DE29800281U1 - Slip ring transmitter - Google Patents

Description

Applicant: Walter Kraus GmbH

Electrical engineering
Aindlinger Str. 13 8 6167 Augsburg

Representatives: Patent attorneys

Dipl.-Ing. H.-D. Ernicke Dipl.-Ing. Klaus Ernicke Schwibbogenplatz 2b D-86153 Augsburg

Date: 13.01.1998

File: 920-12 er/sw

OJ DE-G 298 OO 281.7

Note: Walter Kraus GmbH 30.03.1999 er/ge DESCRIPTION

Slip ring transformer

The invention relates to a slip ring transmitter with the features in the preamble of the main claim.

Such a conventional slip ring transmitter is known, for example, from DE-43 14 164 Al, DE-C-10 36 371, DE-AS-12 75 672 or US-A-2,404,969. It consists of an internal shaft with a surrounding frame on which the slip rings and brushes are arranged and held so they can move relative to one another.

In practice, such slip ring transformers sometimes also have a rotary encoder for measuring the rotational position and the rotational movements between the shaft and the frame. With known rotary encoders, there is a problem with the cable routing because the cable has to be routed along the outside of the frame or housing of the slip ring transformer, which makes it necessary to loop it around.

US-A-5,231,374 deals with the transmission of measurement signals from a sensor arranged on a rotating part to a stationary evaluation unit. The rotating part can be, for example, a vehicle axle or the like. The sensor connected to the rotating part measures physical influences, e.g. pressure, voltage, temperature, speed, acceleration, etc., that act on the rotating part. The rotating part is connected to a slip ring transmitter, with which the sensor signals are to be transmitted to the static evaluation unit. The measurement signal from the sensor is also amplified,

before it is transmitted to the external evaluation unit via the slip ring transmitter.

It is therefore an object of the present invention to provide a slip ring transmitter with a more suitable rotary encoder.

The invention solves this problem with the features in the main claim.

&iacgr;&ogr; The slip ring transformer according to the invention has the advantage that the cable of the rotary encoder can be guided along the inner shaft of the slip ring transformer. This prevents looping around. The rotary encoder cable can be guided together with the adjacent cables for the brushes or the slip rings.

In contrast to the usual rotary encoder designs, the invention has a connection on the inside of the rotary encoder, which is usually connected to the shaft. This means that the rotary encoder cable can be laid without stress. It is particularly advantageous if the shaft is designed as a hollow shaft, because all cables can be routed through its interior in a protected manner.

Advantageous embodiments of the invention are specified in the subclaims.

The invention is illustrated by way of example and schematically in the drawings. In detail:

Figure 1: a longitudinal section through a

Slip ring transformer with a rotary encoder,

Figure 2: a top view of the

Slip ring transformer of Figure 1 and 10

Figure 3: an enlarged detailed view of the

Encoder and its cable connection in half section according to Figure 1.

Figure 1 shows a slip ring transmitter (1) in longitudinal and half section, which has an internal shaft (5), preferably a hollow shaft, and a surrounding frame (14) or housing. The shaft (5) and the frame (14) are movable relative to one another and are mounted in particular so as to be rotatable about the central longitudinal axis. The brushes (10) or slip rings (11) are arranged on the shaft (5) and on the frame (14). Power lines (12, 13) lead to the brushes (10) and slip rings (11). In the embodiment shown, the slip rings (11) are on the shaft (5) and the brushes (10) on the frame (14). However, the arrangement can also be reversed. In the embodiment shown, the shaft (5) is also rotatable relative to the frame (14), which is held relatively stationary.

However, the kinematic assignment can also be reversed.

The frame (14) consists of two or more axial rods, which are anchored at the top and bottom in a cross-connecting head plate (8) or a base plate (9). The head plate (8) also contains, for example, the roller bearing for the internal shaft (5). The shaft or hollow shaft (5) can in turn

have several clamping rods evenly distributed in a circle, on which the slip rings (11) are mounted and held.

The slip ring transmitter (1) has a rotary encoder (2) for measuring the relative rotational positions and rotational movements between the shaft (5) and the frame (14). The rotary encoder (2) is preferably arranged centrally on the slip ring transmitter (1) in the area of the head plate (8) above the shaft bearing. It has an inner part (3) connected to the shaft (5) and a surrounding outer part (4) which is connected to the frame (14), e.g. via the head plate (8). The inner part (3) and the outer part (4) are mounted so they can rotate relative to one another, with the axes of rotation of the rotary encoder (2) and the slip ring transmitter (1) being aligned.

The rotary encoder (2) is designed as an electrical rotary encoder in any suitable manner. It can be a rotary encoder (2) with relative, cyclic absolute or absolute measurement. The rotary movements between the inner part (3) and outer part (4) are sensed, for example, via one or more disks, which can preferably be done contactlessly using a light barrier arrangement, a capacitive or inductive sensor or in any other suitable manner.

The rotary encoder (2) emits electrical measurement or control signals, which are fed via a line (7) to a control circuit or any other suitable further processing. An evaluation or control circuit can also be integrated into the rotary encoder (2).

The cable connection (6) for the single or multi-core cable (7) is located on the inner part (3). It is designed, for example, as a soldering lug or as a cable outlet. The

The inner part (3) can have a suitable recess in relation to the surrounding outer part (4) to ensure free access to the cable connection (6). Alternatively, there can also be a certain axial projection.

The line (7) is guided along the shaft (5) starting from the inner part (3). In the preferred design of the shaft (5) as a hollow shaft, the line (7) is laid axially in its interior. It can be laid together with the lines (13) for the slip rings (11), which are also located inside. However, it can also be guided separately from these. In another alternative embodiment, the line (7) can also be guided in the wall of the shaft (5) in a suitable manner.

As Figure 3 shows, the inner part (3) of the rotary encoder (2) is connected to the shaft (5). The cable (7) is guided and laid inside the shaft bearing via a suitable passage on the connecting part between the shaft (5) and the inner part (3). The cable (7) follows the rotary movements of the inner part (3) and the shaft (5) without any stress.

In the embodiment shown with the shaft (5) that can rotate relative to the frame (14), the outer part (4) of the rotary encoder (2) is designed as a stator, while the inner part (3) connected to the shaft (5) functions as a rotor. This kinematic assignment can also be reversed, if, for example, the frame (14) can rotate relative to a relatively stationary shaft (5).

Modifications to the embodiment shown are possible in various ways. For example, the design and mutual arrangement of shaft (5) and frame (14) can be chosen as desired. The design of the rotary encoder (2) is also arbitrary.

LIST OF REFERENCE SYMBOLS

1 slip ring transformer

2 encoders

3 Inner part, rotor

4 Outer part, stator

5 Shaft, hollow shaft

6 Cable connection

7 Cable, encoder 8 Head plate

9 Footplate

10 Brush

11 Slip ring

12 Cable, brushes

13 Cable, slip ring

14 Frame

Claims (5)

Φ β 9 ·' ■ # *· - 7 CLAIMS FOR PROTECTION 1.) Slip ring transmitter with an internal shaft and a surrounding frame as well as an electrical rotary encoder, which has an inner and outer part that can move relative to each other, characterized in that the line connection (6) is arranged on the inner part (3) of the rotary encoder (2) and the line (7) along the &iacgr;&ogr; shaft (5). 2.) Slip ring transmitter according to claim 1, characterized characterized in that the inner part (3) is designed as a rotor.
15 3.) Slip ring transmitter according to claim 1 or 2, characterized in that the shaft (5) is connected to the inner part (3). 4.) Slip ring transmitter according to claim 1, 2 or 3, characterized in that the line connection (6) is designed as a soldering lug or as a cable outlet. 5.) Slip ring transmitter according to one of claims 1 to 4, characterized in that the shaft (5) is designed as a hollow shaft, with the line (7) being guided through its interior.