JPS6234423Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a winding of an induction electric device that is concentrically inserted into a core leg, and particularly relates to an improvement of an inner winding in which a conductor is wound adjacently through an interlayer insulator.

In transformer windings in which the inner and outer windings are fitted into core legs and arranged concentrically and housed in a cooling medium, when a short circuit occurs, the axial component of the leakage magnetic field causes a leak between the two windings. This produces a radial radial force (repulsive force between both windings) that tries to widen the main gap between the two windings. That is, the outer winding is subjected to a tensile stress in the circumferential direction in an attempt to increase its diameter, and the inner winding is conversely subjected to a force directed toward the center that tends to reduce its diameter. In other words, the inner winding is compressed in the circumferential direction, and for example, the winding shown by the solid line in FIG. 1 tends to collapse as shown by the dotted line. In order to prevent this, conventionally, as shown in FIG. 2, a spacing piece 3 was inserted between the inner winding 1 and the core leg 2, which receive the mechanical force directed toward the center as indicated by the arrow, for reinforcement.

Now, as shown in FIG. 3, the breaking pressure F _B of a winding formed by winding a conductor 31 having a thickness t and a width b in n turns through an interlayer insulator 32 is as follows.

F _B =E・I(m ² -1)/R ³ I=ny・^{t 3}・b/12 where E=Longitudinal elastic modulus of the conductor I=Area moment of inertia of the conductor m=Number of effective support points of the spacing piece About 1/2 of the actual number of support points.

R = average radius of inner winding y = constant determined by structure and manufacturing technology It is 1y3.

Conventionally, paper or film has been used as an interlayer insulator, but this is soft and allows each conductor to deform almost freely between layers when mechanical force is applied. Therefore, the value of y becomes close to 1, the breaking limit pressure F _B decreases, and the number of spacing pieces increases,
Not only does it require more man-hours and materials to manufacture, but it also has disadvantages such as a reduction in cooling area and excessive temperature rise.

The present invention has been devised in view of this point, and aims to improve the conventional drawbacks and provide a winding wire with a small number of spaced pieces. This objective was achieved by bonding adjacent conductors together to increase the moment of inertia of the conductors. That is, a conductor is wound using a so-called prepreg insulation material, which is an insulating material such as film, glass tape, or non-woven fabric impregnated with a semi-hardened resin, as interlayer insulation, and after completion, the resin is hardened by heating or other methods to connect radially adjacent conductors. It is what makes comrades stick together. This makes each conductor nearly integral, ie, y is a number close to 3, and the winding is greatly strengthened.

However, since the prepreg is expensive, it may be used to the minimum necessary extent, for example, for a plurality of times adjacent to the innermost conductor in the radial direction, and the rest may be carried out as usual. The reason why it was used on the inner diameter side is that the mechanical force applied to each conductor is ultimately applied to the innermost part, and as long as this part is not deformed, it will not break.

FIG. 4 shows an embodiment of the present invention, which is the same as FIG. 3 except for the interlayer insulator 41 impregnated with semi-cured resin.
The figure shows a winding cross section in which the interlayer insulator 41 is used for n ₁ times on the inner diameter side, and the conventional interlayer insulator 32 is used for the other n ₂ times. In this case, the moment of inertia _I2 of the winding is approximately as follows and is strengthened.

I ₂ ≈t ³ ·b/12 (n ³ ₁ +n ₂ ) In this way, the spacer pieces can be reduced to the necessary minimum. Alternatively, if there is a significant margin for the electromagnetic mechanical force in the event of a short circuit, the spacing piece may be omitted, and only a coolant free flow path may be provided between the inner diameter surface of the inner winding and the core leg. In this case, there is an advantage that the cooling area increases and efficiency improves.

In addition, in the above explanation, we talked about fixing adjacent conductors via an interlayer insulator, but
In the present invention, suitably insulated conductors may be directly fixed. In addition, the present invention can be applied to induction electric devices other than transformers, and can be applied not only to plate-shaped windings but also to windings of other shapes, such as the multilayer cylindrical winding shown in Fig. 5. Interlayer insulator 7
As No. 1, a material impregnated with the semi-cured resin may be used. Alternatively, the present invention can of course be applied not only to two windings but also to an intermediate winding that receives a mechanical force directed toward the center in a multi-winding structure.

As is clear from the above explanation, in the winding of an induction electric appliance in which the inner winding and the outer winding are fitted into the core leg, at least the inner diameter part of the inner winding receives a large mechanical force toward the center in the event of a short circuit. A mechanically reinforced winding is obtained by fixing a plurality of directionally adjacent conductors on mutually opposite adjacent surfaces. In addition, the number of spacing pieces that support the winding from the inner diameter side can be reduced, which not only reduces the number of man-hours and materials, resulting in lower costs, but also increases the cooling area, making it possible to provide a winding of an induction electric appliance with good characteristics.

[Brief description of the drawings]

Fig. 1 is a rough deformation diagram of the winding, Fig. 2 is a plan view of an induction electric winding, Fig. 3 is a vertical cross-sectional view of a conventional winding,
FIGS. 4 and 5 are longitudinal sectional views of windings according to an embodiment of the present invention. 1: Inner winding, 2: Iron core leg, 32, 41, 7
1: Interlayer insulator.

Claims (1)

[Claims for Utility Model Registration] 1. An inner winding in which a conductor is wound adjacent to each other with an interlayer insulator interposed therebetween, and an outer winding arranged concentrically with the inner winding are fitted into a core leg. A winding of an induction electric appliance housed in a cooling medium, characterized in that a plurality of radially adjacent conductors of at least the innermost conductor of the inner winding are fixed at mutually opposing adjacent surfaces. winding. 2. In the winding described in claim 1 of the utility model registration claim, the conductor of the innermost conductor of the inner winding is hardened and fixed through an interlayer insulator impregnated with resin. Characteristic induction wire windings. 3. In the winding described in either of claims 1 and 2 of the claims for utility model registration, there is no bridging material between the inner diameter surface of the inner winding and the core leg to form a free flow path for the cooling medium. A winding wire for induction electric appliances that is characterized by: