JPS59122332A - Fixing method of winding - Google Patents

Abstract

PURPOSE:To improve the thermal transmission between the surface of a winding and the wall of a core slot by interposing a semiconductive elastic layer between the winding and the wall of the slot, thereby rigidly fixing the winding in the slot of the core. CONSTITUTION:A mica tape is wound as a ground insulator 2 in the prescribed number of turns on a winding conductor 1 formed by bundling a plurality of strands. Further, to form a semiconductive layer thereon, semiconductive tapes formed of aromatic polyamide fiber and carbon fiber are butted or lap wound. Subsequently, epoxy resin immersed in the tapes is heated and cured to secure the insulator 2 to the layer 3. An elastic sheet 4 which exhibits semiconductive property is bonded to one side face of the thus constructed winding. As the sheet, silicone rubber sheet which contains conductive carbon black is employed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method C1 for fixing a winding contained in an iron core (one contained in a rotating electrical machine).

[Technical background of the invention and its problems] ^ The surface of the winding to which C2 is fixed in the iron core slot of a voltage rotating electric machine L2 is insulated to ground L1, so that the electric field applied thereto is uniform C2, and the winding surface and the slot wall A semiconducting layer is formed to prevent partial discharge in the gap generated between the two. In large rotating electric machines such as turbine generators and water turbine generators where the full impregnation insulation method cannot be used, this semiconducting layer is usually applied to the surface of the first winding after the ground insulation has hardened. Recently, ground insulation has been formed by winding mica tape, and semiconductive tape made of aromatic polyamide fibers and carbon fibers has been wrapped around the outer circumference of the mica tape.
(b) A method of simultaneously impregnating or hardening an epoxy resin to harden the ground insulation and form a semiconductive layer has also come to be used. When using the back cloth method, the adhesion between the ground insulation and the semiconducting layer is extremely strong, but on the other hand, the surface of the semiconducting wire is thinly traversed by the impregnated epoxy cutting edge, making the surface extremely smooth. Therefore, even if the winding constructed in this way is placed in the core slot, a ripple spring or side spacer is driven between the winding 1i111 surface and the slot wall f1, and the winding is fixed, the winding surface remains extremely smooth and hard. Since it is already completed, sufficient binding force cannot be obtained. Further, since the slot wall surface has small irregularities, the slot wall and the winding side surface do not come into contact over the entire surface, but only partially. Therefore, heat transfer between the winding wire and the slot a becomes poor, and there is a drawback that the heat generated in the winding conductor cannot be effectively dissipated to the iron core side.

[Object of the Invention] The present invention was made in order to solve the above-mentioned problem of chipping. [Summary of the Invention] In order to achieve the above object, the winding fixing method of the present invention (in part 2, aromatic polyamide fiber and carbon fiber When a winding having a semiconductor layer formed on its surface is housed in an iron core slot, a semiconducting elastic layer is interposed between the winding and the slot wall.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described in which the present invention is added to Figure C. A mica tape is wound a predetermined number of times as ground insulation 2 on a winding F4 conductor 1 formed by bundling a plurality of wires. Furthermore, in order to form a semiconductive layer 3 thereon, a semiconductive tape (for example, A Carbon (trade name, Nippon Aroma Co., Ltd.)) made of aromatic polyamide fibers and carbon fibers is wound in a butt or overlapping manner. Thereafter, the epoxy resin impregnated into the mica tape is heated and cured to fix the ground insulation 2 and the semiconductive layer 3. An elastic sheet 4 exhibiting elasticity is adhered to one side of the winding wire constructed in this manner. It has excellent corona resistance, arc resistance, and ozone resistance, making it the most preferable elastic material for use in rotating machines.The physical properties of the semiconductive silicone rubber sheet used in this example are shown in the table. The silicone rubber sheet is electrically conductive between the winding surface and the core slot wall, and its surface resistivity ρ8< It needs to be 10Ω.If the thickness of the semiconductive silicone rubber sheet is 1u or less, ρ,
The physical properties of the semiconductive silicone rubber sheet are required to achieve a volume resistivity of <10'Ω. If the resistance value of the semiconductive silicone rubber sheet is too low, heat will be generated due to eddy current loss within the semiconductive silicone rubber sheet. In order to suppress the eddy current loss to 1/1 of the copper loss of the winding conductor, a volume resistivity of ρ9>10Ω is required, and in this embodiment, A in Table 1 was used. The thickness of the semi-tetraelectric silicone rubber is O52 to 0.8-a, and the width is the height of the winding or slightly narrower than that. The length shall be the iron core length. The adhesive for bonding the semiconductive silicone rubber sheet to the surface of the winding is a strong adhesive that provides frost and gas insulation between the semiconductive layer and the semiconductive silicone rubber sheet.

After pasting the semi-conductive silicone rubber sheet on one side of the winding, the winding is inserted into the slot of the iron core 5 (the two sides are placed on the same side, and the semi-conductive silicone rubber sheet is pasted on the other side of the winding). The spring or side spacer 6 is driven in and fixed.The potential on the coil surface is equal to the potential on the iron core through the semiconductive silicone rubber sheath N2, so the ripple spring or side spacer does not need to be semiconductive.

Next, f2, the effect of the method of fixing the winding of the present invention constructed as described above (the two will be explained in detail). When the winding is fixed in the core slot by the spacer, the slot is elastically deformed to match the shape of the slot, and the slot wall and the semiconductive silicone rubber sheet come into complete contact. Therefore, the winding is firmly fixed within the core slot. Also, the heat transfer between the slot wall and the semiconductive silicone rubber sheet is significantly improved, and the heat generated in the winding is effectively dissipated through the semiconductive silicone rubber sheet.

In the example shown in 11 above, a semiconductive silicone rubber sheet was used as the semiconductive elastic sheet, but it exhibits semiconductivity, has good heat resistance and corona resistance, and easily undergoes elastic deformation, making it difficult to form a slot wall. Other materials can also be used as long as they are in complete contact with the material.

Further, in the above embodiment, a semiconductive elastic sheet is attached to the side surface of the winding wire with an adhesive (for example, semiconductive room temperature vulcanizable silicone rubber is applied to the side surface of the winding wire and then cured.
A semiconductive elastic layer may be formed on the side surface of the winding.

[Effects of the Invention] As explained above, the present invention is configured such that the two-handed conductive elastic body on the side surface C of the winding is adhered so that the slot wall and the semi-conductive elastic body are in complete contact with each other. The winding can be fixed to the iron core with a greater restraining force than before. Also, heat transfer between the windings and the iron core is significantly improved by C2. This makes it possible to increase the current density flowing through the windings, contributing to larger capacity, lighter weight, and smaller size devices.

[Brief explanation of the drawing]

The figure is a sectional view of a slot portion of a rotating electrical machine that employs an embodiment of the winding fixing method of the present invention. 1... Winding conductor 2... Earth insulation 3... Semi-conducting layer 4... Elastic sheet 5... Iron core

Claims (1)

[Claims] 1. When the winding wire having a semiconducting layer formed on the surface thereof having aromatic polyamide fibers and carbon fibers is placed in the iron core slot≦2, two-handed conduction C1 is carried out between the winding wire and the slot wall. A winding fixing method characterized by interposing a flexible elastic layer. The method of fixing the winding described in paragraph 1.