CN110462945B

CN110462945B - Grounding contact

Info

Publication number: CN110462945B
Application number: CN201880021331.XA
Authority: CN
Inventors: S·舍勒
Original assignee: Stemmann Technik GmbH
Current assignee: Stemmann Technik GmbH
Priority date: 2017-06-23
Filing date: 2018-04-19
Publication date: 2022-08-09
Anticipated expiration: 2038-04-19
Also published as: EP3642910C0; EP3642910A1; DE102017113911B4; DE102017113911A1; CN110462945A; EP3642910B1; WO2018233749A1

Abstract

The invention relates to a ground contact for the controlled diversion of current, comprising a brush holder (2), wherein the brush holder (2) comprises a base plate (3) and at least one brush box (4) for accommodating a brush (6), and the at least one brush box (4) is connected to the base plate (3) in a form-fitting manner.

Description

Grounding contact

Technical Field

The invention relates to a grounding contact for controlled deflection of an electric current.

Background

The ground contact is a low-ohm bridge that protects critical parts of the component from damage due to high currents. In rail technology, the ground contact conducts the current around critical locations (e.g., wheel bearings).

DE4127336a1 discloses a brush holder which forms a return contact and/or a ground contact between components that are movable relative to one another on a rail vehicle. The brush holder has at least one metallic brush box, in which the brush is movably arranged, and at least one pressure device, which is held in a recess on the brush box and exerts a force on one end of the brush. The brush box transitions integrally into the base plate. The base plate with the brush box is a casting.

Furthermore, the manufacture of such brush holders is complicated by the internal contour of the brush box. The cast brush box must be cut with a relatively high stock removal. These tools are costly. Another disadvantage is that the brush box is not subject to standardization and therefore the dimensions of the brush box may vary.

Disclosure of Invention

The object of the invention is to provide a ground contact with a compact and robust brush holder, which can be produced inexpensively and simply and is suitable for standardization.

The object is achieved according to the invention by a grounding contact for the controlled deflection of current, comprising a brush holder which comprises an electrically conductive base plate and at least one brush box for accommodating a brush, and which is connected to the base plate in a form-fitting manner, the brush box having a clamping tongue by means of which the brush box is held clamped on the base plate, the clamping tongue having hooks at its free end which engage behind an edge of a brush box receptacle in the base plate, the brush box having a support surface for supporting on the underside of the base plate, the brush box extending completely through the brush box receptacle.

The present invention relates to a grounding contact for controlled diversion of current (i.e. so that current is directed in a controlled manner). The ground contact includes a brush holder having a base plate and at least one brush box for receiving a brush. The at least one brush box is connected to the base plate in a form-fitting manner.

An advantage of the grounding contact according to the invention is the modular design in terms of the brush box. The cost for the machining step is reduced by dividing the brush holder into the base plate and the brush box manufactured separately from the base plate. The substrate and the brush box can be produced separately from one another by laser and water jet cutting methods. The costs of the mold and the die for the casting mold in the casting process are no longer incurred. Machining using laser and water jet methods results in a smaller cut amount. The entire brush box need not be cut out. The modular construction principle of the brush holder allows an improved flexibility of the production method and a reduction of the production time. According to the invention, it is possible by the modular construction principle of the brush holder to standardize the brush box and to manufacture it as a mass product, independently of the construction of the base plate.

The invention provides that the brush box is designed as a standard component for a correspondingly universal brush with dimensions of 40 × 20mm or 32 × 12.5 mm. Standardized brush boxes having other dimensions may also be used in the present invention. The brushes are preferably metal graphite brushes, which are also referred to as carbon brushes. However, the brush can also be made of other metals or metal alloys with high electrical conductivity and can contain copper, silver or molybdenum, for example.

The ground contact has a contact means in the form of a litz wire which can be connected to the base plate and which conducts the current to the brush. The litz wire is flexible and allows the brush to track under the influence of spring force. The connection between the base plate and the litz wire is realized by a tubular cable lug on the litz wire, by means of which the litz wire is screwed to the base plate in an electrically conductive manner.

Of importance to the invention is the form-locking connection between the base plate and the brush box. The base plate has at least one brush box receiving portion for receiving the at least one brush box. By means of the form-fitting connection of the base plate to the brush box, the brush box can be easily assembled and easily replaced if necessary, for example if the brush box is damaged or worn. The form-locking connection is releasable.

The supporting substrate is preferably a planar plate made of an electrically conductive material, in particular metal. Advantageously, the brush box has clamping tongues by means of which the brush box is held clamped on the base plate. The clamping tongues preferably have hooks at their free ends, which hooks act behind the edge of the brush box receptacle in the base plate. The clamping tongues are arranged on at least three sides of the brush box. Since the brushes are substantially rectangular, the brush box also has a substantially rectangular cross section. A diametrically opposed arrangement of the clamping tongues is desirable. The arrangement of three clamping tongues also enables a sufficient fixing of the brush box. The form-locking connection to the clamping tongues has the following advantages: the connection between the base plate and the brush box can be made without further fastening means (for example screws, pins or rivets) and the use of tools is therefore eliminated. This makes assembly easy. The clamping force of the clamping tongues is selected to be so great that the clamping tongues do not have to be secured against rebounding by additional securing means.

The brush box has a support surface for supporting on the underside of the base plate. Preferably, the support surface is adjacent to the fixed end of the clamping tongue. Thereby, the brush box is clampingly held in a direction perpendicular to the base plate.

The brush box extends completely through the brush box receptacle. The clamping tongue or hook protrudes from the base plate. By combining a positive-locking connection with a clamping connection, the brush box is securely fixed and a correct guidance of the brushes is ensured.

The base plate may have a corresponding number of brush box receiving portions for a plurality of brushes. Whereby a larger current can be transmitted. The operational safety is likewise improved. Preferably, the base plate has three brush box receiving portions. In this case, the individual brush boxes can preferably be produced separately. It is also possible to produce a plurality of brush boxes as a common component, which is subsequently connected to the base plate.

In order to apply a spring force to the brushes in the brush box in the longitudinal direction of the brush box, a spring element is provided, which is preferably configured as a wound spring strip. The spring element has the task of exerting a spring force on the brush, so that the brush always bears against the slide body in order to transmit the current. Preferably, the spring element is fixed in the brush box. For this purpose, the spring holder is fitted in the brush box, so that the holding force for the spring element is absorbed by the brush box itself. No force is introduced into the substrate. The brush box, which comprises the spring holder and the spring element, forms a separate structural assembly, which is provided for coupling to the base plate.

There is no need for the brush box to be implemented to be electrically conductive. The brush is connected to the base plate in an electrically conductive manner via a litz wire. The brush box can therefore be made of a non-conductive material, in particular of plastic. This has the following advantages: the entire ground contact is easier and also more advantageous in terms of its manufacture. The brush box can be produced in particular as an injection-molded part at low cost. Another advantage is the good slip properties of some plastics, which in turn is optimal for guiding the brushes in the brush box.

In order to protect the ground contact from mechanical loads (e.g. stone impacts), the ground contact preferably has a cover which protects the brush with the electrical terminals, the contacts and the litz wires. The cover can be fixed to the base plate in a non-positive and/or positive manner, for example by means of screws.

Drawings

The invention will be explained in more detail below with the aid of embodiments shown in the schematic drawings. Wherein:

fig. 1 shows a side view of a brush holder known from the prior art;

fig. 2 shows a top view of the brush holder according to fig. 1;

fig. 3 and 4 show perspective views of a ground contact with a cover according to the invention;

fig. 5 shows a top view of a ground contact without a cover according to the present invention;

fig. 6 shows an axial section through the ground contact according to fig. 5 with a cover according to the invention;

fig. 7 shows a cross-sectional view of the ground contact according to fig. 5 with a cover according to the invention;

FIG. 8 shows a top view of a ground contact having a plurality of brush boxes and brushes in accordance with the present invention, an

Fig. 9 shows a sectional view of the grounding contact according to the invention according to fig. 8.

Detailed Description

Fig. 1 and 2 show a brush holder 2, as is known from the prior art. The brush holder 2 has a base plate 3 and a brush box 4. The base plate 3 and the brush box 4 are integrally and materially uniformly constructed. The brush box 4 is shown for accommodating brushes, not further shown.

Fig. 3 and 4 each show a perspective view of a ground contact 1 according to the invention. The ground contact 1 has a base plate 3, a brush box 4, and a brush 6. The base plate 3 and the brush box 4 are not integrally formed according to the invention. The base plate 3 has a brush box receiving portion 5 into which the brush box 4 is inserted. The outer contour of the brush box 4 corresponds to the contour of the brush box receptacle 5 in the base plate 3, so that a precise fit of the brush box 4 in the brush box receptacle 5 of the base plate 3 is ensured. The area above the base plate 3 is protected by a cover 7, which is fixed to the base plate 3 by means of screws.

Fig. 3 shows that the brush 6 projects with one end from the brush box 4. The one end of the brush 6 is in contact with a not-shown member (slip ring) so as to conduct current out through the member. Fig. 4 shows an electrically insulating base plate 16 on the underside of the base plate 3, which has a recess for the brush box 4 arranged in the middle.

Fig. 5 shows the grounding contact 1 according to the invention of fig. 3 and 4 in a top view without the cover 7. The substrate 3 has a rectangular shape. A brush box receiving portion 5 for receiving the brush box 4 is provided at the center of the base plate 3. The brush 6 is disposed in the brush box 4. The electrical contact means 8 in the form of a flexible strand is connected to the base plate 3 of the ground contact 1 via two interfaces 9 and establishes an electrically conductive connection between the base plate 3 and the brush 6. In this exemplary embodiment, the brush 6 has two contact means 8 (litz wires), wherein a cable lug 9 is fastened to the base plate 3 by means of screws. At the respective opposite end of the base plate 3, a receptacle for a tube connector lug 10 is provided, which is likewise fastened to the base plate 3 by means of screws. Via a feed line, not shown in detail, the current is fed via the screwed-on tube connector lug 10 to the base plate 3 for further feeding.

Fig. 6 is a cross-section along the line a-a according to fig. 5. In contrast to fig. 5, the ground contact 1 is closed by a cover 7, the cover 7 covering a large area of the contact means 8, the brush 6 and the base plate 3. The brush box 4 extends completely through the brush box receiving portion 5. The brush box 4 is held clamped on the base plate 3 by means of clamping tongues 11 (fig. 6 and 7). The clamping tongues 11 have hooks 17 on their free ends 12, which act on the upper side of the base plate 3. The upper side of the substrate 3 is the side to which the cover 7 is fixed. The lower side of the substrate 3 is the side of the substrate 3 opposite to the upper side. The terms "upper side" and "lower side" or "upper" and "lower" do not limit the installation position of the ground contact 1.

The brush box 4 has a support surface 13 for supporting on the underside of the base plate 3. The support surface essentially consists of a projection or a recess in the brush box 4, which together with the hook 17 of the clamping tongue 11 forms a positive-locking connection for receiving the base plate 3 (fig. 7).

Fig. 7 shows a further sectional view of the ground contact 1 with the cover 7 according to fig. 5. Fig. 7 shows a spring holder 14 for receiving a spring element 15. The spring holder 14 is connected to the brush box 4 in a form-fitting manner. The spring holder 14 penetrates the brush box receptacle 5 together with the spring element 15 and with the brush box 4. The spring element 15 is a coiled spring strip which is pressed onto the brush 6 from the upper side. In operation, one end of the brush 6 bears against a rotating component, not shown, so that the brush 6 wears out. The brush 6 is movably supported in the brush box 4, wherein the force exerted by the spring element presses the brush 6 against the rotating member.

Fig. 8 shows a plan view of the ground contact 1 according to the invention with a plurality of brush boxes 4 and brushes 6. The base plate 3 has a substantially circular or pan-shaped form in plan view, due to the connection for the current supply. The base plate 3 has three brush box receiving portions 5. The two brush box receptacles 5 are opposite, wherein the third brush box receptacle 5 is arranged laterally to the first two brush box receptacles 5. In this exemplary embodiment, the brush box 4 also extends as a separate component through the brush box receptacle 5 of the base plate 3 and is connected to the latter in a form-fitting and clamping manner by means of the clamping tongues 11. In each case three brush boxes 4 are provided with a brush 6, which is connected to the base plate 3 via the contact means 8 and by means of an interface 9.

Fig. 9 shows section B-B of fig. 8. Fig. 9 shows a spring element 15 in the form of a wrap spring bar which presses the respective brush 6 against a relatively movable component 18 (slip ring) for current transmission. Fig. 9 also shows that the ground contact 1 with its brush box 4 extends through the retaining device 19. The holding means 19 extend substantially parallel to the substrate 3.

Reference numerals

1 ground contact

2 Brush holder

3 substrate

4 electric brush box

5 Brush case receiving portion

6 electric brush

7 cover

8 contact device

9 cable connector lug

10-tube type cable connector lug

11 clamping tongue

1211 free end

134 of the support surface

14 spring holder

15 spring element

16 bottom plate

17 hook

18 member

19 holding device

F spring force

Claims

1. A grounding contact for controlled deflection of current, comprising a brush holder (2), wherein the brush holder (2) comprises an electrically conductive base plate (3) and at least one brush box (4) for accommodating a brush (6), and wherein the at least one brush box (4) is connected to the base plate (3) in a form-fitting manner, wherein the brush box (4) has clamping tongues (11) by means of which the brush box (4) is held clamped on the base plate (3), wherein the clamping tongues (11) have hooks (17) at their free ends (12), which act behind the edge of a brush box receptacle (5) in the base plate (3), wherein the brush box (4) has a support surface (13) for supporting on the underside of the base plate (3), wherein the brush box (4) extends completely through the brush box receptacle (5).

2. The grounding contact according to claim 1, characterized in that the clamping tongues (11) are arranged on at least three sides of the brush box (4).

3. The ground contact according to claim 1 or 2, characterized in that the base plate (3) has a plurality of brush box receptacles (5).

4. The earth contact as claimed in claim 1 or 2, characterized in that a spring element (15) is provided in the brush box (4) in order to apply a spring force (F) to the brushes (6) in the brush box (4) in the longitudinal direction of the brush box (4).

5. The grounding contact according to claim 4, characterized in that the spring element (15) is fixed in a brush box (4).

6. The ground contact according to claim 1 or 2, characterized in that the brush box (4) is made of plastic.