EP0911918A2 - Arrangement for the transmission of medium frequency current using a slip ring transmitter - Google Patents

Abstract

Electrical power is transmitted between parts with relative movement by a slip ring arrangement. This has a carrier (8) consisting of multiple thin metal foils (4) in a sandwich construction. Between adjacent foils are insulating layers (5) with electrical connections provided by pin inserts (7).

Description

In industry, medium frequencies are becoming increasingly common Currents used to make inductive couplings improve. In this context, for example Welding transformers on robots, all frequency controlled Motors, transmitters and receivers for mobile phones, Radio and television as well as data transmission technology etc. typical applications for inductive coupling.

Practice has shown that with increasing frequency of the Induction current the efficiency of the above Application examples increases disproportionately. So e.g. a transformer when doubling the Frequency with approx. Factor 4 in weight and volume. As disruptive influence in the transmission of medium-frequency However, induction currents occur the physical effect on that the current flow with increasing frequency to the Edge zone of an electrical conductor is pushed. Out of it results in only the outer one at high frequencies Layer or edge zone can be used with a conductor can.

For the future successful use of Slip ring transmission systems achieve the transmission medium-frequency currents are becoming increasingly important. Of the However, the disadvantage of today's technology is that the Use of medium-frequency currents in slip ring transmission systems only with very large geometric Dimensions is possible. Such dimensions are therefore necessary because enough edge zone of the conductor for the Transfer must be provided.

If theoretically a round one at 50 Hz currents Solid rod can be used as a ladder to the necessary Transmitting electricity can with medium frequency currents, approx. 30 kHz, only one "tube" as an equivalent conductor cross-sectional area be used. So the higher the Frequency, the thinner the "tube". Same thing However, the conductor cross-section must be able to transmit currents remain, which results in a "Pipe" must be larger in diameter to be sufficient To provide the edge zone as a ladder.

The "pipe" mentioned above is a physical model to understand. Indeed, in practice Solid profiles and wires are used, the inner core of which Power transmission hardly contributes. The core of the leader Basically only brings dead weight and is not physically / technically for power transmission efficient.

This problem is in the form of permanently laid lines detached from waveguides or copper pipes. For the application in endlessly rotatable power transmission systems, namely the slip ring transmitter, leads the described physical effect to mechanically very large and heavy Devices. These devices would be on the market in this form not be accepted. Furthermore, that is with today Operating principle of the slip ring transmitters Carbon brushes practically unusable at high frequencies, because the sintered materials meet the required Do not allow current densities in the peripheral zones and thus would cause self-destruction.

Starting from the prior art, it is an object of the invention a technologically new one with grinding tracks and Pantograph-equipped arrangement for transmission to create medium frequency currents that only come from the desired current-carrying edge zone.

The solution to this problem consists in the features of Claim.

The invention is based on the knowledge that the PCB technology for the development of Slideways and pantographs appear suitable. Consequently, the innovative essence of the invention is several thin metal foils in sandwich arrangement mechanically stable to fix and electrically connect.

Then it becomes a writable in the physical model "Pipe" in the longitudinal direction in several segment strips so to speak cut open and these are then stacked.

There is one between each segment strip Insulating layer.

In a practical embodiment, several thin Metal foils incorporating insulation layers too layered in a stack of films. Multiple in the longitudinal direction of the film stack evenly distributed Vias ensure homogeneous distribution the current density. Through the stacked metal foils only the desired cross section remains Peripheral zone, which means the construction volume by far more than that Half is reduced.

The uniform and safe electrical Through-contacting the metal foils with each other and to a connection contact can e.g. thereby realized be that a hole perpendicular through the foil package drilled and the wall of the resulting hole is copper-plated. The holes used must be used because of the homogeneous power distribution with very small Diameters are introduced. The length of the hole, depends on the number of metal foils relatively large. The ratio diameter / length is approximately 1: 8 to 1:10.

By suitable arrangement of the metal foils and by The installation of grounded electrical screen surfaces can the entire system is electromagnetically compatible to the outside be designed.

Because a slip ring transmitter consists of a rotating and a standing part consists of the principle of action to guarantee both parts are designed the same. With the rotating The counterpart to the grinding track comes the attachment of the contact elements. Here is care to wear that of the flowing in the metal foils Current can be concentrated in these contact elements must, with an acceptable level of efficiency To ensure power transmission.

A well-known slip ring transformer for 150 A at 600 VAC 50 Hz currently fits in a hat box. The same Slip ring transformer with a current of 150 A and 16 kHz is about the size of a truck wheel. the main goal The invention is now the 16 kHz slip ring transformer from truck wheel size to hat box size. Around To achieve this goal, the above described new technological measures carried out.

What for use on the closed ring, like described, applies, is also on straight ladder to apply.

Figur 1

in der Perspektive einen elektrischen Leiter im physikalischen Modell;

Figur 2

die Segmente gemäß Figur 1 in gestapelter Form, ebenfalls in der Perspektive;

Figur 3

in der Perspektive einen elektrischen Leiter in Form eines Folienstapels, teilweise im Schnitt, und

Figur 4

einen Querschnitt durch einen Schleifringübertrager mit Folienstapel gemäß Figur 3.

The invention is explained in more detail below on the basis of exemplary embodiments illustrated in the drawings. Show it:

Figure 1

in perspective an electrical conductor in the physical model;

Figure 2

the segments of Figure 1 in a stacked form, also in perspective;

Figure 3

in perspective an electrical conductor in the form of a film stack, partly in section, and

Figure 4

4 shows a cross section through a slip ring transmitter with a film stack according to FIG. 3.

Thereafter, as can be seen in FIG. 1, a physical model shown tube 1 in Longitudinal direction in several segment strips 2 cut open, in the embodiment six Segment strips 2. These are then one above the other stacked (Figure 2).

There is one between each segment strip 2 Insulating layer 3.

In a practical embodiment according to Figure 3 several thin metal foils 4 incorporating Insulation layers 5 layered to a film stack 6. Repeatedly in the longitudinal direction of the film stack 6 evenly distributed vias 7 ensure a homogeneous distribution of current density. Through the stacked metal foils 4 remains as a conductor cross section only the desired edge zone.

The uniform and safe electrical contact the metal foils 4 with each other and not closer to one The illustrated connection contact can e.g. thereby be realized that a hole is perpendicular through the Foil package 6 drilled and the wall of the resulting Lochs is copper-plated. The holes used must here because of the homogeneous current distribution in very small diameters can be introduced. The length of the Bore, depending on the number of metal foils 4, is relatively large. The ratio diameter / length is about 1: 8 to 1:10.

By suitable arrangement of the metal foils 4 and the introduction of grounded electrical screen surfaces the whole system can be electromagnetic outside be made compatible.

Since a slip ring transmitter 8 (Figure 4) from one rotating part 9 and a standing part 10, to guarantee the principle of operation, both parts 9, 10 designed in principle the same. With the rotating part 9 there is the attachment of the contact elements 11. Care is taken here that the in the Metal foils 4 flowing current in these contact elements 11 is focused to with an acceptable To ensure efficiency of power transmission.

In Figure 4, the insulating layers 5 are by a Glass hard tissue formed, which at the same time the stability both the rotating parts 9 and the standing Part 10 guaranteed.

The axis of rotation of the slip ring transmitter 8 is with Designated 12.

The standing part 10 is on the radially outer circumference provided a guide ring 13. The guide ring 13 is via only schematically through center lines 14 illustrated screws with the standing part 10th connected. In the guide ring 13 is a guide groove 15 formed, in which the radially outer peripheral region 16 of the rotating part 9 engages in a sliding manner.

List of reference symbols

1

- Pipe

2nd

- segment strips

3rd

- insulating layer

4th

- metal foils

5

- insulation layers

6

- Stack of films

7

- plated-through holes

8th

- slip ring transmitter

9

- rotating part of 8th

10th

- standing part of 8th

11

- contact elements

12th

- axis of rotation v. 8th

13

- guide ring

14

- screws

15

- guide groove

16

- outer circumference v. 9

Claims (1)

Arrangement for the transmission of medium frequency currents in a slip ring transmitter (8), in which the current leading areas made of several thin metal foils (4) exist in sandwich assignment, with two neighboring ones Metal foils (4) through an insulating layer (5) electrically separated from each other, but via vias (7) are connected to one another in an electrically conductive manner.

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