Slip ring brush holder

Abstract

The device according to the invention comprises a brush holder for receiving a brush for transmitting electrical power between a rotating part and a fixed part of a slip ring, the brush holder having at least a first electrically conductive contact member 1 and a second electrically insulating guide member 2.

Description

Technical Field

[0001] The present invention relates to a brush holder or sleeve for a slip ring brush or slip ring carbon brush (hereinafter referred to as a "brush" for simplicity). Brushes are used to transmit power and / or electrical signals between components rotating relative to each other. They typically consist of a block of silver graphite, copper, or the like, which is held by a brush holder or fixture. At least one brush made of a conductive material slides on a slideway made of a conductive material. The galvanic contact between the slideway and the brush transmits the current. The entire arrangement is often referred to as a slip ring. Background Art

[0002] DE 10 2013 204 004 A1 describes a brush holder in a slip ring assembly using blind rivets. A disadvantage here is the non-detachable connection, which makes it impossible to replace the brush in the event of a fault.

[0003] DE 10 026 176 A1 shows a retaining and contacting device for sliding contacts made of a curved sheet metal part. Due to the manufacturing process, the curved sheet metal part includes a radius that can lead to inaccurate guidance of the brushes. Furthermore, the distance between the conductive curved part and the adjacent runner is small, which can easily lead to undesirable electrical flashovers.

[0004] EP 0 662 736 A1 discloses a brush having a large number of brush wires, wherein the individual brush wires are welded into a sleeve. This large number of brush wires complicates production and makes the brush susceptible to malfunction during use. In particular, individual brush wires may bend or break and make unintended electrical contact with one of the adjacent runners.

[0005] EP 1 453 155 A2 discloses brushes with individual wires soldered to the surface of a printed circuit board. While this allows for simple parallel connection, the high susceptibility to failure due to mechanical stress on the solder joints is disadvantageous.

[0006] Furthermore, DE 741 640 shows a brush holder for a slip ring for measurement purposes, wherein the brushes are held in an insulating retaining element, preferably made of glass. This retaining element is held in a metal sleeve. The brushes are electrically contacted via wires that are guided through an insulating cap at the end of the retaining element opposite the slideway. The metal sleeve, which is not used to guide the brushes, extends directly to the slideway, making this design unsuitable for transmitting high voltages using several parallel slideways.

[0007] Furthermore, DE 197 55 507 A1 shows a brush holder for a mechanically commutated electric motor, which has a support plate and a brush guide tube attached to the support plate. The guide tube, made of brass sheet, is held by a two-piece insulating housing. In this case, the insulating housing does not serve to guide the brushes and enlarges the structure, making it impossible to arrange adjacent concentric runners closely together. Summary of the Invention

[0008] The invention is based on the object of designing a holder for brushes of a slip ring assembly in such a way that good manufacturability of the brush holder is achieved and at the same time reliable electrical insulation from adjacent slideways is ensured.

[0009] This object is achieved by a device according to claim 1. Advantageous configurations of the invention are given in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present invention will be described below by way of examples with reference to the accompanying drawings.

[0011] Figure 1 Shown is the fully assembled brush holder without the brushes,

[0012] Figure 2 shows the contact members,

[0013] Figure 3 Another embodiment according to the present invention is shown in a perspective view.

[0014] Figure 4 Shown in plan view Figure 3 An embodiment of

[0015] Figure 5 Shown in side view Figure 3 An embodiment of

[0016] Figure 6 Shown in accordance with Figures 3 to 5 A top view of a printed circuit board or substrate used in an embodiment of the present invention;

[0017] Figure 7 A side view showing the brush holder with the brushes inserted, and

[0018] Figure 8 Shown is a view of a brush with associated springs and wiring. DETAILED DESCRIPTION

[0019] The brush holder according to the present invention includes a conductive contact member 1 and a non-conductive guide member 2 .

[0020] The conductive contact member 1 is adapted to allow an electrical coupling connection with a base plate 3 of a brush holder.

[0021] In addition to the contact member 1, the non-conductive guide member 2 also serves to hold and guide the brushes. Because the guide member 2 is made of an electrically insulating material, the insulation distance between the conductive parts of the brush holder and the adjacent runners of the slip ring assembly that are not part of the brush holder is increased, thereby achieving a significantly higher air or insulation distance. This makes it possible to transmit higher voltages between the brush holder, brushes 6, and runners while maintaining the same geometry.

[0022] Figure 1 The fully assembled multi-part brush holder according to the present invention is shown, with the brushes 6 not yet inserted. The conductive contact member 1 is at least partially pressed into the conductive substrate 3 (here, a printed circuit board), thereby providing an electrical coupling. The non-conductive guide member 2 is connected to the contact member 1 via a form-locking connection. This configuration allows for a simultaneous form-fit connection with the substrate 3 via the form-fit connection of the contact member 1 and the guide member 2.

[0023] The brushes 6 are typically elongated blocks of carbon or graphite having a rectangular cross-section chosen to enable good electrical contact to be made with the slideway.

[0024] The contact member 1 and the guide member 2 extend linearly along the longitudinal direction of the brush 6 (ie, in the direction in which the brush 6 is pressed against the slideway).

[0025] Figure 2 A contact component 1 is shown which is designed such that it is suitable for press-fitting technology in a substrate 3 .

[0026] In the brush holder according to the invention, electrical contact is achieved via an electrically conductive contact member 1 , which is preferably arranged on a side of the base plate 3 facing away from the slideway.

[0027] The insulating guide member 2 holds and guides the brushes 6 on the side of the base plate 3 facing the slideway.

[0028] In many applications, it is necessary to arrange several slideways concentrically with each other in order to transmit different signals or current phases. Due to the limited space available, it is desirable to keep the distance between the concentric slideways as small as possible.

[0029] Since the brushes 6 use as much of the width of the runners as possible for reliable transmission, there is a risk of arc flashover between the edge of the brush holder and the adjacent runners. To prevent this, the invention proposes to hold the brushes 6 in an insulating guide member 2 on the side of the base plate 3 facing the runners.

[0030] On the other hand, when transmitting greater electrical power, it is no longer possible to divert the current solely via the spring 7 that biases the brush 6 in the brush holder against the runner. Therefore, according to the present invention, the contact member 1 is electrically conductive. This contact element holds and guides the brush 6 on the side of the base plate 3 facing away from the runner. Since the brush 6 does not wear on this side of the base plate 3, the risk of arc flashover is significantly reduced. Furthermore, the brush holders can be distributed along the circumference of the runner, preventing flashover between multiple contact members 1 of adjacent runners.

[0031] like Figure 8 As shown, as standard, a cable 9 (preferably a copper cable) is stamped into the brush 6 (e.g., a carbon brush), a spring 7 is screwed onto the cable 9, and then a contact plate 8 is welded to the cable 9. The contact plate 8 provides the electrical connection between the carbon brush 6 and the contact member 1. When this complete brush block is installed in the system, the brush 6 is inserted into the contact member 1 and fixed by the screw cap 10, as shown in FIG. Figure 7 When maintenance is required, to replace worn brushes 6, screw cap 10 is loosened again, and the worn brushes 6, along with spring 7, copper cable 9, and contact plate 8, are removed and replaced with new ones. The primary purpose of spring 7 is to press brush 6 against the slideway while current is conducted through copper cable 9 and contact 1.

[0032] If you can Figure 2 As seen in FIG, the insulating guide member 2 is connected to the contact member 1 by means of spring clips passing through the base plate 3 such that they are aligned linearly in the longitudinal direction of the brush 6.

[0033] Preferably, the contact member 1 is connected to the substrate 3 in an electrically conductive manner, e.g. Figure 2 The contact pins indicated in FIG are visible. These contact pins can make contact with corresponding conductive strips on the substrate 3.

[0034] According to the present invention, since the internal gaps of the contact member 1 and the guide member 2 are identical, aligned with each other, and adapted to the peripheral contour of the brush 6, a receiving space for the brush 6 is defined, and the brush 6 is guided by both the guide member 2 and the contact member 1 during operation. Figure 8 The spring 7 shown in FIG presses the brush 6 against the slideway. During operation, the brush 6 can move toward the slideway along its longitudinal direction so as to compensate for the wear of the brush 6.

[0035] Figures 3 to 6 Another embodiment of the present invention is shown.

[0036] To ensure better and more secure contact with the slideway, in this embodiment, several brushes 6 (five in the example shown) are arranged so that they can contact the slideway. In this case, it is preferred to design the guide members 2 as a single piece for all or several of the brushes 6 of the slideway, which facilitates assembly. Furthermore, in this case, it is preferred to connect the guide members 2 to the base plate 3 using screws 4 that penetrate the base plate 3 and engage in threaded holes in the common guide member 2.

[0037] In the case of smaller batches, a common guide member 2 for a plurality of brushes 6 can be easily manufactured by 3D printing so that the brushes 6 are arranged on a circular segment corresponding to the radius of the slideway. In the case of larger batches, the guide member 2 can also be manufactured in a classic manner by pressure die casting or injection molding.

[0038] In order to improve the stability of the guide member 2, ribs 5 are formed between the individual guide sections of the brushes 6. This makes it possible to keep the wall thickness of the guide sections themselves low, which contributes to the compact design of the guide member 2. Furthermore, these ribs 5 preferably include a recess at the end facing the slideway so that they do not come into contact with the slideway, even if the slideway is uneven or dirty, in order to avoid damage.

[0039] As a preferred alternative, it is provided that on the side of each contact member 1 facing away from the slideway there is an opening through which the brush 6 can be replaced, as described above. This opening is closed during operation by a cover 10 which, together with the contact plate 8, serves as an abutment for the spring 7 pressing the brush 6 against the slideway.

[0040] However, the present invention is not limited thereto. It is also possible to separate the contact member 1 and the guide member 2 from each other at different positions and use Figure 8 brush blocks.

[0041] Different options are available for connecting the contact member 1 and the guide member 2 : they can be connected by form fit, force fit, material fit or adhesive.

[0042] Alternatively, they may be secured by rivets, snap rings or snap connections.

[0043] In a preferred embodiment, Figures 3 to 6 In the case of a screw thread, these elements are connected to each other.

[0044] In another preferred embodiment, the contact member 1 is electrically conductively connected to the substrate 3 by means of a press-in technique or a solder connection.

[0045] In another embodiment (not shown), the guide members 2 of adjacent slideways may be made in one piece, so that a plurality of guide members 2 may be securely attached to the desired position with a few screws.

[0046] For example, five brushes 6 can be provided for each slide, and 25 brushes 6 can be combined in an array for contacting the five slides for the three phases of the current, for the ground connection and the neutral conductor. The array can be extended for further slides, for example, for transmitting control or data signals (if the control or data signals are also to be transmitted via the sliding contacts).

[0047] In this case, it is important to ensure that a sufficient distance is maintained between the contact members 1 of adjacent slideways to prevent electrical flashover, for example by leaving an intermediate distance between the contact members 1 close to a common slideway and by arranging the contact members 1 of adjacent slideways adjacent to this intermediate distance, i.e. in a gap.

Claims

1. A brush holder for receiving a brush (6) of a slip ring assembly, the brush holder comprising at least one guide member (2) and a contact member (1), wherein: The contact member (1) is electrically conductive, while the guide member (2) is electrically insulating, and wherein both members (1, 3) are configured to hold and guide a common brush (6).

2. The brush holder according to claim 1, wherein The contact member (1) and the guide member (2) are connected to each other by at least one of form fit, press fit, material fit and adhesive.

3. The brush holder according to any one of the preceding claims, wherein The contact member (1) and the guide member (2) are connected to each other by at least one of a rivet, a snap ring and a snap connection.

4. The brush holder according to any one of the preceding claims, wherein The contact member (1) and the guide member (2) are connected to each other by screw threads.

5. The brush holder according to any one of the preceding claims, wherein The contact member (1) is electrically conductively connected to the substrate (3) by one of a press-fit technique and a solder connection.

6. The brush holder according to any one of the preceding claims, wherein The contact member (1) and the guide member (2) include a receiving space for receiving the brush (6), the receiving space corresponding to the shape of the brush (6) and thus capable of holding and guiding the brush (6).

7. The brush holder according to any one of the preceding claims, wherein The plurality of guide members (2) are formed in one piece.

8. The brush holder according to claim 7, wherein: The plurality of guide members (2) are arranged along a portion of a circle, the radius of the circle corresponding to the radius of the slideway to be contacted.

9. The brush holder according to claim 7 or 8, wherein: The plurality of guide members (2) are arranged to contact a plurality of concentrically arranged slideways.

10. The brush holder according to claim 7, 8 or 9, wherein: The plurality of guide members (2) are connected to each other via ribs (5).

Images