EP3182529B1 - Contact ring unit - Google Patents

Description

FIELD OF TECHNOLOGY

The invention relates to a slip ring unit for transmitting electrical currents between two relatively rotatable component groups, according to claim 1.

Slip ring units usually consist of two component groups, namely a stator and a rotor. The stator often comprises brush elements, whereas the rotor usually has a plurality of concentric slip rings. In operation, the brush elements have sliding contact with the rotating slip rings. Such slip ring units are used in many technical fields to transmit electrical signals or electrical power from a stationary to a rotating electrical unit.

For example, corresponding slip ring units are used in support arms such as in medical technology, where signals, for example video signals, and electrical power, possibly for lighting, between relatively rotating units must be transmitted.

STATE OF THE ART

In the patent EP 1 502 330 B1 a slip ring unit for transmitting signals and currents is shown. There slip rings are disclosed which have a plurality of spring contacts, which are formed by Materialausnehmung and deformation. The spring contacts are movable along a bending line oriented in the tangential direction.

From the publication DE 199 22 056 A1 An instrument for medical purposes is known in which inwardly curved Kotaktfedern contact a jacket of a wave. The disclosed arrangement has two identically arranged axially one behind the other slip rings.

The publication DE 10 2007 033 647 A1 discloses a sliding bearing with a contact spring tongue which contacts a bearing pin.

SUMMARY OF THE INVENTION

The invention has for its object to provide a slip ring unit which operates reliably, only a comparatively small space and claimed is easy to produce.

This object is achieved by the features of claim 1.

Accordingly, a slip ring unit according to the invention comprises a first and a second component group, wherein the two component groups are arranged rotatable relative to each other about an axis. The slip ring unit is suitable for transmitting electrical currents or signals between the two component groups over several revolutions. The first component group has at least one brush element and the second component group has at least one circumferential slip ring. The brush element has at least one contact tongue for transmitting the electrical currents or signals, wherein the at least one contact tongue is produced by partial separation and radial bending. The contact tongue is bent around a bending line, with an axial direction component runs. In particular, the bending line can run parallel to the axis. The slip ring and the brush element are arranged radially relative to one another, ie at a radial distance, opposite one another and in particular with an axial overlap, wherein the slip ring is contacted by the brush element or is electrically contacted.

In the following, electrical currents are to be understood as currents which are required for the transmission of electrical power or else currents, tall, such as gold or silver, or an alloy containing gold or silver.

Advantageously, the slip ring unit has a plurality of concentric slip rings and a plurality of concentric brush elements. In particular, the slip ring unit may comprise at least two concentric slip rings and at least two concentric brush elements arranged in a geometric plane which is oriented orthogonal to the axis. Accordingly, in this case a first slip ring is electrically contacted by a first brush element and a second slip ring is electrically contacted by a second brush element.

If the first component group has a plurality of brush elements and the second component group has several circumferential slip rings, the slip rings have, in particular, different diameters and are arranged at a radial distance concentric with each other and in particular in each case radially opposite one another, in particular with axial overlap.

A contact pair, consisting of a slip ring and a brush element each touch along a circular grinding path. If the slip ring unit has a plurality of such contact pairs, the plurality of sliding tracks may be arranged in one and the same geometric plane, which is oriented orthogonal to the axis, so that the axis orthogonally intersects this geometric plane. Alternatively, the slideways may be arranged in parallel geometric planes which intersect the axis orthogonally.

The brush elements can all be made of geometrically identical metal strips, so that therefore the contact tongues in the circumferential direction each have the same distance. Consequently, the respective concentric brush elements of the slip ring unit, which in particular have different diameters, have a different number of contact tongues per brush element. A first brush element accordingly opposite to a concentric with the first brush element second brush element a different number of contact tongues.

Advantageously, one of the holders or both holders are made of an insulating or dielectric material.

According to one embodiment of the invention, the first component group comprises a first holder and the second component group comprises a second holder. This slip ring unit is configured such that the brush member has a tab and the first holder has a continuous axial direction component slot, the tab being inserted through the slot and plastically deformed such that the brush member is positively secured to the first holder. Alternatively or additionally, the slip ring unit is configured such that the slip ring has a tab and the second holder has a continuous axial directional component slot, the tab being inserted through the slot and plastically deformed (in particular the area of the tab inserted therethrough), so that the slip ring is fixed positively on the second holder.

In a further embodiment of the invention, the tab of the brush element, in particular the area of the tab inserted therethrough, is plastically deformed in a manner such that it is oriented in the radial direction after the deformation has been carried out. Alternatively or additionally, the tab of the slip ring is plastically deformed in a manner that it is oriented in the radial direction after the deformation has been made. Alternatively, the relevant tab can also be twisted, so that there is a plastic deformation in this way.

The slip ring assembly may be configured such that the brush member and / or slip ring has a plurality of tabs and the first holder and / or the second holder has continuous axial directional component slots, with the plurality of tabs inserted through the slots and plastically deformed. In particular, you can be provided with advantage at least two, in a further embodiment, at least three such tabs.

In one development of the invention, the first holder has at least one cavity, in which case the plastically deformed tab of the brush element, in particular the plastic deformed region of the tab, is arranged in the cavity of the first holder. Alternatively or additionally, the second holder has at least one cavity, wherein the plastically deformed tab of the slip ring is arranged in the cavity of the second holder. In particular, the relevant tab does not project out of the holder or the cavity in the axial direction. As a cavity, a cavity or a cavity in the relevant holder can be understood.

In a further embodiment of the invention, the tab of the brush element is electrically contacted with a cable. Alternatively or additionally, the tab of the slip ring is electrically contacted with a cable.

Advantageously, the brush element has a plurality of tabs, wherein at least one of the tabs is referred to as a terminal tab, wherein the terminal tab is electrically contacted with a cable and oriented in the axial direction. In particular, the terminal tab, which is contacted with the cable, remain plastically undeformed. Alternatively or additionally, the slip ring on a plurality of tabs, wherein at least one of the tabs is referred to as a connection tab, wherein the terminal tab is electrically contacted with a cable and is oriented in the axial direction. In particular, the terminal tab, which is contacted with the cable, remain plastically undeformed.

In this case, the at least one of the plastically deformed tabs or the above-defined terminal tab can be electrically contacted by a blade receptacle with the cable, for example by a crimp connection. Alternatively, the at least one of the tabs or the above-defined terminal tab may be electrically contacted by a solder connection to the cable.

According to a development of the invention, the (in particular dielectric) first holder has at least one axially projecting element in the axial direction, on which the brush element is supported in the radial direction. Alternatively or additionally, the (in particular dielectric) second holder has at least one element projecting in the axial direction, against which the slip ring is supported in the radial direction.

Advantageous embodiments of the invention will remove the dependent claims.

Further details and advantages of the slip ring unit according to the invention will become apparent from the following description of an embodiment with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

Figur 1

eine perspektivische Ansicht auf eine erste Bauteilgruppe einer Schleifringeinheit,

Figur 2

eine perspektivische Ansicht auf eine zweite Bauteilgruppe der Schleifringeinheit,

Figur 3

eine Detailansicht eines Bürstenelements und eines Schleifrings der Schleifringeinheit,

Figur 4

eine Teilschnittansicht der Schleifringeinheit,

Figur 5

eine weitere Teilschnittansicht der Schleifringeinheit mit einer Kabelanbindung.

It show the

FIG. 1

a perspective view of a first group of components of a slip ring unit,

FIG. 2

a perspective view of a second component group of the slip ring unit,

FIG. 3

a detailed view of a brush member and a slip ring of the slip ring unit,

FIG. 4

a partial sectional view of the slip ring unit,

FIG. 5

a further partial sectional view of the slip ring unit with a cable connection.

DESCRIPTION OF THE EMBODIMENTS

The slip ring unit comprises a first component group 1 according to the FIG. 1 , which can serve as a stator, for example, and a second component group 2 according to the FIG. 2 which can act as a rotor, for example. The slip ring unit serves for transmitting electrical currents between the first component group 1 and the second component group 2, wherein the component groups 1, 2 are arranged rotatably in the assembled state about an axis A relative to each other. Electric currents are to be understood as currents which are required for the transmission of electrical power or currents which are formed as signals and serve only for the transmission of information.

The first component group 1 has a first holder 1.4, which is designed, for example, as a plastic component. The first holder 1.4 has a first, second and third protruding in the axial direction element 1.41, 1.42, 1.43, which are configured in the illustrated embodiment as a concentric circumferential ridges. These protruding elements 1.41, 1.42, 1.43 are integrally formed on the first holder 1.4. The first holder 1.4 also comprises cavities 1.45 (FIG. FIG. 4 ) or to one side open cavities. The first holder 1.4 can therefore be designed as a one-piece component, for example as an injection-molded component, with integrally formed protruding elements 1.41, 1.42, 1.43 and the cavities 1.45.

Furthermore, the first component group 1 comprises a first, a second and an (inner) third brush element 1.1, 1.2, 1.3, wherein the brush elements 1.1, 1.2, 1.3 are formed in the illustrated embodiment as a multilayer metal strips. The sheet metal strips, in particular from a brass core provided with a silver layer, formed brush elements 1.1, 1.2, 1.3 have before their completion initially a planar geometry and each have a plurality of tabs 1.11 (see the FIG. 4 ) along one of its longitudinal sides, wherein in the FIG. 4 only one tab 1.11 of the first brush element is shown. Analogously, the second and the third brush element 1.2, 1.3 each have a plurality of such tabs. The substantially annular region of each of the brush elements 1.1, 1.2, 1.3 can be referred to as bodies 1.12, 1.22, 1.32 of the brush elements 1.1, 1.2, 1.3.

The brush elements 1.1, 1.2, 1.3 are provided with contact tongues 1.13, 1.23, 1.33, which are produced by partial separation or cutting and bending. Accordingly, the respective formed as a sheet metal strip brush element 1.1, 1.2, 1.3 only partially separated, in particular stamped, so that a compound of the body 1.12, 1.22, 1.32 of the brush element 1.1, 1.2, 1.3 to the contact tongue 1.13, 1.23, 1.33 remains. Subsequently, the contact tongue 1.13, 1.23, 1.33 is bent or embossed by a bending line B. The first brush element 1.1, the second brush element 1.2 and the third brush element 1.3 are therefore each designed as one-piece stamped and bent parts. The bending or embossing is carried out in such a way that at the end of the contact tongues 1.13, 1.23, 1.33 convex surfaces arise.

The brush elements 1.1, 1.2, 1.3 are now bent to concentric rings with different diameters about the axis A. With regard to the protruding elements 1.41, 1.42, 1.43 or the webs, the brush elements 1.1, 1.2, 1.3 in the course of further assembly of the first group of components 1 each radially inwardly disposed, wherein the tabs 1.11 offset by circumferentially offset, axially continuous slots 1.44 ( FIG. 4 ) of the first holder 1.4 are inserted therethrough. Thereafter, most of the tabs are 1.11, in particular the inserted through the slots 1.44 of the first holder 1.4 areas of the tabs 1.11, plastically deformed, in particular bent in the radial direction. In this way, the respective brush element 1.1, 1.2, 1.3 is positively secured to the first holder 1.4, so that an axial and radial fixation with respect to the first holder 1.4 is achieved. The first holder 1.4 is formed so that the bent tabs are arranged 1.11 axially recessed in recesses or cavities 1.45 and thus do not protrude from the contour of the first holder 1.4.

The axially projecting elements 1.41, 1.42, 1.43 or concentric webs serve to support in the radial direction of a respective brush element 1.1, 1.2, 1.3. The contact tongues 1.13, 1.23, 1.33 are bent radially inwards towards the axis A, wherein the bending line B extends parallel to the axis A.

The second component group 2 has a second holder 2.4, which is configured, for example, also as a plastic component. Also, the second holder 2.4 has in the axial direction a first, second and third protruding element 2.41, 2.42, 2.43, which are configured in the illustrated embodiment as a circumferential webs. These protruding elements 2.41, 2.42, 2.43 are integrally formed on the second holder 2.4. In addition, the second holder 1.4 also comprises a cavity 2.45 or a cavity open towards one side.

Furthermore, the second component group 2 comprises a first, second and third slip ring 2.1, 2.2, 2.3. The slip rings 2.1, 2.2, 2.3 have different diameters D2.1, D2.2, D2.3 and are arranged at a radial distance concentric to each other. In the exemplary embodiment presented, the slip rings 2.1, 2.2, 2.3 are designed as multilayer sheet-metal strips, in particular of a silver-plated brass material. The slip rings 2.1, 2.2, 2.3 designed as sheet metal strips initially have a plane geometry before their completion and each have a plurality of tabs 2.11 (FIG. FIG. 4 ) along one of its longitudinal sides.

The slip rings 2.1, 2.2, 2.3 are bent into concentric rings about the axis A. With regard to the protruding elements 2.41, 2.42, 2.43 or the concentric webs, the slip rings 2.1, 2.2, 2.3 are arranged in the course of the further assembly of the second group of components 2 each radially outwardly, the tabs 2.11 offset by circumferentially offset, axially continuous slots 2.44 the second holder 2.4 are inserted through. Thereafter, in particular the regions of the tabs 2.11 inserted therethrough are plastically deformed, in particular bent over in the radial direction. In this way, the respective slip ring 2.1, 2.2, 2.3 is positively secured to the second holder 2.4, so that an axial and radial fixation with respect to the first holder 1.4 is achieved. The axially protruding elements 2.41, 2.42, 2.43 respectively Webs serve to support in the radial direction of a respective slip ring 2.1, 2.2, 2.3.

The component groups 1, 2 thus produced are now joined together. Accordingly, the first component group 1, as shown in the FIG. 1 is shown rotated by 180 ° and axially displaced so far until the first holder 1.4 according to the FIG. 4 at an axial distance a the second holder 2.4 is opposite. In this arrangement, the contact tongues contact 1.13, 1.23, 1.33, in particular their convex surfaces, the concentric slip rings 2.1, 2.2, 2.3 on their outer sides ( FIG. 3 ). The brush elements 1.1, 1.2, 1.3 and the slip rings 2.1, 2.2, 2.3 are designed sleeve-shaped or hollow cylindrical and are provided with axial overlap X ( FIG. 4 ) are mounted to each other in the slip ring unit. Accordingly, therefore, an overlapping arrangement in the axial direction between two electrically contacting brush elements 1.1, 1.2, 1.3 and slip rings 2.1, 2.2, 2.3 before.

For electrical connection of the brush elements 1.1, 1.2, 1.3 and the slip rings 2.1, 2.2, 2.3 per brush element 1.1, 1.2, 1.3 or per slip ring 2.1, 2.2, 2.3 at least one of the tabs is not bent. These tabs, which are not bent over in the illustrated embodiment, will be referred to below as connecting tabs 2.12, wherein in the FIG. 5 only one connecting lug 2.12 of a slip ring 2.1, 2.2, 2.3, here the first slip ring 2.1 is shown. Nevertheless, the brush elements 1.1, 1.2, 1.3 analogously not shown further connection tabs. The connection tabs 2.12 can, for example, as in the FIG. 5 represented by a blade receptacle 2.6, which is crimped to the relevant terminal tab 2.12, electrically connected to a cable 2.5. Alternatively, it is also possible to dispense with the blade receptacle 2.6 and instead to produce a solder joint.

In the mounted state, therefore, electrical currents can be transmitted via the contact tongues 1.13, 1.23, 1.33 between the first and the second component group 1, 2. The bending lines B of the contact tongues 1.13, 1.23, 1.33 run with an axial direction component, in the illustrated embodiment, parallel to the axis A. The deflection of the contact tongues 1.13, 1.23, 1.33 is in the radial direction. The contact tongues 1.13, 1.23, 1.33 have a length L in the circumferential direction and a width w in the axial direction along the bending line B. For the operability of the slip ring unit, it is advantageous if the ratio L / w of length L to the width w is comparatively large. In the presented embodiment, this ratio assumes approximately the value 5.5.

During operation of the slip ring unit, the second component group 2 rotates relative to the first component group 1. As a result, there is a sliding contact between the brush elements 1.1, 1.2, 1.3 and the corresponding slip rings 2.1, 2.2, 2.3. In particular, in each case sliding contacts between the first brush element 1.1 and the first slip ring 2.1, between the second brush element 1.2 and the second slip ring 2.2, and between the third brush element 1.3 and the third slip ring 2.2 are made. The brush elements 1.1, 1.2, 1.3 and the slip rings 2.1, 2.2, 2.3 are circumferentially formed largely closed over 360 °. Even if in the region of a shock of a slip ring 2.1, 2.2, 2.3, the contact with one of the contact tongues 1.13, 1.23, 1.33 would be interrupted or reduced, nevertheless an undisturbed transmission of the currents across the other contact tongues 1.13, 1.23, 1.33 of the same brush element 1.1, 1.2 , 1.3 take place on the slip ring 2.1, 2.2, 2.3. Through the slip ring unit, a transmission of electric currents with unlimited rotation angle, so over any number of revolutions away reachable.

The concentric slip rings 2.1, 2.2, 2.3 and the concentric brush elements 1.1, 1.2, 1.3 are arranged in a geometric plane which is oriented orthogonal to the axis. In particular, the concentric slip rings 2.1, 2.2, 2.3 and the corresponding concentric brush elements 1.1, 1.2, 1.3 each touch each other along a grinding path. In the illustrated embodiment, there are three pairs of brush elements 1.1, 1.2, 1.3 and slip rings 2.1, 2.2, 2.3, so that accordingly there are three sliding tracks. The circular sliding tracks are arranged in one and the same geometric plane, which orthogonal to the axis, so that the axis A intersects this geometric plane orthogonally.

The first holder 1.4 and the second holder 2.4 can be attached to relatively rotatable machine parts or support arms whose relative arrangement defines the distance a. Such machine parts can naturally assume changing directions of rotation in operation and vibrate or initiate shocks in the slip ring unit. As a result of the vibrations or impacts, the axial distance a may be subject to changes in time, albeit only to a limited extent. The present design does not affect the transmission of currents through such operating conditions.

Claims (12)

1. slip-ring unit comprising a first and a second component group (1, 2), wherein the two component groups (1, 2) are arranged, such that they can rotate relative to one another about an axis (A) and the slip-ring unit is suitable for transmitting electric currents or signals between the two component groups (1, 2) over several rotations, wherein

   - the first component group (1) has a brush element (1.1, 1.2, 1.3) and the second component group (2) has a circumferential slip ring (2.1, 2.2, 2.3),

   - the brush element 1.1 1.2, 1.3) has at least one contact tongue (1.13, 1.23, 1.33) for transmitting the electric currents or signals, and the at least one contact tongue (1.13 1.23, 1.33) is created by being partially cut out and bent out radically,

   - the at least one contact tongue (1.13, 1.23, 1.33) is bent out about a bending line (B), which extends with as axial directional component

   and the slip ring (2.1, 2.2, 2.3) and the brush element (1.1, 1.2, 1.3) lie radially opposite and the slip ring (2.1, 2.2, 2.3) is brought into contact with the brush element (1.1 1.2, 1.3) by way of the at least one contact tongue (1.13, 1.23, 1.33),
   wherein
   the slip-ring unit has a number of concentric slip rings (2.1, 2.2, 2.3) and a number of concentric brush elements (1.1, 1.2, 1.3),
   characterized in that
   the brush elements (1.1, 1.2, 1,3) have a differing number of contact tongues (1.13, 1.23, 1.33).
2. Slip-ring unit according to Claim 1, wherein the at least one contact tongue (1.13, 1.23, 1.33) has a length (L) in the circumferential direction and a width (w) in the axial direction along a blending line (B), where the ratio (L/w) of length (L) to width (w) is greater than 2.
3. Slip-ring unit according to one of the preceding claims, wherein the brush element (1.1, 1.2, 1.3) is designed as a one-piece stamped-bent part.
4. slip-ring unit according to one of the preceding claims, wherein the brush element (1.1, 1.2, 1.3) and/or the slip ring (2.1, 2.2, 2.3) is produced from a multilayer metal scrip.
5. Slip-ring unit according to Claim 1, wherein the slip-ring unit has at least two concentric slip rings (2.1, 2.2, 2.3) and at least two concentric brush elements (1.1, 1.2, 1.3), which are arranged in a geometrical plane that is oriented orthogonally in relation to the axis.
6. Slip-ring unit according to one of the preceding claims, wherein the first component group (1) has a first holder (1.4) and the second component group (2) has a second holder (2.1), wherein

   a) the first holder (1.4) has at least one element (1.12) which projects in the axial direction and on which the brush element (1.1, 1.2, 1.3) is supported in the radial direction and/or

   b) the second holder (2.1) has at least one element (2.12) which projects in the axial direction and on which the slip ring (2.1, 2.2, 2.3) is supported in the radial direction.
7. Slip-ring unit according to one of the preceding claims, wherein the first component group (1) has a first holder (1.4) and the second component group (2) has a second holder (2.4), wherein

   a) the brush element (1.1, 1.2, 1.3) has a lug (1.11) and the first holder (1.4) has a slit (1.44), which passes right through with an axial directional component, wherein the lug (1.11) is inserted through the slit (1.44) and plastically deformed such that the brush element (1.1, 1,2, 1.3) is fastened on the first holder (1.4) in a positively looking manner and/or

   b) the slip ring (2.1, 2.2, 2.3) has a lug (2.11) and the second holder (2.4) has a slit (2.44), which passes right through with an axial directional component, wherein the lug (2.11) is inserted through the slit (2.44) and plastically deformed such that the slip ring (2.1, 2.2, 2.3) is fastened on the second holder (2.4) in a positively locking manner.
8. Slip-ring unit according to Claim 7. wherein the lug (1.11) of the brush element (1.1, 1,2, 1.3) and/or the lug (2.11) of the slip ring (2.1, 2.2, 2.3) is plastically deformed in such a way that it is oriented in the radial direction.
9. Slip-ring unit according to either of Claims 7 and 8, wherein the plastically deformed lug (1.11) of the brush element (1.1, 1.2, 1.3) is arranged in a cavity (1.45) of the first holder (1.4) and/or the lug (2.11) of the slip ring (2,1, 2.2, 2.3) is arranged in a cavity (2.45) of the second holder (2.4).
10. Slip-ring unit according to one of Claims 7 to 9, wherein the lug (1.11) of the brush element (1.1 1.2, 1.3) and/or the lug (2.11) of the slip ring (2.1, 2.2, 2.3) is brought into electrical contact with a cable (2.4).
11. Slip ring unit according to one of Claims 7 to 10, wherein the brush element (1.1, 1.2, 1.3) and/or the slip ring (2.1, 2.2, 2.3) has a terminal lug (2.12), which is brought into electrical contact with a cable (2.4), wherein the terminal lug (2.12) is oriented in the axial direction.
12. Slip-ring unit according to Claim 11, wherein the at least one of the lugs (1.11, 2.11; 2.12) is brought into electrical contact with the cable (2.4) by a push-on receptacle (2.3).

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