JPS6134852Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a connection terminal device equipped with an insulator bushing used in a high voltage stator outlet of a hydrogen-cooled rotating electrical machine, particularly a large turbine generator. The terminal boxes of rotating electric machines that use hydrogen gas as a cooling medium, such as large-capacity turbine generators, employ insulator bushings that pass through the terminal boxes in an airtight manner. FIG. 3 shows a conventional example of an airtight mounting structure for this bushing, and reference numeral 1 designates a terminal box fixed to a stator frame (not shown). This terminal box 1 is composed of a box body 2 and a lid 3 that closes the opening of this box body 2, and hydrogen gas is sealed inside. The bushing 4 that penetrates the terminal box 1 includes an insulator tube 5 that houses a conductor (not shown) and a metal insulator tube support 6 that forms a mounting flange around the insulator tube 5 that is attached to the cement 7.
It is fixed and configured by. The bushing 4 is airtightly attached to the outer surface of the lid 3. That is, an elastic packing 8 made of rubber or the like is interposed between the insulator tube 5 forming a part of the flange surface and the lid 3, and the flange portion is fastened to the lid 3 with bolts 9. The tightening elasticity of the elastic packing 8 is controlled by adjusting the thickness of the adjustment plate 10 interposed on the flange surface of the insulator support 6. However, such a structure has the following drawbacks. That is, since the cement that bonds the insulator tube 5 and the insulator tube support 6 is a breathable material, the elastic packing 8 must be installed inside the cement 7, that is, between the insulator tube 5 and the cement. Since the bolt 9 is used to tighten the outside of the cement 7, that is, the insulator support 6, when the bolt 9 is tightened, a tensile force or a shearing force due to a bending moment with the packing part as a fulcrum is applied to the cement part. The cement 7 is strong against compressive force, but is a brittle material against external forces such as bending and tension. Therefore, cracks may occur depending on how tightly the bolt 9 is tightened.
Even if there is no abnormality during tightening, stress is generated and vibrations from operation are added, which can lead to damage. This weakens the elasticity of the elastic packing 8 and impairs airtightness. Also, when replacing the elastic packing 8,
Connection wires and heavy bushings 4 that cannot be carried by hand must be removed from the terminal box, and work efficiency is particularly poor when the terminal box 1 is located below the stator. In addition, a troublesome work of adjusting the adjustment plate 10 to appropriate the compression amount of the elastic packing 8 is added. The purpose of this invention is to provide a connection terminal device for hydrogen-cooled rotating electric machines that can be tightened without applying excessive force to the flange bonding part of the bushing, and that can maintain the sealing gasket while the bushing is attached to the terminal box. It is about providing. An embodiment of the present invention will be described with reference to the drawings. 1st
The figure shows the lead terminal portion of the stator winding attached to the lower part of the stator frame (not shown). The terminal box 1 includes a box body 2 fixed to a stator frame and a lid 3 that closes a lower opening of the box body 2. Hydrogen gas is sealed inside the terminal box 1. A predetermined number of bushings 4 are attached to the lower surface of the lid 3 with bolts 9, and the insulator tubes 5 pass through the holes in an airtight manner. The stator winding connection wire and the external connection wire are electrically coupled to both ends of the conductor 14 passing through the bushing 4 , respectively. The above-mentioned penetrating portion is kept airtight by an elastic packing 11, which will be described later. Next, details of the penetration portion of the bushing 4 will be explained with reference to FIG. The configuration of the bushing 4 is basically the same as the conventional one. That is, a metal insulator support 6 forming a flange having bolt holes is adhesively fixed to the insulator tube 5 with cement 7.
This insulator support 6 is firmly tightened and fixed to the lid 3 with bolts 9. Now, the above-mentioned airtightness is maintained between the lid 3 and the insulator tube 5. As shown in FIG. 2, a packing groove 3b is provided in the hole 3a of the lid 3 so as to open to the inside of the terminal box and to the insulator tube side. An elastic packing 11 made of rubber or the like is attached to the groove 3b so as to surround the insulator tube 5. This elastic packing 11 is pressed by an annular packing holder 12 which is pressed from inside the terminal box and fastened to the lid 3 by a bolt 13. This packing presser 12 has a packing 1 on the inner circumference side.
It has an L-shaped cross section with a protrusion that presses 1, and is divided into two radially. As shown in FIG. 1, an inspection window 15 is detachably attached to the box body 2 of the terminal box 1 . Next, the effect will be explained. According to the above-described structure, since the mounting flange of the bushing 4 and the lid 3 are in contact with each other with smooth surfaces, even when the bolts 9 are tightened, no unreasonable force is applied to the fragile cement portion. In addition, since the gasket 11 that maintains airtightness is detachably attached to the inner surface of the lid 3, the gasket 11 can be removed from the inspection window 15 with the bushing 4 attached.
1 can be tightened or replaced. Therefore, according to this embodiment, the bushing 4
It can be installed without applying unreasonable force to the system, has high reliability in maintaining airtightness, and can simplify maintenance work. Furthermore, as shown in FIG. 3, the bushing 4 used to form a part of the flange surface on the insulator tube 5 in order to abut the packing 8, but since this is no longer necessary, the insulator tube 5 shown in FIG. Since it is only necessary to make the adhesive part of the insulator support 6 slightly thicker as shown in the figure, the outer diameter D of the insulator support 6 can be made smaller than that of the conventional structure. This is effective in reducing the mounting area of the bushing 4 and making the terminal box 1 more compact. As described in detail above, the present invention has an insulator-shaped bushing in which the fixed part of the flange is mechanically bonded with a fragile material, and is fastened to the terminal box with smooth surfaces touching each other, thereby preventing excessive force from being applied to the bonded part. It has excellent mechanical reliability because it does not overhang the bushing, and the sealing bushing is installed in the terminal box so that it can be attached and removed from the inside of the terminal box, making maintenance work on the bushing easy without disassembling the bushing. be able to.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing one embodiment of the connection terminal device for a hydrogen-cooled rotating electric machine of the present invention, Fig. 2 is an enlarged cross-sectional view of the bushing penetration part of the device shown in Fig. 1, and Fig. 3 is a conventional FIG. 3 is a sectional view showing a bushing penetration portion of the connection terminal device of FIG. 1 ... terminal box, 4 ... bushing, 5... insulator tube, 6... insulator tube support, 7... cement, 9... bolt, 11... elastic packing.

Claims (1)

[Scope of Claim for Utility Model Registration] A terminal box provided in the stator frame of a hydrogen-cooled rotating electric machine, and a bushing made of a rod-shaped insulator tube and an insulator support having a flange portion bonded with cement, the said bushing being a terminal box. In a connection terminal device in which a flange portion is attached to the outer surface of the terminal box by passing through the box and fastened with bolts, and the space between the terminal box and the bushing is sealed with a packing, the cement adhesion of the bushing is achieved by tightening the bolts. The fastening surface between the terminal box and the flange is formed to be smooth so that no external force is applied to the terminal box, and the gasket is detachably attached between the terminal box and the insulating tube from inside the terminal box. Connection terminal device for hydrogen-cooled rotating electric machines.