Rotary electrical contact assembly

Abstract

The invention relates to a rolling electrical contact assembly (1) for transferring an electrical current between two relatively rotatable components, comprising at least one power transfer group comprising:-a first electrode (201, 202, 203, 204) and a second electrode (221, 222, 223, 224), each comprising an annular angled electrically conductive contact surface of the same first axis (A1), -at least one roller holder assembly (281) comprising a roller (241) or a pair of rollers, each roller comprising: an annular angled electrically conductive contact surface adapted to roll onto the respective contact surfaces of the first and second electrodes upon rotation of the first electrode, a shaft defining a second axis (A2), each roller (241) is rotatably mounted about the second axis (A2), and at least one pressing means exerting a force F on each roller along the axis. The rolling electrical contact assembly (1) further comprises one or two support members (300, 302) rotatably mounted in position about the first axis, where the second axis (A2) is radial with respect to the first axis (A1), and the contact surface of each roller protrudes from a hole provided in the support member, and the pressure applying 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 components. Background Art

[0002] Many applications require the delivery of electric current to rotating parts, among them machine parts, wind turbines, offshore high voltage swivels or ship pods. Ship pods are propulsion and steering modules used to move and guide a ship by means of propellers that can rotate freely relative to the ship and are driven by electric motors. The electric current supplied to the electric motors is generated inside the ship.

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

[0004] A common solution is a rotating electrical conductor comprising slip rings and brushes, wherein the slip rings or the brushes rotate and one or more sliding contacts are provided. However, in use, when there is no rotation for a long time and the position of the brushes is fixed relative to the slip rings, the current always flows through the same points. This causes serious problems for the surface of the rings (micro-pits and ghosting effects) and leads to an increase in the contact resistance and an increase in the temperature (self-feeding phenomenon). In addition, on the ring parts that are usually not in contact with the brushes, a surface coating may appear due to oxidation phenomena, which may be promoted by the environment, in particular the marine environment. When there is rotation again, the operation of the brushes is affected by changes in the roughness of the contact surface and the contact resistance, and over time, degradation of the brushes and rings occurs.

[0005] Another solution is a rotating electrical conductor comprising a roller bearing, but this solution suffers from the same drawbacks as the previous solution.

[0006] Another type of rotating electrical conductor consists of coaxial rolling rings. The rings, arranged in pairs, roll relative to each other. However, it is difficult to obtain the correct alignment of the rings during assembly, and the resulting electrical contact is uneven because the concentricity of the rings is limited. In addition, only one ring can be used per transmission layer, which means that multiple layers are required in the case of multiple transmissions, which increases the overall space requirements.

[0007] In another solution, a mercury swivel is used. This system has been known for decades. Usually, such swivel conductors are used for low power applications (rather reduced size). The main disadvantage is the use of hazardous materials, which are not compatible with marine or other external applications.

[0008] In another solution, gear assemblies are used. Gears allow the transfer of motion and the transmission of power, since at almost any time there is a tooth in contact with the corresponding part of the wheel. Planetary gears with a series of gears inserted into an external crown are often used in industry.

[0009] In another recent solution, a conical body rolling on a ring is used. In this solution, the conical body is enclosed between disks rotating relative to each other. Such rotating electrical conductors are disclosed, for example, in documents WO0201682A1, WO2021097502A1 and EP3195423B1.

[0010] WO0201682A1 discloses an electrical connector comprising two relatively rotatable members and a bearing assembly, the bearing assembly comprising a body, each body defining a first substantially conical conductive surface, the first substantially conical conductive surface being arranged to be in non-sliding electrical contact with the two members simultaneously in use, the arrangement being such that each body rotates around the conical axis of the body simultaneously with the relative rotation of the two members. Here, the body is arranged in a single-piece annular housing rotatably mounted on a rotating shaft supporting a rotatable member. No more than two bodies can be radially arranged in the housing, allowing no more than two power transmissions. Due to both the absence (or very low) of friction and permanent contact, this solution overcomes the shortcomings of standard sliding contacts. In this electrical conductor, the contact surface of the member is pressed against the contact surface of at least one body by a spring force applied in the direction of the axis of rotation of the rotatable member. However, manufacturing must be performed with very high precision to obtain a line contact formed between the contact surfaces, especially when a single body defines two different conductive surfaces. In practice, the formation of such a line contact may be interrupted by manufacturing tolerances and / or wear during operation.

[0011] In order to overcome this shortcoming, document WO2021097502A1 provides the following electrical connector, in which the angled contact surfaces of the rotatable member are free in the assembled state, so that their angular position can be changed relative to the angular position of the supporting part of the member. This is obtained by manufacturing the angled contact surface of the rotatable member in a thin metal plate (maximum thickness of 2mm). When the angled contact surface of the rotatable member is pressed against the angled contact surface of a rolling body by the spring force applied in the direction of the rotation axis of the member, the pressure tilts the angled contact surface of the rotatable member so that they coincide with the angled contact surface of the rolling body in the assembled state. This allows to ensure the formation of line contact between the contact surfaces. However, due to the low thickness of the angled contact surface of the rotatable member, the assembly cannot be used to transmit high currents. In this electrical connector, the rolling body is also arranged in an annular housing, and the installation of the annular housing is not described in detail. If multiple power transmissions are required, the arrangement requires the provision of multiple layers of rollers / members.

[0012] EP3195423B1 provides a rotating conductor of similar structure, which can be used to transmit high current in a stable and continuous manner. The document teaches that the contact surface is placed in rolling contact under high contact pressure to obtain very stable and effective current transmission. Continuous rolling contact under high pressure allows for a fine mechanical "cold forming" effect (plastic deformation), resulting in smoothing of the surface and an increase in surface hardness. Such pressure is obtained by arranging a spring element, which biases the angled contact surface of each rolling body in the plane of the radial axis around which the rolling body rotates in the direction of the rotation axis of the rotatable member. However, since the rolling body is fixed to the central axis around which the rotatable member rotates, when multiple transmissions are required, multiple layers of rolling bodies are required, which increases the size of the conductor in the axial direction. In addition, the assembly of each rolling body to the central axis is quite complicated. In addition, due to the structure of the member and the fixing of each rolling body to the central axis, the overall weight of the rotating conductor is quite high. Such weight may lead to a lack of stability during use.

[0013] Therefore, there remains a need for an improved rotating electrical conductor having a simple and compact structure allowing high current transfer. Summary of the invention

[0014] The present invention relates to a rolling electrical contact assembly for transmitting electric current between two relatively rotatable components having a specific arrangement of rollers. DETAILED DESCRIPTION

[0015] According to a first aspect, a rolling electrical contact assembly for transmitting electric current between two relatively rotatable parts is proposed, such an assembly comprising at least one power transmission group, the at least one power transmission group comprising:

[0016] - a first electrode and a second electrode, each electrode comprising at least one annular angled electrically conductive contact surface, the contact surfaces of the electrodes having a common first axis and the first electrode being rotatably mounted about said first axis.

[0017] The rolling electrical contact assembly is characterized by:

[0018] - said at least one power transmission group comprises at least one roller retainer assembly, said at least one roller retainer assembly comprising: (i) a roller or a pair of rollers, each roller comprising an annular angled conductive contact surface adapted to roll onto corresponding contact surfaces of the first electrode and the second electrode when the first electrode rotates about a first axis; (ii) an axis defining a second axis, said roller or a pair of rollers being rotatably mounted about the second axis; (iii) at least one pressure applying device, said at least one pressure applying device applying a force F on said roller or a pair of rollers along said axis; and (iv) a mounting element,

[0019] - the rolling electrical contact assembly further comprises: (i) a single support member (usually in the form of a plate) rotatably mounted about the first axis and having a thickness less than the minimum diameter of the contact surface of each roller, or (ii) two support members (usually in the form of a plate) rotatably mounted about the first axis and assembled to each other at a distance spaced apart along the first axis less than the minimum diameter of the contact surface of each roller, and

[0020] -Each roller retainer assembly of at least one power transmission group is mounted at a position (i) on a single supporting member or (ii) between two supporting members, wherein the second axis defined by the shaft is radial relative to the first axis, the contact surface of the roller or a pair of rollers extends from a corresponding hole provided in the supporting member, and the at least one pressure-applying device applies a force F to the roller or a pair of rollers in the direction of the first axis to push the roller contact surface of each roller onto the corresponding contact surface of the electrode, and the mounting element of each roller retainer assembly cooperates with the corresponding mounting element provided in the supporting member.

[0021] By providing a roller retainer assembly, the present invention allows pre-assembly of rollers and easier installation / disassembly of rollers in the rolling electrical contact assembly of the present invention, thereby improving the manufacturing process and reducing the duration of maintenance operations. In particular, the contact pressure of a roller or a pair of rollers in the roller retainer assembly can be accurately adjusted and applied to the transmission group. When multiple transmission groups are provided, appropriate contact pressure can be applied to each roller to enable rolling without slipping. In addition, the support member forms a subassembly with the roller retainer assembly, which can be easily installed / disassembled in the rolling electrical contact assembly of the present invention, thereby further improving the manufacturing process and reducing the duration of maintenance operations. The specific arrangement of the roller retainer assembly and the support member also facilitates the accurate installation of the roller on the support member, thereby achieving accurate installation of the roller relative to the electrode, thereby enabling the wear during operation to be reduced.

[0022] As described above, the single support member (usually in the form of a plate) has a thickness less than the minimum diameter of the contact surface of each roller, and once the roller retainer assembly is mounted on the single support member, the contact surface of each roller extends from both sides of the single support member.

[0023] Similarly, two support members (usually in the form of plates) are assembled to each other along the first axis at a distance less than the minimum diameter of the contact surface of each roller, and once the roller retainer assembly is mounted on the two support members, the contact surface of each roller protrudes from the two support members. In other words, the overall size of the assembled support members measured along the first axis is less than the minimum diameter of the contact surface of each roller.

[0024] In an embodiment, the mounting elements of the roller retainer assembly and the mounting elements of the support member may be nesting elements that allow very easy installation without the need for tools. These nesting elements may be male and female nesting elements, such as pins or rods or fingers or tabs or brackets that cooperate with holes or recesses or grooves or slots, or any other similar cooperating male / female elements. This embodiment is particularly advantageous in embodiments comprising two support members.

[0025] In another embodiment, the mounting elements of the roller retainer assemblies and the mounting elements of the support plate may include a pair of fixing lugs for each roller retainer assembly, each fixing lug being fixed to the support member and fixedly receiving one end of the shaft of the roller retainer assembly. Advantageously, the pair of fixing lugs are fixed to the same face of the support member. The fixing lugs of all roller retainer assemblies may be fixed on the same side of the support member or on opposite sides thereof. This embodiment is particularly advantageous in embodiments comprising a single support member.

[0026] In an embodiment comprising two support members, the support members may be assembled to each other by means of spacers for ease of installation.

[0027] In an embodiment comprising two support members, the support members may be parallel support plates.The subassembly formed by the roller retainer assembly mounted on the support members is then formed in a simple manner without increased weight compared to a solution in which the rollers are fixed directly to the first axis.

[0028] In conjunction with any of the previously described embodiments, each roller retainer assembly may comprise a housing housing the roller or pair of rollers rotatably mounted about the shaft fixed to the housing, the housing having two opposing holes through which the contact surface of the roller or pair of rollers protrudes. These opposing holes are thus open along the first axis. Such a housing may protect the roller and its rotatable mounting on the shaft from dust and may also facilitate mounting of the at least one pressure applying device.

[0029] In an embodiment, in combination with or without any of the foregoing embodiments, for smooth rotation, each roller or a pair of rollers of the roller retainer assembly can be rotatably mounted around an axis by means of a bearing. Such bearings can be selected from rolling element bearings, sliding bearings and fluid bearings. Rolling element bearings contain rolling elements in the shape of a sphere, cylinder, needle or truncated cone. Preferred rolling element bearings are angular ball bearings. In particular, such angular ball bearings can improve the rotational stability of the rollers by accommodating the combined loads applied to the rollers, i.e., radial and axial loads acting simultaneously. Sliding bearings are also named "sliding contact bearings" or "sliding bearings" and generally include a bearing surface without rolling elements. Such sliding bearings can be integral with the rollers, or can be bushings inserted into the rollers and having a bearing surface of the shaft accommodating the rollers. Preferred sliding bearings include a Bushings made of. Sliding bearings are cheap, compact and lightweight. Fluid bearings such as hydrostatic bearings or hydrodynamic bearings rely on pressurized gas or liquid to carry loads and eliminate friction. In fluid bearings, stationary and rotating surfaces are separated by a thin film of lubricant such as oil, air, water or process fluid. In hydrodynamic fluid film bearings, when lubricant is introduced into the converging geometry between the surfaces, a film pressure is generated by the relative motion (rotation) of the surfaces, which separates the surfaces. In hydrostatic bearings, the fluid is pressurized externally by a pump. Fluid bearings can improve the contact between the rollers and the corresponding electrodes.

[0030] In an embodiment, in combination with or without any of the foregoing embodiments, the at least one roller retainer assembly may include a pressure regulating device cooperating with the at least one pressure applying device to regulate the force F. The force F can then be adjusted to a predetermined value, which can be selected to optimize the contact between the contact surfaces. Such a force F is for example adjusted between 10N and 200N, preferably between 30N and 60N, or between any two of the foregoing values. The pressure regulating device may for example be suitable for regulating the length of an elastic device such as a spring, in particular a compression spring. The pressure regulating device may for example include a nut screwed onto a threaded portion of the shaft.

[0031] In an embodiment, in combination or not with any of the preceding embodiments, the at least one pressure applying means may comprise an elastic element mounted on the roller retainer assembly to apply a force F on the roller or pair of rollers of the roller retainer assembly. Such an elastic element may be, for example, a compression spring mounted around an axis.

[0032] In an embodiment, in combination with or without any of the preceding embodiments, for each roller of the at least one power transmission group, the contact surface of the roller and the corresponding contact surface of the electrode may have the same angle α i , the angle αi A contact line L is defined between the second axis and formed between the contact surface of the roller and the corresponding contact surface of the electrode. i Between, and α i The value is equal to the contact line L i The value of the angle passing through the intersection point between the first axis and the second axis.

[0033] Such α i The value of in combination with a pressure applying means urging the rollers radially in the direction of the first axis provides a stable electrical contact with limited slip and reduced wear sensitivity of both rollers and electrodes, thereby allowing extended maintenance intervals, as well as reduced electrical contact resistance to reduce electrical losses.

[0034] In an embodiment, in combination or without any of the preceding embodiments, for each roller, α i The value of may be equal to or less than 45°, preferably equal to or less than 35° or 25°, most preferably equal to or less than 15°, typically between 5° and 20°. Such an angle allows to obtain a compact assembly in the direction of the first axis.

[0035] In an embodiment, in combination with or without any of the foregoing embodiments, each contact surface may be formed on the outer surface of a body, and optionally, the body is an annular body of an electrode or a wheel-shaped body of a roller. Such an arrangement of an electrode body or a roller body enables weight reduction relative to a body in the form of a disc. In an annular body or a wheel-shaped body, the amount of material can be limited to that necessary to manufacture the contact surface.

[0036] In particular, at least one contact surface, optionally both contact surfaces, selected from the contact surface of the roller and the corresponding contact surface of the electrode can be plated or coated with a material having a higher conductivity than the material of its body. This makes it possible to reduce the overall cost of the body by using high conductivity materials only at locations where electrical transmission is required. The coating material or plating material can be selected from silver, gold and high conductivity copper alloys. By way of example, the coating can be performed by electrolytic deposition or by spraying of a molten alloy or by applying a resin filled with a conductive powder. The conductive metal plate can also be brazed on the surface.

[0037] In an embodiment, in combination with or without any of the foregoing embodiments, the rolling electrical contact assembly of the present invention may further include a conductive grease between the contact surface of the roller and the corresponding contact surface of the electrode. The use of the grease enables the reduction of mechanical wear, thereby improving contact stability, while the conductivity of the grease allows the electrical resistance between the contact surfaces to be limited.

[0038] In an embodiment, in combination or not with any of the foregoing embodiments, each contact surface of the roller may have a roller average diameter that is smaller than the electrode average diameter of the corresponding contact surface of the electrode, optionally with a ratio of the roller average diameter to the corresponding electrode average diameter of 1:20 to 1:1, preferably 1:8 to 1:4. Such an arrangement allows a compact assembly to be provided in the direction of the first axis.

[0039] In an embodiment, in combination with or without any of the foregoing embodiments, each roller retainer assembly of the at least one power transmission group may include a pair of rollers, wherein each roller includes an annular angled conductive contact surface, and when the second electrode rotates about the first axis, the contact surfaces of the two rollers roll onto the same corresponding contact surface of the first electrode and the second electrode or roll onto two adjacent corresponding contact surfaces of the first electrode and the second electrode. By providing two rolling contact surfaces for the same pair of first and second electrodes, higher currents can be transmitted with reduced electrical losses relative to the case of adding a single contact surface of the roller.

[0040] In an embodiment, in combination with or without any of the foregoing embodiments, the rolling electrical contact assembly of the present invention may also include a first electrically insulating support and a second electrically insulating support, the first electrically insulating support being rotatably mounted relative to the first axis, the first electrode of each power transmission group being mounted on the first electrically insulating support, and the second electrode of each power transmission group being mounted on the second electrically insulating support, and optionally, the first electrically insulating support and the second electrically insulating support defining a housing. Such an arrangement provides a compact assembly that is easy to install. The electrically insulating support may have a conical shape with its apex facing the support member of the roller, or may preferably be a parallel plate.

[0041] In an embodiment, in combination with or without any of the foregoing embodiments, the rolling electrical contact assembly of the present invention may include two or more power transmission groups, wherein the first electrode, the corresponding second electrode of one power transmission group are arranged concentrically relative to the first electrode, the corresponding second electrode of at least one other power transmission group, and the second axes of the rollers of all transmission groups are arranged in the same plane perpendicular to the first axis and the rollers of all transmission groups are mounted on (i) a single support member or (ii) two support members. Such an arrangement allows the rolling electrical contact assembly to be compact in the direction of the first axis, thereby allowing two or more different current and / or signal transmissions, and with a reduced number of pieces, because, for example, the first electrode can be fixed to the same first electrically insulating support and the second electrode can be fixed to the same second electrically insulating support.

[0042] When the rollers of different power transmission groups have very different sizes (especially different diameters), the electrically insulating support on which the electrodes are concentrically arranged can have a conical shape, the apex of which is facing the supporting member of the roller, or can be parallel plates (the size of the body of the electrode along the first axis can then vary). When the rollers of different power transmission groups have similar sizes (especially rollers of the same or similar diameter), the electrically insulating support on which the electrodes are concentrically arranged can be parallel plates. In any embodiment, in order to reduce the weight of the rolling electrical contact assembly of the present invention and reduce its overall height, and also for easier manufacturing, the electrically insulating support on which the electrodes are mounted can be parallel plates.

[0043] In an embodiment, in combination or without any of the preceding embodiments, the first electrodes of two or more power transmission groups may be concentrically arranged on the same first electrically insulating support perpendicular to the first axis, and the second electrodes of two or more power transmission groups may be concentrically arranged on the same second electrically insulating support perpendicular to the first axis.

[0044] In an embodiment, in combination or without any of the foregoing embodiments, each power transmission group may further include at least a first electrical terminal electrically connected to the contact surface of the first electrode and at least a second electrical terminal electrically connected to the contact surface of the second electrode, and the rolling electrical contact assembly may be adapted to conduct a current of at least 700A, more preferably at least 1000A, from the first electrical terminal to the second electrical terminal. For example, for a copper electrode and about 2 mm 2 The contact surface area at 70N / mm 2 Up to 80N / mm 2 Currents up to 700A are measured via four rollers at a contact pressure of 1.38°.

[0045] The maximum current allowed to pass through a transmission group can be determined by a person skilled in the art through calculation / experiments based on: the area of ​​the contact surface (depending on the number of rollers and the width of the contact surface), the resistance of the material of the contact surface, the contact resistance between the contact surfaces (which depends on the pressure applied by the pressure-applying device and the material used), the roughness of the contact surfaces, the final grease present between the surfaces, etc.

[0046] The rolling electrical contact assembly according to the present invention can be used in a ship nacelle, a wind turbine, an offshore installation such as a floating production storage and offloading vessel (FPSO) or an offshore floating structure ("float") for a wind turbine, or in a machine component such as, but not limited to, a part of a welding machine or a part of a pyrolysis furnace. The rotating conductor can also be used to transmit electrical signals from one contact surface to another contact surface at data rates up to 1 Gb / s and higher.

[0047] According to a second aspect, a rotating system for being rotatably connected to an external power source is proposed, the rotating system comprising a motor, characterized in that the rotating system also comprises a rolling electrical contact assembly according to the present invention, wherein the second electrode of each power transmission group of the rolling electrical contact assembly is intended to be electrically connected to the external power source, and the first electrode of each power transmission group of the rolling electrical contact assembly is electrically connected to the motor.

[0048] According to a third aspect, in a first embodiment, a method for assembling a rolling electrical contact assembly, in particular a rolling electrical contact assembly as disclosed above, is disclosed, such method comprising:

[0049] 1) providing at least one power transmission group comprising a first electrode and a second electrode, each electrode comprising at least one annular angled conductive contact surface, the contact surfaces of the electrodes having a common first axis, and the first electrode being rotatably mounted about said first axis,

[0050] 2) at least one roller retainer assembly is provided for each power transmission group, the at least one roller retainer assembly comprising: (i) a roller or a pair of rollers, each roller comprising an annular angled conductive contact surface adapted to roll onto corresponding contact surfaces of the first electrode and the second electrode when the first electrode rotates about a first axis; (ii) an axis defining a second axis, the roller or the pair of rollers being rotatably mounted about the second axis; (iii) at least one pressure applying device, the at least one pressure applying device applying a force F on the roller or the pair of rollers along the axis; and (iv) a mounting element,

[0051] 3) providing a single support member (usually in the form of a plate) having a thickness less than the smallest diameter of the contact surface of each roller,

[0052] 4) mounting the at least one roller retainer assembly to a single support member by cooperation of the mounting elements of the at least one roller retainer assembly with corresponding mounting elements of the single support member, each roller retainer assembly being mounted at a position on the single support member, wherein the second axis defined by the shaft is radial relative to the first axis, the contact surfaces of the roller or a pair of rollers protrude from corresponding holes provided in the single support member, and the at least one pressure applying device applies a force F on the roller or a pair of rollers in the direction of the first axis to push the roller contact surface of each roller onto the corresponding contact surface of the electrode,

[0053] 5) A single support member is rotatably mounted about a first axis.

[0054] According to a third aspect, in a second embodiment, a method for assembling a rolling electrical contact assembly, in particular a rolling electrical contact assembly as disclosed above, is disclosed, such method comprising:

[0055] 1) providing at least one power transmission group comprising a first electrode and a second electrode, each electrode comprising at least one annular angled conductive contact surface, the contact surfaces of the electrodes having a common first axis, and the first electrode being rotatably mounted about said first axis,

[0056] 2) at least one roller retainer assembly is provided for each power transmission group, the at least one roller retainer assembly comprising: (i) a roller or a pair of rollers, each roller comprising an annular angled conductive contact surface adapted to roll onto corresponding contact surfaces of the first electrode and the second electrode when the first electrode rotates about a first axis; (ii) an axis defining a second axis, the roller or the pair of rollers being rotatably mounted about the second axis; (iii) at least one pressure applying device, the at least one pressure applying device applying a force F on the roller or the pair of rollers along the axis; and (iv) a mounting element,

[0057] 3) providing two supporting members, in particular two supporting plates,

[0058] 4) mounting said at least one roller retainer assembly to a support member by cooperation of a mounting element of said at least one roller retainer assembly with a corresponding mounting element of the support member, each roller retainer assembly being mounted at a suitable position between two support members spaced apart along said first axis by a distance less than a minimum diameter of a contact surface of each roller, wherein a second axis defined by the shaft is radial relative to the first axis, the contact surfaces of said roller or a pair of rollers protrude from corresponding holes provided in the support member, and said at least one pressure applying device applies a force F on said roller or a pair of rollers in the direction of the first axis to push the roller contact surface of each roller onto said corresponding contact surface of the electrode,

[0059] 5) Assembling two supporting members, in particular two parallel supporting plates, to each other,

[0060] 6) The two support members are rotatably mounted around a first axis, in particular the assembled support members.

[0061] In both embodiments, a very easy and fast installation of the rolling electrical contact assembly can then be obtained, allowing easy maintenance.

[0062] In any of the preceding embodiments, the step of providing at least one roller retainer assembly may include:

[0063] (2a) molding and / or machining a roller body having a wheel shape,

[0064] (2b) providing a contact surface on the roller body, for example by plating, to obtain a roller,

[0065] (2c) assembling the roller or pair of rollers into a roller retainer assembly by mounting the roller or pair of rollers on a shaft and mounting a pressure device and optionally a pressure adjustment device,

[0066] (2d) Optionally, the pressure is set by adjusting a pressure regulating device. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The invention is explained with the help of examples showing possible embodiments of the invention.

[0068] Figure 1 A perspective view showing an embodiment of a rolling electrical contact assembly according to the present invention.

[0069] Figure 2 yes Figure 1 A perspective cross-sectional view of a contact assembly.

[0070] Figure 3 is a perspective cross-sectional view of an embodiment of a roller bearing assembly.

[0071] Figure 4 is a simplified cross section showing the contact surface between the electrode and the roller.

[0072] Figure 5 is a perspective view of an embodiment of a second portion of the housing housing a second electrode.

[0073] Figure 6 is a perspective view of an embodiment of a first portion of a housing housing a first electrode.

[0074] Figure 7 is a perspective view of an embodiment of a roller retainer assembly to be mounted on two support members.

[0075] Figure 8 is a perspective view (partially shown in section) of another embodiment of a roller retainer assembly mounted on a single mounting member.

[0076] In the following description, the same reference numerals are used to designate the same or similar elements.

[0077] Figures 1 to 5 1 shows an embodiment of a rolling electrical contact assembly 1 comprising a plurality of power transmission groups, here four, referenced as 2 i, where i = 1, 2, 3, 4. In the following description, "i" refers to the number of the power transmission group and is marked as 12 i The reference numerals (i=1, 2, 3 or 4 in the example) indicate the element designated by reference numeral 12 and belong to the i-th power transmission group. However, the present invention is not limited to a specific number i of power transmission groups, and other rolling electrical contact assemblies with one, two, three, five, six or more power transmission groups can be envisaged. In other words, i is a non-empty integer, and preferably 1≤i≤8.

[0078] Each power transmission group 2 i The first electrode 20 includes i and the second electrode 22 i and at least one roller 24 i The first electrode 20 i and the second electrode 22 i The second electrode 22 is a circular electrode having the same central axis A1 when assembled. i is a static electrode, and the first electrode 20 i Mounted rotatably about a central axis A1.

[0079] Each electrode 20 i ,twenty two i The conductive contact surface 200 includes at least one annular angled conductive contact surface 200 i , 220 i Preferably, it is a single annular angled contact surface, as shown in the drawings. The annular contact surface 200 of the electrode i , 220 i When assembled, they have the same symmetry axis, which is also named as the "first axis" in the present invention and corresponds to the central axis A1 here. In other words, the contact surface 200 i , 220 i is a frustoconical surface.

[0080] Each roller 24 i The conductive contact surface 240 is mounted about a second axis A2 which is radial (perpendicular) to the first axis A1 and includes an annular angled conductive contact surface 240. i , the conductive contact surface 240 i Suitable for the first electrode 20 i When rotating around the first axis A1, the first electrode and the second electrode roll to the corresponding contact surface 200 i , 220 i In other words, roller 24 iRolling on two opposite tracks formed by the corresponding contact surfaces of the first electrode and the second electrode of the power transmission group. In the present invention, when the contact surfaces belong to the same power transmission group, they are said to be corresponding. Therefore, the contact surface 240 i It is also a frustoconical surface.

[0081] Finally, the power transmission group 2 i including at least one roller 24 i At least one pressure-exerting device 26 (usually one or two) associated and exerting a force F along the second axis A2 in the direction of the first axis A1 i The pressure device 26 i The roller contact surface 240 is suitable for i Push onto the corresponding contact surface 200 of the electrode i , 220 i In the assembly 1 shown in the attached drawings, each power transmission group 2 i With four rollers 24 i However, the present invention is not limited to each power transmission group 2 i A specific number of rollers, the number of which may vary depending on the size of the electrode. Preferably, the power transmission group 2 i A plurality of rollers (two or more) are provided, advantageously regularly arranged around the first axis A1 , in order to balance the overall weight.

[0082] like Figure 4 As more clearly shown in FIG. 2 , for the same power transmission group 2 i Each roller 24 i , the contact surface of the roller is 240 i and the corresponding contact surface 200 of the electrode i , 220 i have the same angle α i , the angle α i A contact line L defined between the second axis A2 and the contact surface of the roller and the corresponding contact surface of the electrode is formed. i between.

[0083] like Figure 4 As shown, in a preferred embodiment, for the power transmission group 2 i Each roller, α i The value is equal to the contact line L i The value of the angle passing through the intersection O between the first axis A1 and the second axis A2. This rule applies to all power transmission groups.

[0084] In other words, the same power transmission group 2 i Roller 24 i The contact surface is at an angle αi The same value of angle is formed, and the angle value varies between different power transmission groups. Figure 4 As can be seen above, for different power transmission groups 2 i The roller with the largest radius is the power transmission group 2 farthest from the first axis A1. 4 The contact surface is at an angle α 4 The angle α 4 Angle α of the contact surface of the next power transmission group smaller than the first axis A1 direction i , and the power transmission group 2 closest to the first axis 1 The angle α with the maximum value 1 Therefore, α 4 <α 3 <α 2 <α 1 .

[0085] In other words, in this preferred embodiment, each roller contact surface 240 i Form a with equal to 2×α i The apex of the truncated cone is the intersection point O between the axis of the truncated cone (the second axis A2) and the first axis A1. i The definition of is such that the roller can roll without slipping. For proper stability operation, α i It should preferably be up to 45°, preferably up to 25°, and more preferably below 15°.

[0086] In another embodiment, all power transmission groups 2 i Roller 24 i The contact surface is at an angle α as defined above. i The same value of the angle is formed. This means that the power transmission groups 2 from different i The rollers have different radii. Then different power transmission groups 2 i The contact surfaces of the electrodes follow the same imaginary conical form, thereby increasing the overall height. This means providing electrodes with bodies of different heights (measured along the first axis) supported on a plate support perpendicular to the first axis, or providing electrodes with bodies of the same height supported on a conical support.

[0087] Regardless of the embodiment, the corresponding angled contact surface 200 i , 220 i , 240 i Usually, each is formed on the main body 202 i ,222 i , 242i on the outer surface of, as shown in the accompanying drawings. Advantageously, Figures 4 to 6 As best seen above, the first electrode 20 i and the second electrode 22 i A main body 202 having a ring shape i ,222 i , and roller 24 i Having a wheel-shaped body 242 i (See Figure 3 , Figure 4 , Figures 7 and 8 ). The annular main body 202 i ,222 i and wheel-shaped body 242 i Both have a frustoconical outer surface on which a contact surface 200 is formed. i , 220 i , 240 i These frustoconical outer surfaces, more particularly the (frustoconical) contact surfaces formed thereon, each have an average diameter which can be defined as the average of their largest diameter and their smallest diameter.

[0088] The ratio of the roller mean diameter to the corresponding electrode mean diameter may be from 1:20 to 1:1, preferably from 1:20 to 3:4, most preferably from 1:8 to 1:4 or any ratio within the aforementioned limits.

[0089] By way of example, the following dimensions may be envisaged:

[0090] - the average diameter of the electrode contact surface is between 100 mm and 640 mm, preferably between 200 mm and 400 mm,

[0091] - The average roller contact surface diameter is between 10 mm and 100 mm.

[0092] Typically, in the rolling electrical contact assembly of the present invention, the average diameter of the contact surface of all rollers is similar or the same to limit the overall height. However, other configurations may be contemplated.

[0093] Roller body 242 i The roller body is usually made of metal, preferably copper or a copper alloy (which may contain, for example, zirconium or zinc for mechanical properties). The roller body usually has a contact surface 240 as follows i , the contact surface 240 i The plated or coated layer is made of a conductive metal having a higher conductivity than the metal of the body, such as silver, gold and a highly conductive copper alloy, preferably silver or a copper alloy (eg containing about 1% to 3% silver).

[0094] In the present invention, as shown in the accompanying drawings, each roller 24i Pre-installed to the roller retainer assembly 28 i In. Figure 7 As best seen above, in one embodiment, each roller retainer assembly 28 i The housing 280 contains a roller 24 rotatably mounted about an axis 282 fixed to the housing 280. i The housing 280 has two opposite holes 283 and 284, and the roller 24 i Contact surface 240 i Protrudes through the two opposing holes 283 , 284 .

[0095] like Figure 7 As can be seen from the figure, the housing 280 can be simply made of a tubular element with a rectangular cross section, and the roller 24 i More specifically, the roller body 242 i Therefore, the dimension of the housing 280 from one hole 283 to the other hole 284 (ie, the height of the tubular element along the first axis A1 when the housing is installed in the assembly 1) is smaller than the contact surface 240 of the roller. i to avoid any interference of the housing with the respective contact surfaces of the first electrode and the second electrode.

[0096] Roller 24 i It is mounted on the shaft 282 by means of a bearing 285, here an angular ball bearing 285, arranged to support loads applied on the frustoconical outer surface of the roller body. However, other rolling element bearings or other bearings such as sliding bearings or fluid bearings are also possible.

[0097] Here, the pressure device 26 i Includes roller or roller retainer assembly 28 i The elastic element 260 exerts a force F on the housing 280. The roller retainer assembly 28 i This embodiment further includes a pressure regulating device 262 to adjust the force F.

[0098] In the present invention, as shown, the pressure applying device 26 i Roller retainer assembly 28 iHere, the elastic element 260 is a compression spring arranged between one end 282a of the shaft 282 and the housing 280, and the adjusting device 262 includes a nut 263 screwed on the end 282b of the threaded portion of the shaft. More specifically, as shown, the shaft 282 passes through the housing 280 from one side to the other side. On one side of the housing 280, the elastic element 260 is placed around the shaft 282 and one side abuts against a stop plate 286 near the first end 282a of the shaft 282, and the other side abuts against the housing 280 or against the end of a sleeve 288 inserted into the housing 280 and accommodating the shaft 282. On the opposite side of the housing 280, the end 282b of the shaft 282 has a threaded portion on which the nut 263 is screwed. Therefore, by tightening the nut 263 more or less on the threaded portion of the shaft, the length of the elastic element 260 can be adjusted, and thus the force F applied to the housing 280, and thus the force F applied along the roller along the second axis.

[0099] exist Figure 7 The housing 280 shown in FIG. 1 is sized to accommodate a single roller body 242 rotatably mounted on an axle 282. i In another embodiment not shown, the housing 280 may be sized to accommodate two roller bodies 242 rotatably mounted on the same shaft 282. i , the two roller bodies 242 i For example, they are separated by elastic elements such as elastic washers. In such a case, the contact surfaces of the two rollers cooperate with the same contact surface of the first electrode and the second electrode or with adjacent contact surfaces of the first electrode and the second electrode. In the latter case, each of the first electrode and the second electrode can therefore have two different but electrically connected adjacent contact surfaces.

[0100] Roller retainer assembly 28 i Also included are mounting elements adapted to engage on the support member. Here, these mounting elements include two pins 289, 290 extending perpendicularly to the second axis of the roller. Such mounting elements are, for example, fixed to the shaft 282 so as to rotatably support the roller (or a pair of rollers) at the opposite ends of the shaft 282. In the embodiment shown, one of the mounting elements 290 forms the nut 263 of the pressure regulating device.

[0101] It should be noted that even if the housing 280 is omitted, the pressure applying device 26 is provided. i In other words, the roller retainer assembly 28 i It may include a shaft 282, a roller 24 i (or a pair of rollers) are preferably rotatably mounted about the shaft 282 by means of the aforementioned bearing 285 and optionally a sleeve 288. Optionally, the roller retainer assembly 28 iA pressure regulating device 262 and / or a housing 280 may also be included.

[0102] It is worth noting that the roller retainer assembly 28 i Can be standardized, that is to say, the same housing can be used for roller bodies of different sizes and different pressure values.In addition, the pressure can be adjusted before the roller retainer assembly is assembled into the rolling contact assembly.

[0103] By way of example, by using a roller with an outer radius between 26 mm and 28 mm, a force F between 30 N and 60 N can be obtained, resulting in a contact pressure between 9 MPa and 20 MPa. If the radius of the roller is increased, the force also needs to be increased to ensure rolling without slipping. This can be done simply with the help of a pressure regulating device.

[0104] In the present invention, as shown in the drawings, each roller retainer assembly 28 i It is not directly mounted on the first axis A1 but supported by the roller support assembly 30, such as Figure 2 and Figure 3 In the embodiment represented in these figures, the roller bearing assembly 30 comprises two bearing members 300, 302 which are rotatably mounted about a first axis A1 and are assembled to each other along the first axis at a distance less than the minimum diameter of the contact surface of each roller. i Each roller retainer assembly 28 i The rollers 24 are engaged between these support members 300, 302. To this end, each support member 300, 302 is provided with a hole 304, and each roller 24 i Contact surface 240 i The contact surface 240 extends through the hole 304 so that the contact surface 240 i Thus, as shown in the drawings, the overall size of the assembled support members 300, 302 measured along the first axis A1 is smaller than the minimum diameter of the contact surface of each roller, and once the roller retainer assembly 28 is assembled, the roller retainer assembly 28 is assembled. i Mounted on two support members, the contact surface of each roller projects from the two support members.

[0105] In the embodiment shown, the support members 300, 302 are plates, 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 can be assembled with each other at the above distance along the first axis.

[0106] The support members 300, 302 are typically made of an electrically insulating material (or a material covered or plated with an electrically insulating material), such as a polymer. These support members 300, 302 (here in the form of discs) form a base support for all rollers and are easily adjustable according to the number / size of rollers.

[0107] The mounting elements of the roller retainer assemblies cooperate with corresponding mounting elements provided in the support members 300, 302. In the illustrated embodiment, the pins 289, 290 of each roller retainer assembly nest within slots 305, 306 provided in the support plates (see FIG. Figure 3 ). The present invention is not limited to such mounting elements. For example, the housing 280 (its edges) may be directly engaged and nested within a slot or groove of a support member. In other words, the mounting element may be formed within the housing 280 or may be a part thereof.

[0108] exist Figure 8 In another embodiment shown, a single support member 300' may be used to support the roller retainer assembly 28. i Such a single support member 300' is usually in the form of a plate having a thickness less than the smallest diameter of the contact surface of each roller, such as Figure 8 Part shown. Figure 8 In the illustrated embodiment, the roller retainer assembly 28 i Similar to reference Figure 7 The illustrated embodiment depicts the roller retainer assembly 28. i , and differs from it mainly in the mounting elements. Figure 8 In the present invention, the same components are designated by the same reference numerals, and reference is made to the above description for more details.

[0109] exist Figure 8 In the embodiment, the mounting element includes each roller retainer assembly 28 iA pair of fixing lugs 289' and 290'. Each fixing lug 289', 290' is fixed to a single support member 300' and to the shaft 282 of the roller retainer assembly. In the example shown, each fixing lug has an "L" shape. However, the present invention is not limited to a specific form of the fixing lug, as long as each lug can be fixed to a single support member 300' and fixed to one end of the shaft 282. In the example shown, each fixing lug includes two holes 289'a, 289'b; 290'a, 290'b: a first hole 289'a, 290'a; a second hole 289'b, 290'b for accommodating the shaft 282. The third hole 289'c, 290'c can be configured to introduce a pin or screw (not shown) to fix the shaft 282 to the fixing lugs 289', 290'. Alternatively or in combination, one element selected from among the shaft 282 and the single support member 300 ′ may be welded to the fixing tab.

[0110] Therefore, as shown in the figure, once the roller retainer assembly 28 i Mounted on a single support member, the contact surface of each roller protrudes from both sides of the single support member 300'.

[0111] As in the embodiment with two support members, here a single support member 300' is provided with holes 304', each roller 24 on both sides of the single support member 300' i Contact surface 240 i The roller retainer assembly 28 may extend through the hole 304'. i The fixing to the single supporting member 300 ′ may be on the same side of the single supporting member 300 ′ or on both sides of the single supporting member 300 ′.

[0112] As in the embodiment including two support members, each roller retainer assembly 28 i The housing 280 and / or the pressure regulating device 262' may or may not be included to adjust the force F. In this embodiment, a simple nut 263' mounted on the threaded portion of the end 282b of the shaft 282 may be used as the pressure regulating device 262', where the nut is arranged between the fixing tab 290' and the housing 280. Figure 8 In the example shown, the stop plate 286 is distinct from the fixing tab 289'. Alternatively, the stop plate 286 may be integral with the fixing tab 289'.

[0113] As previously mentioned, the support members 300, 302, 300' are rotatably mounted about the first axis A1, for example by means of bearings 308, thereby allowing the support members 300, 302, 300' to rotate when the rollers rotate on the electrodes. Figures 1 to 3 and Figure 7 In the embodiment shown, the support members 300, 302 are rotatably mounted to the central hub 70 of the rolling electrical contact assembly. The central hub 70 thus defines a first axis A1. Figure 8 The single support member 300' described may be similarly mounted.

[0114] The support members 300, 302 are assembled to each other, for example, by means of a spacer 310 extending between the support members to ensure that the support members 300, 302 are spaced apart from each other by the above distance and are screwed or otherwise fixed to each support member. A rigid and strong roller support assembly 30 is then obtained. Similarly, a rigid and strong roller support assembly 30 is also obtained using a single support member 300'.

[0115] The roller bearing assembly 30 is therefore relatively easy to design and install because the plurality of roller retainer assemblies 28 i The free position that can be located on the support member 300' and partly between the support members 300, 302. As shown in the embodiment shown in the drawings, four power transmission groups 2 are provided. i Each set includes four roller retainer assemblies 28 i .

[0116] The distance between the support members 300, 302 can allow an operator to perform maintenance on the roller support assembly 30 (e.g., adding more grease to the contact surface of the rollers and / or adjusting the pressure of each roller retainer assembly), for example, via a trapdoor 53 described below. Such maintenance can be simplified when a single support member 300' is provided.

[0117] like Figure 5 and Figure 6 As more clearly shown in FIG. 1 , the rolling electrical contact assembly 1 also includes a power transmission group 2 mounted thereon. i The first electrode 20 i The first electrical insulating support 40 and each power transmission group 2 are mounted thereon i The second electrode 22 i The first electrically insulating support 40 is rotatably mounted relative to the first axis A1. In the illustrated embodiment, the first electrically insulating support 40 and the second electrically insulating support 42 are respectively fixed, for example, screwed, to the first component 51 and the second component 52 of the housing 50. Therefore, the first component 51 is rotatably mounted relative to the first axis A1 and can rotate around the axis, while the second component 52 cannot rotate around the first axis A1.

[0118] Alternatively, the first electrically isolating support 40 and the second electrically insulating support 42 may define the housing 50. For example, the first electrically isolating support 40 and the first part 51 of the housing may be made of the first part without joining and assembling, and the second electrically insulating support 42 and the second part 52 of the housing may be made of the second part without joining and assembling.

[0119] In the illustrated embodiment, the housing 50 is provided with a shutter 53 to provide access to the roller bearing assembly 30 .

[0120] The two parts 51, 52 of the housing 50 are assembled to close the housing while allowing the first part 51 to rotate relative to the second part 52. Preferably, the housing 50 is closed in a watertight manner, for example by using suitable sealing joints between the two parts 51, 52, in particular when used in a corrosive environment, such as a marine environment.

[0121] In the illustrated embodiment, the first support 40 and the first part 51 of the housing are fixedly mounted on the central hub 70, which is a rotating part around the first axis A1, while the second support 42 and the second part 52 of the housing are fixed parts, and the central hub 70 can rotate in the fixed part via the bearing 54. However, the present invention is not limited to this arrangement as long as the first support 40 rotates around the first axis A1 and the second support 42 is a fixed part. The tightly closed housing 80 (see Figure 2 ) can be fixed to the second part 52 of the housing to surround the bearing 54 and partially surround the outer surface of the second part 52 and the central hub 70 and the electrical connector 62 described below i and its wiring.

[0122] As shown in the figure, when two or more power transmission groups 2 are set i When a power transmission group 2 i The first electrode 20 i and the second electrode 22 i Relative to other power transmission groups 2 i The first electrode and the second electrode are arranged concentrically, here in the same plane perpendicular to the first axis A1. The space between the concentric electrodes will be large enough to avoid any electrical contact between the electrodes. Optionally, an electrically insulating material can be provided between the annular electrodes. In the embodiment shown, the first electrode 20 i The second electrode 22 is concentrically arranged on the first electrically insulating support 40 and i Concentrically arranged on a second electrically insulating support 42. Here, the two electrically insulating supports 40, 42 are in the form of plates, perpendicular to the first axis and therefore parallel to each other, which enables a compact configuration along the first axis. As already explained, other configurations (conical forms) are conceivable.

[0123] With such a concentric arrangement of electrodes, all transmission groups 2 i Roller 24 i has a second axis A2 arranged in the same plane perpendicular to the first axis A1. i Roller 24 i Engaged between the two support members 300 , 302 .

[0124] Each power transmission group 2 i Also includes an electrical connection to the first electrode 20 i The contact surface of the first electrical terminal or connector 60 i and electrically connected to the second electrode 22 i The contact surface of the second electrical terminal or connector 62 i If a large current is transmitted, it can be passed through the electrode 20 i ,twenty two i Providing more than one connector 60 i , 62 i In the embodiment shown, the connector is provided by means of electrically insulating supports 40, 42 and a housing 50. It should be noted that all power transmission groups 2 i Connector 60 i , 62 i Due to the concentric arrangement of the electrodes there is also sufficient space.

[0125] The rolling electrical contact assembly 1 of the present invention is advantageously adapted to conduct an electric current of at least 700 A, more preferably at least 1000 A, from the first electrical terminal to the second electrical terminal.

[0126] If you need to increase the current, there are several solutions available while maintaining a certain compactness:

[0127] -. Additional rollers can be added to the same power transmission group 2 i (In the embodiment shown in the figures, each power transmission group has 4 rollers, but 2 or even 4 rollers may be provided);

[0128] -.Increasing the width of the electrode and arranging an additional roller in the same power transmission group; in this case, two rollers are mounted on the same shaft with a flexible part between them to keep the pressure uniform; by enlarging the contact width between the roller and the electrode, higher currents can be transmitted;

[0129] -. Increasing the contact width between the roller and the electrode by enlarging the width of both the electrode and the roller; the contact width can be enlarged up to a threshold value above which limited contact may be obtained due to surface defects and / or non-uniform pressure. Above such a threshold value, two rollers rolling on the same pair of electrodes should be provided.

[0130] The latter two embodiments also make it possible to use the rolling contact assembly at higher speeds (to expand the range of applications) since the diameter of the electrodes does not increase too much.

[0131] In order to reduce mechanical wear and improve contact stability, grease or oil is usually added between the contact surface of the roller and the corresponding contact surface of the first electrode and the second electrode. The grease or oil can be selected among conductive greases (for example, grease types used for electrical connections of plug sets) to limit the resistance between the contact surfaces. Such a grease can be an oil, which is a non-conductive oil including a suspension of conductive lubricating particles, preferably graphite particles. Suitable greases or lubricating oils are disclosed in EP3149812. Two exemplary brands of oils that can be successfully applied are high quality penetrating oils, graphite-based oils, for example, sold by Griffon under the trade name Oils or lithium-based oils sold, for example, by Klüber under the trade name Synthesin PDL Oil for sale.

[0132] The rolling electrical contact assembly 1 of the present invention can be part of a rotating system 100 to be rotatably connected to an external power source PW. Such a rotating system 100 includes a motor 110 and a rolling electrical contact assembly 1. Then the second electrode of each power transmission group of the rolling electrical contact assembly 1 can be connected to the external power source PW via a connector 62, for example. i The first electrode of each power transmission group of the rolling electrical contact assembly is electrically connected to the external power source PW via the connector 60. i The connection between the rolling electrical contact assembly 1, the external power supply PW and the motor 110 is Figure 1 Schematically represented in .

[0133] The assembly process of the rolling electrical contact assembly 1 of the present invention may include (or comprise) the following steps:

[0134] 1) The first electrode 20 is provided i and the second electrode 22 i At least one power transmission group 2 i ,

[0135] Each electrode comprises at least one annular 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 rotatably mounted about the first axis, for example by placing each power transmission group 2 i The first electrode and the second electrode are assembled to the first electrically insulating support 40 and the second electrically insulating support 42 for installation,

[0136] 2) For each power transmission group 2 i At least one roller retainer assembly 28 is provided i , the at least one roller retainer assembly 28 i including (i) a roller 24 i Or a pair of rollers 24 i Each roller includes an annular angled conductive contact surface 240 i , the conductive contact surface 240 i The first electrode is adapted to roll onto the corresponding contact surfaces 200 of the first electrode and the second electrode when the first electrode rotates around the first axis. i , 220 i (ii) a shaft 282 defining a second axis A2, the roller 24 i Or a pair of rollers 24 i (iii) at least one pressure applying device 26 is rotatably mounted about the second axis A2. i , the at least one pressure applying device 26 i Along the axis, the roller 24 i Or a pair of rollers 24 i (iv) mounting elements 289, 290 or 289', 290',

[0137] 3) a single support member 300' or two support members 300, 302 are provided, in particular each support member has a hole 304', 304 for each roller retainer assembly to pass through, and mounting elements 305', 306' and 305, 306 respectively adapted to cooperate with the mounting elements 289', 290'; 289, 290 of each roller retainer assembly,

[0138] 4) Each roller retainer assembly 28 is assembled by cooperation of mounting elements (289', 290'; 305', 306') (289, 290; 305, 306) respectively. i Mounted to a single support member 300 ′ or to two support members 300 , 302 , wherein the roller retainer assembly 28 i The roller 280 is mounted on a single support member 300' or between two support members spaced apart along the first axis by a distance less than the minimum diameter of the contact surface of each roller, wherein the second axis A2 defined by the shaft 282 is radial relative to the first axis A1, the contact surface of one roller or a pair of rollers protrudes from the holes 304', 304 provided in the support member, and the pressure applying device 26 i In the direction of the first axis, the roller 24 i Or a pair of rollers 24 i A force F is applied to the roller contact surface 240 of each roller.i Push onto the corresponding contact surface 200 of the electrode i , 220 i superior,

[0139] 5) When two support members 300, 302 are provided, the support members are assembled to each other, for example with the aid of a spacer 310, to obtain a roller support assembly 30,

[0140] 6) The bearing member is rotatably mounted about the first axis, such as by mounting the roller bearing assembly 30 to the central hub 70 .

[0141] In particular, step 1) may include (or comprise):

[0142] 1a) at least one first electrode 20 i and at least one second electrode 22 i Assembled onto the first electrically insulating support (40) and the second electrically insulating support (42), and connect the first electrode and the second electrode to the connector 60 i , 62 i , when the rolling contact assembly is fully mounted, the support member constitutes the housing 50 or is fixed in the housing 50,

[0143] 1b) The electrically insulating bearings 40 , 42 are mounted to the central hub 70 with the roller bearing assembly 30 therebetween, the bearing 42 being fixedly mounted to the central hub 70 and the bearing 40 being rotatably mounted to the central hub 70 .

[0144] Such assembly can be performed quickly and easily.

[0145] At least one roller retainer assembly 28 is provided i Step 2) may include (or comprise):

[0146] 2a) Molding and / or machining the roller body 242 having a wheel shape i ,

[0147] 2b) For example, by plating or coating the contact surface 240 i Set on the roller body 242 i superior,

[0148] To get roller 24 i ,

[0149] 2C) by mounting a roller or a pair of rollers on the shaft 282 and mounting a pressure device 26 comprising, for example, an elastic element 260 i and optionally installing pressure regulating devices 262, 262' to adjust the roller 24 i Or a pair of rollers 24 iAssembled to roller retainer assembly 28 i middle,

[0150] and optionally mounting the rollers in the housing 280,

[0151] 2d) Optionally setting the pressure by adjusting the pressure adjustment device 262, 262', for example by tightening the nut 263, 263' and the screw portion of the shaft 282 supporting the roller or pair of rollers.

[0152] Therefore, such a roller retainer assembly can be easily prepared and then installed in the rolling electrical contact assembly of the present invention.

Claims

1. A rolling electrical contact assembly (1) for transmitting electric current between two relatively rotatable parts, the rolling electrical contact assembly (1) comprising at least one power transmission group (2 i ), the at least one power transmission group (2 i )include: - a first electrode (20 i ) and the second electrode (22 i ), each electrode comprising at least one annular angled conductive contact surface (200 i , 220 i ), the contact surfaces of the electrodes have the same first axis (A1) and the first electrodes (20 i ) is rotatably mounted about said first axis, It is characterized in that - the at least one power transmission group (2 i ) includes at least one roller retainer assembly (28 i ), the at least one roller retainer assembly (28 i ) comprises: (i) a roller (24 i ) or a pair of rollers (24 i ), each roller includes an annular angled conductive contact surface (240 i ), the conductive contact surface (240 i ) is adapted to roll onto corresponding contact surfaces (200) of the first electrode and the second electrode when the first electrode rotates around the first axis. i , 220 i ) on; (ii) defining a shaft (282) of a second axis (A2), the roller (24 i ) or a pair of rollers (24 i ) is rotatably mounted about the second axis (A2); (iii) at least one pressure applying device (26 i ), the at least one pressure applying device (26 i ) along the axis of the roller (24 i ) or a pair of rollers (24 i ) applying a force F thereon; and (iv) mounting the component, - the rolling electrical contact assembly (1) further comprises: (i) a single support plate (300') which is rotatably mounted about the first axis and has a thickness less than the minimum diameter of the contact surface of each roller, or (ii) two parallel support plates (300, 302) which are rotatably mounted about the first axis and are assembled to each other at a distance spaced apart along the first axis less than the minimum diameter of the contact surface of each roller, and - the at least one power transmission group (2 i ) of each roller retainer assembly (28 i ) is mounted at a position (i) on said single support plate or (ii) between said two parallel support plates, wherein said second axis (A2) defined by said shaft is radial relative to said first axis (A1), said contact surface of said roller or a pair of rollers protrudes from corresponding holes (304, 304') provided in said support plate, and said at least one pressure applying device (26 i ) in the direction of the first axis on the roller (24 i ) or a pair of rollers (24 i ) to apply a force F to the roller contact surface (240 i ) is pushed onto the corresponding contact surface (200 i , 220 i ), each roller retainer assembly (28 i ) cooperates with corresponding mounting elements arranged in the support plate.

2. The rolling electrical contact assembly (1) according to claim 1, characterized in that: Each roller retainer assembly (28 i ) comprises a housing (280) which accommodates the roller or a pair of rollers rotatably mounted around the axis fixed to the housing, the housing having two opposite holes (283, 284) through which the contact surfaces of the roller or the pair of rollers protrude.

3. The rolling electrical contact assembly (1) according to any one of claims 1 or 2, characterized in that: Roller retainer assembly(28 i ) of each roller (24 i ) or a pair of rollers (24 i ) is rotatably mounted around the shaft (282) by means of bearings (285).

4. The rolling electrical contact assembly (1) according to any one of claims 1 to 3, characterized in that: The at least one roller retainer assembly includes a pressure-applying device (26 i ) cooperates with a pressure regulating device (262) to adjust the force F.

5. The rolling electrical contact assembly (1) according to any one of claims 1 to 4, characterized in that: The at least one pressure applying device (26 i ) comprises an elastic element (260) mounted on the roller retainer assembly to exert the force F on the roller or a pair of rollers.

6. The rolling electrical contact assembly (1) according to any one of claims 1 to 5, characterized in that: For each roller of the at least one power transmission group, the contact surface of the roller has the same angle α with the corresponding contact surface of the electrode i , the angle α i A contact line L is defined between the second axis and formed between the contact surface of the roller and the corresponding contact surface of the electrode. i Between, and α i The value is equal to the contact line L i The value of the angle passing through the intersection point between the first axis and the second axis, optionally, for each roller (24 i ), α i The value is equal to or less than 45°.

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

8. The rolling electrical contact assembly (1) according to claim 7, characterized in that: On the contact surface of the roller (240 i ) and the corresponding contact surface (200 i , 220 i ) selected from at least one contact surface (200 i , 220 i , 240 i ) coated or plated with a material that has a higher conductivity than the material of its host.

9. The rolling electrical contact assembly (1) according to any one of claims 1 to 8, characterized in that: Each contact surface of the roller (240 i ) has a corresponding contact surface (200) smaller than that of the electrode i , 220 i ) of the electrode average diameter, optionally the ratio of the roller average diameter to the corresponding electrode average diameter is 1:20 to 1:1, preferably 1:8 to 1:

4.

10. The rolling electrical contact assembly (1) according to any one of claims 1 to 9, characterized in that: The at least one power transmission group (2 i ) of each roller retainer assembly (28 i ) includes a pair of rollers (24 i ), wherein each roller includes an annular angled conductive contact surface, and when the second electrode rotates about the first axis, the contact surfaces of the two rollers roll onto the same corresponding contact surface of the first electrode and the second electrode or roll onto two adjacent corresponding contact surfaces of the first electrode and the second electrode.

11. The rolling electrical contact assembly (1) according to any one of claims 1 to 10, characterized in that: The rolling electrical contact assembly (1) further comprises a first electrically insulating support (40) and a second electrically insulating support (42), wherein the first electrically insulating support (40) is rotatably mounted relative to the first axis, and each power transmission group (2 i ) of the first electrode (20 i ) is mounted on the first electrically insulating support (20), and each power transmission group (2 i ) of the second electrode (22 i ) is mounted to the second electrically insulating support (42), and optionally, the first electrically insulating support and the second electrically insulating support (40, 42) define a housing.

12. The rolling electrical contact assembly (1) according to any one of claims 1 to 11, characterized in that: The rolling electrical contact assembly (1) comprises two or more power transmission groups, wherein one power transmission group (2 i ) are arranged concentrically with respect to the first electrode, the corresponding second electrode of at least one other power transmission group, and the second axes of the rollers of all transmission groups are arranged in the same plane perpendicular to the first axes and the rollers of all transmission groups are mounted to (i) the single support plate (300') or (ii) the two support plates (300, 302).

13. The rolling electrical contact assembly (1) according to claim 12, wherein: The two or more power transmission groups (2 i ) are concentrically arranged on the same first electrically insulating support perpendicular to the first axis, and the two or more power transmission groups (2 i ) is concentrically arranged on the same second electrically insulating support member perpendicular to the first axis.

14. The rolling electrical contact assembly (1) according to any one of claims 1 to 13, characterized in that: Each power transmission group (2 i ) also includes a device electrically connected to the first electrode (20 i ) of the contact surface (200 i ) of at least a first electrical terminal (60 i ) and electrically connected to the second electrode (22 i ) of the contact surface (220 i ) of at least a second electrical terminal (62 i ), and wherein the rolling electrical contact assembly (1) is adapted to transfer a current of at least 700A, more preferably at least 1000A, from the first electrical terminal (60 i ) is led to the second electrical terminal (62 i ).

15. A rotation system (100) for rotatably connecting to an external power source, the rotation system comprising a motor (110), characterized in that: The rotating system also includes a rolling electrical contact assembly (1) according to any one of claims 1 to 14, wherein the second electrode of each power transmission group of the rolling electrical contact assembly is intended to be electrically connected to the external power source, and the first electrode of each power transmission group of the rolling electrical contact assembly is electrically connected to the motor.

16. A method for assembling a rolling electrical contact assembly, comprising: 1) A first electrode (20 i ) and the second electrode (22 i ) of at least one power transmission group, each electrode comprising at least one annular angled conductive contact surface (200 i , 220 i ), the contact surfaces of the electrodes have the same first axis (A1) and the first electrodes (20 i ) is rotatably mounted about said first axis, 2) For each power transmission group (2 i ) at least one roller retainer assembly (28 i ), the at least one roller retainer assembly (28 i ) comprises: (i) a roller (24 i ) or a pair of rollers (24 i ), each roller includes an annular angled conductive contact surface (240 i ), the conductive contact surface (240 i ) is adapted to roll onto corresponding contact surfaces (200) of the first electrode and the second electrode when the first electrode rotates around the first axis. i , 220 i ) on; (ii) defining a shaft (282) of a second axis (A2), the roller (24 i ) or a pair of rollers (24 i ) is rotatably mounted about the second axis (A2); (iii) at least one pressure applying device (26 i ), the at least one pressure applying device (26 i ) along the axis of the roller (24 i ) or a pair of rollers (24 i ) applying a force F thereon; and (iv) mounting the component, 3) providing (i) a single support plate (300') or (ii) two support plates (300, 302) having a thickness less than the smallest diameter of the contact surface of each roller, 4) by at least one roller retainer assembly (28 i ) cooperates with corresponding mounting elements of the support plate to position the at least one roller retainer assembly (28 i ) is mounted to (i) the single support plate (300') or (ii) the two support plates (300, 302), each roller retainer assembly (28i) is mounted on (i) the single support plate or (ii) between the two support plates spaced apart along the first axis by a distance less than the minimum diameter of the contact surface of each roller, wherein the second axis (A2) defined by the shaft is radial relative to the first axis (A1), the contact surface of the roller or a pair of rollers protrudes from a corresponding hole (304, 304') provided in (i) the single support plate or (ii) the two support plates, and the at least one pressure applying device (26 i ) in the direction of the first axis on the roller (24 i ) or a pair of rollers (24 i ) to apply a force F to the roller contact surface (240 i ) is pushed onto the corresponding contact surface (200 i , 220 i )superior, 5) When two support plates are provided, the two support plates are assembled to each other, the two support plates being parallel, 6) rotatably mounting (i) the single support plate or (ii) the two support plates about the first axis.

17. The method for assembling a rolling electrical contact assembly according to claim 16, wherein: The step (2) of providing at least one roller retainer assembly comprises: (2a) molding and / or machining a roller body having a wheel shape, (2b) providing a contact surface to the roller body, for example by plating, to obtain a roller, (2c) assembling the roller or pair of rollers into a roller retainer assembly by mounting the roller or pair of rollers on the shaft and mounting the pressure device and optionally the pressure adjustment device, (2d) Optionally, the pressure is set by adjusting the pressure regulating device.

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