JP2005080436A - Stator for rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a stator for a rotating electric machine by which the occurrence of the discharge between the coil end and the threaded part of a through-bolt can be suppressed. <P>SOLUTION: The stator for the rotating electric machine is composed of an iron core 1 in a hollow columnar shape constituted by laminating a thin steel plate, a coil 2 which is constituted by winding a conductor around a plurality of slots extended in the axial line direction circumferentially apart at intervals on the inner diameter side of the iron core 1 and has the coil end 2a projected from both end faces of the iron core 1, the through-bolt 6 provided on the outer peripheral side of the iron core 1 and for integrating the thin steel plate, and a nut fastened onto the screw 6a at the tip of the through-bolt 6 and constituting a fastening means together with the through-bolt 6. The nut 7 is the stator of the rotating electric machine located in the vicinity of the coil end 2a. A covering part 8, which covers the thread of the screw part 6a with a conductive material and by which the outer peripheral face is made into a smooth face, is provided on the screw 6a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention includes, for example, a nut integrated with a thin steel plate that is screwed to a threaded portion of a tip of a through bolt that penetrates an iron core, and the nut is located in the vicinity of a coil end protruding from the end surface of the core Is related to the stator.

  Conventionally, a hollow cylindrical iron core configured by laminating thin steel plates and a structure in which a lead wire is wound around a plurality of slots extending in the axial direction at intervals in the circumferential direction on the inner diameter side of the iron core. A coil having coil ends projecting from both end faces of the iron core, a through bolt penetrating the iron core, and a nut integrated with the thin steel plate by screwing to a screw portion at the tip of the through bolt A stator of a rotating electrical machine is known in which the nut is positioned in the vicinity of the coil end (see, for example, Patent Document 1).

JP-A-58-86835 (FIG. 1)

  In conventional rotating electrical machine stators, the thread of the threaded portion has a protruding shape at the tip of the penetrating bolt, so that the electric field concentrates at that point, and the high voltage coil end and the grounding potential through bolt A partial discharge occurs between the screw threads and the partial discharge triggers a flash between the coil end surface and the threads, which could damage the main insulation of the coil. There was a problem.

  An object of the present invention is to solve the above-described problems, and it is possible to fix a rotating electrical machine capable of suppressing the occurrence of discharge between a coil end and a threaded portion of a through bolt. The purpose is to have a child.

  A stator of a rotating electrical machine according to the present invention includes a hollow cylindrical iron core configured by laminating thin steel plates, and a lead wire connected to a plurality of slots extending in the axial direction at intervals on the inner diameter side of the iron core in the circumferential direction. A coil having a coil end projecting from both end faces of the iron core, a through bolt provided on the outer peripheral side of the iron core for integrating the thin steel plate, and the through A nut that is screwed into a screw portion at a tip portion of the bolt and constitutes a fastening means together with a through bolt, and the nut is a stator of a rotating electrical machine located in the vicinity of the coil end portion, and in the screw portion, A cover portion is provided in which the thread of the screw portion is covered with a conductive material and the outer peripheral surface is smooth.

  In the stator of the rotating electrical machine according to the present invention, it is possible to suppress the occurrence of discharge between the coil end portion and the thread portion of the through bolt.

  Hereinafter, embodiments of the present invention will be described. In the drawings, the same or corresponding members and parts will be described with the same reference numerals.

Embodiment 1 FIG.
1 is a cross-sectional view of a main part of a stator of a generator according to Embodiment 1 of the present invention.
A generator that is a rotating electrical machine includes a case (not shown), a hollow cylindrical stator provided in the case, and a shaft (not shown) provided on the central axis of the stator, And a rotor (not shown) fixed to the shaft.
The stator has a hollow cylindrical iron core 1 formed by laminating thin steel sheets, and a wire wound around slots (not shown) extending in the axial direction at equal intervals in the circumferential direction on the inner diameter side of the iron core 1. A magnetic flux shunt 3 formed by laminating a coil 2 formed by rotating, a plurality of hollow disk-shaped steel plates 3 a provided on both end faces of the iron core 1, and abutting on both end faces of the magnetic flux shunt 3 A hollow disc-shaped holding plate 4, a through bolt 6 penetrating the iron core 1, the magnetic flux shunt 3 and the holding plate 4, and screwed to the tip of the through bolt 6 via an insulating washer 5, and cooperating with the through bolt 6. Then, a nut 7 in which the iron core 1, the magnetic flux shunt 3 and the pressing plate 4 are integrated, and a cover made of a conductive material that covers the thread of the threaded portion 6a of the through bolt 6 protruding from the nut 7 and has a smooth outer peripheral surface. Part 8. The cover 8 is configured by curing graphite with a silicon resin, for example.

In the coil 2, the conducting wire is wound around each slot of the iron core 1 by, for example, lap winding, the conducting wires are stacked in a plurality of stages in the slot, and bent from the both end surfaces of the iron core 1 into a U shape. And has a coil end portion 2a protruding. Of the surface of the coil 2, conductive paint is applied inside the iron core 1 and in the vicinity of the iron core 1 of the coil end 2 a, and the outer surface of the coil end 2 a near the iron core 1 is substantially the same as the iron core 1 that is a ground potential. The same potential.
The through bolt 6 and the nut 7 constitute fastening means. The fastening means are provided at equal intervals in the circumferential direction of the iron core 1.

  In the stator of the generator configured as described above, the surface potential on the bending deformation side of the coil end portion 2a to which the conductive paint is not applied is large, but in the screw portion 6a of the through bolt 6, the cover portion 8 which is a smooth surface is provided. Since it is formed, electric field concentration is prevented, the occurrence of discharge between the coil end 2a and the threaded portion 6a is suppressed, and the insulation reliability of the coil 2 is improved.

Embodiment 2. FIG.
2 is a cross-sectional view of a main part of a stator of a generator according to Embodiment 2 of the present invention.
In this embodiment, the threaded portion 6 a of the through bolt 6 protruding from the presser plate 4, the nut 7, and the insulating washer 5 are covered with an insulating cover 9.
The cover body 9 is made of, for example, silicon rubber, and prevents the metal surface of the screw portion 6a and the nut 7 from directly facing the coil end portion 2a having a high potential.
Accordingly, the occurrence of electric discharge between the coil end 2a, the screw 6a and the nut 7 is suppressed, and the insulation reliability of the coil 2 is improved.

Embodiment 3 FIG.
FIG. 3 is a cross-sectional view of a main part of the stator of the generator according to Embodiment 3 of the present invention.
The third embodiment is different from the second embodiment in that the cover 10 has a notch 10a.

  Since the leakage magnetic flux generated from the rotor and the coil end 2a is linked to the screw portion 6a and the nut 7, they themselves generate heat. Therefore, when the cover 9 of the second embodiment is used, heat cannot be dissipated, so that the insulating washer 5 provided to suppress the loop current in the through bolt 6 is thermally deteriorated due to the temperature rise of the nut 7 and carbonized. As a result, the insulating function is lost, and there is a risk of melting due to the loop current.

  On the other hand, in this embodiment, by providing the notch 10a, the cooling air which is a cooling medium generated by the rotation of a fan (not shown) provided on the end face of the rotor is indicated by an arrow A. As described above, the threaded portion 6a and the nut 7 pass outside, so that the threaded portion 6a and the nut 7 are directly cooled by forced cooling air, and the above-described inconvenience can be prevented.

Embodiment 4 FIG.
4 is a cross-sectional view of an essential part of a stator of a generator according to Embodiment 4 of the present invention.
In the fourth embodiment, a hollow disk-shaped insulating barrier body 11 is provided between the nut 7 and the hollow disk-shaped pressing plate 4. A bent portion 11 a that is bent toward the magnetic flux shunt 3 is formed on the inner diameter side of the barrier body 11. The barrier body 11 is integrally formed of, for example, glass-epoxy resin.
The inner diameter side of the magnetic flux shunt 3 has a stepped portion formed by changing the inner diameter dimension of the steel plate 3a. The magnetic flux shunt 3 has a magnetic flux leaked from the rotor and the coil end 2a. 1 is prevented. The protrusion 3b at the step portion also causes a new electric field concentration, and there is a possibility of causing a discharge between the protrusion 3b and the coil end 2a.
On the other hand, in this embodiment, since the barrier body 11 having the bent portion 11a is provided, it is possible to prevent the above inconvenience from occurring.

Embodiment 5. FIG.
5 is a partial front view of a stator barrier body 15 of a generator according to Embodiment 5 of the present invention, and FIG. 6 is a cross-sectional view taken along line VI-VI in FIG.
In this embodiment, the barrier body 15 is composed of barrier pieces 15A and 15B divided into a plurality of pieces, and adjacent barrier pieces 15A and 15B are joined by overlapping the step portions 13 and 14 on the side portions. Has been. Reference numeral 12 denotes a through hole through which the through bolt 6 passes.
The barrier body 11 of the fourth embodiment is composed of an integral insulator, and a complicated mold is required to form the barrier body 11 and the manufacturing cost increases. In this embodiment, the barrier body 15 Is composed of barrier pieces 15A and 15B divided into a plurality of pieces, and the mold shape is simplified and the manufacturing cost is reduced.
Further, the adjacent barrier pieces 15A and 15B are joined to each other with the stepped portions 13 and 14 of the side portions overlapped, so that it is possible to reliably prevent discharge from passing between the adjacent barrier pieces 15A and 15B.

In each of the above embodiments, the generator has been described as the rotating electrical machine. However, it is needless to say that the present invention can also be applied to a stator of an electric motor.
Moreover, in each said embodiment, although the penetration bolt 6 penetrated the whole iron core 1, the stator which penetrated a part of iron core may be sufficient. Alternatively, a stator in which thin steel plates are integrated may be formed by penetrating through the outer periphery of a hollow disc that is in contact with both end faces of the iron core, and sandwiching the iron core from both sides in cooperation with the nut. .

It is principal part sectional drawing of the stator of the generator of Embodiment 1 of this invention. It is principal part sectional drawing of the stator of the generator of Embodiment 2 of this invention. It is principal part sectional drawing of the stator of the generator of Embodiment 3 of this invention. It is principal part sectional drawing of the stator of the generator of Embodiment 4 of this invention. It is a partial front view of the barrier body of the stator of the generator of Embodiment 5 of this invention. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Iron core, 2 coil, 3 magnetic flux shunt, 5 Insulation washer, 6 Through bolt, 6a Screw part, 7 Nut, 8 Cover part, 9,10 Cover body, 11, 15 Barrier body, 11A Barrier piece, 11B Barrier piece, Through Bolt, 13, 14 Stepped part.

Claims (5)

A hollow cylindrical iron core composed of thin steel plates;
A coil having a coil end portion that is configured by winding a conducting wire around a plurality of slots extending in the axial direction at intervals in the circumferential direction on the inner diameter side of the iron core and having a coil end protruding from both end faces of the iron core;
A through bolt provided on the outer peripheral side of the iron core for integrating the thin steel plate;
In a stator of a rotating electrical machine comprising a nut that is screwed to a screw portion at a tip portion of the through bolt and constitutes a fastening means together with the through bolt, and the nut is located in the vicinity of the coil end portion,
In the screw portion, a stator of a rotating electrical machine provided with a cover portion that covers a thread of the screw portion with a conductive material and has a smooth outer peripheral surface. A hollow cylindrical iron core composed of thin steel plates;
A coil having a coil end portion that is configured by winding a conducting wire around a plurality of slots extending in the axial direction at intervals in the circumferential direction on the inner diameter side of the iron core and having a coil end protruding from both end faces of the iron core;
A through bolt provided on the outer peripheral side of the iron core for integrating the thin steel plate;
In a stator of a rotating electrical machine comprising a nut that is screwed to a screw portion at a tip portion of the through bolt and constitutes a fastening means together with the through bolt, and the nut is located in the vicinity of the coil end portion,
The screw part and the nut are a stator of a rotating electric machine covered with a cover made of an insulating material.   The stator of the rotating electrical machine according to claim 2, wherein a notch portion through which a cooling medium passes is formed on an outer side in a radial direction of the cover body.   A magnetic flux shunt having a stepped portion on the inner diameter side is interposed between the iron core and the nut, and a plurality of hollow disk-shaped steel plates are laminated, and the stepped portion of the magnetic flux shunt The stator of the rotary electric machine according to claim 2 or 3, wherein a barrier body made of an insulating material is provided between the coil ends.   The stator for a rotating electrical machine according to claim 4, wherein the barrier body is constituted by a plurality of barrier pieces and the adjacent barrier pieces are joined with overlapping step portions of the side portions.

Images