DE102016209581A1 - Contact arrangement for an electric machine - Google Patents

Abstract

In an electrical contact arrangement (100) for an electrical machine (200), a first element (202) of the machine formed with electrically conductive material is movable, in particular rotatable about an axis of rotation (201), relative to at least one second element formed with electrically conductive material ( 205) of the machine. The contact arrangement is provided for the movable, in particular rotatable about the axis of rotation, electrical connection of the electrically conductive material of the first element of the machine with the electrically conductive material of the at least one second element of the machine. In order to achieve a reliable separation of the contact arrangement from a lubricant space (206) of the machine, in which no lubricant can get into the contact arrangement, and mechanical losses, in particular by friction, reduced, preferably at least almost completely avoided, the contact arrangement with respect to the lubricant space by at least one lubricant discharge device (108, 109) completed, wherein the at least one lubricant discharge device is adapted to promote lubricant from the lubricant space against the contact arrangement penetrating lubricant back into the lubricant space.

Description

The invention relates to a contact arrangement for an electrical machine. The invention further relates to an electrical machine with such a contact arrangement. The invention also relates to a vehicle, in particular road vehicle, with such an electric machine.

In the German patent application 10 2014 226 544.4 An electric machine is described in which a rotor formed with an electrically conductive material is mounted movably on at least one bearing element on a support element comprising an electrically conductive material. The rotor and the one supporting element are conductive, in particular, for electrical interference currents caused by electrical interference voltages originating from or fed into the windings of the stator. The electrically conductive material of the one support element is electrically conductively connected to an electrical ground potential. In order to prevent the interference currents from flowing off the rotor in an uncontrolled manner, for example via a central shaft of the electrical machine or radiated as electromagnetic waves and thus causing electromagnetic interference outside the electrical machine, an electrical contact arrangement for the movable low-impedance electrical connection of the rotor to the one Support member provided for deriving the electrical noise from the rotor to the ground potential.

In the German patent application 10 2014 226 544.4 is further described that the contact arrangement with an electrically conductive, movably moldable contact material, in particular an electrically conductive fluid and / or a conductive solid, in the latter preferably an at least substantially powdery solid, is formed. The contact material at least partially fills a space between two electrically conductive contact elements, of which a first with the rotor and a second electrically connected to the one support element.

In the German patent application 10 2014 226 544.4 is also described that the contact arrangement relative to the at least one bearing element can be completed by at least one sealing element, preferably by at least one shaft seal.

The at least one sealing element, e.g. formed with at least one shaft seal, it serves except for holding the electrically conductive contact material within the contact assembly and keeping the contact material away from the at least one bearing element also to keep a lubricant from the at least one bearing element of the contact arrangement, so that no mutual interference between the Contact material and the lubricant occurs, ie neither contact material in the at least one bearing element nor lubricant can get into the contact arrangement.

It turns out that shaft seals, e.g. Radial shaft seals, by friction generate mechanical losses that are undesirable.

DESCRIPTION OF THE INVENTION: OBJECT, SOLUTION, ADVANTAGES The object of the invention is to refine a contact arrangement of the type described above in such a way that a reliable separation is achieved in which neither contact material can get into the contact arrangement in the at least one bearing element, especially lubricant , wherein mechanical losses, in particular by friction, reduced, preferably at least almost completely avoided.

• • vorgesehen ist zum beweglichen, insbesondere um die Rotationsachse drehbeweglichen, elektrischen Verbinden des elektrisch leitenden Materials des ersten Elements der Maschine mit dem elektrisch leitenden Material des wenigstens einen zweiten Elements der Maschine und
• • gegenüber einem Schmiermittelraum durch wenigstens eine Schmiermittel-Abfördereinrichtung abgeschlossen ist, wobei die wenigstens eine Schmiermittel-Abfördereinrichtung dazu ausgebildet ist, vom Schmiermittelraum gegen die elektrische Kontaktanordnung vordringendes Schmiermittel in den Schmiermittelraum zurück zu fördern.

This object is achieved by an electrical contact arrangement for an electrical machine in which a first element of the machine formed with an electrically conductive material is arranged to be movable, in particular rotatable about an axis of rotation, relative to at least one second element of the machine formed with an electrically conductive material, wherein the electrical contact arrangement

• • Provided for the movable, in particular rotatable about the axis of rotation, electrical connection of the electrically conductive material of the first element of the machine with the electrically conductive material of the at least one second element of the machine and
• • is completed with respect to a lubricant space by at least one lubricant discharge device, wherein the at least one lubricant discharge device is adapted to promote from the lubricant space against the electrical contact assembly penetrating lubricant in the lubricant space back.

In this case, a space region of the electric machine is designated as the lubricant space, which contains a lubricant, ie a lubricant in the at least predominantly pasty state, preferably a grease, or a lubricant in an at least predominantly liquid state, preferably a lubricating oil. Normally, it is intended that the lubricant space encompasses all the structural elements of the electric machine to be lubricated during operation of the electric machine and / or cooled with the lubricant, ie that the lubricant reaches and / or penetrates all of these structural elements to such a minimum adequate cooling and / or lubrication is achieved.

Since such a penetration of the electrical contact assembly with the lubricant can lead to a deterioration of the function or even to a complete failure of the electrical contact arrangement and is therefore undesirable, the invention provides for the use of at least one lubricant discharge device. This is or are designed to promote the lubricating space against the electrical contact arrangement penetrating lubricant back into the lubricant space. In contrast, a sealing element of conventional design, e.g. formed with a shaft seal, is dispensed in the at least one lubricant discharge device according to the invention specifically to a basically hermetic seal for the lubricant, since this a very close fit against mutually movable components, for. makes the shaft seal required, whereby although a tight and thus lubricant-tight concern of the mutually movable components to each other is achieved, but also a high friction is obtained.

In contrast, the inventively provided, at least one lubricant discharge device is light, i. with at most low frictional forces, movable, wherein instead of the hermetic seal for the lubricant the function occurs, this from the space occupied by the contact means, i. from the contactor, to promote; more precisely, in the space occupied by the contactor, i. into the contactor, penetrating and / or penetrating lubricant from this space occupied by the contactor, i. from the contact device to promote back out and back into the lubricant space, so that the contact device remains free of lubricant or is freed again by penetrated lubricant and this lubricant is available again in the lubricant space.

The invention is based on the finding that a penetration of lubricant, in particular in a small amount, in the space area occupied by the contact device, i. in the contact device, the functionality of the electrical contact arrangement is not or only imperceptibly impaired, as long as the first element of the machine and the at least one second element of the machine are not moved against each other. Accordingly, in order to maintain the operability of the electrical contact assembly, it suffices to carry off the lubricant while keeping the operation of the machine in operation and to keep it away during the operation thereof. Thus, the continuous hermeticity of the electrical contact assembly with respect to the lubricant space, i. on a conventional, frictional sealing element can be omitted.

The invention thus enables a further reduction of friction losses in the electrical contact arrangement according to the invention and thus in an electric machine designed with the electrical contact arrangement according to the invention. There is a further reduction in the maintenance effort and an increase in the reliability while at the same time cost-effective design, i. Production, achieved.

• • umfasst wenigstens eine der wenigstens einen Schmiermittel-Abfördereinrichtung wenigstens ein erstes, mit dem ersten Element der Maschine verbundenes Abfördereinrichtungselement und wenigstens ein zweites, mit dem wenigstens einen zweiten Element der Maschine verbundenes Abfördereinrichtungselement,
• • sind das wenigsten eine erste Abfördereinrichtungselement und das wenigstens eine zweite Abfördereinrichtungselement gegeneinander beweglich, insbesondere um die Rotationsachse drehbeweglich, angeordnet und grenzen über an den Abfördereinrichtungselementen drehsymmetrisch ausgebildete Förderflächen aneinander,
• • ist zwischen je zwei aneinandergrenzenden Förderflächen je ein Förderspalt gebildet und öffnet je einer dieser Förderspalte sich einerseits zur Kontaktanordnung und andererseits zum Schmiermittelraum hin, und
• • ist wenigstens eine der je zwei aneinandergrenzenden Förderflächen mit schmiermittelfördernden Förderelementen, insbesondere schraubenförmig entlang einer Umfangsrichtung der Förderflächen sich erstreckenden, bevorzugt sich zum Schmiermittelraum hin öffnenden, Ausnehmungen, ausgebildet.

Advantageous embodiments of the invention are characterized in the subclaims. According to a particularly preferred in view of the features, properties and advantages described above development of the electrical contact arrangement according to the invention

• At least one of the at least one lubricant discharge device comprises at least a first discharge device element connected to the first element of the machine and at least one second discharge device element connected to the at least one second element of the machine,
• • the at least one first discharge device element and the at least one second discharge device element are movable relative to one another, in particular rotatable about the rotational axis, and adjoin one another via conveying surfaces which are rotationally symmetrical on the discharge device elements,
• • is formed between each two adjoining conveying surfaces depending on a conveying gap and opens one of these conveying gaps on the one hand to the contact arrangement and on the other hand to the lubricant space out, and
• At least one of the two adjoining conveyor surfaces with lubricant-conveying conveyor elements, in particular helically along a circumferential direction of the conveyor surfaces extending, preferably, the lubricant chamber opening towards recesses formed.

A lubricant discharge device of the type according to the invention is thus formed with a first and a second, mutually movable, in particular about the rotational axis of the electrical contact assembly and thus the electric machine rotatable, discharge device element. In particular, in this case the first discharge device element is connected to the first element of the machine and the second discharge device element is connected to at least one of the at least one second element of the machine. The first and the second Abfördereinrichtungselement are each formed with at least one surface, which are referred to as conveying surfaces and each other and in particular to the rotation axis concentric and spaced apart from each other and against each other movable, in particular rotatable about the axis of rotation, are arranged.

Between each two opposing conveying surfaces on both discharge device elements, i. between each one conveying surface of each one of the at least one first discharge device element and each one conveying surface of each of the at least one second discharge device element, one conveying gap is formed in each case. In this case, the conveying surfaces may be cylindrical and arranged opposite each other in the radial direction to the axis of rotation. According to another embodiment, the conveying surfaces may also be formed as circular disks or circular rings and arranged opposite each other in the axial direction of the axis of rotation, the surfaces may be configured conical or have any other rotationally symmetrical design. At least one of every two opposite each other, i. a conveying gap between forming, conveying surfaces is formed with lubricant-promoting, in particular helically along a circumferential direction of the conveying surfaces, recesses formed. These recesses open preferably to the lubricant space, optionally also to the electrical contact arrangement.

The spacing of the conveying surfaces and thus of the discharge device elements relative to one another ensures that the discharge device elements can move without friction relative to one another, in particular with the first or the second element of the electric machine, can rotate. This allows a low-loss operation. The conveying gap is preferably dimensioned in such a way that lubricant that has penetrated therein is dragged against one another by the conveying surfaces when the conveying surfaces move, thereby supplying the lubricant-conveying, in particular helically along the circumferential direction of the conveying surfaces extending, recesses, in particular thread-shaped grooves. Through the recesses, the conveying direction of the lubricant to the lubricant space is deflected out, so this supplied to the lubricant space. The only occurring friction loss thus arises due to fluid friction in the conveying gap and in the recesses and is very low.

• • ist das wenigstens eine zweite Element der Maschine als Stützelement ausgebildet und ist das elektrisch leitende Material des wenigstens einen zweiten Elements mit einem ein elektrisches Massepotential führenden Element elektrisch leitend verbindbar und
• • ist die elektrische Kontaktanordnung vorgesehen zum Kurzschließen elektrischer Störspannungen und Ableiten elektrischer Störströme vom ersten Element der Maschine an das Massepotential.

In a further preferred embodiment of the electrical contact arrangement according to the invention

• • The at least one second element of the machine is designed as a support element and the electrically conductive material of the at least one second element with an electrical ground potential leading element electrically conductively connected and
• • The electrical contact arrangement is provided for short-circuiting electrical interference voltages and deriving electrical interference currents from the first element of the machine to the ground potential.

It is to features and details of at least one second element of the machine, so the at least one support element, for the sake of simplicity and to avoid repetition expressly to the statements in the German patent application 10 2014 226 544.4 to this at least one support member reference; the local, this at least one support element relating disclosure is by reference to the German patent application 10 2014 226 544.4 expressly included in the description of the present invention.

Accordingly, this embodiment is particularly preferably used for reliably dissipating interference currents from the first element of the electrical machine to the ground potential and in particular to prevent radiation in the form of electromagnetic waves. This is preferably applicable to disturbances emanating from a stator of the machine, which is operated via a pulse-controlled inverter driven in the form of a steep pulse, and interspersed in the first element of the machine. For a reliable deriving of such interference currents, even in a long-term operation of the machine, it is important that the contact arrangement used for this purpose reliably and permanently provides an electrically conductive, in particular low-impedance, connection, i. has a constant, low-resistance contact resistance. The contact arrangement designed according to the invention also fulfills these requirements for use in an electrical machine that is at least partially covered by the lubricant space.

• • umfasst das ein elektrisches Massepotential führende Element ein mit elektrisch leitendem Material ausgebildetes, die elektrische Maschine wenigstens teilweise umschließendes Gehäuse, insbesondere ein mit einem mit elektrisch leitendem Material ausgebildetes Gehäuse, und/oder ist durch dieses gebildet,
• • ist insbesondere das wenigstens eine zweite Element der Maschine einstückig mit dem Gehäuse ausgebildet und/oder mit dem Gehäuse elektrisch leitend verbunden.

According to a further preferred embodiment of the electrical contact arrangement according to the invention

• The element carrying an electrical ground potential comprises and / or is formed by a housing formed with electrically conductive material and enclosing the electrical machine at least partially, in particular a housing formed with an electrically conductive material,
• In particular, the at least one second element of the machine is integrally formed with the housing and / or electrically conductively connected to the housing.

The housing advantageously forms both a mechanical protection and an electromagnetic protection or anti-interference device. In particular, in this case, the connection between the housing and the support element or support elements is also formed non-positively, so that the housing can act on the electric machine acting or generated by her driving forces.

• • ist das erste Element der Maschine von einem Rotor der elektrischen Maschine gebildet und über wenigstens ein Lagerelement drehbeweglich gegenüber dem wenigstens einen zweiten Element gelagert und
• • ist das wenigstens eine Lagerelement im Schmiermittelraum angeordnet, so dass insbesondere die wenigstens eine Schmiermittel-Abfördereinrichtung dazu ausgebildet ist, vom wenigstens einen Lagerelement gegen die elektrische Kontaktanordnung vordringendes Schmiermittel zum wenigstens einen Lagerelement zurück zu fördern.

In another embodiment of the electrical contact arrangement according to the invention

• • The first element of the machine is formed by a rotor of the electric machine and rotatably supported by at least one bearing element relative to the at least one second element and
• • The at least one bearing element is arranged in the lubricant space, so that in particular the at least one lubricant discharge device is adapted to promote from at least one bearing element against the electrical contact arrangement penetrating lubricant to at least one bearing element.

This embodiment is in particular designed to derive interference currents from the rotor caused by the stator in the rotor of the electric machine to the at least one second element of the machine. The interference currents are guided via the contact arrangement and kept away from the at least one bearing element, so that a fluctuating and indefinite electrical conductivity of this at least one bearing element can exert no influence on the discharge of interference currents. The lubricant discharge device used in accordance with the invention makes it possible to arrange the at least one bearing element in the lubricant space and thus to operate in a particularly simple manner with little wear, without adversely affecting the operating conditions and the durability of the contact arrangement by penetrating lubricant.

A further preferred embodiment of the electrical contact arrangement according to the invention is characterized by an embodiment comprising an electrically conductive, movably moldable contact material, in particular an electrically conductive fluid and / or a conductive solid, preferably an at least substantially powdery solid, wherein the electrically conductive contact material has a space between at least two electrically conductive contact elements of the electrical contact arrangement at least partially fills, of which at least a first contact element with the first element of the machine and at least one second contact element with the at least one second element of the machine is electrically connected. Particularly preferred in this embodiment of the contact arrangement according to the invention is a electrically low impedance conductive, movably formable contact material is used.

In this embodiment of the contact arrangement, preferably formed with a metallic material, electrically conductive contact elements form an at least substantially closed, rigid boundary of the space region in which the electrically conductive, preferably niederimpedante, movably moldable contact material is included, and at the same time serve an electrical contact of the electrically conductive, preferably low-impedance, moveable contact material, ie an electrically conductive connection of the electrically conductive, preferably niederimpedanten movably moldable contact material with the first element of the machine on the one hand and the at least one second element of the machine on the other. During operation, movements occurring between the first element of the machine, on the one hand, and the at least one second element of the machine, on the other hand, are thus absorbed by the electrically conductive, preferably low-impedance, movably moldable contact material or lead to a continuous deformation thereof, wherein the electrical connection between the contact elements or the first element of the machine on the one hand and the at least one second element of the machine on the other hand via the electrically conductive, preferably niederimpedanten, movably moldable contact material is continuously maintained. Particularly advantageously, the electrically conductive, preferably niederimpedante, movably moldable contact material is formed with an electrically conductive fluid, which is simple, safe and low-friction deformable and at the same time ensures a good electrical contact with the contact elements. Further advantageous as electrically conductive, preferably low-impedance, moveable contact materials are also conductive solids in powder form, e.g. Graphite powder or the like.

A contact arrangement formed with an electrically conductive, preferably low-impedance, movably moldable contact material, in particular an electrically conductive, preferably low-impedance fluid and / or a conductive, preferably low-impedance solid, preferably an at least substantially powdery solid, enables a particularly low-resistance or fluctuation-free contact resistance and thus a particularly effective interference suppression. Such a contact arrangement is also at least almost wear and thus maintenance-free and thus material-saving and inexpensive operable. These benefits are made by the Use of the at least one lubricant discharge device according to the invention even further increased.

In a further embodiment, the contact elements of the contact arrangement may be formed by the discharge device elements of the lubricant discharge device or connected thereto, in particular integrally connected.

According to a preferred development of the electrical contact arrangement according to the invention, the electrically conductive contact material is formed with an electrically conductive ferrofluid, i. with a liquid that reacts to magnetic fields without solidifying. A ferrofluid consists of magnetic particles a few nanometers in size, which are colloidally suspended in a carrier liquid - usually in oil or water, rarely wax, with the addition of surfactants to make the suspension more stable. Due to the content of electrically conductive particles, the ferrofluid can be made electrically conductive, which makes it possible, e.g. can be used very advantageously in electric machines for vehicle drives. A special advantage is the reaction of the ferrofluid on magnetic fields, which makes it possible in a very simple manner to guide the ferrofluid by applying a magnetic field to a desired location or to keep it - here within the contact arrangement.

Accordingly, according to a further preferred embodiment of the invention, the electrical contact arrangement is formed with at least one magnetic element for guiding the ferrofluid in the space region between the electrically conductive contact elements. This can be very easy and effective leakage of the ferrofluid from the contact arrangement can be prevented, this measure is also inexpensive and allows a maintenance-free construction.

In the embodiment of the contact arrangement in which the electrically conductive contact elements, which are preferably formed with a metallic material, form an at least substantially closed, rigid boundary of the spatial region, in which the electrically conductive, preferably low-impedance, movably moldable contact material is enclosed, it is advantageous to enclose this spatial region between them electrically conductive contact elements bordering surfaces of oppositely arranged electrically conductive contact elements rotationally symmetrical to the axis of rotation, while planar and / or concentric designed. In a simple case, these surfaces are at least almost completely flat or cylindrical or conical or designed in the same shape or a combination of these shapes. A particularly simple design is achieved with circular cylindrical designed and concentric with each other and aligned with the axis of rotation surfaces.

In accordance with yet another embodiment of the electrical contact arrangement according to the invention, the surfaces of the oppositely arranged contact elements surrounding the spatial region between the contact elements are suppressed with surface-enlarging, preferably interlocking formations and / or demixing and / or agglomeration of constituents of the conductive fluid and / or of the conductive solid Structures designed. With this measure, it is also possible to use a contact material whose electrical conductivity is relatively low, in particular lower than that of the contact elements, since the surface through which the interference currents flow, that is to say the contact elements. the conductor cross-section of the contact material, can be increased. Preferably, the distance of opposing contact elements is chosen as low as possible, so that the length of the current paths of the interference currents as small as possible and thereby the resulting contact resistance of the contact material and thus the contact arrangement is minimized. Preference is given to the contact elements with profilings, e.g. in the nature of surface waves, or in the form of interlocking pots, slices, fins or the like, for enlarging the surfaces, i. Contact surfaces, between the contact elements and the contact material, e.g. the fluid or powder. This results in the lowest possible contact resistance between the contact elements.

The profiling also serves to bring about a permanent circulation of the fluid or powder in order to counteract a not entirely exclude segregation of the suspension or deposition. The demultipating and / or agglomeration of constituents of the conductive fluid and / or of the conductive solid preventive structures serve advantageously to ensure a long service life of the contact material and thus to provide a maintenance-free or maintenance-free machine. These advantages are further enhanced by the use according to the invention of the at least one lubricant discharge device.

The above object is further achieved by an electrical machine with an electrical contact arrangement of the type described above.

The above object is also achieved by a vehicle, in particular road vehicle, formed with an electrical machine of the type described above and / or with an electrical contact arrangement of the type described above.

Such a designed electric machine and a vehicle designed in this way have the properties and advantages explained above. In particular, by using the invention, a arranged in a lubricant space or a lubricant space performing electric machine is provided which is designed with a reliable, durable and maintenance-free interference suppression, in particular radio interference suppression, and a vehicle with these advantages.

Brief description of the drawings

In the drawing, in which matching elements in all figures are given the same reference numerals and to which a repeated description of these elements is omitted, show:

1 1 is a partial view of an example of an electrical machine, in particular for a hybrid drive of a motor vehicle, in which an embodiment of a contact arrangement according to the invention is used, in a roughly schematic longitudinal sectional view,

2 the arrangement after 1 with a detailed reproduced embodiment of an inventive contact arrangement in a rough schematic representation,

3 the embodiment of the inventively embodied contact arrangement according to 2 with a detailed representation of an embodiment of an inventively embodied lubricant discharge device in a perspective reproduced longitudinal section,

4 the embodiment of the inventively embodied lubricant discharge device in the perspective reproduced longitudinal section after 3 to illustrate the operation, and

5 the embodiment of the inventively embodied contact arrangement according to 2 to 4 in different exploded views.

The embodiments of the invention shown in the drawing will be described in more detail below.

Preferred embodiment of the invention

In 1 is an electrical machine 200 for a hybrid drive of a motor vehicle roughly schematically shown in a partial view, in a longitudinal section, a half of the electric machine 200 up to a rotation axis 201 one of a first element of the machine 200 forming rotor 202 the machine 200 reproduces. The rotor 202 is with a metallic, ie electrically conductive, rotationally symmetrical, hollow shaft or sleeve-like configured bearing portion 203 formed, with which the rotor 202 via two bearing elements designed as ball bearings 204 on a second element of the machine 200 forming support element 205 is stored. With the hollow shaft or sleeve-like design bearing section 203 encloses the rotor 202 the support element 205 and the two ball bearings 204 , The support element 205 protrudes through the storage section 203 through and carries the ball bearings 204 on its outer circumference. The support element 205 is here also hollow, ie sleeve-like, and rotationally symmetrical about the axis of rotation 201 ( 101 ) educated. ball-bearing 204 , Support element 205 and storage section 203 are formed with electrically conductive materials.

Further structural details of the machine 200 are not relevant to the invention and therefore not shown.

The electric machine 200 is further formed with a stator, also not shown, are caused by the switching edges of a generated by a pulse inverter and applied to windings of the stator clocked motor voltage noise voltages that are disturbing currents in the rotor 202 and its storage section 203 which are radiated as high-frequency electromagnetic waves, unless they are shorted to an electrical ground potential. It is advisable to, the support element 205 to connect to such a ground potential, in particular vehicle mass, so that the support element 205 forms an electrical ground potential leading element.

An electrical connection for short-circuiting the interference currents in the rotor 202 against the support element 205 exists here on the storage section 203 , the support element 205 and the ball bearings 204 , However, here are the ball bearings 204 their better and simplified lubrication and thus increased load capacity and half life in a lubricant space 206 arranged in which there is a filling of a usually electrically insulating lubricant. By this necessarily contained, electrically insulating lubricant, the ball bearings 204 a strongly fluctuating, speed and temperature-dependent electrical conductivity, which is not only unsuitable for safe short-circuiting of the interference currents, but to further interference voltages between the bearing section 203 and support element 205 leads, which are then also emitted.

For a safe, fluctuation-free, low-impedance electrical connection for a To obtain reliable short-circuiting of interference currents is therefore in the space between the bearing section 203 , the support element 205 as well as the bearing elements 204 an electrical contact arrangement 100 inserted, at least partially ring-like the support element 205 encloses along the outer circumference or to the bearing section 203 adjoining along its inner circumference. The contact arrangement 100 is both with the storage section 203 as well as with the support element 205 electrically connected and bridges the bearing elements 204 electrically, so that not only their conductivity fluctuations for short-circuiting the interference currents play no role, but by keeping the interference currents from the bearing elements 204 also their wear is reduced.

A more detailed representation of an inventively constructed electrical contact arrangement 100 shows 2 in a partial view of - in constructional detail slightly, for the description of the invention, however, modestly modified electrical machine 200 according to 1 , The contact arrangement 100 comprises two first contact elements 101 that with the storage section 203 and thus the rotor 202 electrically connected, and a second contact element 102 that with the support element 205 is electrically connected, as described in more detail below.

In a room area 103 between each one of the first 101 and the second 102 the contact elements is an electrically conductive, moveable contact material 104 the room area 103 at least partially, preferably at least almost completely, filled in, through which a movable electrically conductive connection between the first contact elements 101 on the one hand and the second contact element 102 on the other hand, and thus between the support element 205 and the storage section 203 is formed. The room area 103 is formed here as a substantially circular cylindrical gap, ie in the illustrated embodiment of the contact arrangement 100 are the space area 103 between the contact elements 101 . 102 bordering surfaces, ie contact surfaces, 105 the oppositely arranged contact elements 101 . 102 at least essential, the function of the contact arrangement 100 decisively determining parts as concentric with one another and with the axis of rotation 201 formed circular cylinder shaped. This allows for easy manufacture and assembly of the contact arrangement 100 ,

As a contact material 104 is in the contact arrangement 100 advantageously provided an electrically conductive fluid. Such contact materials allow at least almost frictionless and thus lossless rotational movement of the rotor 202 opposite the support element 205 and have at least almost independently of speed and / or temperature, a contact resistance which is at least virtually constant over time as well. By an electrical bridging of the bearing elements 204 with such a contact material 104 becomes an at least almost trouble-free short-circuiting of the interference currents from the rotor 202 to the support element 205 achieved.

Particularly preferred here is as an electrically conductive fluid 104 an electrically conductive ferrofluid selected. Such a ferrofluid 104 is durable, maintenance-free, non-corrosive or toxic and thus environmentally friendly and also easy in the space area 103 einbringbar and there leak-proof to lead or keep, ie in the area 103 safe against leakage from the room area 103 together. Particularly advantageous is the contact arrangement 100 to hold the ferrofluid 104 in the room area 103 with an at least substantially annular magnetic element 106 or optionally with one or more at least substantially partially annular magnetic elements 106 for guiding the ferrofluid 104 in the room area 103 between the contact elements 101 . 102 educated. In the embodiment according to 2 is an annular magnetic element 106 concentric with the axis of rotation 201 in the axial direction, ie in the direction of the axis of rotation 201 , one behind the other between the first two, also annular, to the axis of rotation 201 concentric contact elements 101 arranged in a row and is in its axis of rotation 201 concentric position through a likewise annular, to the axis of rotation 201 concentric magnet holding element 107 fixed. The contact elements 101 . 102 are here of magnetically conductive material, preferably magnetizable steel, formed and form pole pieces of the magnetic element 106 to that of the magnetic element 106 caused magnetic field for holding or guiding the ferrofluid 104 bundled through the room area 103 respectively. The course of the magnetic field, ie the magnetic circuit, is in 2 with a loop-shaped arrow 121 symbolizes. Both the magnetically non-conductive magnetic holding element serve this purpose 107 radially outside the magnetic element 106 as well as a magnetic non-conductive area 122 radially inside the magnetic element 106 and outside the second contact element 102 the avoidance of a magnetic short circuit between the first contact elements 101 , Optionally, in the magnetically non-conductive area 122 be arranged a further magnetic holding element.

Close to the contact arrangement in the axial direction, ie in Direction of the rotation axis 201 , on both sides in a lubricant space 206 taken up ball bearings 204 on, ie the contact arrangement is in the axial direction, ie in the direction of the axis of rotation 201 , on both sides of a lubricant space 206 bounded. Opposite this lubricant space 206 is the contact arrangement 100 by each side in the axial direction of a lubricant discharge device 108 . 109 completed, wherein the lubricant discharge facilities 108 . 109 are designed to from the lubricant space 206 against the electrical contact arrangement 100 , especially against the room area 103 , penetrating lubricant on both sides in the axial direction in the lubricant space 206 to promote back. In this case, the first lubricant discharge device 108 and the second lubricant discharge device 109 with the above-described construction elements of the contact arrangement 100 combined into a common assembly.

The first lubricant discharge device 108 includes one with the first element 202 the machine 100 ie with the bearing section 203 connected first discharge device element 110 and one with the second element, ie the support element, 205 the machine 100 connected second discharge device element 111 , The second lubricant discharge device 109 includes one with the first element 202 the machine 100 ie with the bearing section 203 connected first discharge device element 112 and one with the second element, ie the support element, 205 the machine 100 connected second discharge device element 113 , The first ever delivery device element 110 respectively. 112 and the second delivery device element 111 respectively. 113 are against each other about the axis of rotation 201 rotatably arranged. The first discharge device elements 110 . 112 are therefore rotatable relative to the support element 205 rotatably arranged second discharge device elements 111 . 113 ,

Over at the discharge facility elements 110 . 111 . 112 . 113 around the axis of rotation 201 rotationally symmetrical circular cylindrical trained conveying surfaces 114 . 115 . 116 respectively. 117 border the first discharge device elements 110 . 112 and the second discharge device elements 111 . 113 in to the axis of rotation 201 radial direction opposite each other. Between each two adjoining conveyor surfaces per a conveying gap is formed; ie between the conveying surface 114 the first discharge device element 110 the first lubricant discharge device 108 and the conveying surface 115 the second discharge device element 111 the first lubricant discharge device 108 is a first funding gap 118 formed, as well as between the conveying surface 116 the first discharge device element 112 the second lubricant discharge device 109 and the conveying surface 117 the second discharge device element 113 the second lubricant discharge device 109 is a second conveyor gap 119 educated. Each of these conveyor columns 118 respectively. 119 opens on the one hand to the contact arrangement, ie the contact elements 101 . 102 and the room area 103 , and on the other hand to the lubricant space 206 out.

The conveyor surfaces 114 . 116 the first discharge device elements 110 . 112 both lubricant discharge facilities 108 . 109 are lubricious, helical along a circumferential direction of the conveying surfaces 114 . 116 extending, recesses 120 educated. These recesses 120 open in the illustrated embodiment, both the lubricant space 206 as well as the electrical contact arrangement 100 out.

The the conveyor column 118 . 119 forming spacing of the conveyor surfaces 114 . 115 . 116 respectively. 117 and thus the discharge conveyor elements 110 . 111 . 112 respectively. 113 to each other ensures that the discharge conveyor elements 110 . 111 . 112 respectively. 113 move against each other without friction, especially with the first 202 or the second element 205 the electric machine 200 can turn against each other. This allows a low-loss operation. The conveyor column 118 . 119 are dimensioned such that it has penetrated lubricant during movement of the conveying surfaces 114 . 115 . 116 respectively. 117 against each other from the conveyor surfaces 114 . 115 . 116 respectively. 117 , prefers 114 . 116 , is dragged while doing the lubricant-promoting, helically along the circumferential direction of the conveyor surfaces 114 . 115 . 116 respectively. 117 extending recesses 120 , which are designed in particular as thread-shaped grooves, is supplied. Through the recesses 120 the conveying direction of the lubricant to the lubricant space 206 deflected towards the lubricant so the lubricant space 206 fed. The only resulting friction loss is thus caused by fluid friction in the conveyor columns 118 . 119 and in the recesses 120 and is very low.

In the illustrated embodiment, the second discharge device elements 111 . 113 the first 108 and second 109 Lubricant removal device together with the second contact element 102 integrally formed of magnetically conductive material, in particular magnetizable steel. Advantageously, the second discharge device elements 111 . 113 together with the second contact element 102 formed by an at least substantially smooth-walled, circular cylindrical sleeve and thereby easy and inexpensive to produce and assemble. This sleeve is on the support element 205 the electric machine 200 mounted and / or pressed and thus mounted not only simple and mechanically stable, but thus also in a reliable, low-impedance electrical connection with the support element 205 brought. Radially inwardly, this sleeve forms a smooth, stably integral termination or wrap around the entire contact assembly 100 ,

In contrast, the first discharge device elements 110 . 112 the first 108 and second 109 Lubricant removal device made of magnetically non-conductive material, in particular non-magnetic steel. So the magnetic circuit 121 from the first contact elements 101 although by the second contact element 102 forming magnetically conductive sleeve, but from the lubricant discharge facilities 108 . 109 kept away, so that prevents the contact material 104 , ie the ferrofluid, in the conveyor column 118 . 119 pulls, but is achieved that the contact material 104 on the room area 103 remains concentrated.

Further, the first discharge device element 112 the second lubricant discharge device 109 sleeve-shaped extended in the way that with this sleeve-shaped extension 123 the entire contact arrangement 100 ie the entire assembly of the first contact elements 101 , the magnetic element 106 with the magnet holding element 107 , the first discharge device element 110 the first lubricant discharge device 108 and the first discharge device element 112 the second lubricant discharge device 109 , is enclosed. In particular, the first contact elements are located 101 electrically good, ie low impedance, conductive at a radially inwardly directed inner surface of the sleeve-shaped extension 123 at. The first discharge device element 112 is with a radially outwardly directed outer surface of the sleeve-shaped extension 123 in the storage section 203 of the rotor 202 used electrically low impedance connected, in particular pressed. These are the inner and outer surfaces of the sleeve-shaped extension 123 also circular cylindrical and at least substantially smooth-walled. In this way, the total contact arrangement 100 formed as a compact, robust, easy to manufacture and mountable or usable assembly and thus a reliable, low-resistance electrical connection between the rotor 202 and the support element 205 created.

Also preferred is the sleeve-shaped extension 123 in the axial direction both over the first discharge device element 112 the second lubricant discharge device 109 on the one hand and on the first discharge device element 110 the first lubricant discharge device 108 on the other hand extended to a certain extent, that between the discharge conveyor elements 110 . 112 and thus the lubricant discharge facilities 108 . 109 on the one hand and the bearing elements 204 on the other hand depending on an additional section of the lubricant space 206 is formed, in which the lubricant from the lubricant discharge facilities 108 . 109 is promoted, ie in these additional sections, the subsidized lubricant is added.

3 shows the contact arrangement 100 to 2 with a detailed representation of the first and the second lubricant discharge device 108 . 109 in a perspective reproduced longitudinal section through the axis of rotation 201 , In the figure part a) is a sectional view of an assembly drawing of the contact arrangement 100 with two bearing elements 204 played. The figure part b) shows the first discharge device element 112 the second lubricant discharge device 109 with the sleeve-shaped extension 123 in the axial direction. The figure part c) shows the first discharge device element 110 the first lubricant discharge device 108 and the figure part d) shows the entire first lubricant discharge device 108 ie, the first discharge device element 110 the first lubricant discharge device 108 together with the sleeve-shaped, one-piece combination of the second discharge device elements 111 . 113 and the second contact element 102 , With the arrows 124 is a designated direction of rotation of the rotor 202 with the storage section 203 , the first contact elements 101 , of the magnetic element 106 , the first conveyor elements 110 . 112 and the sleeve-shaped extension 123 designated. Shown is the arrangement of the conveyor surfaces 114 . 116 the first discharge device elements 110 . 112 with the helical, lubricant-promoting recesses formed therein 120 , In addition, the figure part a) shows a connection of the first contact elements 101 , of the magnetic element 106 and the first Abfördereinrichtungselements 110 the first lubricant discharge device 108 with one or more - in particular three - connecting elements 125 , which are preferably formed with screws and a robust connection of said construction elements of the contact arrangement 100 cause.

4 shows the contact arrangement after 3 , wherein Figure part a) of 4 with the figure part a) of 3 , Figure part b) of 4 with the figure part d) of 3 and Figure c) of the 4 with the figure part c) of 3 matches. The example of the first lubricant discharge device 108 their mode of operation is shown. the sleeve-shaped combination of second contact element 102 and the second discharge device elements 111 . 113 forms the conveying surfaces 115 respectively. 117 along its outer circumference. Of these, the conveying surface 115 the second discharge device element 111 the first lubricant discharge device 108 the conveying surface 114 the first discharge device element 110 the first lubricant discharge device 108 arranged radially opposite; between the conveyor surfaces 114 and 115 is the first conveyor gap 118 educated. The first discharge device element 110 rotates during operation in the direction of rotation 124 , In the conveying gap penetrating or penetrated lubricant, in particular oil, is on the conveying surface 114 the first discharge device element 110 entrained with the rotation and thereby enters the helical, lubricant-promoting recesses 120 , Through this, formed as a thread-shaped grooves recesses 120 the lubricant is laterally, ie in the axial direction of the contact arrangement 100 out, distracted and into the lubricant space 206 promoted. This conveying direction is indicated by an arrow 126 symbolizes. In the second lubricant discharge device 109 are, as in 3 , Part figure b), shown, the recesses 120 formed in opposite directions, so that here the conveying direction 126 is in opposite directions and thus also from the contact arrangement 100 out has.

5 shows the embodiment of the present invention formed contact arrangement 100 together with two bearing elements 204 after the 2 to 4 in different exploded views, in the figure part a) in a complete, perspective side view and in the figure part b) in longitudinal section. For this purpose, an assembly drawing is shown in each case. The exploded views are opposite to the 2 to 4 around two spacer rings 127 supplemented, of which each one axially on the outside of each of the first contact elements 101 followed.

LIST OF REFERENCE NUMBERS

100

Electrical contact arrangement

101

First contact element of 100 ; Pole shoe too 106

102

Second contact element of 100

103

Space between 101 and 202

104

Contact material in 103

105

Contact surface of 101 . 102

106

Magnetic element of 100

107

Magnetic holding element to 106 from 100

108

First lubricant removal device of 100

109

Second lubricant removal device of 100

110

First discharge element of 108

111

Second discharge device element of 108

112

First discharge element of 109

113

Second discharge device element of 109

114

Conveying surface of 110

115

Conveying surface of 111

116

Conveying surface of 112

117

Conveying surface of 113

118

First conveyor gap of 108 between 114 from 110 and 115 from 111

119

Second funding gap of 109 between 116 from 112 and 117 from 113

120

Screw-shaped, lubricant-promoting recesses in 114 . 116

121

Magnetic circuit of 106 above 101 . 102 . 103 respectively. 104

122

Magnetically non-conducting region radially inward 106

123

Sleeve-shaped extension of 112

124

Arrow: Direction of rotation of 202 . 203 . 101 . 106 . 110 . 112 and 123

125

Connecting element, in particular screw

126

Arrow: conveying direction for lubricant in 118 . 119

127

spacer

200

Electric machine

201

Rotation axis of 202

202

First element / rotor of 200

203

Storage section of 202

204

As a ball bearing trained bearing elements of 200

205

Second element / support element of 200

206

lubricant space

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102014226544 [0002, 0003, 0004, 0019, 0019]

Claims (10)

Electrical contact arrangement ( 100 ) for an electric machine ( 200 ), in which a first element formed with an electrically conductive material ( 202 ) the machine ( 200 ), in particular about a rotation axis ( 201 ) rotatably, relative to at least one formed with an electrically conductive material second element ( 205 ) the machine ( 200 ), wherein the electrical contact arrangement ( 100 ) Is provided for the movable, in particular about the axis of rotation ( 201 ) rotatably, electrically connecting the electrically conductive material of the first element ( 202 ) the machine ( 200 ) with the electrically conductive material of the at least one second element ( 205 ) the machine ( 200 ) and • against a lubricant space ( 206 ) by at least one lubricant discharge device ( 108 . 109 ), wherein the at least one lubricant discharge device ( 108 . 109 ) is adapted from the lubricant space ( 206 ) against the electrical contact arrangement ( 100 ) penetrating lubricant into the lubricant space ( 206 ) back to promote. Electrical contact arrangement ( 100 ) according to claim 1, characterized in that • at least one of the at least one lubricant discharge device ( 108 . 109 ) at least a first, with the first element ( 202 ) the machine ( 200 ) connected to the conveyor element ( 110 . 112 ) and at least a second, with the at least one second element ( 205 ) the machine ( 200 ) connected to the conveyor element ( 111 . 113 ), • at least one first discharge device element ( 110 . 112 ) and the at least one second discharge device element ( 111 . 113 ) are movable relative to one another, in particular about the axis of rotation ( 201 ) are rotatably mounted, arranged and over at the discharge device elements ( 110 . 111 . 112 . 113 ) rotationally symmetrical conveying surfaces ( 114 . 115 . 116 . 117 ), • between two adjacent conveyor surfaces ( 114 . 115 ; 116 . 117 ) one conveying gap each ( 118 ; 119 ) is formed and each one of these conveyor column ( 118 ; 119 ) on the one hand to the contact arrangement ( 100 ) and on the other hand to the lubricant space ( 206 ), and • at least one of the two adjoining conveyor surfaces ( 114 . 115 ; 116 . 117 ) with lubricant-promoting conveying elements, in particular helically along a circumferential direction of the conveying surfaces ( 114 . 115 . 116 . 117 ) extending, preferably to the lubricant space ( 206 ), recesses ( 120 ), is trained. Electrical contact arrangement ( 100 ) according to claim 1 or 2, characterized in that • the at least one second element ( 205 ) the machine ( 200 ) is formed as a support element and the electrically conductive material of the at least one second element ( 205 ) is electrically conductively connectable to an element carrying an electrical ground potential, and • the electrical contact arrangement ( 100 ) is provided for short-circuiting electrical interference voltages and deriving electrical interference currents from the first element ( 202 ) the machine ( 200 ) to the ground potential. Electrical contact arrangement ( 100 ) according to claim 3, characterized in that • the element which conducts an electrical ground potential comprises an electrical machine ( 200 ) at least partially enclosing housing, in particular a housing formed with an electrically conductive material, and / or formed by this, in particular the at least one second element ( 205 ) the machine ( 200 ) is integrally formed with the housing and / or electrically conductively connected to the housing. Electrical contact arrangement ( 100 ) according to one or more of the preceding claims, characterized in that • the first element ( 202 ) the machine ( 200 ) of a rotor of the electric machine ( 200 ) and at least one bearing element ( 204 ) rotatable relative to the at least one second element ( 205 ) is mounted and • the at least one bearing element ( 204 ) in the lubricant space ( 206 ) is arranged, so that in particular the at least one lubricant discharge device ( 108 . 109 ) is adapted from the at least one bearing element ( 204 ) against the electrical contact arrangement ( 100 ) penetrating lubricant to at least one bearing element ( 204 ) back to promote. Electrical contact arrangement ( 100 ) according to one or more of the preceding claims, characterized by an embodiment with an electrically conductive, moveable contact material ( 104 ), in particular an electrically conductive fluid and / or a conductive solid, preferably an at least substantially powdery solid, wherein the electrically conductive contact material ( 104 ) a space area ( 103 ) between at least two electrically conductive contact elements ( 101 . 102 ) of the electrical contact arrangement ( 100 ) at least partially, of which at least one first contact element ( 101 ) with the first element ( 202 ) the machine ( 200 ) and at least one second contact element ( 102 ) with the at least one second element ( 205 ) the machine ( 200 ) is electrically connected. Electrical contact arrangement ( 100 ) according to claim 6, characterized in that the electrically conductive contact material ( 104 ) is formed with an electrically conductive ferrofluid. Electrical contact arrangement ( 100 ) according to claim 7, characterized in that the contact arrangement ( 100 ) with at least one magnetic element ( 106 ) for guiding the ferrofluid in the space area ( 103 ) between the electrically conductive contact elements ( 101 . 102 ) is trained. Electric machine ( 200 ), characterized by an electrical contact arrangement ( 100 ) according to one or more of the preceding claims. Vehicle, in particular road vehicle, characterized by an electric machine ( 200 ) according to claim 9 and / or an electrical contact arrangement ( 100 ) according to one or more of claims 1 to 8.

Images