ROTARY ELECTRICAL CONDUCTOR

Description

Field of the invention

[0001] The invention relates to a rotary conductor comprising a first circular body having a first metal circular contact surface, a first center line and a first electrical terminal attached to the first contact surface, a second circular body having a second metal circular contact surface attached to a second electrical terminal and rotatable about a second center line, wherein the first and second metal contact surfaces engage in rolling contact, the metals of the contact surfaces having a predetermined hardness and a corresponding yield pressure.

Background of the invention

[0002] When electrical current needs to be transferred between parts that show relative rotation, such as machine parts, wind turbines or offshore high voltage swivels, many different solutions are known, some of which allow a limited angle of rotation while others allow unlimited rotational angles.

[0003] In known slide contacts, such as available from Schleifring or Cavotec, a stack of rings or discs is contacted by one or more sliding contacts or carbon brushes per ring to provide electrical contacts. The slide contacts have several disadvantages such as wear of the contact surfaces. Wear is counteracted by the use of expensive metal alloys and reduced contact pressures between the slide contacts and the rings. Many carbon or composite brushes also contain oil providing lubrication and reducing wear. Typical carbon brushes are used for power transfer, whereas gold or silver brushes are used for transfer of electrical signals.

[0004] Furthermore, the known slide contacts are sensitive to vibrations, due to the low contact pressures between the sliding contact members and the rings. Too low contact pressures may lead to spark forming. Also, in corrosive environments such as in wind turbines and cranes that are used in maritime environments, the conductivity between the sliding contact members and the rings may decrease due to corrosion. Finally, the known conductors are less suitable for successive smaller rotations or oscillations and changes in the direction of rotation.

[0005] Another category of current transfer devices is formed by electricity chains connected to machines or robots, which are suitable for limited rotational angles. Despite limited angles of rotation, fatigue loading of the copper conductors by repeated bending may result in a reduced operational life cycle.

[0006] Other solutions for transferring electric current from a stationary body to a rotating member utilize liquid metal (e.g. mercury), which however is highly toxic and can only be used for transfer of limited power.

[0007] A rotary conductor is known having coaxial rings, the gap between which is bridged by circular rings that are deformed into a slightly oval shape by the pressures applied. This system is relatively costly due to the expensive gold/silver surface and is subject to fatigue weakening of the deforming rings. Furthermore, the whole conductor needs to be protected against oxidation by preventing oxygen from entering the internals, which would lead to corrosion of the contact surfaces.

[0008] From US 5,501,604 a rotary conductor according to the pre-amble of claim 1 is known. In this reference a planetary power or signal transmission band-gear system is described in which the flexible metal bands of planet gear assemblies are preloaded against the flexible metal bands of the sun and ring wheels. In so doing, the bands on the planet gear assemblies deform elastically to provide greater area contact, band deformations ranging between 50 µm and 250 µm. The degree of preloading is dependent on the particular application, a device designed for the transmission of power requiring a higher preloading force than that designed for signals only.

[0009] The power that can be transmitted with the known device is limited in view of the relatively high electrical resistance across the rotating conductors. The lay-out of the known transfer device is relatively complex in view of the combination of the conducting bands with intermeshing gears that drive the rotary motion.

[0010] It is, in view of the above, an object of the present invention to provide a rotary conductor with which high currents can be transferred in a stable and continuous manner between parts that rotate relative to one another. It is a further object of the invention to provide a rotary conductor which is suitable for high speed signal transfer between rotating parts.

[0011] It is again an object of the present invention to provide a rotary conductor that is of a simple construction and can be easily manufactured, installed and serviced or repaired. It is finally an object of the invention to provide a rotary conductor that has reduced sensitivity to vibrations, corrosion and that can operate reliably when subject to small reciprocating movements.

Summary of the invention

[0012] Hereto a rotary conductor according to the invention is characterized in that the metals of the contact surfaces having a predetermined hardness and a corresponding yield pressure, a contact pressure between the contact surfaces being greater or equal to at least 10%, preferably at least 15% of the yield pressure of the contact surface metal having the lowest hardness such that the contact surfaces are smoothed by plastic deformation, wherein said pressure ensures that sufficient frictional engagement between the contact surfaces is present to avoid slipping and to ensure a pure rolling motion without requiring the presence of intermeshing teeth.

[0013] It was found that by placing the contact surfaces into rolling contact at high contact pressures, a very stable and efficient transfer of electric current can be obtained. It is assumed that due to the high pressures, uneven surface textures in the metal on metal contact surfaces are evened out and the contact surfaces are brought in a closely mating relationship such that a highly conductive current path is established, while wear is prevented by the rolling metal on metal contact.

[0014] During manufacture of the conductor, the contact surfaces are smoothened by any suitable means such as machining, forging, rolling or other methods. However, at microscopic level still significant valleys and peaks remain. To further smoothen the surface of the conductors, the invention teaches to apply prior to and/or during use, the rolling configuration of the conductors at high contact pressures such that the microscopic peaks on the contact surfaces are smoothened by plastic deformation and bright smooth contact surface is obtained.

[0015] By the high rolling contact pressures it was found for copper alloy rings that the Ra value, which is the arithmetic average of the absolute values of profile height variations from the mean line, recorded over the evaluation length, ranged between 1.6 µm and 6.3µm prior to plastic deformation, while the Ra value after rolling at high contact pressures was found to lie between 0.1 µm and 0.8 µm. The continuous rolling contact at high pressures according to the invention was found to have a fine mechanical "cold forming" effect (plastic deformation), causing a smoothening of the surfaces while also the surface hardness was found to increase (work-hardening) by a factor of 2-2.5 for the investigated copper alloy.

[0016] With the term "yield pressure" as used herein, the pressure is intended at which the deformations in the metal change from being elastic to being plastic. In absence of data for the yield pressure of a particular metal, as an approximation the yield stress can be taken. For instance for a copper alloy of which a yield stress of 120N/mm<2> is indicated, a contact pressure on this basis is set at least 12 N/mm<2>, preferably at least 18N/mm<2>.

[0017] With the term "rolling contact" as used herein, is meant a movement of one contact surface along the other substantially without any slip between the contact surfaces, one of which rotates around a central axis.

[0018] The "hardness" as defined herein can be measured by the Brinell Hardness (BH), wherein the contact pressure during manufacturing of the conductors by pre-rolling of the contact surfaces, or during use, is about at least 50% of the Brinell Hardness (HB). Hereby plastic deformation of the contact surfaces is achieved. For a copper alloy, the contact pressure on the basis of a Brinell Hardness of between 40 and 45 is set at at least 20-22.5 N/mm<2>

[0019] The rotary conductor according to the invention may be produced by applying an initial rolling contact of the first and second contact surfaces at an initial relatively high value, the contact pressure during use of the rotary conductor being reduced to 33%- 50% of the initial value. The rotary conductor may comprise a first ring with an internal contact surface, and a second wheel-shaped or ring-shaped conductor of smaller diameter rolling on the internal contact surface. Alternatively, the first rotary conductor may be ring-shaped or wheel -shaped with an external contact surface, one or more second ring- or wheel -shaped conductors rolling along the external contact surface.

[0020] The metals used in the rotary conductor comprise highly conductive metals such as silver, gold, copper and aluminium or an alloy thereof.

[0021] Preferably, the contact pressure between the first and second contact surfaces is at least 20N/mm<2> for contact surfaces comprising copper and at least about 40 N/mm<2> for contact surfaces comprising phosphor bronze

[0022] Although it is preferred that a flat metal on metal contact is established, the rotary conductor according to the invention may have first and second contact surfaces that are provided with meshing teeth in order to counteract any slipping movement.

[0023] The first body may comprise a ring-shaped outer body having an inner contact surface with a first centre line and a first radius, the second body comprising a second circular body having an outer contact surface with a second centre line and a second radius, the second center line being at a distance from the first center line, which distance is smaller than the second radius.

[0024] The outer body may be stationary and the second body may be rotatable around the first centre line, the second terminal comprising a universal joint conductor that is with one end connected to the rotatable inner body and with its other end connected to a rotary support that is situated on the first centre line. The transfer of current via the universal joint provides a stable and reliable solution which does not suffer from vibrations, which allows rotation of the bodies at high speed, which accommodates high-frequency signal transfer and/or transmission of high currents without the risk of spark formation at little loss.

[0025] In an embodiment of a rotary conductor according to the invention , the first conductor is ring-shaped, the second conductor being wheel-shaped, the second conductor having a smaller diameter than the first conductor and having at least a 20% higher yield value than the first conductor. The wheels material is harder than the ring material. The wheels are prerolled before assembly of the rotary conductor, and the rings are machined before assembly. After assembly, the rings are rolled by a temporarily higher contact pressure that is sufficient to roll the weaker ring material.

[0026] A further embodiment of a rotary conductor according to the invention comprises at least two outer bodies that are supported in a spaced-apart relationship, each connected to a respective terminal, the inner bodies comprising corresponding spaced-apart ring-shaped members rotatably mounted on a rotary support that is rotatable around the first centre line, about an axis situated at a radial distance from the central first center line. The outer bodies form a stack of ring-shaped conductors, one for each phase of current to be transferred. The inner ring-shaped bodies rotate jointly and roll along the inner tracks of the outer bodies to provide parallel current paths. The current is divided evenly over the various rotating conductors. Hereby it is ensured that even if one conductor would lose proper contact, no sparking and consequent material damage will occur as the other conductors can temporarily accommodate the higher current.

[0027] A further rotary conductor has a first body that comprises a ring-shaped angled contact surface with a central axis, the second body comprising at least one radial angled ring-shaped contact surface rotatably mounted around a radial axis, which axis is rotatable around the central axis of the first body. The conical second bodies that rotate about the radial axis provide for stable and even load distribution on the first ring shaped conductors, allowing high contact pressures while not being subject to wear.

[0028] Preferably the first body is provided with opposed and spaced-apart angled contact surfaces that are each contacted by a respective body having a radial angled ring-shaped contact surface rotatably mounted around a radial axis, which axis is rotatable around the central axis of the first body. In this even load distribution the axial pressures exerted on the first body compensate each other so that high contact pressures are possible.

[0029] The second body may comprises a spring element that contacts the at least one radial contact surface for biasing the radial contact surface in the direction of the central axis. The spring biasing elements provide an adjusting force for equalising the contact forces and for removing any play in the radial direction.

[0030] In a preferred embodiment, the rotary conductor comprises conducting oil between the first and second contact surfaces. Surprisingly it was found that the voltage loss between the conductors is strongly reduced by use of oil film between the rotating bodies. In combination with the high pressure, a reduction in resistance of over 20% could be achieved. The oil used may be insulation oil, such as transformer oil. However, the best results were found when using an oil that is a non-conducting penetrating oil that comprises a suspension of conducting lubricating particles, preferably graphite particles.

[0031] The rotary conductor according to the invention is suitable for conducting currents from the first electrical terminal to the second electrical terminal of at least 10 A, preferably at least 25 A, more preferably at least 100 A. For copper electrodes having a contact surface area of about 2mm<2>, currents of up to 60A/mm<2> were measured at a contact pressure of 100-150 N/mm<2> and of up to 4-5A/mm<2> at pressures of 30-50N/mm<2>. For copper electrodes, a minimum pressure of 20N/mm<2> is applied. For electrodes comprising phosphor bronze, currents of up to 40A/mm2 were achieved at pressures of 40-600N/mm<2>.

[0032] The rotary conductor according to the invention can be used in wind turbines, offshore installations such as Floating Production Storage and Offloading vessels (FPSO's), or in machine parts. The rotary conductors can also be used for transmitting electrical signals from one contact surface to the other at data rates of up to 1 Gb/s and higher.

Brief description of the drawings

[0033] Some embodiments of a rotary conductor will by way of non-limiting example be described in detail with reference to the accompanying drawings. In the drawings:

Fig.1 shows a schematic representation of a stationary ring-shaped outer conductor and an eccentric rotating inner conductor,

Figs. 2a and 2b-2c show a schematic cross-sectional view through the contact interface of the conductors prior to, and after rolling contact at high contact pressures, respectively,

Fig. 3 shows a detail of a universal joint conductor connecting to the rotating conductor,

Fig. 4 shows a perspective view of a rotary conductor in a stacked configuration, having a universal joint conductor,

Fig. 5 shows a schematic view of an embodiment with springbiased conical conductors, and

Fig. 6 shows a side view of the embodiment of fig. 4 .

Detailed description of the invention

[0034] Fig. 1 shows a rotary conductor 1 for the transfer of current from a rotating terminal 4 to a stationary terminal 5. In figure 1 , conductor 3, in the form of a stationary outer ring, has a first centreline C1, and an internal radius R1 and forms a raceway for second conductor 2, being formed by an inner ring or cylinder having a second centreline C2 at a distance s from first centreline C1 and a radius R2, wherein s = R1-R2. The centreline C2 will move along the circular path with radius s about the first center line C1. The pattern of movement of the terminal 4 connected to the circumference of conductor 2 is formed by the combined rotation about the second center line C2 and the rotation of the center line C2 about C1. In this embodiment, R2 preferably is about the size of R1 so that the curvature of inner and outer rings only slightly differ and a large contact surface for current transfer is available.

[0035] For the following metals, the minimum contact pressures apply:

Pure Aluminium	15	7.5
Gold	20	10
Silver	25	12.5
Pure Copper	40	20
Electrical Copper	45	22.5
Phosphor Bronze	90	45
Mild Steel	110	55

[0036] Fig. 2a shows a schematic cross-sectional view through the contact surfaces of conductors 2,3 prior to engaging the surfaces at high contact pressures. The Ra values are relatively high and the contact interface is limited.

[0037] Figs. 2b and 2c show the conductors 2,3 in a contacting and in a separated state, respectively after having been in rolling contact at high contact pressures over a time period of a significant number of cycles, such as during several hours, preferably days. The Ra value has decreased and the number of contact surfaces 2' has increased due to smoothening caused by the plastic deformation.

[0038] Fig. 3 shows a perspective view of the rotary conductor 2, that is supported in a bearing 6 that rotates around the first center line C1. The terminal 4 is formed by a universal joint conductor 7 having a first set of perpendicular hinge axes 8,9 and a second set of perpendicular hinge axes 10,11 connecting to a drive axis 12 along the first center line C1. In this way, the combined translational and rotational movement of the inner conductor 2 are transferred to the rotation of the drive axis 12 about first center line C1. Current from the rotating drive axis 12 can hence be transferred via the universal joint conductor 7 and rotary conductor 2 to the stationary conductor 3.

[0039] Fig. 4 shows an embodiment of a stacked rotary conductor 20 comprising a base plate 21 and two spaced-apart stationary conductors 22, 23 supported by axial supporting rods 24,25 that interconnect the base plate 21 with a top plate 26. A support guiding plate 27 is attached to the base plate 21 so that it can rotate via a bearing construction (that is not shown in the drawing) around the center line C1. A stack of rotating conductors 30, 31 is placed onto the support guiding plate 27, the surfaces of which roll along circular contact surfaces 32,33 of the stacked stationary conductors 22,23 that are mounted on the supporting rods 24,25. Support guiding plates 27, 28 are provided that interact with rotating bearing elements 39,40 which are in line with the conductors 30,31, for providing a stable rolling motion of the conductors 30,31 along the circular tracks of the stationary conductors 22,23. The contact surfaces 30,31 may for instance be provided with teeth that mesh with corresponding teeth of the internal gear plate 37.

[0040] At the top end of the stacked rotary conductor 20, a universal joint conductor 41 connects the conductors 30,31 to the drive member 42, that is rotating around the axis C1.

[0041] Fig. 5 shows an embodiment wherein a first conductor comprises a conical member 50 rotatably supported on a radial axis 51. The radial axis 51 rotates around center line L. The conical member 50 contacts with angled contact surfaces 52, 53 corresponding angled contact surfaces of upper rotary electrode 54 and lower stationary electrode 55. A biasing spring member 56 provides an axially compressive force to maintain a predefined contact pressure between the angled surfaces of the conical member 50 and the upper rotary electrode 54 and the lower stationary electrode 55.

[0042] In fig. 6 it can be seen that rotary electrode 62 comprises upper and lower angled contact surfaces 63,64 that are encased between upper and lower conical electrodes 60,61, such that forces on the electrode 62 balance out and effective current transfer at high contact pressures and high rotational speeds can be obtained. The high contact pressure results in a smooth rolled surface 65.

[0043] With the embodiment according to fig. 6 , multiple contact points between the upper and lower electrodes 63, 64 and a number of conical electrodes 60,61 can be constructed such that the current transferred between the electrodes 63,64 and the electrodes 60,61 can be strongly increased.

Claims

1. Rotary conductor comprising a first circular body (3,22,23) having a first metal circular contact surface, a first center line (C1) and a first electrical terminal (5) attached to the first contact surface, a second circular body (2,30,31) having a second metal circular contact surface attached to a second electrical terminal (4) and rotatable about a second center line (C2), wherein the second center line (C2) is rotatable about the first center line (C1) wherein the first and second metal contact surfaces engage in rolling contact, the metals of the contact surfaces having a predetermined hardness and a corresponding yield pressure, the conductor being suitable for leading currents from the first electrical terminal (5) to the second electrical terminal (4) of at least 10 A, characterised in that the second circular body (2,30,31) is wheel-shaped and that upon rotation of the second center line (C2) about the first center line (C1), a contact pressure between the contact surfaces is greater or equal to at least 10%, preferably at least 15% of the yield pressure of the contact surface metal having the lowest hardness such that the contact surfaces are smoothed by plastic deformation, to ensure that sufficient frictional engagement between the contact surfaces is present to avoid slipping and to ensure a pure rolling motion without requiring the presence of intermeshing teeth.

2. Rotary conductor according to claim 1, wherein prior to use and/or or during use, the contact pressure is about at least 50% of the Brinell Hardness (HB) of the contact surfaces.

3. Rotary conductor according to claim 1, wherein at least one of the metal contact surfaces comprises copper, the contact pressure being at least 20N/mm<2>.

4. Rotary conductor according to claim 1 or 2, wherein at least one of the metal contact surfaces comprises phosphor bronze, the contact pressure being at least 40N/mm<2>.

5. Rotary conductor according to claim 1 or 2, wherein the contact pressure between the first and second contact surfaces is at least 20N/mm<2>.

6. Rotary conductor according to any of the preceding claims, wherein the first body comprises a ring-shaped outer body (3) having an inner contact surface with a first centre line (C1) and a first radius (R1), the second circular body (2) having an outer contact surface with a second centre line (C2) and a second radius (R2), the second center (C2) line being at a distance (S) from the first center line (C1), which distance (S) is smaller than the second radius (R2).

7. Rotary conductor according to claim 6, wherein outer body (3) is stationary and the second body (2) is rotatable around the first centre line (C1), the second terminal (4) comprising a universal joint conductor (7) that is with one end connected to the rotatable inner body (2) and with its other end connected to a rotary support (12) that is situated on the first centre line (C1).

8. Rotary conductor according to any one of claims 1 - 7, characterized in that the second circular body (2) is supported in a bearing (6) that rotates around the first center line (C1).

9. Rotary conductor according to claim 6 or 7, wherein at least two outer bodies (22,23) are supported in a spaced-apart relationship, each connected to a respective terminal, the inner bodies comprising two spaced-apart cylindrical members (30,31) rotatably mounted on a rotary support (27) that is placed at a radial distance from the first center line (C1) and that is rotatable around the first centre line.

10. Rotary conductor according to any of claims 1-6, wherein the first circular body comprises a ring-shaped angled contact surface (54,55), with a central axis (L), the second body comprising at least one radial angled ring-shaped contact surface (52,53) rotatably mounted around a radial axis (51), which axis is rotatable around the central axis (L) of the first body.

11. Rotary conductor according to any of the preceding claims, the conductor being suitable for leading currents from the first electrical terminal to the second electrical terminal of at least 25 A, more preferably at least 50 A.

12. Rotary conductor according to any of the preceding claims, the first conductor being ring-shaped, the second conductor being wheel-shaped, the second conductor having a smaller diameter than the first conductor and having at least a 20% higher yield value than the first conductor.

13. Method of transferring electricity between a first and second circular body in a rotary conductor according to any of the preceding claims, wherein after initial rolling contact of the first and second contact surfaces at an initial relatively high value, the contact pressure is reduced to 33%- 50% of the initial value.

14. Method of transferring electricity between a first and a second circular body in a rotary conductor according to any of the preceding claims, wherein data signals are transferred between the first and second bodies.

Ansprüche

1. Rotierender Leiter, der einen ersten ringförmigen Körper (3,22,23) mit einer ersten ringförmigen Metallkontaktoberfläche, eine erste Mittellinie (Cl) und einen an der ersten Kontaktoberfläche angebrachten ersten elektrischen Anschluss (5), einen zweiten ringförmigen Körper (2,30,31) mit einer zweiten ringförmigen Metallkontaktoberfläche, die an einem zweiten elektrischen Anschluss (4) angebracht und um eine zweite Mittellinie (C2) drehbar ist, wobei die zweite Mittellinie (C2) um die erste Mittellinie (Cl) drehbar ist, wobei die erste und die zweite metallische Kontaktoberfläche in rollendem Kontakt stehen, wobei die Metalle der Kontaktoberflächen eine vorgegebene Härte und einen entsprechenden Fließdruck aufweisen, wobei der Leiter geeignet ist, Ströme von zumindest 10 A von dem ersten elektrischen Anschluss (5) zu dem zweiten elektrischen Anschluss (4) zu leiten, dadurch gekennzeichnet, dass der zweite ringförmige Körper (2,30,31) radförmig ist und dass bei Drehung der zweiten Mittellinie (C2) um die erste Mittellinie (Cl) ein Kontaktdruck zwischen den Kontaktoberflächen größer oder gleich zumindest 10%, vorzugsweise zumindest 15% des Fließdrucks des Kontaktoberflächenmetalls mit der geringsten Härte ist, so dass die Kontaktoberflächen durch plastische Verformung geglättet werden, um sicherzustellen, dass eine ausreichende Reibungsinteraktion zwischen den Kontaktoberflächen vorhanden ist, um ein Rutschen zu vermeiden und eine reine Rollbewegung zu gewährleisten, ohne dass das Vorhandensein von ineinander greifenden Zähnen erforderlich ist.

2. Rotierender Leiter nach Anspruch 1, wobei der Kontaktdruck vor und/oder während der Benutzung zumindest 50% der Brinell-Härte (HB) der Kontaktoberflächen beträgt.

3. Rotierender Leiter nach Anspruch 1, wobei zumindest eine der Metallkontaktoberflächen Kupfer aufweist, wobei der Anpressdruck zumindest 20N/mm<2> beträgt.

4. Rotierender Leiter nach Anspruch 1 oder 2, bei dem zumindest eine der Metallkontaktoberflächen Phosphorbronze aufweist, wobei der Kontaktdruck zumindest 40N/mm<2> beträgt.

5. Rotierender Leiter nach Anspruch 1 oder 2, wobei der Kontaktdruck zwischen der ersten und der zweiten Kontaktoberfläche zumindest 20N/mm<2> beträgt.

6. Rotierender Leiter nach einem der vorhergehenden Ansprüche, wobei der erste Körper einen ringförmigen Außenkörper (3) mit einer inneren Kontaktoberfläche mit einer ersten Mittellinie (Cl) und einem ersten Radius (Rl) aufweist, wobei der zweite ringförmige Körper (2) eine äußere Kontaktoberfläche mit einer zweiten Mittellinie (C2) und einem zweiten Radius (R2) besitzt, wobei sich die zweite Mittellinie (C2) in einem Abstand (S) von der ersten Mittellinie (Cl) befindet, wobei der Abstand (S) kleiner als der zweite Radius (R2) ist.

7. Rotierender Leiter nach Anspruch 6, wobei der Außenkörper (3) stationär ist und der zweite Körper (2) um die erste Mittellinie (Cl) drehbar ist, wobei der zweite Anschluss (4) einen Kardangelenkleiter (7), der mit einem Ende mit dem drehbaren Innenkörper (2) und mit seinem anderen Ende mit einem drehbaren Träger (12), der auf der ersten Mittellinie (Cl) liegt, verbunden ist, aufweist.

8. Rotierender Leiter nach einem der Ansprüche 1 - 7, dadurch gekennzeichnet, dass der zweite ringförmige Körper (2) in einem Lager (6), das sich um die erste Mittellinie (Cl) dreht, gelagert ist.

9. Rotierender Leiter nach Anspruch 6 oder 7, bei dem zumindest zwei Außenkörper (22, 23) in einer beabstandeten Beziehung gelagert sind, wobei jeder mit einem entsprechenden Anschluss verbunden sind, wobei die Innenkörper zwei beabstandete zylindrische Elemente (30,31) aufweisen, die drehbar an einem Drehlager (27) angebracht sind, das in einem radialen Abstand von der ersten Mittellinie (Cl) angeordnet ist und das um die erste Mittellinie drehbar ist.

10. Rotierender Leiter nach einem der Ansprüche 1-6, wobei der erste ringförmige Körper eine ringförmige, gewinkelte Kontaktoberfläche (54, 55) mit einer zentralen Achse (L) aufweist, wobei der zweite Körper zumindest eine radiale, gewinkelte, ringförmige Kontaktoberfläche (52, 53), die drehbar um eine radiale Achse (51) herum montiert ist, aufweist, wobei die Achse um die zentrale Achse (L) des ersten Körpers drehbar ist.

11. Rotierender Leiter nach einem der vorhergehenden Ansprüche, wobei der Leiter geeignet ist, Ströme von zumindest 25 A, vorzugsweise zumindest 50 A, von dem ersten elektrischen Anschluss zu dem zweiten elektrischen Anschluss zu führen.

12. Rotierender Leiter nach einem der vorhergehenden Ansprüche, wobei der erste Leiter ringförmig ist, der zweite Leiter radförmig ist, der zweite Leiter einen kleineren Durchmesser als der erste Leiter besitzt und einen um zumindest 20% höheren Fließdruck als der erste Leiter aufweist.

13. Verfahren zum Übertragen von Elektrizität zwischen einem ersten und einem zweiten ringförmigen Körper in einem rotierenden Leiter nach einem der vorhergehenden Ansprüche, bei dem der Kontaktdruck nach dem anfänglichen Rollkontakt der ersten und der zweiten Kontaktoberflächen mit einem relativ hohen Anfangswert auf 33%- 50% des Anfangswertes reduziert wird.

14. Verfahren zum Übertragen von Elektrizität zwischen einem ersten und einem zweiten ringförmigen Körper in einem rotierenden Leiter nach einem der vorhergehenden Ansprüche, wobei Datensignale zwischen dem ersten und dem zweiten Körper übertragen werden.

Revendications

1. Conducteur rotatif comprenant un premier corps circulaire (3, 22, 23) présentant une première surface de contact circulaire métallique, une première ligne médiane (C1) et une première borne électrique (5) fixée à la première surface de contact, un second corps circulaire (2, 30, 31) présentant une seconde surface de contact circulaire métallique fixée à une seconde borne électrique (4) et pouvant tourner autour d'une seconde ligne médiane (C2), dans lequel la seconde ligne médiane (C2) peut tourner autour de la première ligne médiane (C1), dans lequel les première et seconde surfaces de contact métalliques se mettent en prise en contact de roulement, les métaux des surfaces de contact présentant une dureté prédéterminée et une pression de rupture correspondante, le conducteur étant approprié pour conduire des courants de la première borne électrique (5) vers la seconde borne électrique (4) d'au moins 10 A, caractérisé en ce que le second corps circulaire (2, 30, 31) est en forme de roue et en ce que, lors de la rotation de la seconde ligne médiane (C2) autour de la première ligne médiane (C1), une pression de contact entre les surfaces de contact est supérieure ou égale à au moins 10 %, de préférence à au moins 15 % de la pression de rupture du métal de surface de contact présentant la dureté la plus faible de sorte que les surfaces de contact sont lissées par déformation plastique, afin de garantir qu'une mise en prise par friction suffisante entre les surfaces de contact est présente pour éviter tout glissement et de garantir un mouvement de roulement pur sans que la présence de dents d'engrenage soit nécessaire.

2. Conducteur rotatif selon la revendication 1, dans lequel, avant l'utilisation et/ou pendant l'utilisation, la pression de contact représente environ au moins 50 % de la dureté Brinell (HB) des surfaces de contact.

3. Conducteur rotatif selon la revendication 1, dans lequel au moins l'une des surfaces de contact métalliques comprend du cuivre, la pression de contact étant d'au moins 20 N/mm < 2 >.

4. Conducteur rotatif selon la revendication 1 ou 2, dans lequel au moins l'une des surfaces de contact métalliques comprend du bronze phosphoreux, la pression de contact étant d'au moins 40 N/mm < 2 >.

5. Conducteur rotatif selon la revendication 1 ou 2, dans lequel la pression de contact entre les première et seconde surfaces de contact est d'au moins 20 N/mm < 2 >.

6. Conducteur rotatif selon l'une quelconque des revendications précédentes, dans lequel le premier corps comprend un corps externe de forme annulaire (3) présentant une surface de contact interne avec une première ligne médiane (C1) et un premier rayon (R1), le second corps circulaire (2) présentant une surface de contact externe avec une seconde ligne médiane (C2) et un second rayon (R2), la seconde ligne médiane (C2) étant à une certaine distance (S) de la première ligne médiane (C1), laquelle distance (S) est inférieure au second rayon (R2).

7. Conducteur rotatif selon la revendication 6, dans lequel le corps externe (3) est immobile et le second corps (2) peut tourner autour de la première ligne médiane (C1), la seconde borne (4) comprenant un conducteur de joint universel (7) dont une extrémité est reliée au corps interne rotatif (2) et son autre extrémité est reliée à un support rotatif (12) qui est situé sur la première ligne médiane (C1).

8. Conducteur rotatif selon l'une quelconque des revendications 1 à 7, caractérisé en ce que le second corps circulaire (2) est supporté dans un roulement (6) qui tourne autour de la première ligne médiane (C1).

9. Conducteur rotatif selon la revendication 6 ou 7, dans lequel au moins deux corps externes (22, 23) sont supportés dans une relation espacée, chacun connecté à une borne respective, les corps internes comprenant deux éléments cylindriques espacés (30, 31) montés de manière rotative sur un support rotatif (27) qui est placé à une distance radiale de la première ligne médiane (C1) et qui peut tourner autour de la première ligne médiane.

10. Conducteur rotatif selon l'une quelconque des revendications 1 à 6, dans lequel le premier corps circulaire comprend une surface de contact inclinée de forme annulaire (54, 55), avec un axe central (L), le second corps comprenant au moins une surface de contact de forme annulaire inclinée radiale (52, 53) montée de manière rotative autour d'un axe radial (51), lequel axe peut tourner autour de l'axe central (L) du premier corps.

11. Conducteur rotatif selon l'une quelconque des revendications précédentes, le conducteur étant approprié pour conduire des courants de la première borne électrique vers la seconde borne électrique d'au moins 25 A, plus préférablement d'au moins 50 A.

12. Conducteur rotatif selon l'une quelconque des revendications précédentes, le premier conducteur étant de forme annulaire, le second conducteur étant en forme de roue, le second conducteur présentant un diamètre inférieur au premier conducteur et présentant au moins une valeur de rupture supérieure de 20 % à celle du premier conducteur.

13. Procédé de transfert d'électricité entre un premier et un second corps circulaire dans un conducteur rotatif selon l'une quelconque des revendications précédentes, dans lequel, après le contact de roulement initial des première et seconde surfaces de contact à une valeur initiale relativement élevée, la pression de contact est réduite à 33 % - 50 % de la valeur initiale.

14. Procédé de transfert d'électricité entre un premier et un second corps circulaire dans un conducteur rotatif selon l'une quelconque des revendications précédentes, dans lequel des signaux de données sont transférés entre les premier et second corps.

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