JP5958216B2 - Rotating electric machine stator - Google Patents

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. By providing a magnetic layer on the surface of the conductor, eddy current loss generated in the conductor can be reduced, but eddy current loss can also occur in the magnetic body itself. In addition, since the conductor is covered with the magnetic material, the bending workability of the coil is lowered. 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 electrical 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, and the coil body is provided with a rectangular conductor portion, and an insulation-coated magnetic layer that is an aggregate of magnetic powders provided around the rectangular conductor portion and coated with an insulator; , Including a coil.

  With the above configuration, the leakage magnetic flux in the stator of the rotating electrical machine passes through the insulating coating 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. In addition, since the magnetic powder constituting the insulating coated magnetic layer is electrically separated from each other by an insulator, eddy currents that can occur in the magnetic material are dispersed, and eddy current loss in the insulating coated magnetic layer is also reduced. Can be reduced. Thereby, eddy current loss can be reduced while improving the space factor using a rectangular wire.

  Further, since the insulating coating magnetic layer is an aggregate of magnetic powder coated with resin, it is not necessary to provide a special insulating coating on the coil. Thereby, the bending workability of the winding can be maintained.

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 sectional drawing of a coil. It is a figure which shows the eddy current loss when using the coil of a prior art for the 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.

  1A and 1B are diagrams showing a stator 10 of a rotating electrical machine. FIG. 1A is a cross-sectional view of one slot, and FIG. 1B is a cross-sectional view of a coil. 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, 16 arranged along the circumferential direction of the stator core 12, a slot 18 that is a space between adjacent teeth 14, 16, and a slot 18. A coil body 20 is provided that is wound a plurality of turns.

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

  As shown in FIG. 1B, the coil 22 includes a flat conductor portion 40 and an insulating coating magnetic layer 42 provided around the flat conductor portion 40.

  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 insulating coating magnetic layer 42 is an aggregate of insulating coating magnetic powder 43 in which the periphery of fine magnetic powder 46 is coated with a resin 48. As described above, the insulating coating magnetic layer 42 is formed by bonding fine insulating coating magnetic powders 43 that are electrically insulated from each other with the coated resin 48 to join each other with the resin 48. . The insulating coating magnetic layer 42 is a ferromagnetic layer having conductivity that uniformly and continuously covers the entire outer periphery of the rectangular conductor portion 40 in a state where the insulating coating is applied. The thickness of the insulating coating magnetic layer 42 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.

  The material of the magnetic powder 46 is an iron-nickel alloy. As a method of pulverizing, the lump of the iron-nickel alloy is pulverized and the particle diameter is made uniform. You may use the method of manufacturing a powder iron nickel alloy from the beginning. An example of the diameter of the magnetic powder 46 is about 1 μm. As a material of the magnetic body, a soft magnetic material, iron, or nickel may be used.

  The resin 48 is an electrically insulating resin layer that covers the entire outer periphery of the magnetic powder 46 uniformly and continuously. As the resin 48, an enamel coating of polyamideimide is used. An example of the thickness of the resin 48 is about 0.1 to 0.5 mm. As the enamel coating used for the resin 48, polyesterimide, polyimide, polyester, formal, or the like may be used.

  As a method of covering the entire outer periphery of the flat conductor portion 40 with the insulating coating magnetic layer 42, the resin 48 is heated and softened, and its adhesiveness is used. That is, the insulating coating magnetic powder 43 is uniformly disposed on the outer periphery of the rectangular conductor portion 40 and heated, so that the resin 48 adheres to each other and forms the insulating coating magnetic layer 42. Stick to the outer periphery. In this way, the rectangular conductor portion 40 and the insulating coating magnetic layer 42 are integrated.

  The coil 22 has only one conductor disposed in the circumferential direction of the slot 18. That is, only one turn of the coil 22 is arranged along the circumferential direction in the slot 18. The rectangular conductor portion 40 of the coil 22 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 insulating coating magnetic layer 42 has a rectangular frame shape, and each side of the rectangular frame is 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, a coil of 4 turns is 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 an insulating coating magnetic layer is used. FIG. 3 is a view corresponding to FIG. 1A and uses a coil 28 provided with an insulating coating magnetic layer 42.

  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 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 has an insulating coating magnetic body layer 42 that covers the periphery of the flat conductor portion 40. Since the magnetic powder 46 constituting the insulating coating magnetic layer 42 is a ferromagnetic substance, 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 insulating coated magnetic layer 42 rather than the copper rectangular conductor portion 40. As shown in FIG. 3, leakage magnetic flux 51, 53, 55, 57, 59 from the rotor side flows through the insulating coating 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, since the magnetic powder 46 constituting the insulating coating magnetic layer 42 is electrically insulated and separated by the resin 48 which is an insulating material, eddy currents that can be generated in the magnetic powder 46 are dispersed, and the insulating coating magnetic material Eddy current loss in the body layer 42 can also be reduced.

  Further, since the insulating coating magnetic layer 42 is an aggregate of the magnetic powder 46 coated with the resin 48, it is not necessary to provide a special insulating coating on the coils 22, 24, 26, and 28. Thereby, bending workability of the winding can be maintained, local stress concentration is reduced, and stress during operation of the rotating electrical machine is also reduced.

  Further, the insulating covering magnetic layer 42 is not assembled separately from the rectangular conductor portion 40 but is integrally formed so as to cover the periphery of the rectangular conductor portion 40 by the adhesive force of the resin 48. Therefore, a special assembly process for disposing the insulating coating magnetic layer 42 is not required, and when the coils 22, 24, 26, 28 are wound through the slots 18, they are insulated from the rectangular conductor portion 40. There is no positional deviation between the coated magnetic layer 42 and the coated magnetic layer 42.

  FIG. 4 is a perspective view of the stator 10 of the rotating electrical machine. According to the above configuration, the four-turn coils 22, 24, 26, and 28 accommodated in one slot 18 of the stator 10 of the rotating electrical machine have the insulating coating magnetic layer 42 that covers the periphery of the rectangular conductor portion 40. . Thereby, the leakage magnetic flux from the rotor side flows through the insulating coating magnetic layer 42 and does not flow into the copper rectangular conductor portion 40. Therefore, eddy current loss in the flat conductor portion 40 can be reduced.

  DESCRIPTION OF SYMBOLS 10 Stator of rotary electric machine, 12 Stator core, 14, 16 teeth, 18 slots, 20 Coil body, 22, 24, 26, 28, 29 Coil, 40 Rectangular conductor part, 42 Insulation coating magnetic body layer, 43 Insulation coating magnetic body Powder, 44 Insulating film, 46 Magnetic powder, 48 Resin, 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 in which a coil arranged with one conductor in the circumferential direction in the slot is wound a plurality of turns along the radial direction in the slot;
With
The coil body
A flat conductor part;
An insulation-coated magnetic layer that is an assembly of magnetic powders provided around the rectangular conductor portion and coated with an insulator;
A stator for a rotating electrical machine comprising a coil having

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