DD133875B1 - CONTACT ARRANGEMENT FOR CONTROL UNITS OF TRANSFORMERS - Google Patents

Description

Field of application of the invention;

The invention relates to a contact arrangement for control devices of transformers, wherein the contact system is floatingly mounted. Such contact arrangements are used for switching high currents, in particular in reversing devices of tap changers.

Characteristic of the known technical solutions;

If switches and selectors of tap changers are used, the contact system usually consists of the fixed contact points, the make contacts, and the movable contacts fastened to the insulating contact bars. The movable contacts consist of two identical, mutually mirror-image components

- 201 758

opposing contact parts, e.g. Contact fingers, which are spring-mounted on a contact carrier. Between the contact fingers a spacer sleeve is floating (DL-PS 119 899).

To reduce dor warming in the contact transition points, the copper existing Ivleserkontakte and contact fingers are silvered at highly loaded contacts, as well as the contact fingers additionally provided with so-called Nietschaltstücken. The ITietschaltstücke consist of the carrier material Cu and the contact material Ag »In order to keep the current load of the contact points as small as possible, also a corresponding number of such contact arrangements are arranged in parallel. However, this leads to an undue increase in the overall volume of the entire contact arrangement. In addition, the built-in spacers may cause the top contact finger to rest on the contact carrier, which may result in blockage of the entire contact assembly (for example, an additional offset between the contact blade center and the pinger contact system center).

Object of the invention;

With the invention, the puncture of such contact arrangements should be improved.

Darle ^ un ^. of the invention of the invention;

The invention has for its object to construct the contact system so that ез is held in the center position and the abrasion is low even at high switching frequency.

According to the invention the object is achieved in that the width of the contact fingers is reduced to a minimum. This minimum is determined by the diameter of the rivet head. The contact force is realized by providing a compression spring over each contact finger. These

3 -

-z- 201 758

Feathers are supported against a floating system, consisting of Spannbolaen and clamping plate, from "The located between the contact fingers spacer sleeve v; is designed as an expansion sleeve.

The force exerted by the sleeve spreading force must be so large that the ersielte frictional force can carry the court of the movable contact system, built V V / den-pods, so must be carried by each expansion sleeve only at least the n-th part of the weight of the movable contact system become.

By the clamping action of the expansion sleeves is achieved that the movable contact fingers are held after sliding out of the knife in a position that allows a renewed trouble-free shrinkage of the knife.

It is also also possible to keep the floating contact system medium ^ tensile, pressure or leaf springs in the middle position. To ensure that even when the first contact of the Liesserkontaktes and possibly existing center offset of knife and movable contact system is lifted the same in the corresponding switching level, the outer contact fingers are provided with casserole. These casseroles have more expedient ise the technologically favorable form of a cone, you can be s £ designed that the finger-mounted IJietschaltstücke come into contact only with the last part of the casserole of the blade contact. Practically éз thus comes only to Abrieberschein ^ mgen when the IJietschaltstücke on the horizontal Ыезserflachen with the required contact force to slide *

The chosen design of the movable contact system will make it possible to raise the whole system when lifting an external contact finger. Thus, the casserole wheels are not needed on all central axes, which allows the required narrow construction.

- 201 758

Embodiment;

In one embodiment, the invention will be explained in more detail below.

In the accompanying drawing show:

Pig. 1: a contact system with bevels and associated blade contact,

Pig. 2: a cut through pig. I, Fig. 3: a section through Figo 1,

Fig. 4: the casserole of a contact finger with chamfers on the blade contact.

In order to reduce contact heating, the current is conducted via a plurality of contact fingers 1, which are provided with rivet switching pieces S (FIG. 2). If the final switching division has been reached, the current conduction takes place via the contact carrier 2 and the contact fingers 1 to the blade contact 4. At the outer contact fingers are the casserole cone 3 "Y / ie Figs. 2 and 3 show, the contact system by means of clamping bolt 5 and clamping plate S is held together. The retaining bolt 11 fixes the contact in its position. The sleeve 7 keeps the Eontaktfinger 1 at a distance.

The compression springs 9 realize the contact pressure. By making the holes for the clamping bolt 5 in the contact carrier 2 with an oversize, a floating mounting of the Kontaktyststerna is achieved. Sine or more sleeves 7, which are designed as expansion sleeves prevent tilting of the contact system and keep it in its blittellage, so that atöruxigaireies run-in of the knife can be done. Fig. 4 shows an outer contact finger 1 with casserole 3 at the first casserole for lifting and centering of the

-5- 201 758

Contact system · Without the casserole cone 3 there would be a risk of jamming, especially if the knife and contact system are more center-offset. The casserole 3 causes due to the floating mounting of the entire system lifting all Iiontaktfinger 1, wherein the casserole 3 is formed so that the Nietschaltstück 8 comes into contact only with the last part of the run-up slope of the blade contact 4 The iJietschaltstück 8 is during lifting of the Contact system always removed by a distance of 10 from the knife bevel.

Claims (4)

invention claim 1. Contact arrangement for control devices of transformers, in which a contact carrier Spannbolzcn and clamping plate a plurality of contact parts are arranged floating, characterized in that by means of a spacer sleeve which simultaneously works as an expansion sleeve, or by means of additional pressure, tension or leaf springs, the contact system in Middle position is maintained and that the outer contact fingers of the divided into several parallel sub-fingers contact fingers are provided with enema. 2. contact arrangement according to item 1, gekennze ichnet characterized in that the expansion sleeve consists of an axially slotted, cylindrical tube and a 'Jerkstoff with resilient properties, and the spreading force of one or more sleeves is so large that the resulting frictional forces between the sleeve and Contact carrier corresponds to at least the weight of the movable contact system. 3 · Contact arrangement according to item 1, characterized ichnet characterized in that the additionally mounted on the outer contact fingers inlet guides have the shape of a casserole. 4. Contact arrangement according to item 1 and 3, characterized in that the casserole is provided with a collar. For this 2 sheets of drawings