JPH0142123B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a contact device for an on-load tap-changer of a tap-changing transformer, as described in detail in the preamble of the claims.

Contact devices of this type are often used in load tap selectors for tap-changing transformers. in this case,
Each fixed tap contact is located in the arc of the inner wall of the cylindrical oil container, and below or above it there is a load-side conductor formed as a continuous contact rolling surface. A contact bridge, which can be rolled with rollers both along the path of motion of the individual tap contacts and along a continuous contact rolling surface, connects a single tap contact to the load-side conductor according to its position. . In this case, the contact bridge is moved by a contact bridge carrier made of insulating material, which contains the contact bridge therein and is moved together by an insulating pipe that is installed inside the cylinder and can be rotated step by step. It will be done. Between the contact bridge carrier and the bearing part, which includes the receiving location of the contact bridge, there is a spring which produces a pressure force.

The disadvantages of this type of contact device are that the two roller movement paths do not run exactly parallel along the cylindrical wall and that the roller circumferences of the two movement paths cannot exactly coincide; This is because one roller movement path includes a large number of unit contacts, whereas the other roller movement path is formed as a continuous contact rolling surface. If a unit contact is provided, the roller movement path will necessarily be uneven. The contact bridge must therefore adapt to these irregularities in the roller movement path of the contact unit for each switching step. Furthermore, this causes friction on the roller surfaces, ie in particular on the contact units and the contact rollers, as well as on the receiving locations of the contact bridges.

These frictions cause breakage and create material debris that promotes contamination of the oil filling the load tap selector.

The object of the invention is to improve the contact device described above in such a way that material debris during rolling is avoided as much as possible. This object is achieved by the measures specified in the characterizing part of the patent claims.

The advantages achieved by the invention are, inter alia, that unnecessary material debris is avoided both on the roller surface and in the receiving area of the contact bridge, and that it is therefore also possible to move the contact bridge particularly lightly.

An embodiment of the invention is illustrated in the accompanying drawing, which shows a cross-section of a cylindrical oil container of a load tap selector, and will be described in detail below. In the cylindrical wall 1 of the oil container of the load tap selector, along the upper rolling surface there are a number of stationary tap contacts 2, 3, which have a connecting part 4 for connecting the connecting conductor on the outside. and has a special contact surface 5 on the inside. A continuous contact rolling surface 6 is provided below the tap contacts 2, 3, which is used as a load conductor or as a neutral point of a load tap selector. Each tap contact 2 or 3 can be selectively connected to a load conductor, that is to say to a contact rolling surface 6, by means of a contact bridge 7. The contact bridge 7 has an upper contact roller 8 and a lower contact roller 9, which are connected to each arm of a contact bridge carrier made of insulating material, not shown in detail. 10,11
They are electrically connected to each other through flexible conductors 12. The two arms 10, 11 of the contact bridge carrier, which are not shown in detail, are movable relative to each other. Pressure springs, also not shown in detail, act on these arms 10 and 11 in the usual manner. The contact bridge carriers - also not individually represented - are moved step-by-step in a known manner by drive pipes located inside the oil container so that - as already mentioned - each Alternatively, a fixed tap contact 2 or 3 can be connected with a contact rolling surface 6 forming a load conductor. Fix contact roller 8 Tap contacts 2, 3
The tap contact is provided with a slope 13 in order to make it easier to run onto or roll off the contact surface 5 of the tap contact. Because each contact roller 8, 9 itself is guided in an arm 10 or 11 of the contact bridge carrier, and because both contact rollers 8, 9 are also movable relative to each other according to the flexible conductor 12, the contact bridge The groove 7 can reliably adapt to the irregularities necessarily present in particular on the roller rolling surface with the individual tap contacts 2, 3. Misalignment of the contact bridge is therefore not as important as the necessarily occurring difference in rotational speed of the two contact rollers.

[Brief explanation of drawings]

The attached drawing is an explanatory diagram of a contact device according to the present invention. The correspondence of the main reference numbers in the figure is as follows. 8, 9... Contact roller, 10, 11... Arm, 12... Conductor.

Claims (1)

[Claims] 1. It has a contact bridge that can roll along two circular arc parts, and the contact bridge consists of two contact rollers that are connected to each other on an axis and are located on one contact bridge support part, It has a fixed contact mounted on a circular arc, which is designed as a unit contact and as a concrete rolling surface, with each contact between the two contacts of the two circular arcs being provided by a rollable contact bridge. In a contact device for an on-load tap-changer of a tap-changing transformer in which one-by-one connection is possible, the axial connection of the contact rollers 8, 9 is constituted by a flexible conductor 12, and each The roller is arm 1 of the contact bridge holder.
0,11, wherein both arms 10,11 are movable relative to each other.