JP3302767B2 - Rotor winding end support device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine, and more particularly to a supporting device for a rotor winding end of a large rotating machine such as a variable speed pumping generator.

[0002]

2. Description of the Related Art In a conventional turbine generator, a salient-pole type rotor is employed. Therefore, a rotor winding is wound around a salient-pole magnetic pole which also serves as a structure, and acts during operation. The rotor winding is restrained against centrifugal force by a flange provided on the field pole.

On the other hand, the AC variable-speed pumping generator employs a system in which a three-phase distributed winding provided on a cylindrical rotor is AC-excited, so that the centrifugal force acting during operation is different from the above. It is necessary to support and fix the rotor winding by a method. In the rotor winding of the conventional variable speed pumped generator, FIG.
As shown in FIG. 6, a rotor winding (2) including an upper winding (2a) and a lower winding (2b) is accommodated in a slot of a cylindrical rotor core (1), and a slot (not shown) is provided. The rotor winding end (2c) fixed by a wedge and protruding outward from the end of the rotor core (1) has the rotor winding end (2c) sandwiched at several points in the longitudinal direction. U-shaped bolts (3) for tightening are provided, and the ends of these U-shaped bolts (3) are attached to support rings (5) attached to the ends of the rotor core (1) via stays (4). , And are connected and fixed by a nut (6). In this case, between the U-shaped bolt (3) and the rotor winding end (2c), between the upper winding (2a) and the lower winding (2b), and between the rotor winding end (2c). ) And the support ring (5), an insulation block (7) for ensuring insulation strength corresponding to the winding voltage is arranged so as not to cause discharge to the metal structure at the ground potential. .

In the rotor winding (2) end supporting device having such a configuration, the rotor winding end (2c) is operated during operation.
Is transmitted to the support ring (5) via the U-shaped bolt (3), and if the rigidity of the support ring (5) is sufficiently large, the centrifugal force acts in the outer direction of the rotor winding end (2c). Can be kept extremely small.

[0005]

Generally, as the size of the variable speed generator increases, the excitation voltage of the rotor winding (2) increases. At such a high voltage rotor winding end (2c), a potential difference from the ground potential U-shaped bolt (3) becomes large. It is necessary to increase the interval between the parts (2c). However, in order to increase the distance, the length of the end portion (2c) of the rotor winding must be lengthened, and a structure for supporting the end portion also becomes large.

The present invention has been made in view of the above points, and an object of the present invention is to reduce the insulation strength required at the end of a high-voltage rotor winding such as a large variable speed pumped generator. Another object of the present invention is to provide a supporting device that can be secured without increasing the length of the rotor winding end.

[0007]

A rotor winding end portion projecting outwardly from a cylindrical rotor core end SUMMARY OF THE INVENTION, and support ring attached via a support member to said rotor core end;
A U-shaped bolt for sandwiching the upper winding and the lower winding at the end of the rotor winding and fixing to the support ring;
The U-shaped bolt is connected to the U-shaped bolt and the upper side.
Between the windings, between the upper winding and the lower winding, and
The insulation block inserted between the side winding and the support ring
Rotor winding end fixed to the support ring through
In the supporting device of (1), an insulating layer is provided on at least a portion of the U-shaped bolt facing a side surface of the end of the rotor winding.

[0008]

In the rotor winding supporting device having such a structure, the insulation strength required for the winding is improved by the insulating layer provided on the U-shaped bolt, so that the rotor of the high-voltage variable speed pumped generator can be improved. Sufficient reliability can be ensured without increasing the distance between the ends of the rotor windings adjacent to the windings.

[0009]

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. 1 to 3 show an example of the configuration of a device for supporting a rotor winding end according to the present invention. The upper winding (2a) and the lower winding (2b) of the rotor winding (2) are accommodated in slots (not shown) provided in the rotor core (1), and are supported and fixed by slot wedges. On the inner diameter side of the rotor winding end (2c), a support ring (5) is attached to the end of the rotor core (1) via a stay (4). A plurality of U-shaped bolts (3) for tightening the rotor winding end (2c) are provided at a plurality of locations in the longitudinal direction of the rotor winding end (2c), and the end is a nut (6). ) Are fastened and fixed to the support rings (5). In this case, between the U-shaped bolt (3) and the upper winding (2a), between the upper winding (2a) and the lower winding (2b),
An insulating block (7) is interposed between the lower winding (2b) and the support ring (5).

The upper winding (2) of the U-shaped bolt (3)
(a) An epoxy glass prepreg tape is wound around a portion facing the side surface of the lower winding (2b), and an insulating layer (8) obtained by heat molding and curing is provided. At this time, in order to increase the insulation strength, each insulation block (7) is provided with a groove (9), and is assembled and integrated with the insulation layer (8) of the U-shaped bolt (3).

According to this embodiment, the rotor winding end (2c)
The strength of the insulation between the U-shaped bolt (3) and the conventional U-shaped bolt (3) having no insulating layer (8) is determined by the effect of the insulating layer (8) provided on the U-shaped bolt (3). Since it is higher than the insulation strength between the winding end (2c),
Even when the voltage of the rotor winding (2) is increased, it is not necessary to increase the interval between the adjacent rotor winding ends (2c) as compared with the related art. At this time, the thickness of the insulating layer (8) provided on the U-shaped bolt (3) is adjusted according to the voltage of the rotor winding (2). (Embodiment 2) In a second embodiment shown in FIG. 4, an insulation tube (10) prepared in advance is inserted into a U-shaped bolt (3), and
The same effect as that of the insulating layer (8) is achieved by arranging the insulating layer (8) at the same position as above, and the insulating layer (8) is easily formed on the U-shaped bolt (3).

[0012]

As described above, according to the present invention, even in a high-voltage rotor winding such as a large-sized variable-speed pumping generator, sufficient insulation can be achieved while minimizing the winding end length. It is possible to provide a supporting device for a rotor winding end portion capable of ensuring strength.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a rotor end showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

FIG. 3 is a sectional view taken along the line BB in FIG. 2;

FIG. 4 is a longitudinal sectional view of a rotor end showing a second embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing a conventional example.

FIG. 6 is a sectional view taken along the line CC of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rotor core 2 ... Rotor winding 2a ... Upper winding 2b ... Lower winding 2c ... Rotor winding end part 3 ... U-shaped bolt 4 ... Stay 5 ... Support ring 6 ... Nut 7 ... Insulation block 8 ... insulating layer 9 ... groove 10 ... insulating tube

Claims (1)

(57) [Claims] 1. A rotor winding end portion projecting outwardly from a cylindrical rotor core end, the support member to the rotor core end
And a U-shaped bolt for sandwiching an upper winding and a lower winding at the end of the rotor winding and fixing the lower winding to the support ring . The U-shaped box
Is between the U-shaped bolt and the upper winding,
Between the winding and the lower winding, and between the lower winding and the support
The support block is inserted through an insulating block inserted between the rings.
Of the end of the rotor winding fixed to the bearing
And a rotor winding end supporting device , wherein an insulating layer is provided on at least a portion of the U-shaped bolt facing a side surface of the rotor winding end.