JPS584180Y2 - Vibration damping device for tap changer - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a vibration damping device for a tap changer housed in a transformer.

As shown in FIG. 1, this type of tap changer 1, regardless of whether it is an on-load tap changer or a no-load tap changer,
Generally, the transformer has a built-in suspended structure that is suspended from the top plate 3 of the transformer tank 2 and housed within the tank.

This hanging type built-in structure tap changer 1 has a transformer tank 2.
The top plate 3 of the tap changer 1 has high insulation reliability because the live parts are not exposed to the outside.
It is widely used because of its advantages such as ease of installation and ease of assembly and transportation.

However, a tap changer with a hanging structure has a cantilevered structure with the upper end being a fixed end and the lower end being a free end.Moreover, the mass is concentrated on the free end side, so when transported, etc. When subjected to vibration, a large bending stress is generated on the fixed end (top plate) side, and there is a risk that the hanging member may be damaged or destroyed.

For this reason, an allocation device 4 is provided as shown in FIG. 2, which supports the free end so that it will not be displaced in the horizontal direction even if subjected to horizontal vibration.

That is, the tap changer 1 shown in FIG. 2 houses a switching switch 7 within an insulating outer cylinder 6, while a tap selector 8 for selecting a transformer tap is supported at the bottom of the insulating outer cylinder 6. The lower end of the tap selector 8 is supported by the vibration damping device 4.

This control device 4 has a protrusion 4A projecting downward from the lower end of the tap selector 8 and a steady rest cylinder 4B fixed to the bottom plate of the transformer case 2, and this protrusion 4A is loosely fitted into the steady rest cylinder 4B. By this, the tap changer 1 is damped.

However, when the mounting seat 9 for fixing the steady rest cylinder 4B is welded to the transformer case 2, this vibration damping device 4 is
Since the welding must be done in exact alignment with the mounting position of the tap changer 1, which is installed on the transformer tank 1, the manufacturing error of the transformer tank 2 must be minimized by large-scale sheet metal work, which is a difficult task. was.

In addition, if the fixing position of the mounting seat 9 is deviated, the protrusion 4
When A was inserted into the steady rest cylinder 4B, there was a risk that stress would be concentrated in a part of the joint between the head case 6A of the insulating outer cylinder 6 and the top plate 3.

Furthermore, the work of attaching and removing the steady rest cylinder 4B before or after transporting the transformer had to be carried out inside the narrow tank 2, which created a poor work environment and made it impossible to carry out the work efficiently. .

Furthermore, when a steady rest tube is installed inside a transformer for permanent use, it must be made of an insulating material to ensure ground insulation of the tap changer 1, and the insulating material must have a specified strength. It was expensive because it had to be made to last.

Furthermore, since a sufficient ground insulation distance d must be maintained between the protrusion of the allocation device and the mounting seat, the protrusion 4
The height of the transformer tank 2 must be increased by the provision of the A and the mounting seat 9, which has the disadvantage that the material for the tank and the amount of insulating oil injected into the tank increase.

This invention takes the above-mentioned points into consideration, and aims to provide a vibration damping device for a tap changer that improves the rigidity of the insulating outer cylinder, has good workability, and is economical.

An embodiment of this invention will be described below with reference to the accompanying drawings.

FIG. 3 shows a vibration damping device for a tap changer according to this invention, in which reference numeral 10 is a tank of a transformer, the inside of which is filled with insulating oil.

A tap changer 12 is installed on the top plate 11 of this transformer tank 10.
is suspended and suspended.

The tap changer 12 has a head case 13, and a collar portion of the head case 13 is hooked to an opening in the top plate 11.

An insulating outer cylinder 14 is vertically concentrically installed on the head case 13, and the head case 13 has a mounting seat, to which a switching switch 15 is removably mounted with a mounting bolt or the like. .

Further, the top opening of the head case 13 is closed by a detachable head cover 16 to prevent the charging part from being exposed to the outside.

Thus, the switching switch 15 is fixed to the head case 13 and housed in the insulating outer cylinder 14 when the tap switching device 12 is in operation.

Further, by removing the head cover 16, the switching switch 15 can be lifted from the insulating outer cylinder 14 using a lifting device (not shown), thereby facilitating maintenance and inspection work.

On the other hand, the lower end of the insulating outer cylinder 14 is integrally closed with a bottom metal fitting 17 and has a bottomed shape.
A tap selector 18 is attached to the tap selector 18.

The lower end of this tap selector 18 is located above the bottom plate of the transformer case 10 by a ground insulation distance d.

The bottom metal fitting 17 is firmly fitted with the insulating outer cylinder 14 from below, and has an integrally constructed concave portion 20 for steadying in the center thereof.

A protrusion 21 projecting downward from the lower end of the cylindrical switching switch 15 is fitted into the anti-sway recess 20, and the recess 20 and the protrusion 21 form a vibration damping device 22.

By forming the vibration damping device 22 in this manner and engaging the lower end of the switching switch 15 with the bottom metal fitting 17 via the vibration damping device, the switching switch itself can be utilized as a reinforcing member against lateral vibration.

In addition, the switching switch 15. When the switch is removed and transported, or when the switching switch itself is structurally weak and cannot be used as a reinforcing member, a steady rest body, for example steady rest cylinder 25, can be attached and detached inside the insulating outer cylinder 14 using a mounting bolt or the like. In addition, the tip projection 26 of the steady rest cylinder 25 may be inserted into the recess 20 of the washer 17, thereby reinforcing against lateral vibration.

In this case, the steady rest cylindrical body 25 does not necessarily have to be formed into a cylindrical shape, and can take various shapes.

The steady rest cylinder 25 may be interposed between the switching switch 15 and the insulating outer cylinder 14.

Further, the vibration damping device may have a protrusion formed on the bottom metal fitting and a recessed portion formed on the switching switch or the steady rest cylindrical body.

As mentioned above, the vibration damping device for a tap changer according to this invention does not require difficult installation work such as welding the mounting seat to the bottom plate of the transformer tank or attaching and detaching the steady rest cylinder inside the tank. Not only is it unnecessary, but the workability is good and the insulation is not required because the upper part of the switching switch and steady rest body can be detachably attached to the head case, and the lower part can be supported on the bottom of the insulating outer cylinder. The strength of the tube can be increased, and the structure is simple and can be manufactured economically and inexpensively.

In addition, since there is no need to provide a protrusion or mounting seat at the bottom end of the tap selector, the height of the transformer tank can be reduced accordingly, reducing the amount of tank material and insulating oil used, making it more economical. This has the advantage that it can be made into a small and lightweight transformer.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing the structure of a conventional hanging type tap changer housed in a transformer case, Fig. 2 is a sectional view showing a vibration damping device of a conventional tap changer, and Fig. 3 is a sectional view showing an embodiment of a vibration damping device for a tap changer according to this invention,
FIG. 4 is a sectional view showing a modification of this invention. In each country, the same code indicates the same or equivalent part, and 1
0 is the transformer case, 11 is the top plate, 12 is the tap changer,
13 is a head case, 14 is an insulating outer cylinder, 15 is a switching switch, 16 is a head cover, 17 is a bottom metal fitting, 18 is a tap selector, 20 is a recess for steady rest, 21 is a protrusion, and 22 is a vibration damper. The device 25 is a steady rest cylinder.

Claims (2)

[Scope of utility model registration request] (1) A head case attached to the transformer tank,
A tap changer consisting of a bottomed insulating outer cylinder hanging vertically from the head case, a switching switch housed within the insulating outer cylinder, and a tap selector suspended from the bottom of the insulating outer cylinder. wherein the head case is removably provided with a switching switch or an upper part of a steady rest housed in an insulating outer cylinder for the purpose of temporarily damping vibrations in place of the switching switch;
A vibration damping device for a tap changer, characterized in that a lower end thereof is fitted and supported by the bottom of the insulating outer cylinder to damp lateral vibrations applied to the tap changer. (2) A utility model characterized in that an upper end is fixed inside the head case between the switching switch and the insulating outer cylinder, a lower end is fitted to the bottom of the insulating outer cylinder, and a steady rest is interposed. A vibration damping device for a tap changer according to claim 1.