EP2525448B1 - Contact ring unit - Google Patents

Description

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, inter alia, of two component groups, namely a stator and a rotor. The stator often includes slip ring brushes, whereas the rotor usually has a series of slip rings. In operation, the slip ring brushes have sliding contact with the shell sides of 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.

In the published patent application EP 0 662 736 A1 there is disclosed a slip ring in which a brush holder is carried by an annular member, the annular member being secured between two flanges.

In the publication US 3,026,433 a carrier device for a brush holder is shown. The carrier device is suitable for fixing the brush holder on one side to a console of an electric motor by means of a screw connection.

The invention has for its object to provide a slip ring unit, which allows high reliability and at the same time a simple and economical production.

This object is achieved by the features of claim 1.

In the slip ring unit for transmitting electric currents between a first and a second component group, the two component groups are rotatable relative to each other about an axis. The first component group, for. Example, a stator, comprises at least one slip ring brush, which is attached to a holder which is mounted between two in the direction of the axis offset from each other arranged components (the components may be configured, for example, as a stator-side rings). The second component group, z. B a rotor, has at least one slip ring. The holder and at least one of the components each have at least one active surface through which a positive connection is established between the holder and the at least one component. Due to the positive connection forces can be transmitted with a directional component parallel to the axis.

In the following, electrical currents are to be understood as currents which are required for the transmission of electrical power but also currents which are designed as signals and serve only for the transmission of information.

Advantageously, the slip ring unit is configured so that the holder and both said components each have at least one active surface through which between the holder and the two components in each case a positive connection is made.

At least one of the components advantageously has an undercut and the holder comprises a projection, wherein the undercut and the projection have interlocking active surfaces and cooperate such that between the holder and the at least one component is made a positive connection by which forces one Direction component can be transferred parallel to the axis. Advantageously, the slip ring unit is configured such that both components have an undercut. The slip ring unit can be designed such that the cooperating active surfaces of the holder and of the component engage with an overlap in the circumferential direction. Alternatively or additionally, the slip ring unit can be configured such that the cooperating active surfaces mesh with one another in the radial direction.

The slip ring unit can be designed so that axial tensile stresses can be introduced into the holder with the aid of the positive connection.

In a further embodiment of the invention, the first component group can be rotatable relative to the second component group by means of a roller bearing and serve the component for axial securing of the rolling bearing and in particular be connected to the rolling bearing for this purpose. In particular, one of the components or both can be positively connected to an outer ring of a roller bearing for receiving axial forces. This arrangement is particularly advantageous if the rolling bearing is designed such that this axial forces can be transmitted from the outer ring to the inner ring, so for example when the rolling bearing is designed as a deep groove ball bearing. The slip ring unit can be configured so that these axial forces between the first group of components and the second group of components are transferable, wherein axial tensile forces in the holder can be generated by the axial forces by means of the positive connection.

In a further embodiment of the invention, the first component group may comprise a housing element which serves as a positive radial securing of the positive connection between the holder and the at least one component. In particular, the housing element can radially surround the holder and the at least one component without play in the region of the positive connection. In this case, the housing element may be designed as a hollow cylinder or tubular. In particular, the housing element can be used as a positive radial securing of positive locking Connections serve on both components when the holder and both components each have at least one active surface, is made by the respective between the holder and the components a positive connection.

Advantageously, the slip ring unit on several holders, wherein between the holders and the at least one component in each case a positive connection is made. In particular, the slip ring unit can have two holders, which are advantageously arranged offset by 180 ° about the axis (rotation axis). Alternatively, three holders can be arranged, which are advantageously arranged at an angular distance of 120 ° to each other. In a further embodiment of the invention, four holders can be arranged, which are arranged in particular at an angular distance of 90 ° to each other.

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 embodiments with reference to the accompanying figures.

Figur 1

eine Längsschnittdarstellung einer Schleifringeinheit,

Figur 2a

eine Detailansicht eines ersten Bauteils der Schleifringeinheit,

Figur 2b

eine Detailansicht eines Halters,

Figur 2c

eine Teilschnittdarstellung der Schleifringeinheit,

Figur 3a

eine Seitenansicht eines Halters gemäß einem zweiten Ausführungsbeispiel,

Figur 3b

eine Teildraufsicht des Halters gemäß dem zweiten Ausführungsbeispiel,

Figur 3c

eine Detailansicht eines Bauteils der Schleifringeinheit gemäß dem zweiten Ausführungsbeispiel

Figur 3d

eine Detailansicht der Schleifringeinheit gemäß dem zweiten Ausführungsbeispiel.

It show the

FIG. 1

a longitudinal sectional view of a slip ring unit,

FIG. 2a

a detailed view of a first component of the slip ring unit,

FIG. 2b

a detailed view of a holder,

Figure 2c

a partial sectional view of the slip ring unit,

FIG. 3a

a side view of a holder according to a second embodiment,

FIG. 3b

a partial plan view of the holder according to the second embodiment,

Figure 3c

a detailed view of a component of the slip ring unit according to the second embodiment

3d figure

a detailed view of the slip ring unit according to the second embodiment.

According to the FIGS. 1 . 2a, 2b and 2c the slip ring unit according to the invention comprises a first group of components, which may be referred to as stator 1 and a second group of components, hereinafter referred rotor 2. The slip ring unit is used for transmitting electrical currents between the rotor 2 and the stator 1, wherein the rotor 2 and the stator 1 are arranged rotatable relative to each other about an axis A. The rotor 2 is mounted with respect to the stator 1 with bearings 3, which include an outer ring 3.1, an inner ring 3.2 and rolling elements 3.3 and a, in particular grinding, seal 3.4. The rolling bearing 3 is configured here as a deep groove ball bearing, so that therefore axial forces from the outer ring 3.1 to the inner ring 3.2 and vice versa are transferable.

The rotor 2 comprises a shaft 2.1, which is configured in the present example as a hollow shaft. Radially outside the shaft 2.1 is initially a substantially tubular member 2.4, which may be made of aluminum, for example. Then further radially outward, a support tube 2.5 is arranged, which has recesses 2.51 running in the axial direction.

On electrically insulating support tube 2.5, which may preferably be made of plastic or ceramic, slip rings are 2.2 secured against rotation, which are separated by electrically insulating rings 2.3 with axial distance from each other. For clarity, was omitted in the figures on the presentation of electrical lines. Regardless, in the embodiment, each of the axially spaced-apart slip rings 2.2 is connected at its inner side with an electrical line, each along a recess 2.51 in the axial direction in the rotor. 2 is moved and leaves the rotor 2 through one of the grooves 2.11 at one axial end of the shaft 2.1.

According to the exemplary embodiment, the stator 1 has four holders 1.3 made of an insulating material, here made of a plastic, wherein the holders 1.3 are each arranged offset by 90 ° along a circumferential line. The holder 1.3 have a substantially cuboid base body. At each of the holders 1.3 slip ring brushes 1.2 are attached, which are assigned to the stator 1 and resiliently touch the slip rings 1.2. In the present case, the slip ring brushes 1.2 are designed as a wire bundle. These slip ring brushes 1.2 are made with vias 1.33 (see FIGS. 2b, 2c ) In the main body of the holder 1.3 electrically connected to lines. In the FIGS. 2b, 2c For the sake of clarity, the illustrations of the stator-side electrical lines were omitted.

The holder 1.3 have projections 1.31, which are claw-like formed on the base body. The projections 1.31 have a substantially cylindrical basic shape, wherein the respective cylinder axes are aligned parallel to each other, or the projections are oriented 1.31 parallel to each other. The holder 1.3 is designed in one piece and was made of plastic by means of an injection molding process.

Both the slip ring brushes 1.2 and the slip rings 2.2 are arranged to protect against environmental influences in the interior of a hollow cylindrical housing element 1.1. The interior of the stator is also limited by two components, here two rings 1.4, 1.5. These rings 1.4, 1.5 at the same time form the holder for the outer rings 3.1 of the rolling bearings 3, in particular the rings 1.4, 1.5 are used for axial securing and axial prestressing of the rolling bearings 3. The power transmission between the outer rings 3.1 and the rings 1.4, 1.5 is characterized by radial circumferential paragraphs 1.43, 1.53 of the rings 1.4, 1.5 achieved. The rolling bearings 3 themselves are designed as deep groove ball bearings, so that these axial forces from the stator 1 to the rotor 2 and vice versa are transferable.

According to the FIG. 2a For example, the ring 1.4 has several, here sixteen recesses (four groups offset by 90 °, each with four recesses), which are terminated in the axial direction by bores, so that undercuts 1.42, based on the axial direction arise. Similarly, the second ring 1.5 is configured so that these sixteen recesses (four offset by 90 ° groups with four recesses), which are designed as undercuts 1.52 has.

In the course of assembly of the slip ring unit, the projections 1.31 of each holder 1.3 are pressed into the recesses, in particular the undercuts 1.42, 1.52 of the rings 1.4, 1.5. The projections 1.31 of the holder 1.3 then engage in the undercuts 1.42, 1.51 of the first ring 1.4 and the second ring 1.5, according to the FIG. 1 , which is a sectional view produced by a cutting line passing through two outer projections 1.31 with respect to the holder 1.3. In the FIGS. 2a to 2c In addition, effective areas 1.3a, 1.4a, 1.5a are shown. The holder 1.3 and the two rings 1.4, 1.5 each have these active surfaces 1.3a, 1.4a, 1.5a. By the active surfaces 1.3a, 1.4a, 1.5a, which touch and interlock, so between the holder 1.3 and each of the rings 1.4, 1.5 made a positive connection. In other words, in each case a positive connection is created, which results from the interaction of the undercuts 1.42, 1.51 with the projections 1.31.

The axial distance between projections 1.31 at the axially opposite ends of the holder 1.3 or the associated active surfaces 1.3a is dimensioned so that this (before mounting the holder 1.3 to the rings 1.4, 1.5) is slightly smaller than the axial distance of the undercuts 1.42, 1.52 or smaller than the axial distance of the active surfaces 1.4a, 1.5a of the opposite rings 1.4, 1.5. Since the holder 1.3 have this undersize, created after assembly an axial bias in the holders 1.3. This bias is transmitted by the paragraphs 1.43, 1.53 on the bearings 3, so that they are biased axially to each other. In this respect, axial tensile stresses are introduced into the holder 1.3 with the help of positive connections.

The claw-like integrally formed on the main body of the holder 1.3 projections 1.31 are designed so that they complete flush after mounting on the rings 1.4, 1.5 with the radial outer contour of the rings 1.4, 1.5 or with their outer circumference. The radially outer contour of the projections 1.31 is thus at least partially a cylindrical surface with the diameter of the respective ring 1.4, 1.5 on its outer side. Thus, by sliding the housing element 1.1, a radial securing of the connection, which results from the interaction of the undercuts 1.42, 1.51 with the projections 1.31, is produced.

In the Figures 3a, 3b and 3c a further embodiment is shown, which differs from the first embodiment substantially by the configuration of the positive connections.

In the FIG. 3a is an end view of a holder 1.3 'shown without slip ring brushes, wherein the holder is 1.3' configured on its axially opposite non-illustrated end face analog. The holder 1.3 'has three dovetail-like projections 1.31' and adjacent undercuts 1.32 '. The radial outer side of the projections 1.31 'or of the holder 1.3' extends on a circular line. The projections 1.31 'radially in each case have a contour which is rectilinear and tangentially oriented.

Alternatively, the corresponding contour can also be designed so that it runs on a circular line, so that the projections 1.31 'can rest directly on the shell side of the outer ring 3.2. The radius of the circle line can be the same size as the outer radius of the outer ring 3.2.

According to the FIG. 3b showing a detail of the holder 1.3 'in a plan view, have the projections 1.31' and the undercuts 1.32 'active surfaces 1.3a' on. These active surfaces 1.3a 'are intended to cooperate with active surfaces 1.5a' of a further component, which is also designed here as a ring 1.5 '. The active surfaces 1.5a 'of the ring 1.5' are arranged on three dovetail-like projections 1.51 'and on adjacent undercuts 1.52'.

After assembly is between the holder 1.3 'and the ring 1.5' according to the 3d figure produced a positive connection, which can be transmitted by the positive connection forces with a direction component parallel to the axis A. The active surfaces 1.3a 'and 1.5a' engage each other. Although in the FIG. 3b only one side of the holder 1.3 'is shown, to which a positive connection can be achieved, also in the second embodiment, the opposite side of the slip ring can be equipped with such a compound. Accordingly, the same considerations apply to the production of an axial bias by an undersize of the holder 1.3 'for the second embodiment. Also serves in the second embodiment, the housing member 1.1 as a positive radial securing the positive connection between the interlocking dovetail projections 1.31 ', 1.51' and undercuts 1.32 ', 1.52'. Incidentally, the slip ring according to the second embodiment also has a plurality of holders 1.3 'distributed over the circumference, in the present case four holders 1.3' are used.

Claims (9)

1. Slip ring unit for transmitting electric currents between a first component group (1) and a second component group (2), the two component groups (1, 2) being arranged such that they can be rotated relative to one another about an axis (A),

   - the first component group (1) comprising at least one slip ring brush (1.2) which is fastened to a holder (1.3; 1.3') which is mounted between two components (1.4, 1.5; 1.5') which are arranged offset with respect to one another in the direction of the axis (A), and

   - the second component group (2) having at least one slip ring (2.2),

   characterized in that the holder (1.3; 1.3') and both components (1.4, 1.5; 1.5') in each case have an active face (1.3a, 1.4a, 1.5a; 1.3a', 1.5a'), by way of which a positively lockinq connection is produced in each case between the holder (1.3; 1.3') and the two components (1.4, 1.5; 1.5'), it being possible for forces with a directional components parallel to the axis (A) to be transmitted by way of the positively locking connection, both components (1.4, 1.5; 1.5') in each case having an undercut (1.42, 1.51; 1.32'), and the holder (1.3; 1.3') comprising a projection (1.31, 1.31') for each component, the undercuts (1.42, 1.51; 1.32') and the projections (1.31, 1.31') having active faces (1.3a, 1.4a, 1.5a; 1.3a', 1.5a'), which engage into one another, and interacting in such a way that the positively locking connections are produced between the holder (1.3; 1.3') and the components (1.4, 1.5; 1.5') by way of them.
2. Slip ring unit according to Claim 1, characterized in that axial tensile stresses can be introduced into the holder (1.3; 1.3') with the aid of the positively locking connection.
3. Slip ring unit according to either of the preceding claims, characterized in that the first component group (1) can be rotated relative to the second component group (2) with the aid of an anti-friction bearing (3), and one of the components (1.4, 1.5; 1.5') serves to axially secure the anti-friction bearing (3).
4. Slip ring unit according to Claim 3, characterized in that the anti--friction bearing (3) is configured in such a way that axial forces can be transmitted between the first component group (1) and the second component group (2) by way of the said anti-friction bearing (3).
5. Slip ring unit according to one of the preceding claims, characterized in that the first component group (1) can be rotated relative to the second component group (2) with the aid of two anti-friction bearings (3), and in each case one of the components (1.4, 1.5; 1.5') serves to axially secure in each case one of the anti-friction bearings (3).
6. Slip ring unit according to one of the preceding claims, characterized in that the first component group (1) comprises a housing element (1.1) which serves as a positively locking radial securing means of the positively locking connection.
7. Slip ring unit according to Claim 6, characterized in that the holder (1.3; 1.3') and both components (1.4, 1.5; 1.5') in each case have an active face (1.3a, 1.4a, 1.5a; 1.3a', 1.5a'), by way of which a positively locking connection is produced in each case between the holder (1.3; 1.3') and the components (1.4, 1.5; 1.5'), and the housing element (1.1) serves as a positively locking radial securing means of the positively locking connections on both components (1.4, 1.5; 1.5').
8. Slip ring unit according to Claim 6 or 7, characterized in that the housing element (1.1) is of hollow-cylindrical configuration.
9. Slip ring unit according to one of the preceding claims, characterized in that it has a plurality of holders (1.3; 1.3').

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