DE102023126726B3 - slip ring transmission system - Google Patents

Abstract

Slip ring transmitter system S with a slip ring transmitter 1 arranged in a housing 25 with at least one slip ring 2 rotatably mounted in the housing 25, and with at least one contact carrier 3 which carries at least one contact means which presses against the dynamically moving slip ring 2, wherein for homogenizing the electric field adjacent and coaxial to the slip ring 2 in the region of the at least one contact carrier 3 at least one voltage-carrying toroid 13-16 made of an electrically conductive material is arranged, wherein the toroid 13-16 is at the voltage potential of the slip ring 2.

Description

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

Slip ring transmission systems are used to transmit power or data. At higher voltages of more than 35 kV and with air insulation, the construction effort for the housings of slip ring transmissions increases considerably because the insulation distance between the live parts of the contact system and the grounded housing required to avoid partial discharges inevitably becomes larger. This means that the housings increase significantly in terms of their external dimensions, i.e. in terms of size and weight. The size plays an important role, especially in explosion-proof areas, and should be as small as possible. One example of this is explosion-proof areas for FPSO (Floating Production Storage and Offloading) ships or in offshore wind turbines.

The DE 28 33 129 A1 discloses a slip ring body for electrical machines for power transmission between machine parts that rotate relative to one another. The slip rings have conductor connections on the inside and are contacted radially on the outside by slip ring brushes. The slip rings are insulated and spaced from one another by insulating rings and are fastened to one another in relation to a support body by an internally mountable holder. Slip rings and insulating bodies are held in place by a symmetrically pressed together, central clamping bolt.

The DE 18 54 488 U relates to slip ring bodies in which the insulating bodies are arranged offset from one another in such a way that the air gap distance from slip ring to slip ring can be reduced while maintaining the same creepage distances.

The DE 101 61 740 A1 discloses a slip ring transmitter that can be manufactured and operated more economically with a smaller diameter using carbon/carbon 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 here connected to a cable screw connection on the front.

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

This object is achieved in a slip ring transmission system with the features of patent claim 1.

The subclaims relate to advantageous developments of the invention.

The invention relates to a slip ring transmission system which has a housing and at least one slip ring which can rotate in the housing and at least one contact carrier which carries at least one contact means which presses against the dynamically moving slip ring. The term "dynamic" means that it is not a static, i.e. rigid, system, but that in any case there is a movement between the slip ring and the contact means.

According to the invention, toroids are arranged 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 the at least one contact carrier. The toroids consist of an electrically conductive material.

The toroids do require a certain amount of space in the housing, but the homogenized field means that the distance between current-carrying components and the housing can be significantly reduced. The toroids are used to reduce the inner dimensions of the housing in the axial and radial directions. This also makes the housing smaller in its outer dimensions. The size, material usage and weight are reduced.

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 the top side and one on the bottom side in the axial direction of the slip ring. The toroids can be mechanically connected to the slip ring. The toroids reduce and homogenize the electrical field strength. Their shape prevents peak discharges on the live components.

In a further development of the invention, further toroids with ground potential are 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 the same size, as are the radially outer toroids. The radially inner and outer toroids preferably have the same cross-sectional area.

For example, four toroids can 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 in the sense that the several toroids together surround a hollow cylindrical volume area, in the cylinder wall of which the slip ring and the contact carrier are arranged.

The highest field strength concentrations occur in the area of the contact carrier and in the area of the outer edge of the slip ring, which is closest to the housing. This volume area is completely homogenized by four toroidal toroids arranged in a square.

Preferably, all toroids are arranged in an insulating liquid. The insulating liquid that surrounds the current-carrying parts must not have an insulating effect between the sliding contact and the contact lamellae. Therefore, the contact pressure of the contact body on the slip ring is so great that it always rests against the slip ring, even when it is in the insulating liquid. The surrounding insulating liquid is not in the contact area, it only surrounds it.

The insulating liquid, which is preferably a mineral transformer oil or a synthetic ester liquid, means that the distances between current-carrying and non-current-carrying parts, in particular to the housing, can be significantly reduced due to its higher dielectric strength compared to air. The housing can therefore be smaller in its external dimensions. The contact system is practically free of partial discharges. In both the static and dynamic tests under transformer oil, partial discharges of < 10 pC were measured at a current of 400A AC of the design according to the invention, with the basic interference level already being 1 pC. The slip ring transformer is preferably completely immersed in the insulating liquid so that the air gaps between current-carrying and non-current-carrying parts are filled with insulating liquid. In this sense, the housing of the slip ring transformer system is completely filled with the insulating liquid.

The terms "transformer oil" or "insulating oil" refer to highly refined mineral oils or thin silicone oils that are stable at high temperatures. Synthetic, organic esters can be used as an alternative to classic mineral oil. These can be saturated pentaerythritol tetrafatty acid esters. The ester liquid is non-toxic, easily biodegradable and classified as non-hazardous to water.

To maximize the contact surface of the slip ring transmitter, it is preferably provided that the contact means are in contact with the slip ring on an upper side and a lower side of the slip ring. For this purpose, the slip ring has sliding tracks on the upper and lower sides. The contact means are preferably arranged on a common contact carrier which 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 of which forms an upper and a lower fork section and is connected to one another via a common shaft on the edge of the slip ring.

In an advantageous further development, the contact means on the top and bottom are arranged offset on the contact carrier in the radial direction of the slip ring. If an area of this sliding track is worn, the fork-shaped contact carrier can be rotated by 180° so that the still unused radially adjacent areas of the sliding tracks on the top and bottom come into contact with the contact means. This doubles the service life of the slip ring transmitter without great effort.

The contact carrier is made of aluminum in particular. The number of contact lamellas on the contact carrier is preferably relatively high so that a sufficiently large contact surface is available, so that the contact forces per lamella can be reduced in order to reduce wear and increase the maintenance intervals and service life. In particular, several of the contact carriers can be arranged distributed over the circumference of the slip ring.

In an advantageous further development, several contact lamellas are combined and arranged spring-loaded on a common lamella carrier. The lamella carrier can be connected as such to the contact carrier. In this way, many lamellas can be mounted at the same time and also easily replaced as a set for maintenance or repair purposes. The lamella carrier with the contact lamellas can be provided as strip material. The strip material can be cut to the desired length.

The invention achieves the aim of demonstrating a slip ring transmission system that is suitable for use in the medium and high voltage range, whereby the size of the housing housing is reduced. The toroids homogenize the electric field within the housing and thus contribute to reducing the size of the housing despite their volume. The insulation distances within the housing or adjacent to the slip ring transformer are significantly shorter than in slip ring transformers without toroids. An insulating liquid can further reduce the insulation distances.

The voltage-carrying components of the slip ring transmission system, i.e. the slip ring, are preferably held by at least one insulator and/or the contact carrier is preferably held by at least one insulator. The insulator preferably has at least one threaded rod made of glass fiber reinforced plastic (GRP) cast into a base body for attachment to adjacent components. The insulator therefore has no metallic components. The base body is preferably made of an epoxy resin. The epoxy resin is preferably free of air inclusions.

The threaded rod preferably has the same shape inside and outside the base body. The thread shape on the outside of the threaded rod is securely held when the material of the base body is cast around it. The thread of the threaded rod is preferably continued identically outside the base body. This design of the threaded rod is the simplest in terms of production technology.

Alternatively or in addition to the thread, anchoring means can be formed on the threaded rod, such as projections or recesses that deviate from the thread shape, in order to improve the positive connection between the material of the base body and the threaded rod, i.e. to improve the pull-out security of the threaded rod in the longitudinal direction and/or the torsion security.

The insulating bodies preferably have a profiled surface to extend the creepage distance. They are preferably long-rod insulators. The ends of the base body are therefore at a relatively large distance from one another. The creepage distance is correspondingly long. The threaded rods are preferably located in the central longitudinal axis of the base body. They are located at a distance from one another so that the core of the base body, i.e. the area between the inner ends of the threaded rods, is formed exclusively by the epoxy resin. The threaded rods are specifically used to attach the slip ring and/or the contact carrier to the insulator or insulators, or to attach the insulator to the housing of the slip ring transmitter system.

Such insulators are particularly well suited to the desired compact design of the slip ring transmission system and complement the positive effects of the toroids and the insulating fluid.

• 1 eine perspektivische Ansicht eines Kontaktträgers an einem Schleifring;
• 2 den Kontaktträger der 1 in einer Seitenansicht;
• 3 den Kontaktträger der 1 in einer Perspektive von schräg unten;
• 4 den Kontaktträger der 1 in einer Perspektive von schräg oben;
• 5 einen Lamellenträger in einer perspektivischen Ansicht;
• 6 einen Schleifring in einer perspektivischen Ansicht;
• 7 eine Darstellung des elektrischen Feldes in einer Schnittebene durch den Schleifring der 6;
• 8 einen Isolator in einer Seitenansicht und
• 9 den Isolator der 8 im Längsschnitt.

The invention is explained in more detail below using embodiments shown in schematic drawings. They show:

• 1 a perspective view of a contact carrier on a slip ring;
• 2 the contact carrier of the 1 in a side view;
• 3 the contact carrier of the 1 in a perspective from below;
• 4 the contact carrier of the 1 in a perspective from above;
• 5 a slat carrier in a perspective view;
• 6 a slip ring in a perspective view;
• 7 a representation of the electric field in a section plane through the slip ring of the 6 ;
• 8 an insulator in a side view and
• 9 the insulator of the 8 in longitudinal section.

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

Further components of the slip ring transmitter 1 are a slip ring 2 and a contact carrier 3, which is fork-shaped here and overlaps an upper side 4 of the slip ring 2 as well as an underside 5 of the slip ring 2. The area overlapped on the upper and lower sides is referred to as the sliding contact area 6.

The contact carrier 3 consists of an upper and a lower half 7, 8, whereby both halves are essentially identically configured. The two halves protrude over an edge 9 of the slip ring 2 and are connected radially at the edge to form a common current-carrying shaft. They are screwed together. The 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 3 to 5 can be recognized. 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 referred to as a 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 3 and 4 can be seen. The respective contact means 10, 11 are thus opposite one another in the axial direction, but are arranged 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 from brass.

The housing 25 is filled with an insulating liquid to such an extent that the insulating gaps between current-carrying components and non-current-carrying components are filled with the insulating liquid. The insulating liquid is a mineral transformer oil or a synthetic ester liquid. The 1 to 5 The components shown are located completely within the insulating liquid. This allows the structural distances between current-carrying components, in particular to the earthed housing, to be reduced.

An inventive measure for reducing the size is demonstrated by the 6 and 7 explained. The 6 shows a slip ring 2 with a dimensioning different from the 1 to 5 However, the same reference symbols are retained for functionally identical components. 6 further shows a contact carrier 3. Further contact carriers 3 can be arranged distributed over the circumference. In order to homogenize the electric field, toroids 13-16 made of an electrically conductive material are arranged adjacent to and coaxially with the slip ring 2 in the area of the contact carrier 3. In particular, there are four toroids 13-16 which, according to the illustration of the 7 are arranged in a square, with the contact carrier 3 and the edge 9 of the slip ring 4 arranged in the middle of the square. The toroids 13-16 are arranged in pairs. Two concentric toroids 13, 14 are located on the 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 diameter of the other two, radially inner toroids 14, 16 is smaller than the diameter of the slip ring 2.

The 7 describes a 1-phase structure of a slip ring transformer, in a 3-phase structure the three identically constructed phases are arranged vertically stacked. The 7 It is clear that the toroids 13 -16 homogenize the electric field that builds up around the current-carrying components. In addition, according to the illustration of the 7 two further grounded toroids 17, 18 are arranged underneath the voltage-carrying toroids 13-16 and in the same way two further grounded toroids 19, 20 are arranged on the top of the slip ring 2. These toroids 17-20 are at ground potential. They also cause a homogenization of the electric field. All toroids are located within the insulating liquid, so that the height of the slip ring transformer can be significantly reduced in the axial and radial directions.

The 7 also shows an insulator 21 which is in the 8 in the side view and in the 9 is shown in longitudinal section. The special feature of this insulator 21 is that it does not contain any metal components. The insulator 21 has a base body 22 made of cast epoxy resin, which is free of air inclusions. Threaded rods 23, 24 made of glass fiber reinforced plastic (GRP) were cast into the insulator. By avoiding metal components, this insulator 21 has particularly favorable properties for use in the slip ring transmitters according to the invention, which are to have a particularly small size and are to be used in particular in explosion-proof areas or offshore wind turbines.

Reference symbol:

1

slip ring transformer

2

slip ring

3

contact carrier

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 agent

11

slat carrier

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

base body

23

threaded rod

24

threaded rod

25

Housing

S

slip ring transformer

Claims (3)

Slip ring transmitter system (S) with a slip ring transmitter (1) arranged in a housing (25) with at least one rotatably mounted 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), characterized in that for homogenizing the electric field, adjacent and coaxial with the slip ring (2) in the region of the at least one contact carrier (3) at least one voltage-carrying toroid (13-16) made of an electrically conductive material is arranged, wherein the toroid (13-16) is at the voltage potential of the slip ring (2). Slip ring transmission system (S) according to claim 1 , characterized in that several of the toroids (13-16) are arranged at an axial distance on both sides of a slip ring (2). Slip ring transmission system (S) according to claim 2 , characterized in that two toroids (13-16) are arranged on either side of a slip ring (2), wherein the toroids (13-16) are arranged concentrically.

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