Rotary machine, and method for transmitting an electrical current

Abstract

The invention relates to a rotary machine (10) comprising a current transmission device (11) for transmitting an electrical current into or out of a rotor (13) of the machine, said rotor being formed with at least a slip ring (14) and / or a shaft (12) and / or a commutator, and to a method for transmitting an electrical current into or out of a rotor of a rotary machine, said rotor being formed with at least a slip ring and / or a shaft and / or a commutator, wherein the current transmission device comprises at least one contact element (20), preferably in the form of a brush, for contacting the slip ring or the shaft or the commutator, in such a way that a sliding contact surface (21) of the contact element can be contacted with a rotor contact surface (18) of the slip ring or of the shaft or of the commutator in order to form electrically conductive sliding contact between the sliding contact surface and the rotor contact surface, wherein the sliding contact surface and / or the rotor contact surface can be lubricated with an oil-like fluid, wherein the slip ring and / or the shaft and / or the commutator has at least one outlet opening (37) via which the oil-like fluid can be supplied to the sliding contact surface and / or to the rotor contact surface.

Description

[0001] December 12, 2024

[0002] Schunk Carbon Technology GmbH G / HOS-064-WO 4822 Bad Goisern Scu / Bmu

[0003] Rotating machine and method for transmitting an electric current

[0004] The invention relates to a rotating machine comprising a current transmission device for transmitting an electric current into or from a rotor of the machine, the rotor being designed with at least one slip ring and / or a shaft and / or a commutator, and a method for transmitting an electric current into or from a rotor of a rotating machine, the rotor being designed with a slip ring and / or a shaft and / or a commutator, wherein the current transmission device comprises at least one contact element, preferably designed as a brush, for contacting the slip ring or the shaft or the commutator, such that a sliding contact surface of the contact element can be contacted with a rotor contact surface of the slip ring or the shaft or of the commutator to form an electrically conductive sliding contact between the sliding contact surface and the rotor contact surface.wherein the sliding contact surface and / or the rotor contact surface can be lubricated with an oil-like fluid. A current transmission device of the type described above is well known from the prior art and is regularly used for transmitting an electric current into or from a rotor of a rotating machine, the rotor being configured with at least one slip ring and / or a shaft and / or a commutator. If the current transmission device is configured for transmitting an electric current into a rotor, the current transmission device can be configured for transmitting the electric current into at least one slip ring or commutator of the rotor. The machine can be an electric machine, in particular a synchronous machine, especially a current-excited or separately excited one, or a DC machine. If the current transmission device is configured for transmitting an electric current from a rotor,The current transmission device can be designed to transmit or divert the electric current from a rotor shaft, preferably into a stator of the machine. This avoids unwanted current flow through bearing points on the shaft, which could lead to surface damage to the bearing bodies or bearing rings due to spot welding.

[0005] The power transmission device typically comprises at least one contact element, usually designed as a brush, for contacting the slip ring or shaft or commutator, such that a sliding contact surface of the contact element can be contacted with a rotor contact surface of the slip ring or shaft or commutator to form an electrically conductive sliding contact between the sliding contact surface and the rotor contact surface.

[0006] Furthermore, the machine is regularly designed as a wet-running machine, meaning it operates with lubrication using an oil-like fluid. In this case, the sliding contact surface and / or the rotor contact surface are lubricated with an oil-like fluid during operation. In a machine known from the prior art, the oil-like fluid is supplied to the sliding contact surface and / or the rotor contact surface via at least one channel of a current transmission device within the machine. This method of supplying the oil-like fluid from the outside to the sliding contact surface and / or the rotor contact surface is imprecise, so that uniform lubrication of the sliding contact surface and / or the rotor contact surface is not guaranteed.Particularly at high machine speeds, there is regularly an insufficient supply of the oil-like fluid to the sliding contact surface and / or the rotor contact surface, which leads to increased wear on the sliding contact surface and the rotor contact surface, thereby adversely shortening the service life of the machine, especially of the slip ring, shaft or commutator.

[0007] The present invention is therefore based on the objective of proposing a rotating machine and a method for transmitting an electric current, which has or enables an increased service life.

[0008] This problem is solved by a rotating machine having the features of claim 1 and a method for transmitting an electric current having the features of claim 16.

[0009] The rotating machine according to the invention comprises a current transmission device for transmitting an electric current into or from a rotor of the machine, the rotor being designed with at least one slip ring and / or a shaft and / or a commutator, wherein the current transmission device comprises at least one contact element, preferably designed as a brush, for contacting the slip ring or the shaft or the commutator, such that a sliding contact surface of the contact element can be contacted with a rotor contact surface of the slip ring or the shaft or the commutator to form an electrically conductive sliding contact between the sliding contact surface and the rotor contact surface, wherein the sliding contact surface and / or the rotor contact surface can be lubricated with an oil-like fluid, and wherein the slip ring and / or the shaft and / or the commutator has at least one outlet opening.via which the oil-like fluid can be supplied to the sliding contact surface and / or the rotor contact surface.

[0010] According to the invention, the current transmission device is designed to transmit an electric current into or from a rotor of a rotating machine, the rotor being configured with at least one slip ring and / or a shaft and / or a commutator. If the current transmission device is configured to transmit an electric current into a rotor, it can be configured to transmit the electric current into at least one slip ring or commutator of the rotor. The slip ring or commutator can be arranged on the shaft. The machine can be an electric machine, in particular a synchronous machine, especially a current-excited or separately excited one, or a DC machine. The rotor of the synchronous machine can include an excitation winding electrically connected to the slip ring for generating a magnetic excitation field.The rotor contact surface can, in particular, be a circumferential contact surface of the slip ring. The commutator can, in particular, be a drum commutator, an end commutator, or a planar commutator. The rotor contact surface can, in particular, be a circumferential contact surface or an end contact surface of the commutator. The DC machine can, for example, be a component of a fuel pump. Accordingly, a fuel pump can include the DC machine. Furthermore, the machine can be a gearbox. If the current transmission device is designed to transmit an electric current from a rotor, the current transmission device can be designed to transmit or conduct the electric current from a shaft of the rotor, preferably into a stator of the machine. This avoids undesired current flow through bearing points of the shaft, which could lead to surface damage of the bearing bodies or bearing rings due to spot welding.The power transmission device then functions as a shaft grounding device. The rotor contact surface can, in particular, be a shaft contact surface.

[0011] According to the invention, the current transmission device comprises at least one contact element, preferably designed as a brush, for contacting the rotor or slip ring or shaft or commutator, such that a sliding contact surface of the contact element can be contacted with a rotor contact surface of the rotor or slip ring or shaft or commutator to form an electrically conductive sliding contact between the sliding contact surface and the rotor contact surface.

[0012] According to the invention, the sliding contact surface and / or the rotor contact surface can be lubricated with an oil-like fluid. The machine is therefore designed as a wet-running machine. The application of the oil-like fluid to the sliding contact surface and / or the rotor contact surface provides lubrication, thus reducing friction between the sliding contact surface and the rotor contact surface. This, in turn, leads to reduced wear of the sliding contact surface and the rotor contact surface, thereby advantageously increasing the service life of the machine, the slip ring, the shaft, or the commutator.Furthermore, the application of the oil-like fluid to the sliding contact surface and / or the rotor contact surface advantageously dissipates heat, particularly from friction between the sliding contact surface and the rotor contact surface, thus eliminating the need for a ventilation device, saving installation space and advantageously increasing the efficiency of a machine or gearbox into which the machine can be integrated.

[0013] According to the invention, the slip ring and / or the shaft and / or the commutator has at least one outlet opening through which the oil-like fluid can be supplied to the slip ring and / or the rotor contact surface. By supplying the oil-like fluid from within, precise delivery of the fluid to the slip ring and / or the rotor contact surface can be achieved, ensuring uniform lubrication of the slip ring and / or the rotor contact surface. Particularly at high machine speeds, this ensures a sufficient supply of the oil-like fluid to the slip ring and / or the rotor contact surface, thereby reducing wear on the slip ring and the rotor contact surface and thus advantageously increasing the service life of the machine, especially of the slip ring, shaft, or commutator.

[0014] Advantageously, the outlet opening can be located on the rotor contact surface or adjacent to the rotor contact surface.

[0015] The oil-like fluid can be pressurized during feeding.

[0016] Advantageously, the rotor, in particular the slip ring and / or the shaft and / or the commutator, can have at least one passage extending through the slip ring and / or the shaft and / or the commutator, wherein the passage can include the outlet opening. Accordingly, the passage can form a conduit for the oily fluid. The passage can be simply designed as a bore or milled groove. No additional design features on the power transmission device or other external precautions are required.

[0017] Advantageously, the passage can extend perpendicular, obliquely, or parallel to a rotational axis of the machine, a longitudinal axis, a rotational axis of the shaft, or a rotational axis of the slip ring or commutator. The passage can also extend obliquely to the rotational axis of the machine, the longitudinal axis, the rotational axis of the shaft, or the rotational axis of the slip ring or commutator in a flow direction of the oily fluid through the passage towards the rotor contact surface.

[0018] Advantageously, the passage can be designed as a round or oblong hole. The longitudinal direction of the oblong hole can run parallel or at an angle to the axis of rotation of the machine.

[0019] Advantageously, the shaft can be designed as a hollow shaft, with the passage leading into a cavity within the hollow shaft. An inlet opening opposite the outlet opening allows the passage to then open into the cavity. Accordingly, the oily fluid can be supplied via the hollow shaft or the cavity, from where it can reach the sliding contact surface and / or the rotor contact surface via the passage fluidically connected to the cavity. In other words, the cavity can form an additional conduit for the oily fluid. Cooling or lubrication of the machine, particularly the rotor, can also be achieved via the hollow shaft or the cavity using the oily fluid. In a machine that already has cooling or lubrication...If lubrication, in particular of a rotor of the machine, is provided via a shaft of the rotor designed as a hollow shaft, the passage can be easily formed subsequently without the need for additional design measures, in particular on the power transmission device.

[0020] Advantageously, the slip ring and / or the shaft and / or the commutator can have at least two, in particular uniformly circumferentially distributed, outlet openings or passages. The uniform circumferential distribution of the at least two outlet openings or passages, that is, n outlet openings or passages, where n is a natural number greater than or equal to two, means that any two outlet openings or passages adjacent in one circumferential direction of the slip ring and / or the shaft and / or the commutator are spaced apart from each other at an angle of 360° / n in the circumferential direction. This allows for even more uniform lubrication of the sliding contact surface and / or the rotor contact surface.Passages can also be arranged side by side, especially in groups, in particular such that a connecting line imaginary between the outlet openings or passages runs parallel or obliquely to the axis of rotation of the machine.

[0021] Advantageously, the current transmission device can include at least one spring assembly by means of which the sliding contact surface can be pressed against the rotor contact surface. This ensures optimized contact and the formation of a uniform film of the oily fluid. The spring assembly allows the sliding contact surface to be pressed against the rotor contact surface with a contact pressure of 2 N / cm². 2 up to 35 N / cm 2 The spring assembly can contact the contact element, in particular with an end section of the spring assembly, and thus press the contact element against the slip ring, the shaft, or the commutator.

[0022] The spring assembly can be designed with at least one bimetallic strip or bimetal. A bimetallic strip is a metal strip or band made up of two superimposed layers of different metals. The term "strip," especially as part of the term "bimetallic strip" or "metal strip," is to be understood broadly. Besides strip-shaped configurations in the strict sense, it also includes other geometries, such as disc-shaped or plate-shaped configurations. The two layers are connected to each other, in particular by a material bond and / or a form-fit connection. Due to the different coefficients of thermal expansion (CTE), especially the coefficients of linear expansion, of the metals used, the metal strip or band changes its temperature when it changes.The metal strip is a shape of the metal strip or band. A change in shape manifests itself as a bend. This change in shape, or bend, in turn leads to a change in the spring force of the spring assembly formed with the metal strip or band, and thus to a change in the contact pressure with which the sliding contact surface of the contact element is pressed against the rotor contact surface of the slip ring, shaft, or commutator by means of the spring assembly. The underlying idea of ​​this embodiment is therefore not so much aimed at the deformation of the spring assembly or the bimetallic strip, but rather at the resulting change in the spring force. The design of the spring assembly with the bimetallic strip thus enables an adjustment of the contact pressure that depends on the temperature of the spring assembly, in particular the bimetallic strip, or the temperature of the contact element or the temperature of the oily fluid.Potential lifting of the contact element from the slip ring, shaft, or commutator, where the sliding contact surface of the contact element no longer makes contact with the rotor contact surface of the slip ring, shaft, or commutator, and where this lifting is caused by the viscosity of an oily fluid, which changes depending on the temperature of the oily fluid, and in particular decreases with increasing temperature, can be avoided by adjusting the contact pressure in a temperature-dependent manner. Therefore, sparking and thus damage and wear on the sliding contact surface of the contact element and the rotor contact surface of the slip ring, shaft, or commutator can be avoided or reduced, thereby advantageously increasing the service life of the machine, especially of the slip ring, shaft, or commutator.Furthermore, mechanical power losses resulting from friction between the contact element or the sliding contact surface and the slip ring or the shaft or the commutator or the rotor contact surface can be reduced.

[0023] Advantageously, the bimetallic strip can be a metal strip or band. The bimetallic strip can consist of a first layer of a metal with a first coefficient of linear expansion and a second layer of a second metal with a second coefficient of linear expansion arranged on top of the first layer. Here, "metal" can refer to either a pure metal or a metal alloy. Therefore, the first metal and / or the second metal can be a pure metal or a metal alloy.

[0024] Advantageously, the spring arrangement can include a spring element.

[0025] Advantageously, the spring element can be formed at least partially or section by section, in particular at least at its end or at at least one end section of the spring element, from the bimetallic strip, or the spring element, formed separately from the bimetallic strip and preferably of conventional design or not formed from a bimetallic strip, can be mechanically coupled to or engage with the bimetallic strip. If the spring element is formed at least partially from the bimetallic strip, at least one end section of the spring element that contacts or engages with the contact element and / or, if present, at least one end section of the spring element that does not contact or engage with the contact element can be formed from the bimetallic strip. Otherwise, the spring element can be formed conventionally or not from a bimetallic strip.The spring element can be formed entirely from the bimetallic strip, or over its entire length. The spring element can then form the spring assembly. If the spring element, preferably conventional or not formed from a bimetallic strip, is separate from the bimetallic strip, the spring assembly can comprise both the spring element and the bimetallic strip, or the spring assembly can be formed by both the spring element and the bimetallic strip. The bimetallic strip, which is mechanically coupled to or engaged with the spring element, can exert a force on the spring element that varies depending on the temperature of the spring assembly, particularly the temperature of the bimetallic strip. Depending on the temperature and the arrangement of the bimetallic strip, this force can be essentially in the same direction as the spring force of the spring element or in the opposite direction.In all cases, the bimetallic strip changes the spring force when the temperature of the spring assembly, in particular the bimetallic strip, changes.

[0026] Advantageously, the spring element can be designed as a coil spring, a rolling band spring (in particular a simple or double rolling band spring), a helical compression spring, or a torsion spring. A coil spring or rolling band spring exhibits low force loss over a stroke. If the spring element is designed as a coil spring or rolling band spring, it can be formed from a helical bimetallic strip or a rolled bimetallic band. The torsion spring can engage with the contact element via a first leg section and engage with the bimetallic strip (which is formed separately from the torsion spring) via a second leg section, thus being mechanically coupled to the bimetallic strip.The bimetallic strip can engage with an end of the helical compression spring facing the contact element, i.e., it can be positioned between the helical compression spring and the contact element, or with an end of the helical compression spring facing away from the contact element. The spring element or the bimetallic strip can be formed from a sheet of metal. A spring force or a range of spring force variation can then be easily adjusted by changing the sheet width and / or thickness.

[0027] The spring assembly or spring element can contact the contact element, in particular with an end section of the spring assembly or spring element, or engage with the contact element with the end section.

[0028] The spring element can be arranged on a rigid or rotatable mounting point on the power transmission device. In particular, the spring element, which may be designed as a coil spring, roller spring, or torsion spring, can be arranged on a rotatable mounting point on the power transmission device, especially via a thread, particularly a screw element. The bimetallic strip, which is separate from the spring element and mechanically coupled to it, can act on the mounting point, the screw element, or the spring element itself, depending on the temperature, particularly that of the bimetallic strip, causing the spring element to rotate, thereby changing the spring force of the spring element. The mounting point can be rotatable by at least 90°, preferably at least 180°.

[0029] Advantageously, the spring arrangement, in particular the bimetallic strip, can be arranged and / or designed on the current transmission device such that an increase in temperature, in particular of the spring arrangement, in particular of the bimetallic strip, and / or of the contact element and / or of an oily fluid, can reduce the contact pressure, and an increase in the contact pressure can be achieved when the temperature decreases, or vice versa. When reducing the contact pressure, it can also be reduced to essentially zero. In particular, the bimetallic strip, which is designed separately from the spring element, can press against the spring element in such a way that the spring element is effectively deactivated in its spring action on the contact element. The spring arrangement, in particular the spring element, or...The bimetallic strip, particularly its end section, can bend away from the contact element or spring element to reduce the contact pressure when the temperature of the contact element, the oily fluid, or the spring assembly (especially the bimetallic strip, which is thermally coupled to the contact element) increases. Conversely, when the temperature of the contact element, the oily fluid, or the spring assembly (especially the bimetallic strip, which is thermally coupled to the contact element) decreases, the bimetallic strip can bend towards the contact element or spring element to increase the contact pressure. The increase or decrease in the temperature of the contact element or the oily fluid...The temperature of the spring assembly, particularly the bimetallic strip, can result from an increase or decrease in frictional heat caused by an increase or decrease in the machine's rotational speed. This frictional heat arises from friction between the contact element or the sliding contact surface and the slip ring, shaft, commutator, or rotor contact surface, or from general machine heat loss. Thus, the spring force with which the spring assembly or spring element presses on the contact element, and consequently the contact pressure, can be increased at a comparatively low temperature or during cold running, and decreased at a comparatively high temperature.Alternatively, conversely, the spring arrangement can be arranged and / or designed on the current transmission device in such a way that, in the event of an increase in temperature, in particular of the spring arrangement, in particular of the bimetallic strip, and / or of the contact element and / or of the oily fluid, a contact pressure can be increased and, in the event of a decrease in temperature, the contact pressure can be decreased.

[0030] Advantageously, engine oil and / or transmission oil can be used as the oil-like fluid, which is regularly present in an engine or transmission, as the machine may be designed.

[0031] The rotor can comprise a plurality of slip rings or commutators, particularly those arranged on the shaft. Each slip ring or commutator can then have a rotor contact surface.

[0032] The contact element can be made of a first carbon material, preferably copper-free, or based on graphite.

[0033] The rotor contact surface, the slip ring, the shaft, or the commutator in a region of the rotor contact surface can be made of a second carbon material, preferably copper-free, or based on graphite or a metal or metallic material.

[0034] Advantageously, the contact element, preferably rod-shaped, can have the sliding contact surface on its end face. The spring assembly can then make contact with the contact element from the rear.

[0035] The longitudinal axis of the contact element can extend transversely to the longitudinal axis or axis of rotation of the shaft, or the axis of rotation of the slip ring or commutator. The longitudinal axis of the contact element, or an extension of the longitudinal axis of the contact element in the direction of the slip ring, commutator, or shaft, can pass through the axis of rotation of the slip ring or commutator, or the longitudinal axis or axis of rotation of the shaft.

[0036] The contact element can, for example, have a circular, square, or rectangular cross-section. Advantageously, the slip ring, shaft, or commutator can have a plurality of rotor contact surfaces, preferably at least two, and in particular two or three. The rotor contact surfaces, viewed in the direction of the axis of rotation of the slip ring, shaft, or commutator, can preferably be spaced equally or equidistantly from one another and run parallel to each other. Each rotor contact surface can then be assigned to a phase.

[0037] Advantageously, the slip ring can comprise a carrier sleeve made of an electrical insulating material, preferably polymer, and at least one, in particular two, contact rings arranged on the carrier sleeve, which can be made of an electrically conductive material, wherein the contact ring can preferably have the rotor contact surface on its outer circumference. The carrier sleeve can form a recess or a passage into which the shaft can engage or through which the shaft can pass in order to position the slip ring on the shaft. The carrier sleeve can be manufactured by injection molding. Furthermore, the slip ring can preferably have at least one connection on its inner circumference for the excitation winding.The slip ring comprises at least one conductor, in particular a stranded wire, which can be electrically connected at one end, preferably on the inner circumference, to the contact ring and electrically connectable at the other end to the excitation winding. If the slip ring comprises several contact rings and thus has several rotor contact surfaces, the connections or conductors of the slip ring assigned to different phases can be arranged at a maximum distance or angle from each other on the slip ring or contact ring when viewed in the circumferential direction of the slip ring. For example, the connections or conductors can be offset from each other by an angle of 180° for two phases and by an angle of 120° for three phases. The passage can extend through the carrier sleeve and / or the contact ring. The passage can at least extend through the shaft and the carrier sleeve.

[0038] Advantageously, the current transmission device can comprise a plurality of contact elements. The current transmission device can comprise a plurality of spring assemblies corresponding to the plurality of contact elements, so that each contact element can be associated with one of the spring assemblies.

[0039] Advantageously, the plurality of contact elements can be arranged such that each rotor contact surface of the slip ring, shaft, or commutator can be contacted by means of at least one contact element of the plurality of contact elements or a respective slip contact surface. In other words, a number of contact elements can correspond to at least a number of rotor contact surfaces. In one embodiment of the current transmission device, the current transmission device can comprise at least one first contact element for contacting a first rotor contact surface of the slip ring, shaft, or commutator and at least one second contact element for contacting a second rotor contact surface of the slip ring, shaft, or commutator.The majority of rotor contact surfaces can also be provided by a majority of slip rings or commutators arranged on the shaft.

[0040] Advantageously, the plurality of contact elements can be configured such that the rotor contact surface, or each rotor contact surface, can be contacted by means of at least two, two, or at least three contact elements of the plurality of contact elements, or of a respective sliding contact surface. Therefore, at least two contact elements, in particular two or three contact elements, can be provided for the rotor contact surface, or for each rotor contact surface. In one embodiment of the current transmission device, the current transmission device can comprise at least two first contact elements for contacting a first rotor contact surface of the slip ring, shaft, or commutator, and at least two second contact elements for contacting a second rotor contact surface of the slip ring, shaft, or commutator.Providing multiple contact elements on a single rotor contact surface enables the transmission of a higher current. Furthermore, this avoids hydrodynamic effects and ensures uniform lubrication.

[0041] Advantageously, the current transmission device can be designed such that the two or at least three contact elements of the majority of contact elements are distributed only along a portion of the circumference of the slip ring, shaft, commutator, or rotor contact surface. This advantageously prevents dry running. Furthermore, this allows the current transmission device to be advantageously arranged or mounted laterally on the machine or shaft and eliminates the need for a complex process of mounting it over the shaft or rotor.

[0042] Advantageously, the central angle of a circular arc defined by the part can be between 55° and 170°. The central angle can also be between 90° and 170°. In other words, the central angle is the angle between the two outermost contact elements.

[0043] Depending on the embodiment of the current transmission device, the distances between each pair of adjacent contact elements of the at least three contact elements of the plurality of contact elements in a circumferential direction of the slip ring or shaft or commutator can all be the same, partially different, or different in pairs.

[0044] Advantageously, the current transmission device can include a holding device in which the contact element can be guided, preferably radially or in a radial direction of the slip ring or shaft or commutator, or axially movable.

[0045] In one embodiment of the current transmission device, the holding element can comprise at least one retaining part made of an electrically conductive material, preferably metal, in which the contact element can be guided. The contact element can be electrically connected to the retaining part, in particular by means of a connecting element or a conductor, preferably a stranded wire, of the current transmission device. Thus, the retaining part can simultaneously function as a busbar. The retaining part can be manufactured by stamping. Preferably, the retaining part can be designed as a stamped metal part. The conductor can be pressed or stamped into the contact element at one end and welded, soldered, or mechanically connected, in particular clamped or crimped, to the retaining part at the other end. The spring assembly can be arranged on the retaining part, in particular on a projection of the retaining part.Furthermore, the retaining part may have a connection section with a terminal via which the retaining part can be connected to an electrical line for supplying the electric current or to a pole of a voltage source.

[0046] The holding device can comprise at least one support part made of an electrical insulating material, in particular a polymer, wherein the holding part can be arranged on the support part. In one embodiment of the current transmission device, the current transmission device can comprise a first holding part in which at least one first contact element, in particular three first contact elements, of the current transmission device can be guided, and a second holding part in which at least one second contact element, in particular three second contact elements, of the current transmission device can be guided, wherein the first holding part can be arranged on a first side of the support part and the second holding part can be arranged on a second side of the support part. The first side can be opposite the second side.The first contact element can be designed to contact a first rotor contact surface, and the second contact element can be designed to contact a second rotor contact surface. This allows the contact elements, which contact different rotor contact surfaces or are assigned to different phases, to be electrically isolated from one another. The carrier part can have a receptacle, in particular a through-hole or a recess, for receiving the shaft. Furthermore, the carrier part, particularly its interior, can be free of a channel for the oily fluid.

[0047] In the inventive method for transmitting an electric current into or from a rotor of a rotating machine, the rotor being designed with at least one slip ring and / or a shaft and / or a commutator, the slip ring or the shaft or the commutator is contacted by means of at least one contact element, preferably designed as a brush, of a current transmission device of the machine, such that a sliding contact surface of the contact element is contacted with a rotor contact surface of the slip ring or the shaft or the commutator to form an electrically conductive sliding contact between the sliding contact surface and the rotor contact surface, wherein the sliding contact surface and / or the rotor contact surface is lubricated with an oil-like fluid.wherein an oil-like fluid is supplied to the sliding contact surface and / or the rotor contact surface for lubrication via at least one outlet opening of the slip ring and / or the shaft or the commutator.

[0048] For the advantageous effects of the method according to the invention, reference is made to the advantages description of the machine according to the invention.

[0049] Further advantageous embodiments of the method according to the invention are described in the features of the dependent claims relating to device claim 1. Preferred embodiments of the invention are explained in more detail below with reference to the accompanying drawings.

[0050] They show:

[0051] Fig. 1 is a perspective partial view of a rotating machine;

[0052] Fig. 2 shows a perspective view of a shaft of a rotor of the machine shown in Fig. 1, with a slip ring of the rotor arranged on it;

[0053] Fig. 3 shows a perspective view of a shaft with a slip ring attached to it;

[0054] Fig. 4 shows a perspective partial sectional view of the shaft shown in Fig. 3 with the slip ring attached to it;

[0055] Fig. 5 shows a schematic view of a rotor in a first embodiment;

[0056] Fig. 6 shows a schematic view of a rotor in a second embodiment;

[0057] Fig. 7 shows a schematic view of a rotor in a third embodiment;

[0058] Fig. 8 shows a schematic view of a rotor in a fourth embodiment.

[0059] A combined view of Figures 1 and 2 shows a preferably electric, rotating machine 10, in particular a synchronous machine, comprising a current transmission device 11 for transmitting an electric current, in particular excitation current, to a slip ring 14 of the rotor 13 arranged on a shaft 12 of a rotor 13 of the machine 10, which is shown here only in section. The slip ring 14 comprises a carrier sleeve 15 made of an electrical insulating material, preferably polymer, a first contact ring 16 arranged on the carrier sleeve 15, and a second contact ring 17 arranged on the carrier sleeve 15, wherein the first contact ring 16 and the second contact ring 17 are made of an electrically conductive material. The first contact ring 16 and the second contact ring 17 have a first rotor contact surface 18 and a second rotor contact surface 19, respectively, on their outer circumference.

[0060] The power transmission device 1 1 comprises three first contact elements 20 and three second contact elements (not shown) for contacting the slip ring 14, such that a respective first sliding contact surface 21 of the first contact elements 20 and a respective second sliding contact surface (not shown) of the second contact elements can be contacted with the first rotor contact surface 18 and the second rotor contact surface 19, respectively, to form an electrically conductive sliding contact between the respective first sliding contact surface 21 and the first rotor contact surface 18 and the respective second sliding contact surface and the second rotor contact surface 19. The first rotor contact surface 18 and the second rotor contact surface 19 are each configured as a circumferential contact surface of the slip ring 14, first contact ring 16, and second contact ring 17, respectively. The first contact elements 20 are configured identically to the second contact elements.The current transmission device 1 1 is designed such that the first contact elements 20 or second contact elements are arranged distributed only along a part of a circumference of the slip ring 14, wherein a central angle of a circular arc defined by the part (not shown here) is 55° to 170°.

[0061] Furthermore, the current transmission device 1 1 comprises a spring element 23 forming a spring arrangement 22 of the current transmission device 1 1, respectively, for each first contact element 20 and second contact element, by means of which the respective first sliding contact surface 21 can be pressed against the first rotor contact surface 18 and the respective second sliding contact surface against the second rotor contact surface 19. The spring elements 23 are each designed as a coil spring.

[0062] The current transmission device 1 1 further comprises a holding device 24 in which the first contact elements 20 and the second contact elements are guided radially movably. The holding device 24 comprises a first holding part 25 made of an electrically conductive material in which the first contact elements 20 are guided, and a second holding part (not shown) made of an electrically conductive material in which the second contact elements are guided, wherein the first contact elements 20 are electrically connected to the first holding part 25 and the second contact elements are each electrically connected to the second holding part by means of a conductor 26 of the current transmission device 1 1.

[0063] The first retaining part 25 or second retaining part forms first receiving sections 27 or second receiving sections (not shown here) that receive and guide the first contact elements 20 or second contact elements. The spring assemblies 22 or spring elements 23 are arranged on the first retaining part 25 or second retaining part. The first retaining part 25 or second retaining part forms first projections 28 or second projections (not shown here) on which the spring assemblies 22 or spring elements 23 are arranged. The first projections 28 or second projections serve as rigid mounting points. Furthermore, the first retaining part 25 or second retaining part forms a first connection section 29 with a first connection 30 or a second connection section (not shown here) with a second connection (not shown here). The first connection 30 or second connection serves to connect the current transmission device 1 to a negative terminal (not shown here).Positive terminal of a voltage source (not shown here). By applying a voltage to the current transmission device 11, the electric current, in particular excitation current, can be supplied. Each spring assembly 22 or each spring element 23 contacts a first contact element 20 or second contact element associated with the respective spring assembly 22 or spring element 23 with a respective end section 31 of the spring assembly 22 or spring element 23 on one of the first rear surfaces 32 of the first contact element 20 or the second rear surface 32 of the second contact element (not shown here), which is opposite the first sliding contact surface 21 or second sliding contact surface formed on the end face.

[0064] The holding device 24 further comprises a support part 33 made of an electrical insulating material, wherein the first holding part 25 is arranged on a first side 34 of the support part 33 and the second holding part is arranged on a second side of the support part 33 opposite the first side 34, which is not shown here.

[0065] Furthermore, the rotor 13 has four uniformly circumferentially distributed first passages 35 and second passages 36 extending through the slip ring 14, i.e., the carrier sleeve 15 and the first contact ring 16 and second contact ring 17, respectively, and the shaft 12, wherein the first passages 35 and second passages 36 each have a first outlet opening 37 and a second outlet opening 38, respectively. An oil-like fluid can be supplied via the first outlet opening 37 and second outlet opening 38 to the first sliding contact surface 21 and second sliding contact surface and / or the first rotor contact surface 18 and second rotor contact surface 19 for the purpose of lubricating the first sliding contact surface 21 and second sliding contact surface and / or the first rotor contact surface 18 and second rotor contact surface 19 during operation of the machine. The first outlet openings 37 and the second outlet openings 38 are arranged on the first rotor contact surface 18 and the second rotor contact surface 19, respectively.The first passages 35 and second passages 36, each designed as a round hole, extend perpendicular to a longitudinal axis of the shaft 12 (not shown here). The shaft 12 is designed as a hollow shaft, with the first passages 35 and second passages 36 opening into a cavity 39 of the hollow shaft.

[0066] A combined view of Figures 3 and 4 shows a rotor 40 comprising a shaft 41 and a slip ring 42 arranged on the shaft 41. The slip ring 42 comprises a carrier sleeve 43 made of an electrical insulating material, preferably polymer, a first contact ring 44 arranged on the carrier sleeve 43, and a second contact ring 45 arranged on the carrier sleeve 43, wherein the first contact ring 44 and the second contact ring 45 are made of an electrically conductive material. The first contact ring 44 and the second contact ring 45 have a first rotor contact surface 46 and a second rotor contact surface 47, respectively, on their outer circumference.

[0067] Furthermore, the rotor 40 has four uniformly circumferentially distributed first passages 48 and second passages 49 extending through the slip ring 42 (i.e., the carrier sleeve 43, but not the first contact ring 44 or second contact ring 45) and the shaft 41, wherein the first passages 48 and second passages 49 each have a first outlet opening 50 and a second outlet opening 51, respectively. The first outlet openings 50 and second outlet openings 51 are arranged adjacent to the first rotor contact surface 46 and the second rotor contact surface 47, respectively. The first passages 48 and second passages 49, each designed as a round hole, extend obliquely to a longitudinal axis of the shaft 41 (not shown here) in a flow direction of the oil-like fluid through the first passages 48 and second passages 49, respectively, towards the first rotor contact surface 46 and second rotor contact surface 47, respectively.The shaft 41 is designed as a hollow shaft, with the first passages 48 and second passages 49 respectively leading into a cavity 52 of the hollow shaft.

[0068] Fig. 5 shows a rotor 53 which has two adjacent passages 54, each formed as a round hole. An imaginary connecting line between the passages 54 extends along a rotational axis of the rotor 53 (not shown here).

[0069] Fig. 6 shows a rotor 55 which has two adjacent passages 56, each formed as a round hole. A connecting line imaginary between the passages 56 extends obliquely to a rotational axis of the rotor 55 (not shown here).

[0070] Fig. 7 shows a rotor 57 which has a passage 58 designed as an elongated slot. A longitudinal direction of the passage 58, not shown here, extends along a rotational axis of the rotor 57, also not shown here.

[0071] Fig. 8 shows a rotor 59 which has a passage 60 designed as an elongated slot. A longitudinal direction of the passage 60 (not shown here) extends obliquely to a rotational axis of the rotor 59 (also not shown here). The embodiments shown in Figs. 1 to 8 can be combined with one another in any meaningful way.

Claims

December 12, 2024 Schunk Carbon Technology GmbH G / HOS-064-WO 4822 Bad Goisern Scu / Bmu Patent claims 1. Rotating machine (10) comprising a current transmission device (11) for transmitting an electric current into or from a rotor (13, 40, 53, 55, 57, 59) of the machine, the rotor being formed with at least one slip ring (14, 42) and / or a shaft (12, 41) and / or a commutator, wherein the current transmission device comprises at least one contact element (20), preferably formed as a brush, for contacting the slip ring or the shaft or the commutator, such that a sliding contact surface (21) of the contact element can be contacted with a rotor contact surface (18, 19, 46, 47) of the slip ring or the shaft or the commutator to form an electrically conductive sliding contact between the sliding contact surface and the rotor contact surface, wherein the sliding contact surface and / or the rotor contact surface can be lubricated with an oil-like fluid, characterized in thatthat the slip ring and / or the shaft and / or the commutator has at least one outlet opening (37, 38, 50, 51) through which the oil-like fluid can be supplied to the sliding contact surface and / or the rotor contact surface.

2. Rotating machine according to claim 1, characterized in that the outlet opening (37, 38, 50, 51) is arranged on the rotor contact surface (18, 19, 46, 47) or adjacent to the rotor contact surface.

3. Rotating machine according to claim 1 or 2, characterized in that the rotor (13, 40, 53, 55, 57, 59) has at least one passage (35, 36, 54, 56, 58, 60) passing through the slip ring (14, 42) and / or the shaft (12, 41) and / or the commutator, wherein the passage has the outlet opening (37, 38, 50, 51).

4. Rotating machine according to claim 3, characterized in that the passage (35, 36, 54, 56, 58, 60) extends perpendicularly or obliquely or parallel to a rotational axis of the machine (10).

5. Rotating machine according to claim 3 or 4, characterized in that the passage (35, 36, 54, 56, 58, 60) is designed as a round hole or oblong hole.

6. Rotating machine according to one of claims 3 to 5, characterized in that the shaft (12, 41) is designed as a hollow shaft, wherein the passage (35, 36, 54, 56, 58, 60) opens into a cavity (39, 52) of the hollow shaft.

7. Rotating machine according to one of the preceding claims, characterized in that the slip ring (14, 42) and / or the shaft (12, 41) and / or the commutator has at least two, in particular uniformly circumferentially distributed, outlet openings (37, 38, 50, 51).

8. Rotating machine according to one of the preceding claims, characterized in that the current transmission device (11) comprises at least one spring arrangement (22) by means of which the sliding contact surface (21) can be pressed against the rotor contact surface (18, 19, 46, 47).

9. Rotating machine according to one of the preceding claims, characterized in that the current transmission device (11) comprises a plurality of contact elements (20).

10. Rotating machine according to claim 9, characterized in that the plurality of contact elements (20) is arranged such that each rotor contact surface of a plurality of rotor contact surfaces (18, 19, 46, 47) of the slip ring (14, 42) or the shaft (12, 41) or of the commutator can be contacted by means of at least one contact element of the plurality of contact elements.

11. Rotating machine according to claim 9 or 10, characterized in that the plurality of contact elements (20) is arranged such that the rotor contact surface (18, 19, 46, 47) can be contacted by means of two or at least three contact elements of the plurality of contact elements.

12. Rotating machine according to claim 11, characterized in that the current transmission device (11) is designed such that the two or at least three contact elements (20) of the plurality of contact elements are arranged distributed only along a part of a circumference of the slip ring (14, 42) or the shaft (12, 41) or the commutator, wherein a central angle of a circular arc defined by the part is preferably 55° to 170°.

13. Rotating machine according to one of the preceding claims, characterized in that the power transmission device (11) has a holding device (24) comprises in which the contact element (20) is guided, preferably radially or axially movable.

14. Rotating machine according to claim 13, characterized in that the holding device (24) comprises at least one holding part made of an electrically conductive material, preferably metal. (25) comprises in which the contact element (20) is guided, wherein the contact element is electrically connected to the holding part, in particular by means of a line, preferably stranded wire, of the current transmission device (11).

15. Rotating machine according to claim 14, characterized in that the holding device (24) comprises a support part (33) made of an electrical insulating material, in particular polymer, wherein the holding part (25) is arranged on the support part.

16. Method for transmitting an electric current into or from a rotor (13, 40, 53, 55, 57, 59) of a rotating machine (10) comprising at least one slip ring (14, 42) and / or a shaft (12, 41) and / or a commutator, wherein the slip ring or the shaft or the commutator is contacted by means of at least one contact element (20), preferably designed as a brush, of a current transmission device (11) of the machine, such that a sliding contact surface (21) of the contact element is contacted with a rotor contact surface (18, 19, 46, 47) of the slip ring or the shaft or the commutator to form an electrically conductive sliding contact between the sliding contact surface and the rotor contact surface, wherein the sliding contact surface and / or the rotor contact surface is lubricated with an oil-like fluid, characterized in that at least one outlet opening (37, 38, 50,51) of the slip ring and / or the shaft and / or the commutator, the sliding contact surface and / or the rotor contact surface is supplied with an oil-like fluid for the purpose of lubrication.

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