EP1320155B1 - Slip ring arrangement - Google Patents

Abstract

The device has at least one non-ferrous inner ring (14) embedded in insulating material (19) as a rotor component, a graphite outer ring (15) enclosing the inner ring to form a gap (18), concentrically centered relative to the inner ring by lateral insulating material and electrically coupled to the inner ring by contact lamella (22) bridging the gap and at least one graphite slip contact (34) pressed against the outer ring as a stator component.

Description

The invention relates to a slip ring transformer for transmitting electrical currents and / or signals between a stator and a rotor.

In Schleifringübertragern larger diameter, it is known to use the so-called coal / coal technology. This is the case, for example, with larger generators. In order to be able to determine electrical contacts in the circumferentially closed slip rings, the slip rings must have large wall thicknesses so that sufficiently large threads can be accommodated.

Thus, the use of coal / coal technology in Schleifringübertragern with small diameters and circumferentially closed slip rings is not possible.

Nevertheless, in order to be able to use the coal / coal technique even with slip ring transmitters of smaller diameter, the slip rings have been divided into individual segments and each slip ring segment fixed on a corresponding support body, in particular of brass, by gluing.

In such designs then gaps between the circumferentially successive slip ring segments were unavoidable. The gaps led to electrical interference with the consequence that the transmission of signals, in particular measurement signals, was associated with inaccuracies.

A Schleifringübertrager in which are pressed against the outer ring sliding contacts made of graphite, goes out of the US 2001/0033117 A1 out

The FR 1 063 144 , which is considered to be the closest prior art, describes a carbon slip ring with current dissipation ring. The current dissipation ring is metal and surrounded by a gap at a radial distance from an outer ring of graphite. Inner ring and outer ring are electrically coupled by Stromableitungskörper.

The invention is - starting from the prior art - the object of the invention to provide a slip ring, which is economical to produce and can be operated even with a small diameter in the coal / coal technology.

This object is achieved with the features specified in claim 1.

Thereafter, a circumferentially closed inner ring of a non-ferrous metal, in particular made of brass, is now embedded in an insulating compound as part of a rotor. The insulating compound may be, for example, epoxy resin. The inner ring is electrically contacted with a rotor associated with the electrical connection and connected from here with a front-side cable gland.

On the circumference of the inner ring extends a peripherally also closed outer ring made of graphite. This outer ring is laterally fixed by insulating materials, that it is properly concentric centered to the inner ring. Here, a gap is selectively formed between the inner ring and the outer ring, which, when exposed to heat, has the different coefficients of expansion of e.g. Brass and graphite bill. The temperature range between the ambient temperature and the maximum permissible operating temperature must be taken into account.

In order to constantly produce a perfect electrical coupling between the inner ring and the outer ring while bridging the gap, metallic contact lamellae are provided on the circumferential side of the inner ring, which are arranged over the entire circumference of the inner ring or only over partial areas could be. These contact blades are designed so that they are resilient in itself and in this way can easily follow the changes in the gap size between the inner ring and outer ring due to heat and constantly make the electrical coupling between the inner ring and outer ring.

The contact blades may e.g. made of a copper-beryllium alloy and then treated by heat treatment.

The invention is associated with the particular advantage that the outer ring of graphite can be kept small not only in the wall thickness, but also in diameter. In this way, it is possible to provide compact slip ring transmitters with outer diameters of 200 mm and smaller, which can transmit not only signals, in particular measuring signals, but also electrical currents of up to about 50 amperes.

In addition, the invention ensures that now speeds up to about 60 m / s can be achieved.

Furthermore, with the invention it is achieved that the sliding contact only has to be pressed against the outer ring with a comparatively small force in order to ensure perfect signal and / or current transmission. A low contact pressure leads to a significantly lower wear and ultimately to a longer service life of a slip ring. In addition, the abrasion is very low, so that inside the Schleifringübertragers in principle no pollution can occur and consequently can not be caused by an abrasion-induced pollution electrical short circuits.

To give the contact blades a secure grip on the inner ring, a circumferential groove is incorporated according to claim 2 in the outer surface of the inner ring. In this circumferential groove now the contact blades are distributed over the entire circumference or embedded only in sections. There the contact blades have a central cambered portion, this section is regardless of the size of the gap between the inner ring and outer ring constantly on the inner surface of the outer ring.

The determination of the contact blades in the circumferential groove is effected in particular by clamping on the side of the crown located webs.

A perfect corrosion protection of the contact blades is achieved according to claim 3, characterized in that the adjacent to the contact blades areas of the outer surface of the inner ring are gold plated.

The measure of claim 4 contributes to the fact that a proper power and signal transmission can be ensured without high contact pressure of the sliding contact would be required to the outer ring.

A particularly advantageous embodiment of the invention is seen in the features of claim 5. Such an embodiment generally has a plurality of spaced apart coaxially associated inner rings and outer rings and the outer rings associated sliding contacts. The inner rings are cast here in an insulating compound in the form of an insulating bushing. The outer rings are distanced from each other by insulating materials in the form of insulating rings. To each outer ring two sliding contacts are pressed, which are attached to the ends of pivot arms. The pivot arms point in opposite directions. In order to realize an axially compact design, the each outer ring associated pivot arms are arranged offset to the respective adjacent outer ring in the circumferential direction. A mutual disturbing influence is avoided in this way.

Each inner ring is via electrical connection lines embedded in the insulating bush to a contact terminal at one end of the insulating bushing guided. Cables from this contact connection then lead to an end-face cable gland on the rotor.

According to the features of claim 6, the insulating bushing is fixed on a hollow shaft of the rotor by gluing. This is preferably done only at the ends of the insulating bushing. For this purpose, a longitudinal section of the hollow shaft, which may consist of steel or of another material, provided circumferentially in the approximately central length region of the insulating bushing with a smaller diameter. The outer rings and the insulating rings are successively pushed from a front end of the insulating bushing on the inner rings and the insulating bushing. For this purpose, the insulating bush at one end has a peripheral collar. At the other end a disc is clamped against the last insulating ring, so that then all outer rings and insulating rings are securely fixed in position. The hollow shaft can be mounted on end-side bearings in end walls of the stator.

The each outer ring associated pivot arms are each hinged to a bracket. This holder is fixed on a parallel to the axis of rotation of the rotor extending, fixed in the stator support rod by clamping. The support rod can be fixed for example in the end walls of the stator. The successive brackets are positionally determined by spacers surrounding the support bar.

Figur 1

in der Stirnansicht einen Schleifringübertrager;

Figur 2

einen vertikalen Längsschnitt durch die Darstellung der Figur 1 entlang der Linie II-II in Richtung der Pfeile lla gesehen und

Figur 3

in vergrößerter Darstellung den Ausschnitt III der Figur 2.

The invention is explained in more detail with reference to an embodiment illustrated in the drawings. Show it:

FIG. 1

in the front view of a slip ring transformer;

FIG. 2

a vertical longitudinal section through the representation of Figure 1 along the line II-II seen in the direction of the arrows lla and

FIG. 3

in an enlarged view the detail III of Figure 2.

1, a slip ring transmitter for transmitting electrical currents and / or signals is designated in FIGS.

The slip ring transformer 1 has a hollow shaft 2 made of steel as part of a rotor 3. End of the hollow shaft 2 rolling bearings 4, 5 are provided, which are used in end walls 6, 7 of a stator 8. On the circumference of the end walls 6, 7, a cylindrical shell 9 is fastened by screws 10.

On the hollow shaft 2, an insulating material, in particular epoxy resin, pushed in the form of an insulating sleeve 12 and secured by gluing to the stop on a collar 11. The bonding takes place only at the ends of the insulating bushing 12. For this purpose, the hollow shaft 2 is provided with a peripheral recess 13 in the approximately central longitudinal region of the insulating bush 12.

At the periphery of the insulating bush 12, a total of nine inner rings 14 are cast from brass. As can be seen in particular in FIG. 3, the inner rings 14 have the same outer diameter as the insulating bushing 12. On the circumference of each inner ring 14 is an outer ring 15 made of graphite. Between the outer surface 16 of the inner ring 14 and the inner surface 17 of the outer ring 15, a gap 18 is present, which takes into account the different thermal expansion coefficients of the materials of the inner ring 14 and the outer ring 15. The orientation of each outer ring 15 via lateral insulating compounds, in particular epoxy, in the form of insulating rings 19. The outer diameter of the insulating rings 19 is smaller than the outer diameter of the outer rings 15th

The inner rings 14 have circumferential grooves 20 formed in their outer surface 16. The regions 21 of the outer surfaces 16 adjacent to the circumferential grooves 20 are gold plated. As shown in FIG. 3, contact lamellae 22 are inserted into the circumferential grooves 20. These contact blades 22 have lateral webs 23 and a central crown 24. Via the webs 23, the contact blades 22 in the circumferential grooves 20 by clamping fixed in position. The crowns 24 are permanently on the inner surfaces 17 of the outer rings 15. Due to this configuration, a contact of the inner rings 14 with the outer rings 15 via the contact blades 22 is ensured at each gap size between the inner rings 14 and the outer rings.

The axial position fixing of the outer rings 15 and the insulating rings 19 is effected by a front side with screws 25 on the insulating bush 12 fixable disc 26 which presses the insulating rings 19 and outer rings 15 against a radial collar 27 of the insulating sleeve 12.

Each inner ring 14 is connected in a manner not shown with a contact terminal 28 in the radial collar 27 of the insulating sleeve 12. An electrical connection to a cable gland 29 provided on the end side of the hollow shaft 2 then takes place via this contact connection 28.

In the end walls 6, 7 of the stator 8 are offset in the circumferential direction two support rods 30 releasably fixed. The support rods 30 extend parallel to the axis of rotation 45 of the rotor 3. On the support rods 30 brackets 31 are threaded and clamped. The axial distance of the brackets 31 is fixed by the support rods 30 surrounding sleeves 32. To the brackets 31 pivoting arms 33 pointing in opposite directions are hinged, the end wear sliding contacts 34 made of graphite. The sliding contacts 34 are pressed by tension springs 35 against the outer surface 36 of the outer rings 15.

Of the pivoting arms 33 from not shown electrical connections extend to a cable gland 37 in the end wall 6 of the stator eighth

Designed as a floating bearing 4 is determined by a snap ring 38 in the end wall 6. It is also against an inner annular collar 39 of the end wall 6. The other rolling bearing 5 is a fixed bearing on the one hand over a snap ring 40 and a ring collar 41 on the hollow shaft 2 and on the other hand fixed by a screw 42 fixed to the end wall 7 lid 43 and an annular collar 44 on the end wall 7.

REFERENCE NUMBERS

1

A slip ring transmission

2

hollow shaft

3

rotor

4

roller bearing

5

roller bearing

6

Front wall v. 8th

7

Front wall v. 8th

8th

stator

9

Coat of v. 8th

10

Screws f. 9

11

Collar on 2

12

insulating bush

13

Turn to 2

14

inner rings

15

outer rings

16

outer surface v. 14

17

inner surface v. 15

18

Gap between 16 and 17

19

insulating rings

20

Circumferential grooves in 16

21

Areas next to 20

22

Multilams

23

Stege v. 22

23

Crowning v. 22

25

Screws f. 26

26

disc

27

Radial collar at 12

28

Contact Termination

29

Cable gland

30

support rods

31

Mounts to 30

32

Pods on 30

3.3

swing arms

34

sliding contacts

35

Tension springs on 33

36

outer surface v. 15

37

Cable gland

38

Snap ring f. 4

39

Ring collar on 6

40

Snap ring f. 5

41

Ring collar on 2

42

Screws f. 43

43

Cover at 7

44

Ring collar on 7

45

Rotation axis v. 3

Claims (7)

1. Slipring transmitter, which has at least one inner ring (14), which is embedded in an insulating composition (12) as part of a rotor (3) and consists of a non-ferrous metal, and an outer ring (15), which surrounds the inner ring (14) at a radial distance so as to form a gap (18), consists of graphite, is centred concentrically with respect to the inner ring (14) by lateral insulating compositions (19) and is electrically coupled to the inner ring (14) by metallic contact laminates (22) bridging the gap (18), at least one graphite sliding contact (34), as part of a stator (8), being pressed against the outer ring (15).
2. Slipring transmitter according to Patent Claim 1, in which the contact laminates (22) are fixed in position in a circumferential groove (20) in the outer surface (16) of the inner ring (14) and are pressed in a sprung manner against the inner surface (17) of the outer ring (15) so as to bridge the gap (18) between the inner ring (14) and the outer ring (15).
3. Slipring transmitter according to Patent Claim 1 or 2, in which those regions (21) of the outer surface (16) of the inner ring (14) which are adjacent to the contact laminates (22) are gold-plated.
4. Slipring transmitter according to one of Patent Claims 1 to 3, in which the sliding contact (34) is pressed in a sprung manner against the outer surface (36) of the outer ring (15).
5. Slipring transmitter according to one of Patent Claims 1 to 4, which has at least two inner rings (14) and outer rings (15), which are in each case associated coaxially with one another, and sliding contacts (34), which are associated with the outer rings (15), in which slipring transmitter the inner rings (14) are cast into an insulating composition (12) in the form of an insulating bush at an axial distance from one another, the outer rings (15) are spaced apart from one another by insulating compositions (19) in the form of insulating rings, and the sliding contacts (34), associated with one another in pairs, are pressed against each outer ring (15), the sliding contacts (34) being provided at the ends of pivoting arms (33) which point in opposite directions, and the pivoting arms (33) associated with one outer ring (15) being offset circumferentially with respect to the pivoting arms (33) of the adjacent outer ring (15).
6. Slipring transmitter according to Patent Claim 5, in which the insulating bush (12) is fixed on a hollow shaft (2) by means of adhesive bonding, and the outer rings (15) and the insulating rings (19) are pushed axially onto the inner rings (14) and the insulating bush (12), respectively, and fixed in position on the insulating bush (12).
7. Slipring transmitter according to Patent Claim 5 or 6, in which the pivoting arms (33) associated with one outer ring (15) are articulated on a holder (31), which is fixed, by means of clamping, on a supporting rod (30), which extends parallel to the axis of rotation (45) of the rotor (3) and is fixed in the stator (8).

Images