Current transmission assembly for rotational-speed-dependent lubrication, rotating electrical machine and method for transmitting an electrical excitation current
The current transmission arrangement with speed-dependent lubrication addresses wear and efficiency issues in rotating electrical machines by using an oiling device with rotating disks, enhancing service life and efficiency through reduced friction and eliminating unnecessary systems.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SCHUNK CARBON TECH GMBH
- Filing Date
- 2024-12-19
- Publication Date
- 2026-06-25
AI Technical Summary
Current transmission arrangements for rotating electrical machines, particularly synchronous machines, suffer from increased wear and reduced efficiency due to dry-running conditions, which require additional sealing and ventilation systems, increasing mass and friction, and result in voltage drops at high speeds.
A current transmission arrangement with an oiling device that provides speed-dependent lubrication using an oil-like fluid, applied via a transfer unit with rotating disks, ensuring continuous lubrication across the machine's speed range, reducing friction and heat generation, and eliminating the need for ventilation and complex sealing systems.
The solution enhances the service life of the current transmission device, reduces installation space, and increases efficiency by minimizing wear and friction, while maintaining effective electrical contact at high speeds.
Smart Images
Figure EP2024087383_25062026_PF_FP_ABST
Abstract
Description
[0001] December 19, 2024
[0002] Schunk Carbon Technology GmbH G / HOS-063-WO 4822 Bad Goisern Scu / Kaf
[0003] Current transmission arrangement for speed-dependent lubrication of a rotating electric machine and method for transmitting an electric excitation current
[0004] The invention relates to a current transmission arrangement comprising a current transmission device for a rotating electrical machine, in particular a synchronous machine, for transmitting an electrical excitation current to a slip ring that can be arranged on a shaft of a rotor of the machine, and a method for transmitting an electrical excitation current to a slip ring arranged on a shaft of a rotor of a rotating electrical machine, in particular a synchronous machine, wherein the current transmission device comprises at least one contact element, preferably designed as a brush, for contacting the slip ring, such that a sliding contact surface of the contact element can be contacted with a circumferential contact surface of the slip ring to form an electrically conductive sliding contact between the sliding contact surface and the circumferential contact surface.The invention further relates to a rotating electric machine, in particular a synchronous machine, comprising a current transmission arrangement. The current transmission device typically includes at least one contact element, usually designed as a brush, for contacting the slip ring, such that a sliding contact surface of the contact element can be contacted with a circumferential contact surface of the slip ring to form an electrically conductive sliding contact between the sliding contact surface and the circumferential contact surface. The current transmission device known from the prior art is generally designed as a dry-running machine, i.e., running without lubrication with a lubricant, which, due to increased friction between the sliding contact surface and the circumferential contact surface, results in increased wear of both surfaces, thereby reducing the service life of the current transmission device.The contact area of the slip ring is disadvantageously shortened. Furthermore, if the dry-running power transmission device is integrated into a gearbox, for example, it requires a suitable sealing system to protect the installation space from oil contamination. This system requires additional installation space and causes additional friction losses. The presence of the sealing system thus results in increased mass and friction, which adversely reduces the efficiency of the machine or the gearbox into which it may be integrated. Additionally, the dry-running power transmission device requires a ventilation system to dissipate heat, particularly from friction between the sliding contact surface and the peripheral contact surface. This ventilation system requires further additional installation space and further reduces the efficiency of the machine or gearbox.This problem can be addressed by applying a coolant, such as cooling oil. However, in such general-purpose current transmission arrangements with a coolant device, a voltage drop with increasing rotational speed is observed because there is no longer a sufficient amount of coolant applied. This leads to increased wear on both the slip ring and the contact element.
[0005] The present invention is therefore based on the objective of proposing a current transmission arrangement, a rotating electrical machine and a method for transmitting an electrical excitation current, which has or enables an increased service life, a reduced installation space and increased efficiency even in high speed ranges.
[0006] This problem is solved by a current transmission arrangement having the features of claim 1, a rotating electrical machine having the features of claim 15, and a method for transmitting an electrical excitation current having the features of claim 17.
[0007] The current transmission arrangement according to the invention comprises a current transmission device for a rotating electric machine, in particular a synchronous machine, for transmitting an electric excitation current to a slip ring that can be arranged on a shaft of a rotor of the machine, wherein the current transmission device comprises the slip ring, wherein the current transmission device comprises at least one contact element, preferably designed as a brush, for contacting the slip ring, such that a sliding contact surface of the contact element can be contacted with a circumferential contact surface of the slip ring to form an electrically conductive sliding contact between the sliding contact surface and the circumferential contact surface, wherein the current transmission arrangement includes an oiling device for speed-dependent, preferably continuous,The invention includes lubrication of the slip ring contact surface and / or the circumferential contact surface with an oil-like fluid during machine operation. This lubrication can occur across the entire speed range of the machine. The current transmission arrangement or device according to the invention is designed to transmit an electrical excitation current to a slip ring that can be arranged on the shaft of a rotor of a rotating electric machine, in particular a current-excited or separately excited synchronous machine. From the slip ring, the excitation current can then flow into an excitation winding of the rotor that is electrically connected to the slip ring and can serve to generate a magnetic excitation field. The current transmission device comprises at least one contact element, preferably designed as a brush, for contacting the slip ring, such that...that a sliding contact surface of the contact element can be contacted with a circumferential contact surface of the slip ring to form an electrically conductive sliding contact between the sliding contact surface and the circumferential contact surface. The term "circumferential contact surface" is understood to mean a raceway, preferably strip-shaped, running circumferentially around the outside of the slip ring in a circumferential direction.
[0008] According to the invention, the current transmission device comprises the slip ring. The current transmission device can comprise at least one slip ring or a plurality of slip rings that can be arranged on the shaft. Each slip ring can have at least one circumferential contact surface.
[0009] The current transmission arrangement further comprises an oiling device for the speed-dependent, preferably continuous, oiling of the sliding contact surface and / or the circumferential contact surface with an oil-like fluid during machine operation. The oiling device can be an integral part of the current transmission device or the machine, or an external oiling device designed separately from the current transmission device and the machine. According to the invention, the current transmission arrangement or current transmission device is thus designed as a wet rotor. According to the invention, the oiling device comprises a transfer unit having at least one disk. The at least one disk of the transfer unit is rotationally fixed to the rotor shaft, so that the at least one disk rotates together with the rotor shaft. In this case, the at least one disk rotates at a speed equal to that of the shaft, i.e.,The disc rotates at the same speed as the rotor shaft. The oily fluid can be transferred axially, dependent on the rotational speed, to the sliding contact surface of the contact element and / or to the circumferential contact surface of the slip ring by means of at least one disc of the transfer device. The oily fluid can be applied to the circumferential surface of the disc and, due to the rotation of the disc during machine operation, transferred axially to the sliding contact surface and / or the circumferential contact surface. Within the scope of the invention, the term "axial direction" is to be understood in relation to the axis of rotation of the rotor shaft. For example, due to the rotation of the disc and the resulting centrifugal force, the oily fluid can be flung from the disc onto the sliding contact surface and / or the circumferential contact surface in an axial direction.For this purpose, the disc can preferably have a larger circumference than the contact ring on which the circumferential contact surface can be formed. In other words, the circumferential surface of the disc is located further away from the axis of rotation of the shaft than the circumferential contact surface. It was recognized within the scope of the invention that the centrifugal force acting on the oil-like fluid applied to the outer circumference of the disc changes depending on the rotational speed of the shaft, so that, for example, an increase in the rotational speed of the shaft results in a corresponding increase in the amount of oil-like fluid that can be transferred to the sliding contact surface and / or the circumferential contact surface. Therefore, due to the coupling of the disc to the rotor shaft, the transfer of the oil-like fluid to the sliding contact surface and / or circumferential contact surface can occur depending on the rotational speed of the rotor shaft and can be adjusted by changing the rotational speed.The lubrication system is therefore self-regulating. In other words, the lubrication is automatically adjusted as the rotational speed of the machine's shaft changes.
[0010] The speed-dependent application of the oil-like fluid to the sliding contact surface and / or the peripheral contact surface results in optimized lubrication, thus reducing friction between the sliding contact surface and the peripheral contact surface. This, in turn, leads to reduced wear of both surfaces, thereby advantageously increasing the service life of the current transmission arrangement, current transmission device, or slip ring. Furthermore, the application of the oil-like fluid to the sliding contact surface and / or the peripheral contact surface advantageously dissipates heat, particularly that generated by friction between the sliding contact surface and the peripheral contact surface. This eliminates the need for a ventilation device, saving installation space and advantageously increasing the efficiency of a machine or a gearbox into which the machine can be integrated.Because the disc is rotationally fixed to the shaft, speed-dependent lubrication can advantageously be achieved by means of the transfer device's disc, without requiring a complex control system for the lubrication device based on the rotor speed. Thus, the lubrication device according to the invention ensures uniform lubrication of the slip ring contact surface and / or the circumferential contact surface across the entire speed range in which the machine can be operated. This allows, particularly with relatively large slip ring diameters, an increase in the service life of the power transmission components and makes it easier and more reliable to calculate the wear behavior, especially of the contact element and the slip ring.
[0011] Furthermore, because the power transmission arrangement or device is designed as a wet-running motor, especially when integrated into a gearbox, for example, a corresponding sealing system to protect the installation space against oil contamination, as is necessary with comparable dry-running motors, can be omitted. This advantageously saves further installation space and increases the efficiency of the machine or gearbox. However, the power transmission arrangement or device can include a sealing device to protect a section of the power transmission from the oily fluid, which, compared to a sealing system, has only a negligible impact on the installation space and efficiency of the machine or gearbox into which the machine may be integrated.
[0012] Advantageous embodiments of the invention are the subject of the dependent claims. The scope of the invention also includes all combinations of at least two features disclosed in the description, the claims, and / or the figures. It is understood that the descriptions given regarding the arrangement apply equivalently to the machine and the method according to the invention, without being specifically mentioned for each. In particular, it is understood that common linguistic transformations or a meaningful substitution of respective terms within the scope of usual linguistic practice, especially the use of synonyms supported by generally accepted linguistic literature, are included in the present disclosure without being explicitly mentioned in their respective formulations.
[0013] Advantageously, the disk of the transfer device can be designed as a toothed disk, a fan disk, and / or a wave disk. A toothed disk can be a flat disk with radially arranged teeth or points along its outer circumference. A fan disk can be a disk with teeth or tabs that are arranged, preferably uniformly and overlapping in a fan-like pattern, along the outer circumference of the disk. Within the scope of the invention, a wave disk is a disk whose surface has alternating elevations (wave crests) and depressions (wave troughs). These waves extend radially along the circumference, with the wave disk preferably being simply corrugated and thus having a uniform wave shape over the entire circumference of the disk. The wave shape along the outer circumference of the wave disk can correspond to a sine curve, so that the wave disk is designed as a sine disk.Due to the design of the disc as a toothed disc, fan disc or wave disc, the oil-like fluid can be transferred particularly easily and reliably to the grinding contact surface and / or to the circumferential contact surface.
[0014] The transfer device can have two disks whose circumferential surfaces can be supplied with the oily fluid, the disks being arranged on both sides of the slip ring. The oily fluid can preferably be supplied to the disks from above with respect to the direction of gravity, so that the supply is assisted by gravity. If the transfer device has two disks, it has proven advantageous for the slip ring to have two circumferential contact surfaces, each of which can be formed by a contact ring, with each disk having one circumferential contact surface assigned to it and being arranged axially on the rotor shaft next to the contact ring forming the assigned circumferential contact surface.
[0015] The fluid is supplied to the transfer device, particularly to a disk of the transfer device, via a fluid feed from a fluid reservoir of the lubrication device. The oily fluid can then be discharged onto the disk through an outlet opening of the fluid feed, preferably at one end. Each disk can have a fluid feed connected to the fluid reservoir, which may be designed as a fluid line. Preferably, in the case of multiple disks, the fluid feed has only one outlet opening per disk. The fluid feed can branch, particularly forking, to distribute the oily fluid to the individual disks in the case of multiple disks. The fluid feed preferably terminates above a disk to allow the fluid to be applied to the disk from above.The fluid supply allows for a simple and reliable targeted supply of fluid to at least one disk of the transfer device, whereby the fluid reservoir can be located away from the transfer device, thus saving installation space in the area of the transfer device or the electric machine.
[0016] It has proven advantageous if the motor shaft of the electric machine can be operated at speeds of up to 25,000 revolutions per minute. At such high speeds, up to 25,000 revolutions per minute, speed-dependent lubrication is particularly beneficial.
[0017] Advantageously, the contact element, preferably rod-shaped, can have the sliding contact surface on its end face. A longitudinal axis of the contact element can extend transversely to an axis of rotation of the shaft or an axis of rotation of the slip ring. The longitudinal axis, or an extension of the longitudinal axis in the direction of the slip ring, can pass through the axis of rotation of the slip ring or the axis of rotation of the shaft. The axis of rotation of the slip ring and the axis of rotation of the shaft preferably coincide. The contact element can, for example, have a circular, square, or rectangular cross-section.
[0018] The current transmission device can include at least one spring element by means of which the sliding contact surface is pressed against the circumferential contact surface, preferably with a contact pressure of 7 N / cm². 2 up to 35 N / cm 2The contact surface can be pressed against the surface to ensure optimized contact and the formation of a uniform film of the oily fluid. The spring element can be a spiral or roller spring, which exhibits low force loss over its travel. However, a helical spring can also be used. The speed-dependent lubrication, combined with the contact surface being pressed against the surface by the spring element, ensures proper lubrication and simultaneously prevents the contact element from floating on the film or oil planing, which can lead to a loss of electrical contact between the contact element and the slip ring.
[0019] Advantageously, the slip ring can have a plurality of contact rings, each with a circumferential contact surface. The contact ring has the circumferential contact surface, preferably on its outer circumference. Preferably, the slip ring has at least two contact rings and thus two circumferential contact surfaces, or the slip ring has three contact rings and thus three circumferential contact surfaces. The circumferential contact surfaces, viewed in the direction of the shaft's axis of rotation, can preferably be spaced at equal intervals or equidistant from one another and run parallel to each other. Each circumferential contact surface can then be assigned to a phase.
[0020] It has proven advantageous if each circumferential contact surface is assigned a disk of the transfer device. In other words, the transfer device has the same number of disks as the slip ring has circumferential contact surfaces. Thus, the transfer of the oil-like fluid to each circumferential contact surface can be accomplished with one disk each. The respective disk is preferably arranged axially next to the respective circumferential contact surface to which it is assigned. Furthermore, preferably, the number of fluid feeds of the lubrication device corresponds to the number of disks of the transfer device.
[0021] Advantageously, the slip ring can consist of an electrical component.
[0022] The slip ring comprises a carrier sleeve made of insulating material, preferably polymer, wherein the contact ring, which may be made of an electrically conductive material, is arranged on the carrier sleeve. The carrier sleeve may form a recess or a passage into which the shaft can engage or through which the shaft can extend to position the slip ring on the shaft. The carrier sleeve may be manufactured by injection molding. Furthermore, the slip ring may, preferably on its inner circumference, include at least one connection for the excitation winding or at least one conductor, in particular a stranded wire, which is electrically connected at one end, preferably on its inner circumference, to the contact ring and can be electrically connected at the other end to the excitation winding. If the slip ring comprises several contact rings and thus has several circumferential contact surfaces, connections or conductors assigned to different phases may be provided.The leads of the slip ring, viewed in the circumferential direction of the slip ring, are arranged at a maximum distance or angle from each other on the slip ring or contact ring. For example, the connections or leads can be offset from each other by an angle of 180° for two phases and by an angle of 120° for three phases.
[0023] Advantageously, the current transmission device can comprise a plurality of contact elements. The plurality of contact elements can be arranged such that each circumferential contact surface of the slip ring can be contacted by means of at least one contact element of the plurality of contact elements or a respective slip ring contact surface. In other words, a number of contact elements can correspond to at least a number of circumferential contact surfaces. In one embodiment of the current transmission arrangement, orThe current transmission device can comprise at least one first contact element for contacting a first circumferential contact surface of the slip ring, wherein the first circumferential contact surface is preferably formed on a first contact ring, and a second contact element for contacting a second circumferential contact surface of the slip ring, wherein the second circumferential contact surface is preferably formed on a second contact ring. The plurality of circumferential contact surfaces can also, in principle, be provided by a plurality of slip rings that can be arranged on the shaft.
[0024] Advantageously, the plurality of contact elements can be configured such that the circumferential contact surface, or each circumferential 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 slip ring contact surface. Therefore, at least two contact elements, in particular two or three contact elements, can be provided for the circumferential contact surface, or for each circumferential contact surface. In one embodiment of the current transmission arrangement or current transmission device, the current transmission device can comprise at least two first contact elements for contacting a first circumferential contact surface of the slip ring and at least two second contact elements for contacting a second circumferential contact surface of the slip ring. Providing several contact elements contacting a circumferential contact surface enables the transmission of a higher excitation current.Furthermore, hydrodynamic effects can be avoided and a uniform lubrication can be achieved.
[0025] Advantageously, the current transmission device can be designed such that the two or at least three contact elements of the majority of contact elements, when the current transmission arrangement or device or slip ring is mounted on the machine, are distributed only along a circumferential section of the slip ring or the circumferential contact surface. This advantageously prevents dry running. Furthermore, the current transmission arrangement or device can thus be advantageously mounted laterally on the machine or shaft and does not need to be laboriously fitted over the shaft or rotor. Advantageously, the central angle of a circular arc defined by the circumferential section can be from 55° to 170°. The central angle can also be from 90° to 170°.In other words, the central angle is the angle between the two outermost contact elements.
[0026] Depending on the embodiment of the current transmission arrangement or 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 can all be the same, partially different, or different in pairs.
[0027] 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.
[0028] In one embodiment of the power transmission arrangement or device, the holding element can comprise a 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, which forms a busbar of the power transmission device, by means of a conductor, preferably a stranded wire. Thus, the retaining part can simultaneously function as a busbar. The retaining part can be manufactured by stamping. Preferably, the retaining part can be 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.If the current transmission device comprises a plurality of contact elements, each with a sliding contact surface for contacting a plurality of circumferential contact surfaces, the holding device can include a carrier part made of an electrical insulating material, in particular a polymer, to electrically isolate the contact elements that contact different circumferential contact surfaces or are assigned to different phases. For example, the holding device can then include one holding part for each circumferential contact surface or phase, with the holding parts being arranged on the carrier part.
[0029] In an alternative embodiment of the current transmission arrangement or device, the holding device can be made of an electrical insulating material, preferably polymer and / or ceramic, wherein the current transmission device can comprise a busbar arranged on or in the holding device, the contact element being electrically connected to the busbar by means of a conductor, preferably stranded wire, of the current transmission device. The holding device can be manufactured by injection molding. 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 busbar at the other end.
[0030] Advantageously, the power transmission device can include the lubrication device. Accordingly, the lubrication device can be part of the power transmission device or integrally formed with it. Alternatively, the lubrication device can be included by the machine or be an external lubrication device separate from the power transmission device or machine.
[0031] The excitation current transmitted via the current transmission device can have a current intensity of up to 40 A. The transmission of the excitation current can be continuous or as a constant current.
[0032] Further advantageous embodiments of the current transmission arrangement according to the invention will become apparent from the description of the electrical machine and the method according to the invention.
[0033] In a second aspect, the invention relates to a rotating electrical machine, in particular a current-excited or separately excited synchronous machine, comprising a current transmission arrangement according to the invention.
[0034] A current transmission device of the current transmission arrangement can be provided for the transmission of an electrical excitation current into a slip ring arranged on a shaft of a rotor of the machine, wherein the rotor can include an excitation winding electrically connected to the slip ring for the generation of a magnetic excitation field.
[0035] The machine can include a lubrication device for the power transmission device. Accordingly, the lubrication device can be a component of the machine or integrally formed with it. For example, the supply of the oily fluid to the transfer mechanism of the lubrication device can be controlled by a control device within the machine.
[0036] In a second aspect, the invention relates to a method for transmitting an electrical excitation current to a slip ring arranged on the shaft of a rotor of a rotating electrical machine, in particular a synchronous machine. The slip ring is contacted by means of at least one contact element of a current transmission device, preferably designed as a brush, such that a sliding contact surface of the contact element is contacted with a circumferential contact surface of the slip ring to form an electrically conductive sliding contact between the sliding contact surface and the circumferential contact surface.The sliding contact surface and / or the peripheral contact surface is lubricated with an oil-like fluid by means of an oiling device, the lubricating speed of the machine being dependent on the rotational speed, preferably continuously. The oil-like fluid is transferred to the sliding contact surface and / or the peripheral contact surface by means of a transfer device of the oiling device, a disc of which is non-rotatably connected to the shaft. For this purpose, the oil-like fluid can be applied to the disc, preferably from above, for example from a fluid reservoir, and distributed over the sliding contact surface and / or the peripheral contact surface by means of the disc.Due to the rotationally fixed connection between the shaft and the disc, the disc rotates at the same speed as the shaft. As the shaft's speed changes, the centrifugal force acting on the disc, particularly on its outer circumference, also changes. This, in turn, alters the amount of oily fluid transferred to the sliding contact surface and / or the circumferential contact surface, depending on the rotational speed. Thus, lubrication can be advantageously adapted to the speed of the electric machine.
[0037] The power transmission device and the lubrication device can be part of a power transmission arrangement.
[0038] For the advantageous effects of the method according to the invention, reference is made to the description of advantages of the current transmission arrangement according to the invention.
[0039] Advantageously, engine oil and / or transmission oil, preferably with a kinematic viscosity of 10 mm, can be used as the oil-like fluid. 2 / s up to 30 mm 2 / s at a reference temperature of 40 °C, which is regularly present in a motor or gearbox in which the power transmission arrangement or device may be integrated. Advantageously, the oil-like fluid can be dispensed onto a disk of the transfer device at a constant volume flow rate. Preferably, the oil-like fluid is dispensed at a constant volume flow rate of 10 ml / min to 1000 ml / min. Alternatively, the volume flow rate can also be varied depending on the power output or speed of the machine. The volume flow rate can be generated or adjusted by means of a pump, in particular an oil pump, of the machine.
[0040] It is understood that the aforementioned and subsequently explained embodiments and exemplary embodiments can be implemented not only individually, but also in any combination with one another, without departing from the scope of the present invention. It is also understood that the aforementioned and subsequently explained embodiments and exemplary embodiments relate to the method according to the invention in an equivalent or at least similar manner, without being specifically named for it.
[0041] A preferred embodiment of the invention is explained in more detail below with reference to the accompanying drawing.
[0042] It shows:
[0043] Fig. 1 shows a longitudinal sectional view of a power transmission arrangement according to the invention.
[0044] Figure 1 schematically shows a current transmission arrangement 100 with a current transmission device 10 for a rotating electric machine 20 and with an oiling device 30. The current transmission device 10 comprises a slip ring 11 with two contact rings 12 and 13, as well as contact elements 16 and 17, which are held on the holding device 40. The contact elements 16, 17 for contacting the slip ring 11 are arranged such that a respective end-face sliding contact surface 18, 19 of the contact elements 16, 17 can be contacted with a respective circumferential contact surface 14, 15 of the contact rings 12, 13 to form an electrically conductive sliding contact between the respective sliding contact surface 18, 19 and the circumferential contact surface 14, 15. The contact elements 16, 17 extend with a respective longitudinal axis of the contact elements 16, 17 transversely to a rotational axis 22 of the shaft 21 of the machine 20.It is evident that the axis of rotation of the slip ring 11 coincides with the axis of rotation 22 of the shaft 21, since the slip ring 11 is fixedly mounted on the shaft 21. The contact rings 12, 13 can be arranged on a carrier sleeve made of an electrical insulating material, which is not shown here. The carrier sleeve is connected to the shaft 21 on its inner circumference, and the contact rings 12, 13 are arranged on the carrier sleeve on its outer circumference. Furthermore, the slip ring 11 comprises at least one conductor 24, 25 for each circumferential contact surface 12, 13 or for each contact ring 14, 15, which is electrically connected at one end to the respective contact ring 12, 13 and can be electrically connected at the other end to an excitation winding of the rotor of the electric machine 20 (not shown here).
[0045] The holding device 40 serves to hold the two contact elements 16, 17, wherein the contact elements 16, 17 can be guided in a holding part not shown here and can be radially pre-tensioned against the slip ring 1 1 with a spring element not shown, such that the sliding contact surface 18, 19 is pressed against the circumferential contact surfaces 14, 15.
[0046] The power transmission arrangement 100 further comprises an oiling device 30 for oiling the circumferential contact surfaces 14, 15 with an oil-like fluid. The oiling device 30 has a transfer unit 31 with two disks 32, 33, which can, for example, be designed as toothed disks, as well as two fluid feeds 36, 37 and a fluid reservoir 38. Each disk 32, 33 is assigned a fluid feed 36, 37, so that fluid is supplied to the first disk 32 by means of the first fluid feed 36 and fluid is supplied to the second disk 33 by means of the second fluid feed 37. Fluid can be directed from the fluid reservoir 38 to the respective disks 32, 33 via an opening in the respective fluid supply 36, 37, and applied circumferentially to the disks 32, 33 from above. Furthermore, each disk 32, 33 is assigned to a contact ring 12, 13.Accordingly, the first disk 32 is arranged axially next to the first contact ring 12 and transfers the fluid to the circumferential contact surface 14 of the first contact ring 12, and the second disk 33 is arranged next to the second contact ring 13 and transfers the fluid to the circumferential contact surface 15 of the second contact ring 13. To lubricate the circumferential contact surfaces 14, 15 with the oily fluid, the disks 32, 33 are rotationally fixed to the shaft 21, so that the disks 32, 33 rotate at the same speed as the shaft 21. Due to the centrifugal force caused by the rotation of the disks 32, 33, the oily fluid can be flung onto the circumferential contact surfaces 14, 15 of the contact rings 12, 13. For this purpose, the disks 32, 33 have a larger circumference than the contact rings 12, 13, according to the illustrated embodiment. That is to say,In other words, the circumferential surfaces 34, 35 of the disks 32, 33 are located further away from the axis of rotation 22 of the shaft 21 than the circumferential contact surfaces 14, 15 of the contact rings 12, 13. Thus, speed-dependent lubrication of the circumferential contact surfaces 14, 15 of the contact rings 12, 13 is possible, since a change in the speed of the shaft 21 of the machine 20 also results in a change in the speed of the disks 32, 33 of the transfer device 31, which changes the centrifugal force caused by the rotation of the disks 32, 33 and consequently adjusts the lubrication, in particular the amount of oil-like fluid transferred to the circumferential contact surfaces 14, 15, depending on the speed.
Claims
December 19, 2024 Schunk Carbon Technology GmbH G / HOS-063-WO 4822 Bad Goisern Scu / Kaf Patent claims 1. Current transmission arrangement (100), comprising a current transmission device (10) for a rotating electric machine (20), in particular a synchronous machine, for transmitting an electric excitation current to a slip ring (11) that can be arranged on a shaft (21) of a rotor of the machine (20), wherein the current transmission device comprises the slip ring, wherein the current transmission device comprises at least one contact element (16, 17), preferably designed as a brush, for contacting the slip ring, such that a sliding contact surface (18, 19) of the contact element can be contacted with a circumferential contact surface (14, 15) of the slip ring to form an electrically conductive sliding contact between the sliding contact surface (18, 19) and the circumferential contact surface, characterized in that the current transmission arrangement includes an oiling device (30) for speed-dependent, and preferably continuous,The oiling of the grinding contact surface (18, 19) and / or the circumferential contact surface with an oil-like fluid during operation of the machine comprises, wherein at least one disk (32, 33) of a transfer device (31) is connected to the shaft (21) in a rotationally fixed manner to the oiling device, tung the fluid can be transferred in an axial direction to the grinding contact surface ( 18, 19) and / or to the circumferential contact surface depending on the speed, wherein the disk (32, 33) rotates at a speed of the shaft (21 ).
2. Current transmission arrangement according to claim 1, characterized in that the disk (32, 33) is designed as a toothed disk, fan disk and / or wave disk.
3. Current transmission arrangement according to claim 1 or 2, characterized in that the transfer device (3 1 ) has two disks (32, 33) to whose circumferential surfaces (34, 35) the fluid can be supplied, preferably from above, wherein the disks (32, 33) are arranged on both sides of the slip ring ( 1 1 ).
4. Power transmission arrangement according to one of claims 1 to 3, characterized in that the lubrication device (30) has a fluid supply (36, 37) for supplying the fluid, preferably from above, to the transfer device from a fluid reservoir (38) of the lubrication device (30).
5. Power transmission arrangement according to one of claims 1 to 4, characterized in that the shaft (21 ) can be operated at a speed of up to 25000 rpm.
6. Power transmission arrangement according to one of claims 1 to 5, characterized in that, that the contact element ( 16, 17), which is preferably rod-shaped, has the sliding contact surface ( 18, 19) on its end face.
7. Current transmission arrangement according to one of claims 1 to 6, characterized in that the slip ring ( 1 1 ) has a plurality of contact rings ( 12, 13) each with a circumferential contact surface ( 14, 15).
8. Current transmission arrangement according to one of claims 1 to 7, characterized in that a disk (32, 33) of the transfer device is assigned to each circumferential contact surface ( 14, 15 ).
9. Current transmission arrangement according to one of the preceding claims, characterized in that the slip ring ( 1 1 ) comprises a carrier sleeve made of an electrical insulating material, preferably polymer, wherein the contact ring ( 12, 13 ) is arranged on the carrier sleeve.
10. Current transmission arrangement according to one of the preceding claims, characterized in that the current transmission device (10) comprises a plurality of contact elements (16, 17) and the plurality of contact elements (16, 17) is arranged such that each circumferential contact surface (14, 15) of a plurality of circumferential contact surfaces (11) of the slip ring (11) can be contacted by means of at least one contact element of the plurality of contact elements. 1 1. Current transmission arrangement according to claim 10, characterized in that the plurality of contact elements ( 16, 17) is arranged such that the circumferential contact surface ( 14, 15) can be contacted by means of two or at least three contact elements of the plurality of contact elements.
12. Current transmission arrangement according to one of the preceding claims, characterized in that the current transmission device (10) comprises a holding device (40) in which the contact element (16, 17) is guided, preferably radially movably, wherein the holding device (40) comprises a holding part made of an electrically conductive material, preferably metal, in which the contact element (16, 17) is guided, wherein the contact element is electrically connected to the holding part forming a busbar of the current transmission device (10) by means of a conductor, preferably stranded wire, of the current transmission device, or, wherein the holding device (40) is made of an electrical insulating material, preferably polymer and / or ceramic, wherein the current transmission device (10) comprises a busbar arranged on or in the holding device, wherein the contact element (16, 17) is connected to the busbar by means of a conductor,preferably a stranded wire to which the power transmission device ( 10) is electrically connected.
13. Power transmission arrangement according to one of the preceding claims, characterized in that the power transmission device ( 10) comprises the lubrication device (30).
14. Rotating electrical machine (20), in particular synchronous machine, comprising a current transmission arrangement (100) according to one of the preceding claims.
15. Machine according to claim 14, characterized in that the machine (20) comprises an oiling device (30) of the power transmission arrangement (100).
16. Method for transmitting an electrical excitation current to a slip ring (11) arranged on a shaft (21) of a rotor of a rotating electric machine (20), in particular a synchronous machine, wherein the slip ring is contacted by means of at least one contact element (16, 17) of a current transmission device (10), preferably designed as a brush, such that a sliding contact surface (18, 19) of the contact element is contacted with a circumferential contact surface (14, 15) of the slip ring (11) to form an electrically conductive sliding contact between the sliding contact surface (18, 19) and the circumferential contact surface (14, 15), characterized in that the sliding contact surface (18, 19) and / or the circumferential contact surface is lubricated with an oil-like fluid by means of an lubrication device (30) during operation of the machine (20) in a speed-dependent manner, preferably continuously.wherein the fluid is transferred to the sliding contact surface (18, 19) and / or the circumferential contact surface by means of at least one disk (32, 33) of a transfer device (31) of the lubrication device (30) which is non-rotatably connected to the shaft (21).
17. Method according to claim 16, characterized in that that as an oil-like fluid, engine oil and / or transmission oil, preferably with a kinematic viscosity of 10 mm 2 / s up to 30 mm 2 / s is used at a reference temperature of 40 °C.
18. Method according to claim 16 or 17, characterized in that the oil-like fluid is applied to a disk (32, 33) of the transfer device (3 1 ) at a constant volume flow rate, preferably from 10 ml / min to 1000 ml / min.