EP1610425B1 - Brush spring for slip-ring current collector - Google Patents

Abstract

Each of two brush springs (6) has a long straight shaft (7) and is made of electrically conducting material. A C-section foil (9) of noble metal on the end (8) of the spring makes contact with the rotor (3) of the electrical machine. The spring support (1) has a flat plate (2) with holes (21) to accommodate the folded clamping end (14) of each spring. The end of the long straight spring portion is multiply-folded. A right-angled joggle (13) is succeeded by a straight portion engaging the side of the hole. A gentle curve (17) leads to a clamping portion (16) with a S-bend (18), which passes through the hole and ends on a curve (20) directed toward the center of the flat plate.

Description

The invention relates to a brush spring for a slip ring transmitter according to the features in the preamble of claim 1.

Such a brush spring is one of the prior art by DE 101 58 381 A1. It has a straight extending wire-like contact shaft, which may consist of a copper-beryllium alloy. On the free end of the contact shaft a sleeve of gold is pushed and fixed by crimping. The sleeve facing away from the end of the contact shaft is in a helical spring coil over. At this spring coil is followed by a parallel to the contact shaft extending straight length portion, which merges into an S-shaped bent clamping portion. The free end of the clamping portion points in a direction away from the contact shaft direction.

To fix this brush spring to a board of a stator of a Schleifringübertragers it is necessary to provide not only a bore for receiving the contact shaft in the board, which is coated with an electrically conductive material, but also to arrange a further recess next to the bore, which passes the clamping section allowed. At least the part of the recess must also be coated with electrically conductive material on which the clamping section comes to rest.

Since the contact shaft has to be pushed through the hole, in the known case, the sleeve can be fixed only after the fixation of the brush spring on the board end side of the contact shaft.

The invention is - starting from the prior art - the object of the invention to provide a brush spring for a slip ring, which is not only simpler, but also requires less M ontageaufwand.

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

The essence of the invention is the fact that the contact stem merges over a rectangular step in the clamping section extending in a bending plane with the step. This not only has the advantage that in a circuit board of a stator of a Schleifringübertragers only one recess must be provided, through which the entire clamping portion can be inserted to plant the gradation on the board, but that the contact shaft of the brush spring already before their fixation can be provided on the board with the end-side contact area of a noble metal, in particular gold, which then comes to a slip ring of the rotor part of Schleifringübertragers to the plant. This makes it possible to pre-assemble brush springs in the assembly line process. The assembly a Schleifringübertragers is simplified and made cheaper economically.

If several brush springs arranged side by side, also only a single recess in the board is required. However, it may be provided for the lying in the recess clamping portions of the brush springs frontally opposite each other and adapted to the cross section of the brush springs grooves.

The gradation between the contact shaft and the clamping portion forms according to the embodiment of claim 2 is a part of the two mutually facing U-shaped longitudinal portions having clamping portion of a bracket. This bracket is pushed during assembly through the recess in the board, wherein it is compressed due to its resilient character in the bending plane. If the gradation reaches the underside of the board, the stirrup can spread again, so that the U-shaped longitudinal sections surround the edge regions of the recess, whereby the brush spring is fixed in position.

According to claim 3, the bracket on a trapezoidal contour. This allows the bracket to be easily pushed through the recess. The support region of the clamping portion is formed by two aligned legs of the U-shaped longitudinal sections. The opposite legs of the U-shaped longitudinal sections engage under the board.

Both the insertion of the clamping portion by a particular oval recess of a board and the positional fixation of the brush spring on the board can be achieved with the features of the embodiment of claim 4. This is followed by the gradation on the contact stem a U-shaped bracket. The legs of the bracket have a distance from each other which is greater than the length of the recess in the board. At the end of the stirrup facing away from the gradation, an arcuate curvature connects to the support area of the clamping portion the side facing away from the rotor part of the Schleifringübertragers side of the board forms. The bearing area merges into an S-shaped compensating area, which is then adjoined by an L-shaped clamping area with an end-side clamping leg. By this training is therefore a leg of the bracket at one end face of the recess and a plant leg of the clamping area at the other end face. The clamping leg is angled in the opposite direction to the gradation, so that the brush spring is properly secured to the board after assembly on the board.

For mounting the brush spring on the board, it is only necessary to push the clamping portion under springy compression in the bending plane through the recess. If the abutment area has passed through the recess, the clamping section can relax again, so that then the gradation rests against the side of the board facing the rotor part and the clamping section is fixed over the support area and the clamping area.

The brush spring may be formed from a cross-sectionally round spring wire section. However, it is more advantageous according to the features of claim 5 that the spring wire section has a rectangular cross section, wherein its thickness measured in the bending plane is smaller than the width measured transversely thereto. As a result, sufficient stability is ensured with good resilient properties.

A preferred embodiment of the spring wire section is seen in the features of claim 6. Thereafter, the width to thickness ratio is approximately 3.5: 1.

In view of the fact that brush springs can also be pre-assembled by the inventive design in the assembly line method, it is conceivable according to claim 7, that the contact area is formed by a clamped onto the contact shaft sleeve. This can consist of gold.

It is even more advantageous that, according to the features of claim 8, the contact region is formed by a U-shaped shell, which is welded to the contact shaft via the inner sides of its legs. Preferably, the laser welding is used. Such a design allows greater manufacturing tolerances and also reduces the economic outlay, since less noble material must be used for the contact area, especially since only a peripheral region of the contact area comes to rest on a slip ring.

In this context, it is then expedient according to claim 9 that the cup-shaped contact region consists of a spring-hard gold alloy.

The manufacturing cost of providing less noble material for the contact area is made even more economical that is formed according to the features of claim 10, the contact area by a welded to the contact shaft gold wire. The definition of the gold wire on a flat side of the contact shaft is preferably carried out by resistance welding.

The cost of materials is further reduced even further, especially from a cost point of view, if according to claim 11, the contact shaft consists of a copper-nickel alloy.

According to claim 12, the contact shaft may consist of stainless 1.4310.

Figur 1

im schematischen Vertikalschnitt einen Ausschnitt aus einem Schleifringübertrager;

Figur 2

in vergrößertem Maßstab einen Teilquerschnitt durch die Darstellung der Figur 1 entlang der Linie II-II, in Richtung der Pfeile IIa gesehen;

Figur 3

eine weitere Ausführungsform, ähnlich der Darstellung der Figur 2;

Figur 4

in vergrößertem Maßstab einen Querschnitt durch die Darstellung der Figur 1 entlang der Linie IV-IV, in Richtung der Pfeile IVa ge- sehen;

Figur 5

eine Darstellung ähnlich derjenigen der Figur 1, gemäß einer weiteren Ausführungsform;

Figur 6

in vergrößertem Maßstab den Ausschnitt VI der Figur 5 und

Figur 7

in vergrößertem Maßstab einen Querschnitt durch die Darstellung der Figur 5 entlang der Linie VII-VII in Richtung der Pfeile Vlla gesehen.

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

FIG. 1

in schematic vertical section a section of a slip ring transformer;

FIG. 2

on an enlarged scale, a partial cross section through the representation of Figure 1 along the line II-II, seen in the direction of the arrows IIa;

FIG. 3

a further embodiment, similar to the representation of Figure 2;

FIG. 4

on an enlarged scale, a cross section through the illustration of Figure 1 along the line IV-IV, seen in the direction of the arrows IVa;

FIG. 5

a representation similar to that of Figure 1, according to another embodiment;

FIG. 6

on an enlarged scale, the detail VI of Figure 5 and

FIG. 7

on an enlarged scale, a cross section through the representation of Figure 5 along the line VII-VII seen in the direction of the arrows VIIa.

In the figure, reference numeral 1 denotes a slip ring transmitter illustrated in the diagram with a circuit board 2 of a stator part, not otherwise illustrated, and with a rotor part 3 for the transmission of electrical currents and data.

Both on the rotor part 3 facing side 4 of the board 2 and on the opposite side 5 extending conductor tracks of an electrically conductive material, the width of which depends on what amounts of data or which current in which amperage between the rotor part 3 and to be transmitted to the stator.

The electrical connection between the provided on the circumference with slip rings not shown rotor part 3 and the stator is effected by spring wire sections formed from brush springs 6. Each brush spring 6 has a straight extending contact shaft 7 made of a copper-nickel alloy. At the free end 8 of the contact shaft 7 there is a contact region 9 which cooperates with a slip ring on the rotor part 3. In the embodiment of Figure 1, the contact portion 9 is characterized by a sleeve Gold formed, for example, is determined by crimping on the end 8 of the contact shaft 7.

4, the contact region can also be formed by a U-shaped shell 9a, which is connected via the inner sides 10 of its legs 11 to the contact shaft 7 by laser welding 12. This shell 9a then only needs to lie on the side of the contact shaft 7, where it comes into contact with the slip ring of the rotor part 3. It preferably consists of a spring-hard gold alloy.

As can also be seen from FIG. 1, the contact shaft 7 is provided with a rectangular step 13 at a distance from the contact region 9. At this rectangular gradation 13 is followed by a in a bending plane E-E with the gradation 13 extending clamping portion 14 at. The clamping portion 14 has a support area 15 and a clamping area 16. The support area 15 is formed by an arcuate curvature of one end of a subsequent to the gradation 13 U-shaped bracket 17. The support region 15 passes over an S-shaped compensating region 18 into the L-shaped clamping region 16. This clamping region 16 has an abutment limb 19 and an end-side clamping limb 20 angled away from it. The clamping limb 20 is deflected towards the abutment limb 19 at an angle which is <90 °.

For assembly, a brush spring 6 provided in advance with the contact region 9 or 9a is pushed with the complete clamping section 14 from the side 4 of the board 2 facing the rotor part 3 through an oval recess 21 in the board 2 (FIGS. 1 and 2), wherein the clamping portion 14 in the bending plane EE of the gradation 13, the clamping portion 16 and the support portion 15 is compressed. Has the support portion 15 passes through the recess 21, the clamping portion 14 can expand again, so that then the support portion 15 on the side facing away from the rotor part 3 of the 5 Board 2 is located and the clamping leg 20, the board 2 engages under the recess 21 from her.

As Figure 3 shows, in the arrangement of a plurality of brush springs 6 side by side correspondingly larger recesses 21 a in the board 2 are provided. The mutually opposite areas of the recess 21 a are provided with adapted to the contour of the wire of the clamping portion 14 of the brush springs 6 grooves 22.

Both the rounded end faces of the recess 21 and the grooves 22 of the recess 21 a are coated with an electrically conductive material which is in communication with the conductor tracks on the board 2.

In the embodiment according to FIGS. 5 to 7, a board 2a is provided with cutouts 21b. Otherwise, the board 2a corresponds to the already described board 2 according to FIG. 1.

3 denotes a schematically illustrated rotor part.

The brush spring 6a consists of a spring wire section with a rectangular cross section (Figure 7). In this case, the thickness D measured in the bending plane E-E according to FIG. 7 is smaller than the width B measured transversely thereto. The ratio of the width B to the thickness D of the brush spring 6a is approximately 3.5: 1.

The contact region 9b at the end of the straight extending contact shaft 7 is formed by a short gold wire, which is fixed by resistance welding on the rotor part 3 facing flat side 23 of the contact shaft 7.

At the contact shaft 7 is followed by a rectangular section 13a, a clamping portion 14a. This comprises a U-shaped longitudinal section 24. At this U-shaped longitudinal section 24, a trapezoidally curved bracket 17a connects, which in turn merges into a U-shaped longitudinal section 25. The support area 15a is aligned by two aligned Leg 26 of the U-shaped longitudinal portions 24, 25 are formed, which lie on the side facing away from the rotor part 3 5 of the board 2a, whereas the clamping portion 16a is formed by the U-shaped longitudinal portions 24, 25.

When mounting the brush spring 6a this needs to be pushed only with its bracket 17a through the recess 21b in the board 2a until the gradation 13a of the U-shaped length portion 24, at which a lower leg 27 is formed at the same time, together with the for alignment aligned legs 28 of the other U-shaped longitudinal portion 25 on the rotor part 3 facing side 4 of the board 2a is present. When the legs 27, 28 rest on this side 4 of the board 2a, engage the U-shaped longitudinal portions 24, 25, the edges 29 of the recess 21b, so that the brush spring 6a is perfectly fixed in position.

However, the edges 29 of the recess 21b may be provided with grooves, as illustrated in Figure 3 for the round in cross-section brush spring 6. In the embodiment of FIGS. 5 to 7, the grooves then have a cross section adapted to the cross section of the brush springs 6a.

REFERENCE NUMBERS

1 -

A slip ring transmission

2 -

circuit board

2a -

circuit board

3 -

rotor part

4 -

Page v. 3

5 -

Page v. 3

6 -

brush spring

6a -

brush spring

7 -

Contact shank

8th -

free end v. 7

9 -

contact area

9a -

contact area

9b -

contact area

10 -

Inside pages v. 11

11 -

Thighs v. 9a

12 -

laser welding

13 -

gradation

13a -

gradation

14 -

clamping section

14a -

clamping section

15 -

Support area v. 14

15a -

support area

16 -

Clamping area v. 14

16a -

clamping range

17 -

hanger

17a -

hanger

18 -

compensation range

19 -

Investment limb v. 16

20 -

Clamping leg v. 16

21 -

Recess in 2

21a -

Recess in 2

21b -

Recess in 2a

22 -

Grooves in 21 a

23 -

Flat side v. 7

24 -

U-shaped length

25 -

U-shaped length

26 -

Thighs v. 24, 25

27 -

Thighs v. 24

28 -

Thighs v. 25

29 -

Edges v. 21 b

B -

Width v. 6a

D -

Thickness v. 6a

E-E -

bending plane

Claims (12)

1. Brush spring for a slipring transmitter (1) which comprises a spring wire section (7, 14; 7, 14a), which has a contact shaft (7) extending in a straight line and having an end-side contact region (9, 9a, 9b), which is made from a material which is of a higher quality than the material of the contact shaft (7), in which case a clamping section (14, 14a), which is bent a plurality of times and is split into a bearing region (15, 15a) and into a clamping region (16, 16a), adjoins that end of the contact shaft (7) which is remote from the contact region (9, 9a, 9b), characterized in that the contact shaft (7) merges with the clamping section (14, 14a) via a right-angled step section (13, 13a), said clamping section (14, 14a) extending in a bending plane (E-E) with said step section (13, 13a).
2. Brush spring according to Claim 1, characterized in that the step section (13a) forms part of the clamping section (14a) of a bracket (17a), which clamping section (14a) has two mutually facing U-shaped length sections (24, 25).
3. Brush spring according to Claim 2, characterized in that the bracket (17a) has a trapezoidal contour, the bearing region (15a) being formed by two aligned limbs (26) of the U-shaped length sections (24, 25).
4. Brush spring according to Claim 1, characterized in that the bearing region (15) of the clamping section (14) is formed by an arcuate curvature of one end of a U-shaped bracket (17) which adjoins the step section (13), the bearing region (15) merging with the L-shaped clamping region (16) via a compensation region (18) with an S-shaped curvature, said clamping region (16) having an end-side clamping limb (20) which is bent back in the opposite direction to the step section (13).
5. Brush spring according to one of Claims 1 to 4, characterized in that the spring wire section (7, 14a) has a rectangular cross section, its thickness (D) measured in the bending plane (E-E) being smaller than the width (B) measured transversely thereto.
6. Brush spring according to Claim 5, characterized in that the ratio between the width (B) and the thickness (D) of the spring wire section (7, 14a) is dimensioned, for example, as 3.5:1.
7. Brush spring according to one of Claims 1 to 6, characterized in that the contact region (9) is formed by a sleeve which is clamped onto the contact shaft (7).
8. Brush spring according to one of Claims 1 to 6, characterized in that the contact region (9a) is formed by a U-shaped shell, which is welded to the contact shaft (7) via the inner sides (10) of its limbs (11).
9. Brush spring according to one of Claims 1 to 8, characterized in that the contact region (9a) is made from a spring-hard gold alloy.
10. Brush spring according to one of Claims 1 to 6, characterized in that the contact region (9b) is formed by a gold wire welded onto the contact shaft (7).
11. Brush spring according to one of Claims 1 to 10, characterized in that the contact shaft (7) is made from a copper/nickel alloy.
12. Brush spring according to one of Claims 1 to 10, characterized in that the contact shaft (7) is made from stainless steel 1.4310.

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