. . Thereby, the eddy current loss in the coil in the slot can be reduced while improving the space factor using the rectangular wire.

  Further, in the stator of the rotating electric machine, since the magnetic end layer is not provided at the coil end, the bending workability is improved accordingly, and the coil end can be reduced in size.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structure of the stator of the rotary electric machine in embodiment of this invention, (a) is sectional drawing of a slot, (b) is the figure which looked at the slot from the inner peripheral side, (c) is in a slot. Sectional drawing of a coil, (d) And (e) is sectional drawing of the coil in a coil end. It is a figure which shows the eddy current loss which arises in the coil in a slot when a prior art coil is used for a comparison. It is a figure which shows the eddy current loss reduction in the structure of FIG. It is a perspective view of the stator of the rotary electric machine in the embodiment of the present invention.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In the following description, the coil body is described as being wound by the distributed winding method. However, any coil body may be used as long as it is arranged with a single conductor in the circumferential direction in the slot and wound in a plurality of turns in the radial direction. The thing wound by the winding system is also included. Further, although a coil using a rectangular conductor having a rectangular cross section is described as the coil, a conductor having a substantially rectangular cross section obtained by rounding a rectangular corner, a conductor having a cross section close to an ellipse, or the like may be used. The number of slots of the stator core, the number of turns of the coil, dimensions, thickness, and the like described below are examples for explanation, and can be appropriately changed according to the specifications of the stator of the rotating electrical machine.

  Hereinafter, in all the drawings, one or the corresponding element is denoted by the same reference numeral, and redundant description is omitted.

  FIG. 1 is a view showing a stator 10 of a rotating electrical machine, FIG. 1 (a) is a cross-sectional view of one slot, and FIG. 1 (b) is a view of a slot viewed from the inner peripheral side corresponding to FIG. (C) is sectional drawing of the coil in a slot, (d) And (e) is sectional drawing of the coil in a coil end. The stator 10 of the rotating electrical machine constitutes a rotating electrical machine in combination with a rotor (not shown), and energizes the coil to rotate the rotor in an electromagnetic action, thereby rotating the rotor. The torque is output to the shaft.

  A stator 10 of a rotating electrical machine includes a stator core 12, a plurality of teeth 14 and 16 arranged along the circumferential direction of the stator core 12, a slot 18 that is a space between adjacent teeth 14 and 16, and a slot 18. A coil body 20 is provided that is wound a plurality of turns. The coil ends 30 and 32 are portions that protrude from both ends of the slot 18 in the axial direction of the coil body 20.

  The stator core 12 is an annular magnetic member in which a plurality of teeth 14 and 16 are disposed on the inner peripheral side. In FIG. 4 to be described later, the stator core 12 having 72 teeth 14 is shown. The stator core 12 is formed by laminating a plurality of electromagnetic steel plates having a predetermined shape.

  As shown in FIG. 1A, the coil body 20 is formed by winding a coil, which is arranged with one conductor in the circumferential direction in the slot 18, by winding a plurality of turns along the radial direction in the slot 18. . In FIG. 1, the circumferential direction is indicated by the θ direction, the radial direction is indicated by the R direction, and the axial direction is indicated by the Z direction. In FIG. 1, the coil body 20 is composed of four-turn coils 22, 24, 26 and 28 along the radial direction. Each coil 22, 24, 26, 28 is arranged for one turn between one end and the other end along the circumferential direction of one slot 18. That is, it is arranged with one conductor along the circumferential direction in the slot 18.

  Each of the coils 22, 24, 26, 28 is separated from the coil end 30 on one side in the axial direction of the stator core 12 through the slot 18 to the coil end 32 on the other side, and is separated by 6 slots along the circumferential direction of the stator core 12. The stator winding is configured by a distributed winding method that is inserted into another slot and repeats this.

  The four-turn coils 22, 24, 26, and 28 in the slot 18 have the same structure except for the arrangement position. Each of the coils 22, 24, 26, and 28 is different in the cross-sectional structure in the slot 18 from the cross-sectional structure in the coil ends 30 and 32. FIG. 1B is a view of the slot 18 as seen from the inner circumference side, and shows the coil 22 on the innermost circumference side. The coil 22 will be described as a representative example. The coil 22 includes a partial coil 34 in the slot 18, a partial coil 36 at the coil end 30, and a partial coil 38 at the coil end 32.

  As shown in FIG. 1C, the partial coil 34 at the coil end 30 has a flat conductor portion 40 and an insulating coating 44 provided around the flat conductor portion 40. As shown in FIG. 1D, the partial coil 36 in the slot 18 is provided around the flat conductor 40, the magnetic layer 42 provided around the flat conductor 40, and around the magnetic layer 42. Insulating coating 44 is included. As shown in FIG. 1E, the partial coil 38 in the coil end 32 includes a flat rectangular conductor portion 40 and an insulating coating 44 provided around the flat rectangular conductor portion 40. Thus, the magnetic layer 42 is provided only on the partial coil 36 in the slot 18.

  The flat conductor portion 40 is a conductor wire having a rectangular cross section perpendicular to the direction in which the conductor extends. A highly conductive metal can be used as the conductor material. Copper or the like can be used as the highly conductive metal.

  The magnetic layer 42 is a ferromagnetic layer having conductivity that uniformly and continuously covers the entire outer periphery of the rectangular conductor portion 40. The magnetic material is an iron-nickel alloy, and a plating method is used as a method of forming the magnetic layer 42 on the outer periphery of the flat conductor portion 40. An example of the thickness of the magnetic layer 42 is about 1 μm. As a material of the magnetic body, a soft magnetic material, iron, or nickel may be used.

  The insulating coating 44 is an electrically insulating resin layer that covers the entire outer periphery of the magnetic layer 42 uniformly and continuously. As the insulating coating 44, an enamel coating of polyamideimide is used. The thickness of the insulating coating 44 is determined by the insulation specifications of the stator 10 of the rotating electrical machine. An example of the thickness is about 30 to 50 μm. As the enamel coating used for the insulating coating 44, polyester imide, polyimide, polyester, formal, or the like may be used. Moreover, you may use the glass fiber film which wound glass fiber and impregnated alkyd resin etc. In addition to forming a film by coating, a film such as polyimide, polyester, polyethylene naphthalate, or a thin film sheet may be wound.

  The partial coil 36 in the slot 18 has only one conductor disposed in the circumferential direction of the slot 18. That is, only one turn of the partial coil 36 is arranged along the circumferential direction in the slot 18. The rectangular conductor portion 40 of the partial coil 36 has a rectangular cross section, and each side of the rectangular shape is parallel or perpendicular to the inner wall surface of the slot 18. Therefore, the magnetic layer 42 has a rectangular frame shape, and each side of the rectangular frame is also parallel or perpendicular to the inner wall surface of the slot 18.

  The operation of the above configuration will be described in detail with reference to FIGS. In these figures, coils of four turns are arranged along the radial direction of the slot 18 corresponding to FIG. Of the four-turn coils, one of them is represented by a symbol. FIG. 2 shows an example in which a prior art coil 29 having only a flat rectangular conductor portion 40 and an insulating coating 44 without any magnetic layer is used. FIG. 3 corresponds to FIG. 1B, and uses a coil 28 in which a magnetic layer 42 is provided on a partial coil 36 in the slot 18.

  In FIG. 2, the flow of leakage magnetic fluxes 50, 52, 54, 56, 58 leaking from the rotor side of the rotating electrical machine to the stator core 12 side is shown. The leakage magnetic flux passes through the coil 29 in the slot 18 when entering the teeth 14 from the rotor side and returning to the teeth 16. The coil 29 is composed of a copper rectangular conductor portion 40 and an insulating insulating film 44, both of which have a lower magnetic permeability than the magnetic permeability of the teeth 14, 16, and therefore the leakage magnetic flux 50, 52, 54, 56, 58. Flows in a manner of flow almost unrelated to the presence or absence of the coil 29. Accordingly, the leakage magnetic fluxes 50, 52, 54, 56, and 58 flow through the copper rectangular conductor portion 40 of the coil 29, where eddy current loss occurs.

  In FIG. 3, the coil 28 in the slot 18 has a magnetic layer 42 covering the periphery of the flat conductor portion 40. Since the magnetic layer 42 is a ferromagnetic body, its magnetic permeability is several hundred times higher than the magnetic permeability of the copper rectangular conductor portion 40. Therefore, the magnetic flux tends to flow toward the magnetic layer 42 rather than the copper flat conductor portion 40. As shown in FIG. 3, leakage magnetic flux 51, 53, 55, 57, 59 from the rotor side flows through the magnetic layer 42, but does not flow into the copper flat conductor portion 40. Therefore, the eddy current loss in the rectangular conductor 40 is significantly reduced as compared with FIG.

  Further, the magnetic layer 42 is not assembled separately from the flat conductor portion 40 but is integrally formed by plating so as to cover the periphery of the flat conductor portion 40. Therefore, when the coil 22, 24, 26, 28 is wound through the slot 18 and no special assembly process for arranging the magnetic layer 42 is required, the rectangular conductor portion 40 and the magnetic layer 42 is not displaced.

  FIG. 4 is a perspective view of the stator 10 of the rotating electrical machine. As described in FIG. 2, in the coil ends 30 and 32, the partial coils 34 and 38 of the coil 28 do not have the magnetic layer 42. As described in FIG. 3, since the leakage magnetic flux 51, 53, 55, 57, 59 from the rotor side almost flows between the teeth 14 and 16 and does not flow through the coil ends 30, 32, the rectangular conductor This is because the eddy current loss in the portion 40 is small and the magnetic layer 42 need not be provided. By not providing the magnetic layer 42 on the partial coils 34 and 38 in the coil ends 30 and 32, the coil ends 30 and 32 can be reduced in size accordingly. Further, the bending workability of the partial coils 34 and 38 is improved, the local stress concentration is reduced, and the stress due to the operation of the rotating electric machine is reduced.

  10 Stator of rotating electric machine, 12 Stator core, 14, 16 teeth, 18 slots, 20 Coil body, 22, 24, 26, 28, 29 Coil, 30, 32 Coil end, 34, 36, 38 Partial coil, 40 Flat conductor Part, 42 magnetic layer, 44 insulating film, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59 Leakage magnetic flux.

Claims (1)

A plurality of slots arranged along the circumferential direction of the stator core;
A coil body formed by winding a plurality of turns along the radial direction in the slot, with a coil arranged with one conductor in the circumferential direction in the slot;
With
The coil body
In the slot
A flat conductor part;
A magnetic layer provided around the flat rectangular conductor;
An insulating coating provided around the magnetic layer;
Have
In the coil end that projects to both ends of the slot,
A flat conductor part;
An insulating coating provided around the flat conductor portion;
A stator for a rotating electrical machine comprising a coil having

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