Rotary electrical contact assembly

Abstract

The present invention relates to a rotary electrical contact assembly (1) for transmitting an electric current between two relatively rotatable parts and having at least one power transmission set including the following. - A first electrode (20 1 , 20 2 , 20 3 , 20 4 ), and a second electrode (22 1 , 22 2 , 22 3 , 22 4 ), each having a ring-shaped angled conductive contact surface on the same first axis (A1). - At least one roller holder assembly (28 1 ) having one roller (24 1 ) or a pair of rollers, including the following: - A ring-shaped angled conductive contact surface adapted to rotate on the contact surfaces of the corresponding first and second electrodes while the first electrode is rotating. - A shaft defining a second axis (A2) to which each roller (24 1 ) is rotatably attached. - At least one pressing device for applying a force F to each roller along the shaft. The rotary electrical contact assembly (1) further has one or two support members (300, 302) rotatably attached around the first axis at a position where the second axis (A2) is radial to the first axis (A1). The contact surface of each roller protrudes from an opening provided in the support member, and the pressing device applies a force F in the direction of the first axis.

Description

Technical Field

[0001] The present invention relates to a connector for establishing an electrical connection between two relatively rotatable members.

Background Art

[0002] In many applications, it is necessary to transmit current to rotating components such as machine parts, wind turbines, offshore high-voltage switches, and ship pods. A ship pod is a propulsion and steering module that rotates freely with respect to a ship and is used to move and direct the ship by a propeller driven by an electric motor. The current supplied to the electric motor is generated inside the ship.

[0003] Various solutions for transmitting current to rotating components are known.

[0004] A common solution is a rotating electrical conductor including slip rings and brushes. In this method, either the slip ring or the brush rotates, providing one or more sliding contacts. However, if it does not rotate for a long time during use and the position of the brush is fixed relative to the slip ring, the current always flows through the same point. This causes serious problems (micro-craters and ghost effects) on the surface of the ring, leading to an increase in contact resistance and a temperature rise (self-powering phenomenon). Furthermore, a surface coating may occur on the ring portion that usually does not contact the brush due to oxidation promoted by the environment, especially the marine environment. When rotating again, the operation of the brush is affected by the roughness of the contact surface and the change in contact resistance, and the deterioration of the brush and the ring occurs over time.

[0005] Another solution is a rotating electrical conductor including roller bearings, but this solution also has the same drawbacks as the above solution.

[0006] Other rotating electrical conductors include coaxial rotating rings. The rings arranged in pairs rotate relative to each other. However, it is difficult to correctly align the rings during assembly, and the concentricity of the rings is limited, so the resulting electrical contact is not uniform. Furthermore, since only one ring can be used for each transmission layer, if multiple transmissions are required, the number of layers increases, resulting in an increase in the overall space requirements.

[0007] In another solution, a mercury rotary joint is used. This system has been well known for decades. Usually, such a rotating conductor is used in low-power applications (very small ones). The main drawback is that it uses dangerous materials and is not suitable for marine and other outdoor applications.

[0008] In another solution, a gear assembly is used. Gears can transmit movement and power because almost one tooth is always in contact with the corresponding part of the wheel. A planetary gear with a series of gears inserted into an external tooth crown is widely used in the industry.

[0009] In another recent solution, cones that roll on rings are used. In this solution, the cones are housed between disks that rotate relative to each other. Such rotating electrical conductors are disclosed, for example, in WO0201682A1, WO2021097502A1, and EP3195423B1.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0011] WO0201682A1 discloses an electrical connector including two relatively rotatable members and a bearing assembly, the bearing assembly comprising bodies each defining a first substantially conical conductive surface arranged to be in non-sliding electrical contact with both members simultaneously in use, each body being arranged to rotate about the axis of its cone simultaneously with the relative rotation of the two members. Here, the bodies are arranged within an integral ring-shaped housing rotatably mounted on a rotary axis supporting the rotatable members. Up to two bodies can be arranged radially within the housing, enabling up to two power transmissions. Due to both no friction (or very low friction) and constant contact, this solution overcomes the drawbacks of standard sliding contacts. In this electrical conductor, the contact surfaces of the members are pressed against the contact surfaces of at least one body by a spring force acting in the direction of the axis of rotation of the rotatable members. However, especially when a single body defines two different conductive surfaces, it is necessary to manufacture with very high precision in order to obtain a linear contact formed between the contact surfaces. In practice, the formation of such a linear contact can be hindered by manufacturing tolerances and wear during operation.

[0012] To overcome this drawback, WO2021097502A1 provides an electrical connector in which the angled contact surface of the rotating member is free in the assembled state and its angular position can be changed relative to the angular position of the support portion of the member. This is achieved by making the angled contact surface of the rotating member a thin metal plate (maximum thickness 2 mm). When the angled contact surface of the rotating member is pressed against the angled contact surface of one rotating body by a spring force acting in the direction of the rotation axis of the member, the angled contact surface of the rotating member is inclined by the pressure and coincides with the angled contact surface of the rotating body in the assembled state. Thereby, a line contact between the contact surfaces can be reliably formed. However, since the thickness of the angled contact surface of the rotating member is thin, it is not possible to transmit high currents using this assembly. In this electrical connector, the rotating body is also arranged within a ring-shaped housing, but its attachment is not described in detail. In this arrangement, when multiple power transmissions are required, it is necessary to prepare multiple layers of rollers / members.

[0013] EP3195423B1 provides a rotating conductor with a similar structure that can stably and continuously transmit high currents. This document teaches achieving very stable and efficient current transmission by rolling the contact surfaces in rolling contact with a high contact pressure. Continuous rolling contact at high pressure results in a fine mechanical "cold forming" effect (plastic deformation), making the surface smooth and increasing the surface hardness. Such pressure is obtained by providing a spring element that biases the angled contact surface of each rotating body in the direction of the rotation axis of the rotating member within the plane of the radial axis about which the rotating body rotates. However, since the rotating body is fixed to the central axis that rotates the rotating member, when multiple transmissions are required, multiple layers of rotating bodies are needed, increasing the size of the conductor in the axial direction. Furthermore, assembling each rotating body to the central axis is very complicated. Also, due to the structure of the member and the structure for fixing each rotating body to the central axis, the overall weight of the rotating conductor is considerably increased. Such weight may compromise the stability during use.

[0014] Accordingly, there is still a need for an improved rotary electrical conductor with a simple and compact structure that enables high current transmission. The present invention relates to a rotary electrical contact assembly for transmitting current between two relatively rotatable parts having a specific roller arrangement.

Means for Solving the Problems

[0015] According to a first aspect, a rotary electrical contact assembly for transferring current between two relatively rotatable parts is proposed, the assembly comprising at least one of the following power transmission sets: - A first electrode and a second electrode. Each electrode has at least one ring-shaped angled conductive contact surface, the contact surfaces of the electrodes have the same first axis, and the first electrode is rotatably mounted around the first axis.

[0016] The rotary electrical contact assembly has the following characteristics. - The at least one power transmission set includes at least one roller holder assembly, the roller holder assembly comprising (i) one roller or a pair of rollers each having a ring-shaped angled conductive contact surface adapted to roll on the corresponding contact surfaces of the first and second electrodes while the first electrode rotates around the first axis, (ii) a shaft defining a second axis on which the roller or pair of rollers is rotatably mounted, (iii) at least one pressing device for applying a force F to the roller or pair of rollers along the shaft, and (iv) a mounting element, - The rotary electrical contact assembly further includes (i) a single support member, typically in the shape of a plate, rotatably mounted around the first axis and having a thickness smaller than the minimum diameter of the contact surface of each roller, or (ii) two support members, typically in the shape of plates, rotatably mounted around the first axis and assembled at a distance along the first axis smaller than the minimum diameter of the contact surface of each roller and spaced apart from each other, - Each roller holder assembly of the at least one power transmission set is mounted at a position where a second axis defined by a shaft is radial to a first axis (i) on a single support member or (ii) between two support members, and the contact surface of the roller or pair of rollers projects from a corresponding opening provided in the support member. The at least one pressing device applies a force F to the roller or pair of rollers in the direction of the first axis to press the roller contact surface of each roller against the contact surface of the corresponding electrode, and the mounting element of each roller holder assembly cooperates with a corresponding mounting element provided in the support member.

[0017] By providing a roller holder assembly, the present invention enables pre-assembly of the rollers, facilitates the attachment / detachment of the rollers within the rotary electrical contact assembly of the present invention, improves the manufacturing process, and shortens the maintenance work time. In particular, the contact pressure of the roller or pair of rollers within the roller holder assembly can be accurately adjusted and adapted to the transmission set. When multiple transmission sets are provided, it is possible to apply an appropriate contact pressure to each roller, enabling slip-free rotation. Further, the support member, together with the roller holder assembly, forms a sub-assembly that can be easily attached / detached within the rotary electrical contact assembly of the present invention, further improving the manufacturing process and shortening the maintenance work time. The specific arrangement of the roller holder assembly and the support member also facilitates the accurate attachment of the rollers to the support member, resulting in the rollers being accurately attached to the electrodes and reducing wear during operation.

[0018] As described above, a single support member, typically in the form of a plate, has a thickness smaller than the minimum diameter of the contact surface of each roller. When the roller holder assembly is attached to the single support member, the contact surface of each roller projects from both sides of the single support member.

[0019] Similarly, two support members, typically plate-shaped, are assembled with a distance along the first axis smaller than the minimum diameter of the contact surface of each roller, and when the roller holder assembly is mounted on the two support members, the contact surface of each roller projects from both support members. In other words, the dimension of the holes of the assembled support members measured along the first axis is smaller than the minimum diameter of the contact surface of each roller.

[0020] In one embodiment, the mounting elements of the roller holder assembly and the mounting elements of the support members may be nesting elements that can be mounted very simply without the need for tools. These nesting elements may be male and female nesting elements, such as pins, rods, fingers, tabs, brackets, etc. that cooperate with holes, recesses, grooves, slots, or other similar cooperating male / female elements. This embodiment is particularly advantageous in embodiments including two support members.

[0021] In other embodiments, the mounting elements of the roller holder assembly and the support plate include a pair of fixed tabs for each roller holder assembly, and each fixed tab is fixed to the support member and receives and fixes one end of the shaft of the roller holder assembly. Advantageously, the pair of fixed tabs are fixed to the same surface of the support member. The fixed tabs of all roller holder assemblies can be fixed to the same side or the opposite side of the support member. This embodiment is particularly advantageous in embodiments including a single support member.

[0022] In embodiments including two support members, the support members are assembled with each other by spacers and are easy to mount.

[0023] In embodiments including two support members, the support members may be parallel support plates. The sub-assembly formed by the roller holder assembly mounted on the support members is formed in a simple manner without increasing the weight compared to a solution where the rollers are directly fixed to the first axis.

[0024] In combination with any of the above embodiments, each roller holder assembly can include a housing that rotatably mounts around the shaft fixed to the housing and houses a roller or a pair of rollers (having two opposed openings where the contact surfaces of one roller or a pair of rollers protrude). These opposed openings open along a first axis. Such a housing protects the roller and the rotating mount on the shaft from dust and facilitates the attachment of the at least one pressing device.

[0025] In one embodiment, each roller or a pair of rollers of the roller holder assembly can be rotatably attached around the shaft by bearings, in combination with or without any of the above-described embodiments, for smooth rotation. Such bearings can be selected from rolling element bearings, plain bearings, and fluid bearings. Rolling element bearings include balls, cylinders, needles, or frustum-shaped rolling elements. A preferred rolling element bearing is an angular ball bearing. In particular, such an angular ball bearing can improve the rotational stability of the roller by placing a combined load (i.e., a radial load and an axial load acting simultaneously) applied to the roller. A plain bearing, also called a "sliding contact bearing" or a "sliding bearing", usually includes a bearing surface and does not include rolling elements. Such a plain bearing may be integrated with the roller or may be a bush inserted into the roller and having a bearing surface for receiving the shaft of the roller. A preferred plain bearing includes a bush made of Teflon (registered trademark). Plain bearings are inexpensive, compact, and lightweight. Fluid bearings (such as hydrostatic bearings and hydrodynamic bearings) use pressurized gas or liquid to support the load and eliminate friction. In a fluid bearing, the stationary surface and the rotating surface are separated by a thin film of lubricant such as oil, air, water, or process fluid. In a hydrodynamic fluid film bearing, when the lubricant is drawn into the converging shape between the surfaces, a film pressure is generated that separates the surfaces due to the relative movement (rotation) of the surfaces. In a hydrostatic bearing, the fluid is pressurized externally by a pump. Fluid bearings can improve the contact between the roller and the corresponding electrode.

[0026] In one embodiment, with or without combination with any of the above-described embodiments, the at least one roller holder assembly can include pressure adjusting means for cooperating with the at least one pressing device to adjust the force F. Thereby, it is possible to adjust the force F to a predetermined value that can be selected to optimize the contact between the contact surfaces. Such a force F is adjusted, for example, between 10 N and 200 N, preferably between 30 N and 60 N, or between any two of the above values. The pressure adjusting means may be adapted to adjust the length of elastic means such as a spring, particularly a compression spring. The pressure adjusting means can include, for example, a nut mounted on the threaded portion of the shaft.

[0027] In one embodiment, with or without combination with any of the above-described embodiments, the at least one pressing device can be attached to the roller holder assembly and include an elastic element for applying the force F to the roller or a pair of rollers of the roller holder assembly. Such an elastic element may be, for example, a compression spring attached around the shaft.

[0028] In one embodiment, with or without combination with any of the above-described embodiments, for each roller of the at least one power transmission set, the contact surface of the roller and the contact surface of the corresponding electrode have the same angle α defined between the second axis and the contact line L formed between the contact surface of the roller and the contact surface of the corresponding electrode. i and the second axis. i α i The value of i is equal to the value of the angle at which the contact line L passes through the intersection of the first axis and the second axis.

[0029] Such a value of α i in combination with a pressing device that radially presses the roller in the direction of the first axis provides stable electrical contact with limited slippage, reducing the wear sensitivity of both the roller and the electrode, thus increasing the maintenance interval, reducing the electrical contact resistance, and reducing electrical losses.

[0030] In one embodiment, with or without combination with any of the above-described embodiments, for each roller, the value of α i may be 45° or less, preferably 35° or less, or 25° or less, most preferably 15° or less, and may usually be between 5° and 20°. With such an angle, a compact assembly in the direction of the first axis can be obtained.

[0031] In one embodiment, with or without combination with any of the above-described embodiments, each contact surface can be formed on the outer surface of the body, and optionally, the body is a ring-shaped body of an electrode or a wheel-shaped body of a roller. With such an arrangement of the electrode body or the roller body, weight can be saved compared to a disk-shaped body. In the ring-shaped body or the wheel-shaped body, the amount of material can be limited to the amount necessary to create the contact surface.

[0032] In particular, at least one contact surface selected from the contact surface of the roller and the contact surface of the corresponding electrode, and optionally both contact surfaces, may be plated or coated with a material having a conductivity higher than that of the material of their bodies. Thereby, the overall cost of the body can be reduced by using a high-conductivity material only in the places necessary for transmitting electricity. The material to be coated or plated can be selected from silver, gold, and high-conductive copper alloys. As an example, the coating can be performed by electrolytic deposition, or by projection of a fusion alloy, or by application of a resin filled with conductive powder. A conductive metal plate may be brazed to the surface.

[0033] In one embodiment, with or without combination with any of the above-described embodiments, the rotary electrical contact assembly of the present invention can further include a conductive grease between the contact surface of the roller and the contact surface of the corresponding electrode. The use of the lubricating grease reduces mechanical wear and improves contact stability, while the conductivity of the grease can limit the electrical resistance between the contact surfaces.

[0034] In one embodiment, with or without combination with any of the above-described embodiments, each contact surface of the roller has a roller average diameter smaller than the electrode average diameter of the contact surface of the corresponding electrode, and optionally, the ratio of the roller average diameter to the corresponding electrode average diameter is from 1:20 to 1:1, preferably from 1:8 to 1:4. Such an arrangement can provide a compact assembly in the first axial direction.

[0035] In one embodiment, with or without combination with any of the above-described embodiments, each roller holder assembly of the at least one power transmission set includes a pair of rollers, each roller having a ring-shaped angled conductive contact surface, and the contact surfaces of both rollers rotate on the same contact surface of the corresponding first and second electrodes or on two adjacent corresponding contact surfaces of the first and second electrodes while the second electrode rotates around the first axis. By providing two rolling contact surfaces for the same pair of the first and second electrodes, a higher current can be transmitted with lower electrical losses in a situation where the single contact surface of the roller increases.

[0036] In one embodiment, with or without combination with any of the above-described embodiments, the rotary electrical contact assembly of the present invention further includes a first electrical insulation support and a second electrical insulation support, the first electrical insulation support being rotatably attached to the first axis, the first electrode of each power transmission set being attached to the first electrical insulation support, the second electrode of each power transmission set being attached to the second electrical insulation support, and optionally, the first electrical insulation support and the second electrical insulation support define a casing. Such an arrangement provides a compact assembly that is easy to attach. The electrical insulation support may have a conical shape with its apex facing the support member of the roller, or preferably, it may be a parallel plate.

[0037] In one embodiment, with or without combination with any of the above-described embodiments, the rotary electrical contact assembly of the present invention includes two or more power transmission sets. The first electrode (or the second electrode) of one power transmission set is arranged concentrically with respect to the first electrode (or the second electrode) of at least one other power transmission set. The rollers of all the transmission sets have a second axis disposed in the same plane perpendicular to the first axis and are mounted (i) on a single support member or (ii) on two support members. Such an arrangement can make the rotary electrical contact assembly compact in the first axis direction, enable the transmission of two or more different currents and / or signals, reduce the number of components, and for example, the first electrode can be fixed to the same first electrical insulating support, and the second electrode can be fixed to the same second electrical insulating support.

[0038] When the sizes of the rollers of different power transmission sets are significantly different (especially when the diameters are different), the electrical insulating support with electrodes arranged concentrically has a conical shape with a vertex facing the support member of the roller or may be a parallel plate (in this case, the dimensions of the electrode body along the first axis may be different). When the sizes of the rollers of different power transmission sets are approximated (especially rollers with the same or approximate diameters), the electrical insulating support with electrodes arranged concentrically may be a parallel plate. In any embodiment, in order to reduce the weight and the overall height of the rotary electrical contact assembly of the present invention and also to facilitate manufacturing, the electrical insulating support to which the electrodes are attached may be a parallel plate.

[0039] In one embodiment, with or without combination with any of the above-described embodiments, the first electrodes of two or more power transmission sets are arranged concentrically on the same first electrical insulating support perpendicular to the first axis, and the second electrodes of two or more power transmission sets are arranged concentrically on the same second electrical insulating support perpendicular to the first axis.

[0040] In one embodiment, with or without combination with any of the above-described embodiments, each power transmission set further includes at least one first electrical terminal electrically connected to the contact surface of the first electrode and at least one second electrical terminal electrically connected to the contact surface of the second electrode, and the rotary electrical contact assembly may be suitable for conducting a current of at least 700 A, more preferably at least 1000 A, from the first electrical terminal to the second electrical terminal. For example, in the case of a copper electrode with a contact area of about 2 mm 2 a maximum current of 700 A was measured through four rollers at a contact pressure of 70 - 80 N / mm 2 .

[0041] The maximum current that can pass through one transmission set, as a function of the area of the contact surface, (depending not only on the number of rollers and the width of the contact surface, the electrical resistance of the material of the contact surface, the pressure applied by the pressing device, but also on the contact resistance between the contact surfaces affected by the materials used, the roughness of the contact surfaces, the grease present on the contact surfaces, etc.) can be determined by the calculation / experiment of a skilled person.

[0042] The rotary electrical contact assembly according to the present invention can be used in offshore facilities such as ship pods, wind turbines, floating production storage and offloading facilities (FPSO) and offshore floating structures for wind turbines ( "floaters"), or mechanical parts such as part of a welding machine or part of a pyrolysis furnace (however, it is not limited thereto). The rotary conductor can also be used to transmit electrical signals from one contact surface to the other at a data rate of up to 1 Gb / s or more.

[0043] According to a second aspect, a rotary system rotatably connected to an external power source is proposed, the rotary system includes an electromechanical machine, and further includes a rotary electrical contact assembly according to the present invention, wherein the second electrode of each power transmission set of the rotary electrical contact assembly is intended to be electrically connected to the external power source, and the first electrode of each power transmission set of the rotary electrical contact assembly is characterized in that it is electrically connected to the electromechanical machine.

[0044] According to a third aspect, in the first embodiment, a process for assembling a rotary electrical contact assembly (in particular, the rotary electrical contact assembly disclosed above) including the following is disclosed: 1) Providing at least one power transmission set including a first electrode and a second electrode, each electrode including at least one ring-shaped angled conductive contact surface, the contact surfaces of the electrodes having the same first axis, the first electrode being rotatably mounted about the first axis; 2) Providing for each power transmission set at least one roller holder assembly including: (i) one roller or a pair of rollers, each roller including a ring-shaped angled conductive contact surface adapted to roll on the contact surfaces of the corresponding first and second electrodes while the first electrode rotates about the first axis; (ii) a shaft defining a second axis about which the roller or pair of rollers is rotatably mounted; (iii) at least one pressing device for applying a force F along the shaft to the roller or pair of rollers; and (iv) a mounting element; 3) Providing a single support member having a thickness smaller than the minimum diameter of the contact surface of each roller (typically plate-shaped); 4) Mounting at least one roller holder assembly to the single support member by cooperation of the mounting element of the at least one roller holder assembly and the mounting element of the corresponding single support member at a position where the second axis defined by the shaft is radial to the first axis, the contact surfaces of the roller or pair of rollers protrude from corresponding openings provided in the single support member, and at least one pressing device applies a force F in the direction of the first axis to the roller or pair of rollers to press the roller contact surface of each roller against the contact surface of the corresponding electrode; 5) Mounting the single support member rotatably about the first axis.

[0045] According to a third aspect, in the second embodiment, a method for assembling a rotary electrical contact assembly (in particular, the rotary electrical contact assembly disclosed above) including the following is disclosed: 1) Provide at least one power transmission set including a first electrode and a second electrode (each electrode includes at least one ring-shaped angled conductive contact surface, the contact surfaces of the electrodes have the same first axis, and the first electrode is rotatably mounted around the first axis). 2) Provide at least one roller holder assembly for each power transmission set, including: (i) one roller or a pair of rollers (each roller includes a ring-shaped angled conductive contact surface adapted to roll on the contact surfaces of the corresponding first and second electrodes while the first electrode rotates around the first axis), (ii) a shaft defining a second axis on which the roller or the pair of rollers is rotatably mounted, (iii) at least one pressing device for applying a force F along the shaft to the roller or the pair of rollers, and (iv) a mounting element. 3) Provide two supporting members (in particular, two supporting plates). 4) The second axis defined by the shaft is radial to the first axis, the contact surfaces of the roller or the pair of rollers protrude from corresponding openings provided in the supporting members, and at least one pressing device applies a force F in the direction of the first axis to the roller or the pair of rollers to press the roller contact surface of each roller against the contact surface of the corresponding electrode. At this position, the mounting element of at least one roller holder assembly and the mounting element of the corresponding supporting member cooperate to mount at least one roller holder assembly to the supporting members (between two supporting members spaced apart by a distance smaller than the minimum diameter of the contact surface of each roller). 5) Assemble the two supporting members with each other (in particular, parallelize the two supporting plates). 6) Mount the two supporting members (in particular, the assembled supporting members) rotatably around the first axis.

[0046] In either embodiment, the installation of the rotary electrical contact assembly can be carried out very simply and quickly, facilitating maintenance.

[0047] In any of the above embodiments, the step of providing at least one roller holder assembly can include the following: (2a) shaping and / or machining the roller body into a wheel shape, (2b) providing a contact surface to the roller body (e.g., by plating) to obtain a roller, (2c) assembling the roller or pair of rollers into a roller holder assembly by attaching the roller or pair of rollers to a shaft, attaching a pressure device, and optionally attaching a pressure adjustment means, (2d) optionally setting the pressure by adjusting the pressure adjustment means.

Brief Description of the Drawings

[0048] The present invention is described using examples that illustrate potential embodiments of the present invention.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0049] In the following description, the same reference numerals are used to design the same or similar elements.

[0050] Figures 1 to 5 show embodiments of a rotary electrical contact assembly 1 including a plurality (here four) of power transmission sets 2 i (i = 1, 2, 3, 4). In this specification, "i" refers to the number of power transmission sets, and the reference numeral 12 i (in this example, i = 1, 2, 3, or 4) is designated by the reference numeral 12 and indicates an element belonging to the i-th power transmission set. However, the present invention is not limited to a specific number i of power transmission sets, and other rotary electrical contact assemblies having 1, 2, 3, 5, 6 or more power transmission sets are also contemplated. In other words, i is a non-zero integer, preferably 1 ≤ i ≤ 8.

[0051] Each power transmission set 2 i includes a first electrode 20 i and a second electrode 22 i , and further includes at least one roller 24 i . The first electrode 20 i and the second electrode 22 i are circular electrodes having the same central axis A1 when assembled. The second electrode 22 i is a fixed electrode, and the first electrode 20 i is rotatably mounted around the central axis A1.

[0052] Each electrode 20 i , 22 i has at least one ring-shaped angled conductive contact surface 200 i , 220 i (preferably a single ring-shaped angled contact surface) as shown. The ring-shaped contact surfaces 200 i , 220 i of the electrodes have the same axis of symmetry when assembled, and this axis is also referred to as the "first axis" in the present invention and corresponds to the central axis A1 here. In other words, the contact surfaces 200 i , 220 i are frustum-shaped surfaces.

[0053] Each roller 24 i is mounted around a second axis A2 that is radial (perpendicular) to the first axis A1, and while the first electrode 20 i is rotating around the first axis A1, a ring-shaped angled conductive contact surface 240 i , 220 i is adapted to roll on the corresponding contact surfaces 200 i of the first and second electrodes. In other words, the roller 24 i rolls on two opposite-direction tracks formed by the contact surfaces of the corresponding first and second electrodes of the power transmission set. In the present invention, the contact surfaces correspond when belonging to the same power transmission set. Thus, the contact surface 240 i is also a frustum-shaped surface.

[0054] Finally, the power transmission set 2 i is associated with at least one (usually one or two) roller 24 i and includes at least one pressing device 26 that applies a force F in the direction of the first axis A1 along the second axis A2. This pressing device 26 i is adapted to press the roller contact surface 240 i of the roller against the contact surfaces 200 i of the corresponding electrodes i , 220 i . In the illustrated assembly 1, each power transmission set 2 i is provided with four rollers 24 i . However, the present invention is not limited to a specific number of rollers per power transmission set 2 i , and the number of rollers may vary depending on the dimensions of the electrodes. Preferably, a plurality of rollers (two or more) are provided by the power transmission set 2 i , and it is advantageous to be regularly arranged around the first axis A1 in order to balance the overall weight.

[0055] As more clearly shown in FIG. 4, each roller 24 i of the same power transmission set 2 i ​Regarding the contact surface 240 of the roller i and the contact surface 200 of the corresponding electrode i , 220 i forms an angle α with the second axis A2 and the contact line L i (formed between the contact surface of the roller and the contact surface of the corresponding electrode). i They are the same.

[0056] As shown in FIG. 4, in a preferred embodiment, for each roller of the power transmission set 2 i the value of α i is equal to the value of the angle through which the contact line L i passes through the intersection point O of the first axis A1 and the second axis A2. This rule applies to all power transmission sets.

[0057] In other words, for the rollers 24 i of the same power transmission set 2 i the contact surfaces have an angular shape with the same value of the angle α i but the value of this angle is different for each power transmission set. Further, as can be seen from FIG. 4, for rollers of the same maximum radius belonging to different power transmission sets 2 i the contact surface of the power transmission set 2 4 farthest from the first axis A1 has an angle α i smaller than the angle α 4 of the contact surface of the next power transmission set in the direction of the first axis A1, and the contact surface of the power transmission set 2 1 closest to the first axis has the maximum value of the angle α 1 . Therefore, α 4 < α 3 < α 2 < α 1 is true.

[0058] In other words, in this preferred embodiment, each roller contact surface 240 i forms a frustum of a cone with the apex angle equal to 2×α i , and its apex (vertex) is the intersection point O of the axis of the frustum of the cone (the second axis A2) and the first axis A1. This angle α iThus, the roller can roll without slipping. For proper stable operation, α i should preferably be at most 45°, preferably at most 25°, and more preferably less than 15°.

[0059] In other embodiments, the contact surfaces of the rollers 24 of all the power transmission sets 2 i are, as described above, of a shape such that the values of the angle α i are the same. This means that the rollers of different power transmission sets 2 i have different radii. The contact surfaces of the electrodes of different power transmission sets 2 i follow the same virtual conical shape with an increasing overall height. This means providing electrodes having bodies of different heights (measured along the first axis) supported by a plate support perpendicular to the first axis, or providing electrodes having bodies of the same height supported by a conical support. i In any embodiment, the corresponding angled contact surfaces 200

[0060] , 220 i , 240 i are generally formed on the outer surfaces of the respective bodies 202 i , 222 i , 242 i as shown, respectively. Advantageously, as best shown in FIGS. 4 - 6, the first electrode 20 i and the second electrode 22 i have ring-shaped bodies 202 i , 222 i , and the roller 24 i has a wheel-shaped body 242 i (see FIGS. 3, 4, 7 - 8). The ring-shaped bodies 202 i , 222 i , and the wheel-shaped body 242 i all have contact surfaces 200 i , 220 i , 240 i i ​It has a frustum-shaped outer surface that is formed. These frustum-shaped outer surfaces, more specifically, the (frustum-shaped) contact surfaces formed thereon, each have an average diameter (which can be defined as the average of the maximum diameter and the minimum diameter).

[0061] The ratio of the average diameter of the roller to the average diameter of the corresponding electrode is from 1:20 to 1:1, preferably from 1:20 to 3:4, most preferably from 1:8 to 1:4, or within any of the above limitations.

[0062] As an example, the following dimensions are conceivable: - The average diameter of the electrode contact surface is between 100 mm and 640 mm, preferably between 200 mm and 400 mm. - The average diameter of the roller contact surface is between 10 mm and 100 mm.

[0063] Generally, in the rotating electrical contact assembly of the present invention, in order to limit the overall height, the average diameters of the contact surfaces of all the rollers are similar or the same. However, other configurations may also be desirable.

[0064] Roller body 242 i is usually formed of a metal, preferably copper or a copper alloy (and can contain, for example, zirconium or zinc for mechanical properties). The roller body usually has a contact surface 240 plated or coated with a conductive metal that has higher conductivity than the metal of the body, such as silver, gold, or a highly conductive copper alloy. i Silver or a copper alloy (for example, containing about 1 to 3% silver) is preferred.

[0065] In the present invention, as shown in the figure, each roller 24 i is pre-attached to a roller holder assembly 28 i In one embodiment, as best shown in FIG. 7, each roller holder assembly 28 i is rotatably attached around a shaft 282 fixed to a housing 280 with one roller 24 iincludes a housing 280 that houses it. This housing 280 has two opposing openings 283, 284 through which the contact surface 240 of the roller 24 i protrudes. i As can be seen from FIG. 7, the housing 280 can be easily made of a tubular element with a rectangular cross-section in which the roller 24

[0066] (more specifically, the roller body 242 i ) is arranged. Therefore, the dimension of the housing 280 from one opening 283 to the other opening 284 (i.e., the height of the tubular element along the first axis A1 when the housing is attached to the assembly 1) is smaller than the minimum radius of the contact surface 240 of the roller in order to avoid interference of the housing with the contact surfaces of the corresponding first and second electrodes. i i

[0067] The roller 24 i is attached to the shaft 282 by a bearing 285 (here, an angular ball bearing 285) arranged to support the load applied to the frustum-shaped outer surface of the roller body. However, other rolling bearings or other bearings (such as sliding bearings, fluid bearings, etc.) can also be used.

[0068] Here, the pressure device 26 i is provided with an elastic element 260 that can apply a force F to the roller or to the housing 280 of the roller holder assembly 28 i . In this embodiment, the roller holder assembly 28 i also includes pressure adjustment means 262 for adjusting the force F.

[0069] In the present invention, as shown in the figure, the pressing device 26 i is the roller holder assembly 28 iis part of. The elastic element 260 is, here, a compression spring disposed between one end 282a of the shaft 282 and the housing 280, and the adjusting means 262 includes a nut 263 attached to the threaded end 282b of the shaft. More specifically, as shown in the figure, the shaft 282 traverses the housing 280 from one side to the opposite side. On one side of the housing 280, the elastic element 260 is disposed around the shaft 282, one abuts against the stop plate 286 near the first end 282a of the shaft 282, and the other abuts against the housing 280 or against the end of the sleeve 288 (inserted into the housing 280 and receiving the shaft 282). On the opposite side of the housing 280, the end 282b of the shaft 282 has a threaded portion, and the nut 263 is attached thereto. Therefore, by attaching the nut 263 deeper or shallower to the threaded portion of the shaft, the length of the elastic element 260, that is, the force F acting on the housing 280 (and thus the force F acting on the roller along the second axis) can be adjusted.

[0070] The housing 280 shown in FIG. 7 has dimensions capable of accommodating a single roller body 242 rotatably attached to the shaft 282 i In other embodiments not shown, the housing 280 can have dimensions capable of accommodating two roller bodies 242 rotatably attached to the same shaft 282 i (separated, for example, by an elastic element such as an elastic washer). In such a case, the contact surfaces of both rollers cooperate with the same contact surfaces of the first and second electrodes, or cooperate with the adjacent contact surfaces of the first and second electrodes. In the last case, each of the first and second electrodes can have two adjacent contact surfaces that are separate but electrically connected.

[0071] Roller holder assembly 28 iIt further includes mounting elements adapted to engage with the support member. These mounting elements here include two pins 289, 290 extending perpendicular to the second axis of the roller. Such mounting elements are fixed, for example, to a shaft 282 that rotatably supports the roller (or a pair of rollers) at both ends. In the illustrated embodiment, one of the mounting elements 290 forms the nut 263 of the pressure adjusting means.

[0072] In addition, even when the housing 280 is omitted, the pressing device 26 i is provided. In other words, the roller holder assembly 28 i is the shaft 282 on which the roller 24 i (or a pair of rollers) is rotatably mounted (preferably by the bearings 285 described above), and may optionally include a sleeve 288. Optionally, the roller holder assembly 28 i may further include a pressure adjusting means 262 and / or a housing 280.

[0073] This roller holder assembly 28 i is standardized, so the same housing can be used for roller bodies of various sizes and various pressure values. Further, the pressure can be adjusted before incorporating the roller holder assembly into the rotary joint assembly.

[0074] For example, when using a roller with an outer diameter of 26 - 28 mm, a force F of 30 - 60 N can be obtained, and the contact pressure is 9 - 20 MPa. When the radius of the roller is increased, in order to rotate it smoothly, it is necessary to increase the acting force. This can be easily done by the pressure adjusting means.

[0075] In the present invention, as shown, each roller holder assembly 28 iis not directly attached to the first axis A1, but is supported by a roller support assembly 30 as shown in FIGS. 2 and 3. In the embodiments shown in these figures, this roller support assembly 30 is rotatably attached around the first axis A1 and is assembled to each other at a distance smaller than the minimum diameter of the contact surface of each roller along the first axis, including two support members 300, 302. Each roller holder assembly 28 of all the power transmission sets 2 i is engaged between these support members 300, 302. For this purpose, each support member 300, 302 is provided with an opening 304 in which the contact surface 240 of each roller 24 i protrudes, and this contact surface 240 i can contact the corresponding contact surfaces of the first electrode and the second electrode. Therefore, as shown in the figure, the overall dimensions of the assembled support members 300, 302 (measured along the first axis A1) are smaller than the minimum diameter of the contact surface of each roller, and when the roller holder assembly 28 i is attached to the two support members, the contact surface of each roller protrudes from both support members. i is attached to the two support members, the contact surface of each roller protrudes from both support members. i is attached to the two support members, the contact surface of each roller protrudes from both support members.

[0076] In the illustrated embodiment, the support members 300, 302 are plates, and in particular, parallel support plates, here circular parallel support plates. However, the present invention is not limited to this specific form as long as the support members are assembled to each other at the above-mentioned distance along the first axis.

[0077] The support members 300, 302 are typically formed of an electrically insulating material (or a material covered with or plated with an electrically insulating material) (for example, a polymer). These support members 300, 302 are disk-shaped here, form a base support for all rollers, and can be easily adapted according to the number and size of the rollers.

[0078] The mounting elements of the roller holder assembly cooperate with corresponding mounting elements provided on the support members 300, 302. In the illustrated embodiment, the pins 289, 290 of each roller holder assembly fit into recesses 305, 306 provided in the support plate (see FIG. 3). The present invention is not limited to such mounting elements. For example, the housing 280 (edge) can directly engage and fit into a slot or groove of the support member. In other words, the mounting element may be formed within or be a part of the housing 280.

[0079] In another embodiment shown in FIG. 8, a single support member 300' can be used to support the roller holder assembly 28 i Such a single support member 300' is typically in the form of a plate having a thickness smaller than the minimum diameter of the contact surface of each roller, as partially shown in FIG. 8. In the embodiment shown in FIG. 8, the roller holder assembly 28 i is similar to that of the embodiment described with reference to FIG. 7, mainly differing in the mounting elements. Therefore, in FIG. 8, the same components are designated with the same reference numerals, and the above description is referred to for details.

[0080] In the embodiment of FIG. 8, the mounting element includes the roller holder assembly 28 iEach includes a pair of fixed tabs 289’, 290’. Each fixed tab 289’, 290’ is fixed to a single support member 300’ and to the shaft 282 of the roller holder assembly. In the illustrated example, each fixed tab is “L”-shaped. However, the fixed tabs in the present invention are not limited to a specific shape as long as each can be fixed to a single support member 300’ and to one end of the shaft 282. In the illustrated example, each fixed tab includes two openings 289’a, 289’b; 290’a, 290’b: a first opening 289’a, 290’a; and a second opening 289’b, 290’b for receiving the shaft 282. Third openings 289’c, 290’c may be provided for introducing a pin or screw (not shown) for fixing the shaft 282 to the fixed tabs 289’, 290’. Alternatively, in combination, one element selected from the shaft 282 and the single support member 300’ may be welded to the fixed tab.

[0081] Thus, as shown, when the roller holder assembly 28 i is attached to a single support member, the contact surface of each roller projects from both sides of the single support member 300’.

[0082] Similar to the embodiment having two support members, the single support member 300’ is provided with openings 304’ through which the contact surfaces 240 i of the respective rollers 24 i project. Depending on the dimensions of the single support member 300’, the roller holder assembly 28 i can be fixed to the same side or both sides of the single support member 300’.

[0083] Similar to the embodiment having two support members, each roller holder assembly 28 imay or may not include a housing 280 and / or pressure adjusting means 262' for adjusting the force F. In this embodiment, a simple nut 263' attached to the threaded portion of the end 282b of the shaft 282 can be used as the pressure adjusting means 262', and this nut is disposed between the fixed tab 290' and the housing 280 here. In the example shown in FIG. 8, the stop plate 286 is separate from the fixed tab 289'. Alternatively, the stop plate 286 may be integral with the fixed tab 289'.

[0084] As already described, the support members 300, 302, 300' are rotatably attached about the first axis A1, for example by bearings 308, such that when the roller rotates on the electrode, the support members 300, 302, 300' also rotate. In the embodiments shown in FIGS. 1-3 and 7, the support members 300, 302 are rotatably attached to the hub 70 of the rotary electrical contact assembly. Thus, this hub 70 defines the first axis A1. The same attachment is possible for the single support member 300' described with reference to FIG. 8.

[0085] The support members 300, 302 are assembled to each other, for example, by spacers 310 arranged to extend between the support members, ensuring that the support members are spaced apart from each other by the above-described distance and are fixed to each support member by screwing or other means. In this way, a rigid and resistant roller support assembly 30 is obtained. Similarly, a rigid and resistant roller support assembly 30 can also be obtained using a single support member 300'.

[0086] This roller support assembly 30 can arrange a plurality of roller holder assemblies 28 i at free positions on the support members 300, 302, or 300' (and partially at free positions between them), so the design and installation are relatively easy. As shown in the illustrated embodiment, four power transmission sets 2 i are provided, and each set has four roller holder assemblies 28 iIt has.

[0087] The distance between the support members 300, 302 allows an operator to perform maintenance on the roller support assembly 30 (e.g., adding grease to the roller contact surfaces and adjusting the pressure on each roller holder assembly), for example, through a trap door 53, described below. The provision of a single support member 300' facilitates such maintenance.

[0088] As more clearly shown in FIGS. 5 and 6, the rotary electrical contact assembly 1 includes a power transmission set 2 i First electrode 20 i and a first electrically insulating support 40 on which each power transmission set 2 is mounted. i The second electrode 22 i and a second electrically insulating support 42 to which the first electrically insulating support 40 is attached. The first electrically insulating support 40 is rotatably attached about the first axis A1. In the illustrated embodiment, the first electrically insulating support 40 and the second electrically insulating support 42 are fixed (e.g., screwed) to the first part 51 and the second part 52 of the casing 50, respectively. Thus, the first part 51 is rotatably attached about the first axis A1 and can rotate about this axis, but the second part 52 cannot rotate about the first axis A1.

[0089] Alternatively, the first electrically insulating support 40 and the second electrically insulating support 42 may define the casing 50. For example, the first electrically insulating support 40 and the first part of the casing 51 may be formed from a first part that is not joined or assembled, and the second electrically insulating support 42 and the second part of the casing 52 may be formed from a second part that is not joined or assembled.

[0090] In the embodiment shown, the casing 50 is provided with a trap door 53 for accessing the roller support assembly 30 .

[0091] The two parts 51, 52 of the casing 50 are configured such that the first part 51 is rotatable relative to the second part 52 and are assembled to close the casing. The casing 50 is preferably closed in a watertight manner, for example, by using a suitable seal joint between the two parts 51, 52, especially when used in a corrosive environment such as a marine environment.

[0092] In the illustrated embodiment, the first support 40 and the first part 51 of the casing are fixedly attached onto a hub 70 which is a part rotating about the first axis A1, while the second support 42 and the second part 52 of the casing are fixed parts, and the hub 70 can rotate therein via a bearing 54. However, the present invention is not limited to this arrangement as long as the first support 40 rotates about the first axis A1 and the second support 42 is a fixed part. The sealed housing 80 (see FIG. 2) may be fixed to the second part 52 of the casing so as to surround the bearing 54, a part of the outer surface of the second part 52 and the hub 70, and the electrical connector 62 i and its wiring described later.

[0093] As shown in the figure, when two or more power transmission sets 2 i are provided, the first electrode 20 i and the second electrode 22 i of one power transmission set 2 i are arranged concentrically (here, in the same plane perpendicular to the first axis A1) with respect to the first electrode and the second electrode of the other power transmission set 2 i . The distance between the concentric electrodes is large enough to avoid electrical contact between the electrodes. Optionally, an electrically insulating material can be provided between the ring-shaped electrodes. In the illustrated embodiment, the first electrode 20 i is arranged concentrically on the first electrical insulating support 40, and the second electrode 22 iis arranged concentrically on the second electrical insulating support 42. Here, both electrical insulating supports 40, 42 are in the form of plates perpendicular to the first axis and are thus parallel to each other, so that a compact configuration along the first axis can be obtained. As already explained, other configurations (conical shape) can also be envisaged.

[0094] Due to such a concentric arrangement of the electrodes, all transmission sets 2 i of the rollers 24 i have a second axis A2 arranged in the same plane perpendicular to the first axis A1. Thus, all transmission sets 2 i of the rollers 24 i are engaged between two support members 300, 302.

[0095] Each power transmission set 2 i further includes a first electrical terminal or connector 60 i electrically connected to the contact surface of the first electrode 20 i and a second electrical terminal or connector 62 i electrically connected to the contact surface of the second electrode 22 i When a high current is transmitted, a plurality of connectors 60 i , 22 i per electrode 20 i , 62 i may be provided. In the illustrated embodiment, the connectors are provided via the electrical insulating supports 40, 42 and the casing 50. Since the electrodes are arranged concentrically, note that all power transmission sets 2 i of the connectors 60 i , 62 i also have sufficient space.

[0096] The rotary electrical contact assembly 1 of the present invention is advantageously suitable for guiding a current of at least 700 A, more preferably at least 1000 A, from the first electrical terminal to the second electrical terminal.

[0097] If it is necessary to increase the current, several solutions can be adopted while maintaining a certain degree of compactness: - The same power transmission set 2 i Add additional rollers to it (in the illustrated embodiment, there are 4 rollers per power transmission set, but 2 or 4 rollers can also be provided). - Increase the width of the electrodes and arrange additional rollers on the power transmission set. In this case, attach 2 rollers to the same shaft and arrange a flexible component in between to keep the pressure uniform. By increasing the contact width between the rollers and the electrodes, a higher current can be transmitted. - Increase the contact width between the rollers and the electrodes by increasing the widths of both the electrodes and the rollers. The contact width can be increased up to a threshold value at which contact is restricted by surface defects or non-uniform pressure. When exceeding such a threshold value, it is necessary to provide 2 rollers rolling on the same electrode pair.

[0098] In the last two embodiments, since the diameter of the electrodes does not become too large, it is also possible to use the rotary contact assembly at a higher speed (in order to expand the range of applications).

[0099] In general, lubricating grease is added between the contact surface of the rollers and the corresponding contact surfaces of the first and second electrodes to reduce mechanical wear and improve contact stability. This grease can be selected from electrically conductive greases that limit the electrical resistance between the contact surfaces (for example, the type of grease used for the electrical connection of plug sets). Such a grease may be a non-conductive oil containing a suspension of electrically conductive lubricating particles (preferably, graphite particles). EP3149812 discloses suitable greases or lubricating oils. Two exemplary brands of suitable oils are, for example, graphite-based high-quality penetrating oils such as EVIAL® sold by Griffon, or, for example, lithium-based high-quality penetrating oils such as Synthesin PDL250 / 01® sold by Kluber.

[0100] The rotary electrical contact assembly 1 of the present invention can be part of a rotary system 100 rotatably connected to an external power source PW. Such a rotary system 100 includes an electromechanical machine 110 and a rotary electrical contact assembly 1. The second electrode of each power transmission set of the rotary electrical contact assembly 1 can be electrically connected to the external power source PW via, for example, a connector 62 i and the first electrode of each power transmission set of the rotary electrical contact assembly is electrically connected to the electromechanical machine 110 via a connector 60 i . The connections between the rotary electrical contact assembly 1, the external power source PW, and the electromechanical machine 110 are schematically shown in FIG. 1.

[0101] The assembly process of the rotary electrical contact assembly 1 of the present invention can include the following steps: 1) At least one power transmission set 2 i including a first electrode 20 i and a second electrode 22 i (each electrode includes at least one ring-shaped angled conductive contact surface 200 i , 220 i , and the contact surfaces of the electrodes have the same first axis A1, and the first electrode 20 i is rotatably mounted around the first axis, for example, by assembling the first and second electrodes of each power transmission set 2 i to the first electrical insulation support 40 and the second electrical insulation support 42). 2) Provide at least one roller holder assembly 28 i for each power transmission set 2 i including: (i) One roller 24 i or a pair of rollers 24 i (each roller includes a ring-shaped angled conductive contact surface 240 i , 220 i adapted to roll on the corresponding contact surfaces 200 i of the first and second electrodes while the first electrode rotates around the first axis), (ii) A second axis A2 (the roller 24 i or a pair of rollers 24i a shaft 282 defining that (is rotatably attached), (iii) at least one pressing device 26 i (said roller 24 i or a pair of rollers 24 i is applied with a force F along said shaft), and, (iv) mounting elements 289, 290, or 289’, 290’, 3) providing a single support member 300’ or two support members 300, 302 (in particular, openings 304’, 304 for passing each roller holder assembly, and mounting elements 305’, 306’ and 305, 306 respectively adapted to cooperate with the mounting elements 289’, 290’; 289, 290 of each roller holder assembly), 4) By cooperating the mounting elements (289’, 290’; 305’, 306’)(289, 290; 305, 306) with a roller holder assembly 28 attached to a single support member 300’ i or a roller holder assembly 28 attached between two support members spaced apart by a distance smaller than the minimum diameter of the contact surface of each roller along said first axis, i the second axis A2 defined by the shaft 282 becomes radial to the first axis A1, the contact surface of the roller or the pair of rollers protrudes from the openings 304’, 304 provided in the support member, and the pressing device 26 i acts on the roller 24 i or a pair of rollers 24 i with a force F in the direction of the first axis to press the roller contact surface 240 of each roller i against the contact surfaces 200 i , 220 i of the corresponding electrodes, and position each roller holder assembly 28 i attached to a single support member 300’ or two support members 300, 302, 5) When two support members 300, 302 are provided, assemble the support members with each other (for example, using a spacer 310 to obtain a roller support assembly 30), 6) Attach the support member so that it can rotate around the first axis (for example, by attaching the roller support assembly 30 to the hub 70).

[0102] In particular, step 1) can include the following steps: 1a) At least one first electrode 20 i and at least one second electrode 22 i are assembled to the first electrical insulation support (40) and the second electrical insulation support (42) (which form the casing 50 or are fixed within the casing 50 when the rotary contact assembly is fully attached), and the first and second electrodes are connected to the connectors 60 i , 62 i and 1b) With the roller support assembly 30 sandwiched therebetween, attach the electrical insulation supports 40, 42 to the hub 70 (the support 42 is fixedly attached to the hub 70, and the support 40 is rotatably attached to the hub 70).

[0103] Such assembly can be carried out quickly and easily.

[0104] Step 2) of providing at least one roller holder assembly 28 i can include the following: 2a) Molding and / or machining the roller body 242 i into a wheel shape, and / or 2b) Providing the contact surface 240 i to the roller body 242 i for obtaining the roller 24 i by, for example, plating or coating, 2c) Attaching the roller 24 i or a pair of rollers 24 i to the shaft 282, and attaching, for example, a pressure device 26 i including an elastic element 260 and optionally pressure adjusting means 262, 262', and optionally attaching the roller(s) within the housing 280, thereby i attaching the roller 24i to the roller holder assembly 28 i and assembling it, 2d) Optionally, setting the pressure by adjusting the pressure adjusting means 262, 262' (for example, by tightening the nuts 263, 263' and the threaded portion of the shaft 282 supporting the roller or pair of rollers).

[0105] Therefore, such a roller holder assembly can be easily prepared before being attached to the rotary electrical contact assembly of the present invention.

Claims

1. A rotary electrical contact assembly (1) for transmitting an electric current between two relatively rotatable parts, having at least one power transmission set (2 ｉ ) - The first electrode (20 ｉ ) and the second electrode (22 ｉ ), each electrode includes at least one ring-shaped angled conductive contact surface (200 ｉ , 220 ｉ ), the contact surfaces of the electrodes have the same first axis (A1), and the first electrode (20 ｉ ) is rotatably mounted around the first axis, - said at least one power transmission set (2 ｉ ) has (i) a ring-shaped angled conductive contact surface (240i) adapted to rotate on the contact surfaces (200 ｉ , 220 ｉ ) of the corresponding first and second electrodes while the first electrode rotates around the first axis, of one roller (24 ｉ ), or of a pair of rollers (24 ｉ ), (ii) a shaft (282) defining a second axis (A2) to which the roller (24 ｉ ), or the pair of rollers (24 ｉ ) is rotatably attached, (iii) at least one pressing device (26 ｉ ) for applying a force F along said shaft to the roller (24 ｉ ), or the pair of rollers (24 ｉ ), and (iv) a mounting element, and comprises at least one roller holder assembly (28 ｉ ); - The rotary electrical contact assembly (1) further comprises (i) a single support plate (300') rotatably mounted about a first axis and having a thickness less than the minimum diameter of the contact surface of each roller, or (ii) two parallel support plates (300, 302) rotatably mounted about a first axis and assembled together with a distance less than the minimum diameter of the contact surface of each roller along the first axis. - The second axis (A2) defined by the shaft is radial with respect to the first axis (A1), and the contact surfaces of the roller or pair of roller pairs protrude from corresponding openings (304, 304') provided in the support plate, and the at least one pressing device (26 ｉ ), acting a force F in the direction of the first axis on the roller (24 ｉ ) or pair of rollers (24 ｉ ), at a position where the roller contact surface (240 ｉ ) of each roller is pressed against the contact surface (200 ｉ , 220 ｉ ) of the corresponding electrode, the mounting elements of each roller holder assembly (28 ｉ ) cooperate with corresponding mounting elements provided on the support plate, and each roller holder assembly (28 ｉ ) of the at least one power transmission set (2 ｉ ) is mounted (i) on a single support plate or (ii) between two parallel support plates. A rotary electrical contact assembly is characterized by this.

2. Each roller holder assembly (28 ｉ ) is rotatably attached around a shaft fixed to the housing (280), or includes a housing (280) that houses the roller or a pair of rollers and has two opposed openings (283, 284) from which the contact surfaces of the one roller or the pair of rollers protrude. The rotary electrical contact assembly according to claim 1, characterized in that it comprises the above.

3. Roller holder assembly (28 ｉ ), each roller (24 ｉ ), or a pair of rollers (24 ｉ ) is rotatably attached around the shaft (282) by a bearing (285), the rotary electric contact assembly (1) according to claim 1 or 2.

4. The at least one roller holder assembly includes pressure adjusting means (262) for adjusting the force F in cooperation with the at least one pressing device (26 ｉ ), characterized in that the rotary electrical contact assembly (1) according to any one of claims 1 to 3.

5. said at least one pressing device (26 ｉ ) has an elastic element (260) attached to the roller holder assembly for applying a force F to the roller or a pair of rollers, characterized in that the rotary electrical contact assembly (1) according to any one of claims 1 to 4.

6. For each roller of the at least one power transmission set, the contact surface of the roller and the contact surface of the corresponding electrode form a contact line L between the second axis and the contact surface of the roller and the contact surface of the corresponding electrode ｉ and the same angle α defined therebetween ｉ such that α ｉ has a value equal to the value of the angle at which the contact line L ｉ passes through the intersection of the first axis and the second axis, and optionally, for each roller (24 ｉ ), the value of α ｉ is 45° or less. The rotary electrical contact assembly (1) according to any one of claims 1 to 5

7. Each contact surface (200 ｉ , 220 ｉ , 240 ｉ ) is formed on the outer surface of the main body (202 ｉ , 222 ｉ , 242 ｉ ), and optionally, the main body is a ring-shaped main body (202 ｉ , 222 ｉ ) of an electrode, or a wheel-shaped main body (242 ｉ ) of a roller. The rotary electrical contact assembly (1) according to any one of claims 1 to 6, characterized in that.

8. The contact surface (240 ｉ of the roller) and at least one contact surface (200i, 220i, 240i) selected from the contact surfaces (200 ｉ , 220 ｉ ) of the corresponding electrodes are coated or plated with a material having a conductivity higher than that of the material of their bodies, characterized in that the rotary electrical contact assembly (1) according to claim 7.

9. The average roller diameter of each contact surface (240 ｉ ) of the roller is smaller than the average electrode diameter of the contact surface (200 ｉ , 220 ｉ ) of the corresponding electrode, and optionally, the ratio of the average roller diameter to the average electrode diameter of the corresponding electrode is 1:20 to 1:1, preferably 1:8 to 1:

4. The rotary electrical contact assembly (1) according to any one of claims 1 to 8 is characterized in that.

10. said at least one power transmission set (2 ｉ ) each roller holder assembly (28 ｉ ) has a pair of rollers (24 ｉ ), each roller having a ring-shaped angled conductive contact surface, and while the second electrode rotates about the first axis, the contact surfaces of both rollers rotate on the same contact surface of the corresponding first and second electrodes, or on two adjacent contact surfaces of the corresponding first and second electrodes, the rotary electrical contact assembly (1) according to any one of claims 1 to 9, characterized in that.

11. Further comprising a first electrical insulation support (40) and a second electrical insulation support (42), the first electrical insulation support (40) being rotatably mounted with respect to the first axis, each power transmission set (2 ｉ The first electrode (20 ｉ ) of ) is mounted on the first electrical insulation support (20), each power transmission set (2 ｉ The second electrode (22 ｉ ) of ) is mounted on the second electrical insulation support (42), optionally, the first electrical insulation support (40) and the second electrical insulation support (42) define a casing, characterized in that, the rotary electrical contact assembly (1) according to any one of claims 1 to 10.

12. Having two or more power transmission sets, wherein the first and second electrodes of one power transmission set (2i) are concentrically arranged with respect to the first and second electrodes of at least one other power transmission set, and the rollers of all the transmission sets have a second axis arranged in the same plane perpendicular to the first axis, and are mounted (i) on a single support plate (300') or (ii) on two support plates (300, 302). The rotary electrical contact assembly (1) according to any one of Claims 1 to 11, characterized in that.

13. Two or more power transmission sets (2 ｉ ) in which the first electrodes are arranged concentrically on the same first electrical insulating support perpendicular to the first axis, and two or more power transmission sets (2 ｉ ) in which the second electrodes are arranged concentrically on the same second electrical insulating support perpendicular to the first axis, the rotary electrical contact assembly (1) according to claim 12.

14. Each power transmission set (2 ｉ ), further includes at least one first electrical terminal (60 ｉ ) electrically connected to the contact surface (200 ｉ ) of the first electrode (20 ｉ ), and at least one second electrical terminal (62 ｉ ) electrically connected to the contact surface (220 ｉ ) of the second electrode (22 ｉ ), and the rotary electrical contact assembly (1) is suitable for conducting a current of at least 700 A, more preferably at least 1000 A, from the first electrical terminal (60 ｉ ) to the second electrical terminal (62i). The rotary electrical contact assembly (1) according to any one of claims 1 to 13, characterized in that.

15. Rotatably connected to an external power source, having an electromechanical machine (110), having the rotary electrical contact assembly (1) according to any one of Claims 1 to 14, wherein the second electrode of each power transmission set of the rotary electrical contact assembly is intended to be electrically connected to the external power source, and the first electrode of each power transmission set of the rotary electrical contact assembly is electrically connected to the electromechanical machine. A rotary system (100) characterized by that.

16. 1) Each electrode includes at least one ring-shaped angled conductive contact surface (200 ｉ , 220 ｉ ), the contact surfaces of the electrodes have the same first axis, and a first electrode (20 ｉ ) is rotatably mounted around the first axis, providing at least one power transmission set including the first electrode (20 ｉ ) and a second electrode (22 ｉ ). 2) (i) While the first electrode is rotating about the first axis, a ring-shaped angled conductive contact surface (240 ｉ , 220 ｉ ) adapted to roll on the corresponding contact surface (200 ｉ ) between the first and second electrodes, one roller (24 ｉ ) or a pair of rollers (24 ｉ ), (ii) a shaft (282) defining a second axis (A2) to which the roller (24 ｉ ) or a pair of rollers (24 ｉ ) is rotatably attached, (iii) at least one pressing device (26 ｉ ) for applying a force F along the shaft to the roller (24 ｉ ) or a pair of rollers (24 ｉ ), and (iv) providing at least one roller holder assembly (28 ｉ ) including a mounting element to each power transmission set (2 ｉ ), 3) (i) Providing a single support plate (300') having a thickness less than the minimum diameter of the contact surface of each roller, or (ii) providing two support plates (300, 302). 4) The second axis (A2) defined by the shaft is radial with respect to the first axis (A1), and the contact surface of the roller or pair of rollers projects from corresponding openings (304, 304') provided (i) within a single support plate or (ii) within two support plates, and the at least one pressing device (26 ｉ ) acts on the roller (24 ｉ ) or pair of rollers (24 ｉ ) with a force F in the first axis direction, such that at the position where the roller contact surface (240 ｉ ) of each roller is pressed against the contact surface (200 ｉ , 220 ｉ ) of the corresponding electrode, the at least one roller holder assembly (28 ｉ ) is mounted such that, by cooperation of the mounting element of the at least one roller holder assembly (28 ｉ ) and the mounting element of the corresponding support plate, the at least one roller holder assembly (28 ｉ ) is mounted (i) on a single support plate or (ii) between two support plates spaced apart by a distance less than the minimum diameter of the contact surface of each roller along the first axis, by mounting the at least one roller holder assembly (28 ｉ ) (i) on a single support plate (300') or (ii) on two support plates (300, 302). 5) When two support plates are provided, assembling the two support plates together so as to be parallel to each other. 6) (i) Mounting a single support plate or (ii) two support plates rotatably about a first axis. A method of assembling a rotary electrical contact assembly, comprising.

17. The step (2) of providing at least one roller holder assembly. (2a) Forming and / or machining the roller body into a wheel shape. (2b) Providing a contact surface on the roller body, for example by plating, to obtain a roller. (2c) assembling the roller or pair of rollers into the roller holder assembly by attaching the roller or pair of rollers to a shaft, attaching the pressure device, and optionally attaching the pressure adjustment means; (2d) setting the pressure by optionally adjusting the pressure adjustment means; A method of assembling a rotary electrical contact assembly according to claim 16, comprising:

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