Slip ring transmitter system

Abstract

Slip ring transmitter system S with a housing 25 and with a slip ring transmitter 1 having at least one slip ring 2 rotatable in the housing 25, and with at least one contact carrier 3 which carries at least one contact element 10 which presses against the dynamically moving slip ring 2, wherein at least one sliding contact area 6 between the contact element 10 and the dynamically moving slip ring 2 is embedded in an insulating fluid, wherein the contact element 10 has several contact lamellae 12 under a contact force, and wherein the insulating fluid in the sliding contact area 6 of the contact lamellae 12 with the slip ring 2 is interrupted both when the slip ring 2 is stationary and when it is dynamically moving. The insulating fluid is a mineral transformer oil or a synthetic ester fluid.

Description

[0001] The invention relates to a slip ring transmission system with the features of patent claim 1.

[0002] Slip-ring systems are used to transmit power or data. At higher voltages of over 35 kV and with air insulation, the structural complexity of slip-ring systems increases significantly, because the insulation distance between live parts required to prevent partial discharges inevitably increases. This significantly increases the size and weight of slip-ring systems. However, size plays a crucial role, especially in explosion-proof areas. It should be as small as possible.

[0003] DE 101 61 740 A1 discloses a slip ring assembly that can be manufactured and operated more economically with a smaller diameter using coal / coal technology. It is proposed to embed a circumferentially closed inner ring made of a non-ferrous metal, in particular brass, in an insulating compound as a component of a rotor. The insulating compound can be epoxy resin, for example. The inner ring is electrically contacted with an electrical connection assigned to the rotor and, from there, connected to a cable gland on the end face. The contact carrier carries a contact element with several contact lamellas subject to a contact force.

[0004] DE 101 06 119 A1 discloses a power transmission arrangement for electrical machines, comprising a shaft with electrically conductive sliding elements extending from and coaxially surrounding the shaft, and carbon brushes supported on the sliding elements. Various electrical phases are connected to electrically insulated sliding elements via current paths leading to windings of the electrical machine. To ensure that temperature fluctuations do not negatively affect the power transmission, it is proposed that the sliding elements be made of carbon material or be disc elements containing carbon material.

[0005] DE 30 34 717 A1 discloses a device for computed tomography. An X-ray source is guided in a circle around the hole accommodating the patient. Energy is supplied via slip ring systems coupled to the X-ray wave. The slip ring systems are arranged in a cavity surrounding the hole, which contains an insulating fluid.

[0006] DE 32 21 791 A1 discloses a device for high-voltage transmission between two relatively rotatable insulator bodies, each of which contains an embedded electrode arrangement horizontally enclosing the rotational axis. The two electrode arrangements together form a type of Faraday cage, correcting and reducing the field between the two electrode arrangements and their surroundings. It is explained that the space between the rotor and the stator is filled with an electrically insulating fluid, e.g., oil, which has a significantly higher dielectric strength than air. However, this requires seals between the two relatively rotating parts.

[0007] The task is to demonstrate a slip ring transmission system that can transmit higher voltages greater than 35 kV without increasing the size of the slip ring transmission system too much and yet is almost free of partial discharges under static and dynamic loads.

[0008] This object is achieved in a slip ring transmission system having the features of patent claim 1.

[0009] The subclaims relate to advantageous developments of the invention.

[0010] The invention relates to a slip-ring transmission system comprising a housing and at least one slip ring rotatable within the housing, as well as at least one contact carrier carrying at least one contact means that presses against the dynamically moving slip ring. The term "dynamic" means that it is not a static, i.e., rigid system, but rather that movement always occurs between the slip ring and the contact means.

[0011] At least one sliding contact area between the contact element and the dynamically moving slip ring is embedded in an insulating fluid. The contact element comprises several contact segments subject to a contact pressure. The insulating fluid surrounding the current-carrying parts must not act as an insulation between the sliding contact and the contact segments. Therefore, the insulating fluid is interrupted in the sliding contact area between the contact segments and the slip ring in a dynamically moving slip ring.

[0012] In particular, the sliding contact area, i.e., the sliding track on the slip ring, is gold- or silver-plated. These materials possess high electrical conductivity, are corrosion-resistant, and always ensure the best contact and thus the lowest contact resistance. To ensure a sufficient contact area between the slip ring and the contact medium, several contact lamellas are provided, each subject to a defined contact force. The contact force is so great that the contact lamellas are always in contact with the slip ring. The surrounding insulating fluid is not located in the contact area; it merely surrounds it.

[0013] The insulating fluid, which is a mineral transformer oil or a synthetic ester fluid, has a higher dielectric strength than air, allowing the distances between current-carrying and non-current-carrying parts, especially to the housing, to be significantly reduced. This allows the housing to be smaller. The contact system is virtually free of partial discharges. In both static and dynamic tests at a current of 400 A AC under transformer oil, partial discharges of < 10 pC were measured, although the background noise level is already 1 pC. The slip ring assembly is preferably completely immersed in the insulating fluid so that the air gaps between current-carrying and non-current-carrying parts are filled with insulating fluid. In this sense, the housing of the slip ring assembly system is completely filled with the insulating fluid.

[0014] The terms "transformer oil" or "insulating oil" refer to highly refined mineral oils or low-viscosity silicone oils that are stable at high temperatures. Synthetic organic esters can be used as an alternative to conventional mineral oil. These can be saturated pentaerythritol tetrafatty acid esters. The ester fluid is non-toxic, readily biodegradable, and classified as non-water pollutant.

[0015] To maximize the contact area, it is preferably provided that the contact means are in contact with the slip ring on a top and bottom side of the slip ring. For this purpose, the slip ring has sliding tracks on the top and bottom. The contact means are preferably arranged on a common contact carrier that surrounds an edge of the slip ring. The contact carrier can be configured in a fork shape for this purpose. It can be two mirror-symmetrical components, each forming an upper and a lower fork section and connected to each other via a common shaft at the edge of the slip ring.

[0016] In an advantageous development, the contact elements on the top and bottom are arranged offset on the contact carrier in the radial direction of the slip ring. Should a section of this sliding track become worn, the fork-shaped contact carrier can be rotated 180° so that the unused radially adjacent sections of the sliding tracks on the top and bottom come into contact with the contact element. This doubles the service life of the slip ring assembly without great effort.

[0017] The contact carrier is typically made of aluminum. The number of contact segments on the contact carrier is preferably relatively high to provide a sufficiently large contact surface, allowing the contact forces per segment to be reduced, thus reducing wear and increasing maintenance intervals and service life. In particular, several contact segments can be arranged distributed around the circumference of the slip ring.

[0018] In an advantageous development, several contact blades are combined and arranged spring-loaded on a common blade carrier. The blade carrier can be connected as such to the contact carrier. This allows many blades to be mounted simultaneously and easily replaced as a set for maintenance or repair purposes. The blade carrier with the contact blades can be provided as strip material. The strip material can be cut to the desired length.

[0019] In a further development of the invention, it is provided that toroids are positioned in the housing to homogenize the electric field. The toroids are arranged adjacent to the slip ring and coaxially to the slip ring in the region of at least one contact carrier. The toroids are made of an electrically conductive material. Although the toroids require a certain amount of installation space, the homogenized field can reduce the distance between current-carrying components and the housing. The toroids serve to reduce the axial and radial dimensions of the housing of the slip ring transmitter. Preferably, several of the toroids are arranged at an axial distance on both sides of a slip ring. At least one toroid should be arranged on an upper side and one on the lower side. The toroids can be mechanically connected to the slip ring. The toroids reduce and homogenize the electric field strength.Due to their shape, they prevent partial discharges on the live components.

[0020] Additional toroids with ground potential can be provided in the housing at a distance from the toroids on the slip ring, whereby the overall height can be reduced even further. The overall height can be reduced in particular if two toroids are arranged on the top and bottom of a slip ring, with the toroids being arranged concentrically in pairs. The radially inner toroids are preferably of the same size, as are the radially outer toroids. The radially inner and outer toroids preferably have the same cross-sectional area. Four toroids can, for example, be arranged in a square, with the fork-shaped contact carrier being arranged approximately in the middle of the square. The slip ring should be enclosed by the toroids. The volume range in which the highest field strength concentrations occur, iein the area of ​​the contact carrier and in the area of ​​the outer edge of the slip ring, which is closest to the housing, is completely homogenized by four toroidal toroids arranged in a square.

[0021] The objective of creating a slip ring transmission system for the transmission of high voltages that is as compact as possible is achieved in particular when at least one toroid and in particular all toroids are arranged in the insulating liquid.

[0022] It is advantageous if the voltage-carrying components, i.e. the slip ring and / or the contact carrier, are held by insulators which are not provided with metallic threaded bolts or receptacles for fastening to adjacent components, but have at least one threaded rod made of glass fiber reinforced plastic (GRP) cast into the insulator for fastening to adjacent components. The insulator is preferably made of an epoxy resin that is free of air pockets. The epoxy resin is cast around the at least one threaded rod. In this way, an insulator can be created from whose opposite ends a threaded rod made of an insulating material protrudes, wherein this threaded rod is used to fasten the slip ring and / or the contact carrier to the insulator(s), or the insulator to the housing of the slip ring transmission system.

[0023] The invention achieves the objective of providing a slip ring assembly system suitable for use in medium and high voltage applications, while reducing the size of the housing. The slip ring assembly has multiple segments that do not float even during dynamic movement of the slip ring assembly and are always subjected to sufficient contact pressure so that no arcs are generated between the segments and the slip ring. The insulating fluid enables compact and smaller slip ring bodies to be used even at higher voltages. This allows for the use of smaller housings, which is particularly advantageous in explosion-proof areas. The insulation distances within the housing or adjacent to the slip ring assembly are significantly shorter than with slip ring assemblies in air. Additional toroids for homogenizing the electric field further contribute to the reduction in size.

[0024] The invention is explained in more detail below with reference to exemplary embodiments illustrated in schematic drawings. They show: Fig. 1 a perspective view of a contact carrier on a slip ring; Fig. 2 the contact carrier of the Fig. 1 in a side view; Fig. 3 the contact carrier of the Fig. 1 in a perspective from below; Fig. 4 the contact carrier of the Fig. 1 in a perspective from above; Fig. 5 a slat carrier in a perspective view; Fig. 6 a slip ring in a perspective view; Fig. 7 a representation of the electric field in a section plane through the slip ring of the Fig. 6; Fig. 8 an insulator in a side view and Fig. 9 the insulator of the Fig. 8 in longitudinal section.

[0025] The Fig. 1 shows a section of a slip-ring transmission system S with a purely schematically indicated housing 25 in which a slip-ring transmission 1 is located. Neither the shape, the position, nor the distance of the illustrated wall section of the housing 25 from the slip-ring transmission 1 are to scale in the figures, but are purely schematic.

[0026] The essential components of the slip ring assembly 1 are a slip ring 2 and a contact carrier 3, which is fork-shaped and engages over an upper side 4 of the slip ring 2 as well as under a lower side 5 of the slip ring 2. The area overlapped on the upper and lower sides is referred to as the sliding contact area 6.

[0027] The contact carrier 3 consists of an upper and a lower half 7, 8, both halves being essentially identical in configuration. The two halves project beyond an edge 9 of the slip ring 2 and are radially connected to each other at the edges to form a common current-carrying shaft. They are screwed together. Fig. Figure 2 shows the sectional view and the detailed structure. The contact carrier 3 carries in its upper half 7 and its lower half 8 a contact means 10 comprising several contact lamellae 12, as shown in the Fig. 3 to 5 can be seen. Fig. Figure 5 shows a lamella carrier 11 with several identically configured lamellae 12 with a substantially rectangular cross-section. The lamella carrier 11 with the contact lamellae is collectively referred to as contact means and is attached once to the upper part 7 of the contact carrier 3 and once to the lower part 8, as can be seen from the Fig. 3 and Fig. 4 can be seen. The respective contact means 10, 11 thus lie opposite one another in the axial direction, but are offset from one another in the radial direction of the slip ring 4, so that they each come into contact with different radial areas of the sliding contact area 6. When the contact carrier 3 or the slip ring 4 is turned, the adjacent areas of the sliding contact area 6 can come into contact with the lamellae 12. This can reduce the local wear of the slip ring 4 or increase the service life before the surfaces reach their wear limit. The slip ring is provided in particular with a silver or gold coating. The contact carrier is made in particular of brass.

[0028] The housing 25 is filled with an insulating fluid to such an extent that the air gaps between current-carrying and non-current-carrying components are filled with the insulating fluid. The insulating fluid is a mineral transformer oil or a synthetic ester fluid. Fig. The components shown in Figures 1 to 5 are completely immersed in the insulating fluid. This allows for reduced structural clearances between current-carrying components, particularly to the grounded housing.

[0029] A further measure according to the invention to reduce the size is shown by the Fig. 6 and Fig. 7. The Fig. 6 shows a slip ring 2 with dimensions different from the Fig. 1 to 5. However, the same reference symbols are retained for components with the same function. Fig. Figure 6 further shows a contact carrier 3. Further contact carriers 3 can be arranged distributed over the circumference. To homogenize the electric field, toroids 13-16 made of an electrically conductive material are arranged adjacent to and coaxial with the slip ring 2 in the area of ​​the contact carrier 3. In particular, there are four toroids 13-16, which, as shown in Figure 6, are arranged Fig. 7 are arranged in a square, with the contact carrier 3 and the edge 9 of the slip ring 4 located in the center of the square. The toroids 13-16 are arranged in pairs. Two concentric toroids 13, 14 are located on top and axially offset from two further toroids 15, 16 of the same size adjacent to the underside of the slip ring 4. The radially outer toroids 13, 15 have a diameter that is larger than the diameter of the slip ring 2. The two other, radially inner toroids 14, 16 have a diameter that is smaller than the diameter of the slip ring 2.

[0030] The Fig. 7 describes a 1-phase design of a slip ring assembly; in a 3-phase design, the three identically constructed phases are arranged vertically stacked. Fig. Figure 7 illustrates that the toroids 13-16 homogenize the electric field that builds up around the current-carrying components. In addition, according to the diagram of the Fig. 7, two additional grounded toroids 17, 18 are arranged underneath the live toroids 13-16, and similarly, two additional grounded toroids 19, 20 are arranged on the top side of slip ring 2. These toroids 17-20 are at ground potential. They also homogenize the electric field. All toroids are located within the insulating fluid, allowing the overall height of the slip ring assembly to be significantly reduced in both the axial and radial directions.

[0031] The Fig. Figure 7 further shows an insulator 21 which is inserted into the Fig. 8 in side view and in the Fig. 9 is shown in longitudinal section. The special feature of this insulator is that it contains no metallic components. The insulator 21 has a base body 22 made of cast epoxy resin, which is free of air pockets. Threaded rods 23, 24 made of glass-fiber reinforced plastic (GRP) were cast into the insulator 21. By avoiding metallic components, this insulator 21 has particularly advantageous properties for use in the slip ring assemblies according to the invention, which are intended to be particularly compact and are intended for use in particular in explosion-protected areas or offshore wind turbines. \: 1 slip ring assembly 2 slip ring 3 contact carriers 4 Top of 2 5 bottom of 2 6 Sliding contact area 7 upper part of 3 8 lower part of 3 9 edge of 2 10 contact agents 11 slat carriers 12 contact lamella 13 voltage-carrying toroid 14 voltage-carrying toroid 15 voltage-carrying toroid 16 voltage-carrying toroid 17 grounded toroid 18 grounded toroid 19 grounded toroid 20 grounded toroid 21 Insulator 22 basic bodies 23 threaded rod 24 threaded rod 25 housings S slip ring transmission system

Claims

[1] Slip ring transmitter system (S) with a slip ring transmitter (1) arranged in a housing (25) with at least one rotatable slip ring (2), and with at least one contact carrier (3) which carries at least one contact means (10) which presses against the dynamically moving slip ring (2), wherein the contact means (10) has a plurality of contact lamellas subject to a contact force, characterized by that at least one sliding contact area (6) between the contact means (10) and the dynamically moving slip ring (2) is embedded in an insulating liquid, and wherein the insulating liquid in the sliding contact area (6) of the contact lamellae (12) with the slip ring (2) is interrupted both when the slip ring (2) is stationary and when it is dynamically moving, wherein the insulating liquid is a mineral transformer oil or a synthetic ester liquid. [2] Slip ring transmission system (S) according to claim 1, characterized bythat the contact means (10) on an upper side (4) and a lower side (5) of the slip ring (2) are in contact with the slip ring (2), wherein the contact means (10) are arranged on a common contact carrier (3) which encompasses an edge (9) of the slip ring (2). [3] Slip ring transmission system (S) according to claim 1, characterized by that the contact means (10) on the upper side (4) and the lower side (5) are arranged offset from one another on the contact carrier (3) in the radial direction of the slip ring (2). [4] Slip ring transmission system (S) according to one of claims 1 to 3, characterized by that several contact blades (12) are resiliently arranged on a common blade carrier (11). [5] Slip ring transmission system (S) according to claims 1 to 4, characterized byin that, in order to homogenize the electric field, at least one voltage-carrying toroid (13-16) made of an electrically conductive material is arranged adjacent to and coaxial with the slip ring (2) in the region of the at least one contact carrier (3). [6] Slip ring transmission system (S) according to claim 5, characterized by that several of the toroids (13-16) are arranged at an axial distance on both sides of a slip ring (2). [7] Slip ring transmission system (S) according to claim 5 or 6, characterized by that two toroids (13-16) are arranged on either side of a slip ring (2), wherein the control rings (13-16) are arranged concentrically. [8] Slip ring transmission system (S) according to one of claims 5 to 7, characterized by that the at least one toroid (13-16) is arranged in the insulating liquid. [9] Slip ring transmission system (S) according to one of claims 1 to 8, characterized bythat the slip ring (2) and / or the contact carrier (3) is held by insulators (21) which have a threaded rod (23, 24) made of GRP cast into the insulator (21) for fastening to adjacent components. [10] Slip ring transmission system (S) according to claim 9, characterized by that the insulator (21) consists of an epoxy resin which is free of air inclusions.

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