DE2714227C3 - Sleeve-like insulator - Google Patents

Description

The invention relates to a sleeve-like insulator for the electrically insulated guidance of a first electrical one Conductor in an opening or a recess of a second electrical conductor, wherein the first electrical conductor in partial areas on the inner jacket and the second electrical conductor in partial areas rests on the outer jacket of the sleeve-like insulator.

In electrical devices, especially in devices Ηργ l.eistungsclektronik, it is often necessary to have a electrical conductor passed through another electrical conductor insulated, wherein the both conductors are at different potentials. For example, this problem occurs in power converters where the heat sinks are used by power thyristors to carry current, and in the heat sinks electrical supply lines must be insulated. The isolation and at the same time the leadership One of the two conductors can most easily be determined by observing the air and creepage distances in accordance with the regulations and / or by adding insulating material. Sleeve-like insulators are used for this purpose known of the type mentioned. In the case of higher voltages, the simple intermediate layer of suitable Insulating materials do not always achieve the desired success, as partial discharges can occur, what can lead to malfunctions of the equipment.

As a suitable measure against Tcilcdladungen when routing and insulating a conductor through a For others, therefore, insulation with liquid, with a discharge-resistant material, was used. B. with glass or Porcelain, and also the complete potting made with suitable Gicßhar / cn, with particular with the last insulation method, air connections are to be avoided. However, these methods lead to high manufacturing costs.

The task is to design an insulator of the type mentioned at the beginning in such a way that it both guides of the first conductor as well as a partial discharge-free one Isolation guaranteed.

According to the invention, this object is achieved in that the inner and outer profile of each H'jlsen-

I "cross-section is chosen so that at each point of the sleeve cross-section along the shortest distance between the two conductors is the sum of the air gap between the first conductor and the inner jacket of the air gap between the second conductor and the outer jacket

i ") of the sleeve equal to or greater than a predetermined one Route is.

By supporting the two conductors on the outside or Inner jacket of the sleeve is flawless Leadership of the first leader ensured. There on everyone

-> <> Place of implementation clearly defined in length and maintainable clearances are available, in conjunction with a suitable insulating material the use of partial discharges for the isolator can also be prevented. The inventive

The sleeve-like insulator is also extremely easy to manufacture, since it only has to be put over the first conductor and together with this in the Recess or the breakthrough of the second conductor can be introduced, including neither expensive

to tools, specially trained staff is required. Sleeve-like insulators according to the invention can also be produced in series from a suitable plastic, so that they can be used inexpensively can be.

ΙΊ Preferably the inner and outer profile is each Sleeve cross-section a polygon, circular or elliptical. This allows an adaptation to diverse Cross-sections of the first conductor and the opening or the recess in the second conductor

κι received.

In the following, the sleeve-like insulator according to the invention is described in greater detail by way of example with reference to FIGS. 1 to 6 explained. Different exemplary embodiments are shown in the figures of the isolator. Are there

π provide identical components with the same reference numerals.

Fig. 1 shows on an enlarged scale the detail of a conductor 1, in the opening la a second conductor 2 is insulated. Both the transverse

v) section of the opening la as well as the cross section of the conductor 2 is circular. A sleeve-like insulator 3 shown in section is provided for guidance and insulation, the conductor 1 on the outer sheath 3a and the conductor 2 on the inner sheath 3b of the insulation

■ ») tors 3 is applied, whereby a clear guidance of the Head 2 is given.

In the embodiment of FIG. 1, both the outer profile and the inner profile of the insulator 3 is a square. For the distance J ₁ between the

With conductor 1 and the outer jacket 3a and the air gap S ₁ between the conductor 2 and the inner jacket 3 /) of the insulator 3, the following applies at every point:

.V ₁ + .ν, 2 .V

If, therefore, the distance S in connection with the material of the insulator 3 is chosen so that the air distance given with the distance .S is sufficient to prevent the conversion of partial discharges

these partial discharges at every point in the implementation prevented.

For the selection of the material of the insulator 3 is the dielectric constant and the dielectric strength determining. The dielectric constant should be as small as possible, i.e. H. near the dielectric constant of air. This is the case, for example, with a material under the name Teflon is commercially available.

With FIGS. 2 to 6 it is demonstrated that the idea on which the invention is based, namely the exact maintenance of an air gap at which partial discharge does not yet occur, combined with the simultaneous leadership of a conductor can be realized in a variety of ways. Figs. 2, 4 and 5 show many

corner as a profile for the inner and outer jacket 3o and 3b of the insulator, for example hexagonal, triangular and star-shaped profile. This means that practically every voltage that can be expected between conductors 1 and 2 can be controlled. 3 and 6 show the adaptation of the sleeve-like insulator 3 to special cross-sections of the conductor 2 or the opening la in the conductor 1. In FIG. 3, the insulation of a conductor 2 with a hexagonal cross-section is ensured with a hollow cylindrical insulator. 6 shows the insulation and simultaneous guidance of a conductor 1 with a rectangular cross-section in an opening la with a rectangular cross-section by means of an insulator 3 with an elliptical cross-section.

For this purpose 2 blue drawings

Claims (4)

Patent claims: 1. A sleeve-like insulator for the electrically insulated guidance of a first electrical conductor in a breakthrough or a recess of a second electrical conductor, the first electrical conductor in partial areas on the inner jacket and the second electrical conductor in partial areas on the outer jacket of the sleeve-like insulator, characterized in that the inner and outer profile (3a and 3b) of each sleeve cross-section is chosen so that at each point of the sleeve cross-section along the shortest distance between the two conductors (1 and 2) the sum of the air gap (s ₂ ) between the first conductor (2) and the inner jacket (3 b) and the air gap (S ₁ ) between the second conductor (1) and the outer jacket (3fl) of the sleeve is equal to or greater than a predetermined distance (S) . 2. Isolator according to claim 1, characterized in that the inner and outer profile of each Sleeve cross-section is a polygon (Fig. I, Fig. 2, Fig. 4 and Fig. 5). 3. Isolator according to claim 1, characterized in that that the inner and outer profile of each sleeve cross-section is circular (Fig. 3). 4. Isolator according to claim 1, characterized in that that the inner and outer profile of each sleeve cross-section is elliptical (Fig. 6).