WO2015177417A1

WO2015177417A1 - System for driving and guiding a swing joint

Info

Publication number: WO2015177417A1
Application number: PCT/FR2015/050564
Authority: WO
Inventors: René Perratone
Original assignee: O.S.C Offshore Systems Concepts
Priority date: 2014-05-20
Filing date: 2015-03-06
Publication date: 2015-11-26
Also published as: FR3021290A1; EP3152107B1; FR3021290B1; EP3152107A1

Abstract

The invention relates to a system (17) for driving and/or guiding a swing joint (1), comprising first and second coplanar arms (22', 22'') engaging with a female member (3) of a swing joint (1) using coupling and/or attachment means (21), a beam (23) being substantially transverse and coplanar and engaging with the first and second arms (22', 22''). The first and second arms (22', 22'') respectively comprise first and second double-acting and dual-rod cylinders (28', 28''), the power supplies of which advantageously intersect at the rear and front chambers (28'cl, 28'c2, 28''c1, 28''c2). The invention also relates to a fluid transfer system, a mooring system, and a buoyant unloading, storage, and production unit that comprises a drive and/or guide system (17) consistent with the invention.

Description

Rotary joint drive and guide system

The invention relates to the field of rotary joint drive and / or guide systems. These are used for all types of use and preferably but not exclusively in connection with fixed or mobile platforms and floating production, storage and offloading units, in the field of offshore.

An oil platform is a unit allowing the exploitation of hydrocarbon fields at sea, that is to say to extract, produce or store oil and / or other gases, such as, as examples non-limiting, hydrocarbons, said products being located on the high seas at sometimes very large depths.

There are two types of hydrocarbon deposit and / or offshore gas platforms:

- Firstly, fixed platforms that rely on the seabed and can thus be rigidly connected to oil wellheads and underwater pipelines, also called "pipelines" according to Anglo-Saxon terminology;

- Next, floating production units, storage and unloading, generally known under the name Anglo-Saxon "Floating Production Storage and Offloading", hereinafter referred to as FPSO.

As a preferred but nonlimiting example, a rotary joint will be considered in its application to within a floating production, storage and unloading unit.

Such a floating unit is generally in the form of a ship moored to the seabed by a system, permanent or disconnectable, allowing, depending on the environmental conditions, the rotation of floating supports around the central docking point, in principle a turret mooring.

On said floating supports, various equipment is present and allow:

treating hydrocarbons from an underwater reservoir and separating oil from other components such as, by way of non-limiting examples, gases, water and sand;

- To store oil and / or other gases in advance, so that they can subsequently be exported using shuttle boats, also known as the "Shuttle tanker";

- to reinject into the tank water and / or gas extracted from oil and / or other gases, which can not be stored on the floating supports;

injecting into chemical oil well heads chemicals used to protect said wells against corrosion phenomena and the formation of various by-products that may disturb the operation of said wells;

to control by means of hydraulic and / or electrical controls underwater installations. A mooring turret is connected to a floating support by a rolling system, said rolling system enabling the vessel to pivot about the geostatically attached part of the turret, said turret being attached to an anchoring system. A turret can advantageously be located inside, that is to say by inserting itself at the bow of the ship, or outside, that is to say by constituting an additional piece to the bow of said ship, its position depending mainly on the structure of the hull of the ship and the number of flexible lines connected to the turret.

In addition, on the fixed part of the mooring system, a fluid transfer system allows the connection of underwater piping to the floating production unit. Indeed, within the turret, a rotating joint, also referred to as the "rotary joint", or an assembly of rotating joints, also known by the English names "swivel" or "swivel stack", allows to put a transfer of fluid between the geostatic portion and the free system of the vessel that rotates around the turret.

Thus rotating joints ensure that all fluids, whether gaseous or liquid, are safely transferred geostatic parts, such as, as non-limiting examples, oil wells, pipes submerged in the seabed, collectors, hoses, system allowing movements. There are two main types of rotating joints:

tubular rotating joints, also known by the English names "pipe swivel" and "in-line swivel"; toroidal rotating joints, also known by the Anglo-Saxon name "toroidal swivel".

Tubular rotary joints are the simplest fluid transfer systems. They include a single fluid passage. When more than one fluid passage is required, toroidal rotary joints are preferred or preferred: because of their large diameter, it is possible to provide a large number of fluid passages by stacking and / or assembling several toroidal rotating joints.

An example of a "conventional" toroidal rotary joint comprises a number of main components. It comprises a male limb, also referred to as "internal limb" or "fixed limb", and a female limb, also referred to as "outer limb" or "rotatable limb", movable relative to the limb. other and kept concentric and coaxial by means of a mechanical bearing. By way of non-limiting example, such a bearing is advantageously a three-roll bearing, also known by the English name "3-race roller bearing". In principle, the mechanical bearing allows positioning, transmission of forces and rotation between the male and female members by replacing the sliding in a bearing. A toroidal chamber is formed between the male and female members, constituting a closed enclosure. It is through this chamber that the transfer of fluid takes place. A plurality of chambers may be present within the same rotary joint to ensure the passage or transfer of one or more fluids. To ensure tightness within a rotary joint, one or more seals can be arranged on each side of the toroidal chamber, allowing the formation of a narrow fluid passage. The seals take place respectively within grooves provided for this purpose. The grooves may advantageously but non-limitatively result from open-hole recesses formed on the surface in the inner wall of one or the other of the male and female members.

Such rotary joint modules are integrated within a fluid transfer system consisting of an assembly of rotary joint modules. Figure 1 shows such an assembly of rotary joint modules. The assembly of rotary joints comprises in particular rotary joints 1, 1 'and 1', adapted for the transfer of fluids. However, other rotary joint modules can be used to allow other transfers. As non-limiting examples, mention may be made in particular of:

an optical rotary connector 13 and an electric rotary connector 14, also known by the English names "Optical Swivel" and "Electric Swivel", which allow the transfer of power and information;

other rotary connectors 15 and 16, also known by the English name "Utility Swivel", allowing the transfer of all products and additives necessary for the transfer and the proper functioning of the transfer system, such as chemical agents, hydraulic agents, air or other gases, fire fighting water or evacuation;

drive and / or guide systems of the rotary joint modules 17, 17 'and 17' 'make it possible to assist the fluid transfer system 12 and maintain the rotating joints 1, 1' and 1 '.

Such drive and / or guide systems are advantageously used to rotate the female members of the rotating joints, used to transfer the different fluids between the male member, in other words the fixed part, and the female member, in other words the female part. rotating part, of a docking system of a floating production unit, also referred to as "FPSO". This clever rotation drive is achieved by transmitting a mechanical torque. Such a drive and / or guide system is designed to withstand the friction loads generated by the various rotating joints, said joints sliding on their respective friction surfaces, including the grooves where the seals are located. Such a drive and / or guide system does not affect the variation of the seal extrusion clearance. Each rotary joint module is equipped with an independent drive and / or guide system, designed to allow relative linear movements of all the modules of the rotating joints, while keeping the orientation of the female member at all times. aligned with the ship in position, when the ship turns freely around the male member of the mooring system. As a result, such a drive and / or guide system makes it possible to drive the Female member rotational joints rotating. The drive and / or guide system is such that the only degree of freedom existing is the rotation around the axis of revolution of the mooring system, and consequently the assembly of rotating joints and each module of Turning joint. This rotation is generated by the transmission of a torque, corresponding to a rotational force applied to an axis. Such a pair can be expressed as a system of two antiparallel forces, that is to say that the two forces have the same direction but opposite directions, of the same magnitude acting at two distinct points. The only effect of a couple is therefore to create or prevent a rotational movement.

A drive and / or guide system advantageously comprises an assembly of articulated arms, said articulated arms co-operating with the female member of a rotary joint. The female member may advantageously be integral with one or more, advantageously, protruding projecting ears, said ears themselves including openings or recesses. The drive and / or guide system comprises one or more protuberances, advantageously two. The recesses of the ears are advantageously dimensioned to receive said protuberances and thus ensure cooperation between the rotary joint and the drive system and / or guide. In addition, such a drive system and / or guide may include additional hooking and / or attachment means to ensure assembly and cohesion of the system and the rotary joint. Such drive and / or guide systems cooperate with gantries, also known as gantry structures, mooring systems and in particular mooring turrets. Alternatively, they can be directly integrated with said gantries within the turrets and constitute a single entity.

Among the known drive and / or guide systems, there are four mainly used systems, described with reference to FIGS. 2a to 2d:

a drive ring, also known by the English name "Ring type", illustrated in conjunction with FIG. 2a;

- A torsion beam, also known as the Anglo-Saxon "Torsion Beam type", described in connection with Figure 2b;

an articulated beam, also known under the name "Articulated Beam type", illustrated in connection with FIG. 2c; a beam in tension / compression, also known under the name "Tension-Compression Beam type", described with reference to FIG. 2d.

According to FIG. 2a, the drive and / or guide system, commonly known as the "drive ring", comprises a floating ring 20 made of a material having the resistance necessary to withstand the load imposed by a module of Turning joint. The term "ring" means any quadrilateral with rounded or non-rounded corners, which may be oblong, ellipse or ovoid. The definition of the term "ring" should not be limited to the examples just mentioned in document. The floating ring 20 comprises one or more, advantageously two, protuberances 20p, sized to cooperate advantageously with the driving lugs 21 projecting from a female member of a rotary joint. In addition, such a ring cooperates with a docking system, such as by way of non-limiting example, a gantry 30, the means of joints for the implementation of sliding pivot connections. Such sliding pivot connections allow two degrees of freedom, translation and axial rotation. The ring can move laterally and longitudinally with respect to the system. The rotation drive is finally performed when a torque is transmitted to the system.

According to FIG. 2b, driving lugs 21 are advantageously fixed to a driving and / or guiding system 17 by any means, with the aid of the distal portions of two driving arms 22, said arms being substantially parallel and integrated into the system. Each arm 22 advantageously comprises a protuberance 22e, said protuberance being positioned substantially around its distal portion and dimensioned to fit into a recess arranged within each projecting driving lug 21 of a female member 3 and to ensure cooperation of the arm 22 and the female member 3. At the other end, the proximal portions of the two drive arms 22 cooperate with each of the ends of an articulated beam 23 by means of two joints 23a allowing the implementation of ball joints or pivots. Such ball joints provide the complete link in translation between the drive arms and the articulated beam 23, but the leave free in rotation. They thus comprise three degrees of connection, the three translations, and three degrees of freedom, the three rotations. Thus, the rotational drive is finally achieved by a torsion of the articulated beam 23. The term "torsion" means the stress on the beam, said beam being subjected to the action of a pair acting in parallel planes .

According to FIG. 2c, like the torsion beam device described in connection with FIG. 2b, driving lugs 21 are advantageously fixed to the driving and / or guiding system 17 by any means, to the using the distal portions of two drive arms 22, said arms being substantially parallel and integrated in the system 17. Each arm 22 advantageously comprises a protuberance 22e, said protuberance being positioned substantially around its distal portion and dimensioned to fit in. a recess formed in each projecting driving lug 21 of a female member 3 and ensuring the cooperation of the arm 22 and the female member 3. At the other end, the proximal portions of the two drive arms 22 cooperate with an articulated beam by means of two joints 23a allowing the implementation of ball joints, at least pivotal connections. In this embodiment, the proximal portions of the arms 22 no longer cooperate with the ends of said articulated beam 23, but with a central portion of the articulated beam. The hinged beam 23 cooperates itself, by means of hinges 23b, allowing the implementation of ball joints or pivot, at its ends with a drive structure, such as by way of example non-limiting, a gantry 30. Thus, the rotational drive is finally achieved by a locking of the articulated beam 23, when a torque is transmitted to the system 17.

According to FIG. 2d, like the torsion beam and articulated beam devices described respectively in connection with FIGS. 2b and 2c, the drive lugs 21 are advantageously fixed to the driving and / or guiding system 17 by any means, using the distal portions of two drive arms 22, said arms being substantially parallel and integrated into the system. Each arm 22 advantageously comprises a protuberance 22e, said protuberance being positioned substantially around its distal portion and dimensioned to fit into a recess formed in each projecting driving lug 21 of a female member 3 and to ensure cooperation of the arm and the female limb. At the other end, the proximal portions of the two arms 22 each cooperate with a triangular support 24 by means of a hinge 23a allowing the implementation of a ball joint, at least a pivot connection. The two triangular supports 24 are themselves interconnected by means of a beam 23, said beam being transverse relative to the two arms 22 drive. The connections between the beam 23 and the supports 24 are in principle ball joints or pivots, materialized using suitable joints 23b. Furthermore, the two triangular supports 24 also cooperate with a drive structure, such as by way of non-limiting example, a gantry 30, by means of joints 24a allowing the implementation of ball joints or pivots. Thus, the rotational drive is finally achieved by blocking the transverse beam, said beam working in tension or compression when a torque is transmitted to the system. The term "tension" means any constraint that the beam undergoes when it is subjected, at its ends, to two forces directed towards the outside of the beam; such forces are materialized by the various ball joints present in the system. By contrast, the term "compression" means any constraint that the beam undergoes when it is subjected, at its ends, to two forces directed towards the inside of the beam.

Another embodiment of a drive system and / or guide is described in connection with Figure 2e. As with the torsion beam, articulated beam and tension / compression beam devices described respectively in connection with FIGS. 2b to 2d, drive lugs 21 are advantageously fixed to the drive system and / or guidance by any means, using the distal portions of two drive arms 22, said arms being substantially parallel and integrated with the system 17. At the other end, the proximal portions of the two drive arms 22 cooperate with a articulated beam 23 via triangular plates 26, by means of two hinges 23a for the implementation of ball joints. In this embodiment, the proximal portions no longer cooperate with the ends of said articulated beam, but with a central portion of the articulated beam 23. The articulated beam 23 cooperates itself, by means of joints 23b allowing the implementation pivots or ball joints, at its ends with a drive structure, such as by way of non-limiting example, a gantry. In addition, the beam 23 comprises a connecting arm 25 allowing the transmission of a torque by means of a lever arm 25. Each end of such a lever arm 25 cooperates with one of the plates 26 by means of an articulation allowing the implementation of a first pivot connection 23c.

Although the drive systems and / or guide, described in connection with Figures 2a to 2e, allow to drive and / or guide the rotary joint modules to ensure the transfer of fluid, they have many disadvantages. Each drive system and / or guide is a mechanical system and therefore imposes the application of constraints, such as by way of non-limiting examples, torsion, compression and / or voltage, on the system and more particularly on the beams and the arms. Although these elements, more precisely the beams and the arms, are made of materials adapted to withstand the stresses applied and / or applicable, under the effect of the stresses undergone, a material and subsequently the beams and arms of the system. drive and / or guide, can suffer different consequences, that is to say, they can have three types of different deformations. "Deformation" means any substantial change or modification (e) of a material or element with respect to its rest position. A deformation can be temporary if it disappears with the withdrawal of external forces whereas it is permanent when it remains even in the absence of constraints. However, all materials, beams and arms have a limit to being able to deform. When the stresses exerted are too great, they cause the breaking of the material. Each material has a specific resistance threshold which corresponds to the limit threshold of the level of stress that it can undergo without breaking. Thus, three types of deformations are to be counted:

firstly, an elastic deformation: the material or element deforms proportionally to the applied force and returns to its original shape when the stress stress disappears. This is a temporary and reversible change;

sometimes followed by plastic or permanent deformation: the material does not return to its original shape when the stress or stress disappears, residual deformation remains. This is an irreversible change.

and finally rupture: the stress or stress exceeds the intrinsic resistance of the material or resistance threshold of the element and causes its rupture.

When a material or element is subjected to repetitive or time-varying stresses, it may become more fragile. This phenomenon is called "mechanical fatigue". In this case, instead of simply deforming, the material or the element will eventually present cracks and possibly break. The fatigue is characterized in particular by a range of stress variation that can be well below the resistance threshold of a material or element. The invention makes it possible to meet all or some of the disadvantages raised by the known solutions.

Among the many advantages provided by a drive system and / or guide a rotary joint according to the invention, we can mention that it allows:

to prevent the deformation of the materials composing the drive and / or guide system, to make the displacements more flexible;

to eliminate the torsion, tension and / or compression stresses applied to the different members of a driving and / or guiding system;

- to ensure a longer life of a drive system and / or guide;

reduce the weight and cost of a drive system and / or guide and thus simplify the number of elements making up the system;

to lighten the structure of the drive and / or guide systems and thus reduce the size of such systems; to replace a mechanical system by a mixed system combining mechanical and hydraulic, sometimes even pneumatic.

To this end, it is particularly provided a drive system and / or guide a rotary joint comprising:

first and second coplanar arms, the distal portions of said first and second arm cooperating with a female member of a rotating joint by means of hooking and / or fastening;

a beam being substantially transverse and coplanar and cooperating with the proximal portions of the first and second arms;

In order to eliminate the torsion, bending or compression stresses applied to the beam, the first and second arms or the gantry, the first and second arms respectively comprise first and second double rod cylinders. In addition, the first cylinder comprises a piston, a rear chamber and an anterior chamber on either side of said piston, said chambers being of the same section. Similarly, the second cylinder comprises a piston, a rear chamber and an anterior chamber on either side of said piston, said chambers being of the same section as the rear and front chambers of the first cylinder. Furthermore, to allow cross-feeding of the jacks, the rear chamber of the first jack cooperates with the anterior chamber of the second jack by means of a first duct. In the same way, the rear chamber of the second cylinder cooperates with the anterior chamber of the first cylinder by means of a second conduit.

Advantageously, to allow better transmission of the mechanical torque, the first and second arms are substantially parallel.

In order to regulate the pressure inside the first and second conduits and thus prevent fluid accumulation, the first and second conduits are rigid. To absorb the movements due to small angles, the proximal portions of said arms cooperate with the female member by means of a ball joint.

Alternatively, the proximal portions of said arms cooperate with the female member by means of a pivot connection.

According to a last variant, the proximal portions of said arms cooperate with the female member by means of a recess connection.

Advantageously, the first and second cylinders are pneumatic.

Preferably, the first and second cylinders are hydraulic. According to a second object, the invention relates to a fluid transfer system, comprising a rotary joint module, said rotary joint module cooperating with a drive system and / or guide, said drive system and / or guide cooperating with a gantry. To optimize fluid transfer and reduce fatigue loads on the system, said fluid transfer system comprises a drive system and / or guide according to the invention. According to a third object, the invention relates to a mooring system comprising a mooring turret, within which is arranged a fluid transfer system. In order to simplify transfers on a petroleum platform, the mooring system advantageously comprises a fluid transfer system according to the invention. According to a fourth object, the invention relates to a floating unit for unloading, production and storage. Said unit advantageously comprises a mooring system according to the invention.

Other features and advantages will emerge more clearly on reading the following description and on examining the figures that accompany it, among which:

- Figure 1, previously described, illustrates a known assembly of rotary joint modules;

FIGS. 2a to 2e, previously described, show five known drive and / or guide systems;

- Figures 3a and 3b schematically describe a drive system and / or guide 1 according to the invention;

FIGS. 3c and 3d illustrate examples of jacks used in drive and / or guide systems.

Figures 3a and 3b show schematically a drive system and / or guide a rotary joint according to the invention. Such a drive and / or guide system 17 advantageously comprises an assembly of articulated arms 22, said articulated arms cooperating with a female member 3 of a rotary joint. The arms 22 are advantageously made of a material capable of withstanding stresses applied to the arms. The term "stress" means the tendency of a material to deform under the effect of external forces exerted on said arms. As described in connection with Figures 3a and 3b, the arms 22 are preferably two in number, to allow the transmission of torque and consequently the rotational drive of the rotary joint 1. They will be named in the following document "first and second arm ". The first and second arms of a drive system and / or guide according to the invention are at least coplanar and preferably parallel. The distal portions 22d of the first and second arms 22 'and 22''advantageously cooperate with the female member 3 of the rotary joint 1, said female member being rotated relative to the male member 2. Such cooperation can be done using hooking means and / or fastening means 21, said means being integral with or integral with the female member 3. Such hooking and / or fastening means 21 may preferably be in the form of two projecting ears. drive, one for each arm, or any equivalent support, said ears being advantageously welded, bolted or fixed by any other means. The distal portions 22d can cooperate with the drive lugs according to different mechanical connections, in particular:

a recessed connection, which prevents any movement of the arms relative to the drive lugs,

a pivot connection, which guarantees the free rotation of the arms, according to their axes of revolution.

a spherical connection, also known by the name "spherical connection", preferred solution, which completely links the drive lugs and the distal parts of the arms, but leaves said arms and ears completely free to rotate. Such a ball joint allows each of the distal portions of the two arms to move at small angles in all directions and reduces the biasing of the arms at the female member 3 of the rotary joint. The fatigue load is thus greatly reduced. Furthermore, the proximal portions 22p of the first and second arms 22 'and 22''advantageously cooperate with a beam 23 substantially transverse to the first and second arms. Alternatively, the proximal portions 22p of each arm could directly cooperate with a gantry 30. Similarly to the distal portions of the first and second arms 22, this cooperation can be organized around different mechanical links, as preferred examples but not limiting, pivot, ball or flange connections 23a. Moreover, in a variant, the beam 23 can be directly integrated with the gantry 30, present within the mooring system and in particular within a mooring turret.

The first and second arms 22 'and 22''each comprise a jack 28. Such a jack may be integrated within such an arm or constitute the entire arm 22. A jack is a mechanical member allowing the creation of a translational movement along the axis of said member. A cylinder can also be considered as a linear actuator that converts the energy of a fluid under pressure into mechanical energy. A cylinder is characterized by its stroke, that is to say the length of the displacement to ensure, by the diameter of its piston and by the pressure of the fluid, said diameter and said pressure depending on the effort developed. According to the fluid used, two main types of jacks can be distinguished: the pneumatic jacks, in which the fluid used is mainly compressed air, advantageously but not limitatively between 2 and 10 bars, and the hydraulic jacks, in which the fluid used is mainly pressurized oil, up to 350 bar. Preferably, the first and second arms 22 'and 22''comprise first and second jacks 28' and 28 ''. A jack is generally made of a cylinder closed at both ends, defining one or more cavities. Inside said cavity, a moving part, in principle a piston 28p, is mounted on a first rod 28tl rigid, and allows to separate the volume of the cavity into two chambers 28c1 and 28c2, isolated one of the other. The two rooms are preferably of the same section. According to a conventional embodiment, the term "anterior chamber" 28c2, the chamber does not contain the first rod 28tl of the cylinder and "rear chamber" 28cl the chamber containing the first rod 28tl of the cylinder. The proximal portion of the first rod 28tl of the jack 28 thus cooperates with the surface of the piston 28p opening into the rear chamber 28c1, that is to say that said proximal portion of the first rod 28tl is fixed to said surface by any means . One or more openings 28o, in one or the other of the two chambers, ensure the introduction or the evacuation of the fluid and consequently the displacement of the piston. Moreover, the first rod 28tl guarantees the transmission of a force in the form of a pressure and by way of consequence of a displacement. Such a cylinder 28 may advantageously have a damper (not shown in FIGS. 3a to 3d) in order to obtain a slowdown at the end of the movement so as to avoid a shock of the piston on the bottom of the cavity. inside the cylinder. A cylinder also includes seals for sealing at the piston 28p between the two chambers of the cavity and / or between the first rod and the cylinder body. The first rod 28tl advantageously cooperates with the distal portion 22p of the arm, while the end of the cylinder body, opposite to said first rod, advantageously cooperates with the proximal portion 22p of the arm 22. Similarly, the first rod 28tl can advantageously cooperate with the proximal portion 22p of the arm, while the end of the cylinder body, opposite to said first rod, can advantageously cooperate with the distal portion 22d of the arm. Said cooperations are made using any means of attachment and / or hooked known allowing the embodiment of a mechanical linkage, as preferred but non-limiting examples, pivot links, ball or flush.

A cylinder 28 may also be characterized by its mode of action. In particular, two types of mode of action can be distinguished: the single acting cylinders, known under the name "VSE", and the double acting cylinders, known under the name "VDE". As illustrated in connection with FIG. 3c, a jack 28 is said to be simple effect when the jack works only in one direction, ie only one chamber is supplied with fluid, preferably the anterior chamber, and as a result, the arrival of the pressure is only through a single opening 28o, driving the piston 28p in one direction. The return of the piston 28p is performed under the action of a spring 28r, an equivalent system or an external force. As described with reference to FIG. 3d, a jack is said to be double acting when the jack is working in two directions, that is to say that the jack VDE has two possible feeds, through the anterior chamber 28c2 or by the rear chamber 28cl. the pressurized fluid is thus sent on either side of the piston 28p as a function of the desired work. Such a jack 28 has two openings 28ol and 28o2 for supplying the device with fluid. Furthermore, a pressure is applied alternately on each side of the piston 28p, said piston thus moving in one direction and then in the other. During the pressure supply of the anterior chamber 28c2, the piston 28p moves to reduce the posterior chamber 28c1, said piston compressing or "chasing" the fluid from the rear chamber 28c1. When feeding pressure to the rear chamber 28c1, the piston 28p moves in the opposite direction, said piston 28p compressing or "flushing" fluid from the anterior chamber 28c2. The pushing force, that is to say when the first rod 28tl comes out of the jack cavity, is slightly greater than the pulling force, that is to say that the first rod 28tl penetrates the cylinder cavity 28: in fact, the pressure does not act on the surface of the piston 28p occupied by the first rod 28tl fixed to said surface, generally opening into the rear chamber 28c1 of the cavity. Pressure and effort are not identical in both chambers previous 28c2 and posterior 28cl since the material inlet, represented by the inlet of the first rod 28tl, is performed within the rear chamber 28cl only.

To overcome this disadvantage, cylinders 28 double rod are used. The principle of said double rod cylinders, illustrated in connection with Figure 3d, is as follows: the first rod 28tl between and out of the cylinder 28 within the rear chamber 28cl. As previously explained, in this configuration, certain problems appear concerning, in particular, the pressure and the force to be applied, but also the guiding in translation of the jack. The proximal portion of a second rod 28t2 of the jack thus cooperates with the surface of the piston 28p opening into the anterior chamber 28c2, that is to say that said proximal portion is fixed to said surface by any means. Said second rod 28t2 advantageously has a section substantially identical to the first rod, but may be of different length. Furthermore, the distal portion of said second rod may be advantageously free. The first and second rods are advantageously parallel, but not necessarily in mirror to each other, that is to say that their respective attachment points on the piston are not necessarily substantially identical. Preferably, the longitudinal axes of the first and second rods 28tl and 28t2 coincide with the longitudinal axis of the arm with which the jack cooperates, that is to say that the first and second rods are in the extension of said arm.

According to a preferred exemplary embodiment, illustrated by FIGS. 3a and 3b, a drive system and / or guide 17 according to the invention comprises a jack 28 with double rod in each arm 22.

As explained above, the first and second arms 22 'and 22' 'advantageously comprise respectively first and second jacks 28' and 28 '', advantageously double-stemmed and double-acting. Each actuator has two openings, a 28o2 in the anterior chamber 28c2 and a 28ol in the rear chamber 28c1, said openings alternately permitting the supply and escape of fluid within the anterior and posterior chambers. Thus, the first cylinder 28 'has an opening 28o2 in its anterior chamber 28c2 and a 28ol in its rear chamber 28c1, said rear chamber 28c1 allowing the insertion of the first rod 28tl within it. In the same way, the second cylinder 28 '' has an opening 28o2 in its anterior chamber 28c2 and a 28ol in its rear chamber 28c1, said rear chamber allowing the insertion of the first rod 28tl within it. When the first rod 28tl "enters" inside the cylinder, the opening 28ol within the posterior chamber 28c1 provides the supply of pressurized fluid, while the opening 28o2 within the anterior chamber 28c2 ensures the exhaust of the fluid. In contrast, when the first rod "exits" from the inside of the cylinder, the opening 28ol within the rear chamber 28cl ensures the escape of the fluid, while the opening 28o2 within the anterior chamber 28c2 ensures the supply of pressurized fluid.

In order to compensate for the deformation stresses of the structure of the driving and / or guiding system, as examples, the torsional, flexural or compressive stresses applied to the drive and / or guide systems known and previously described in connection with FIGS. 2a to 2e, the first and second jacks 28 'and 28'' present in said system are fed by means of crossed connections, advantageously in closed circuit, that is to say that:

the posterior chamber 28c1 of the first jack 28 'co-operates with the anterior chamber 28c2 of the second jack 28' 'by means of a first duct 27', that is to say that the openings within the posterior chamber 28c1 of the first cylinder 28 'and within the anterior chamber 28c2 of the second cylinder 28' 'are connected to each other by means of a first fluid line.

the posterior chamber 28c1 of the second jack 28 '' cooperates with the anterior chamber 28c2 of the first jack 28 'by means of a second duct 27' ', that is to say that the openings in the posterior chamber 28c1 of the second cylinder 28 '' and within the anterior chamber 28c2 of the first cylinder 28 'are connected relative to each other by means of a second fluid line.

Such crossed connections allow servo-control of the first and second jacks 28 'and 28''to stretch the first and second arms 22' and 22 '' in the same direction and thus reduce the strain stresses applied to the first and second arms 22 'and 22'', the beam 23 or the gantry 30. The first and second conduits 27' and 27 '' can be rigid or flexible and consist of a material capable of withstanding the pressure imposed by the fluid. Preferably, the first and second conduits are rigid to prevent swelling and / or accumulation due to pressure.

As previously described with reference to FIG. 1, a rotary joint drive and / or guide system 17 is in principle used within a fluid transfer system 12. Such a fluid transfer system generally comprises at least one fluid transfer system. minus two rotary joint modules, chosen among, by way of non-limiting examples, rotary joints for fluid transfer, rotary connectors optical and electrical. At least one drive and / or guide system according to the invention is employed within such a fluid transfer system. All or part, that is to say at least the ends, of the beam 23 of a drive system 17 and / or guide according to the invention advantageously cooperate with a gantry 30, also known under the name Anglo-Saxon "gantry structure". Cooperation means any relevant fixation by any means. As a variant, such a beam 23 can be directly integrated within said gantry 30.

The transfer systems, by means of a gantry, are generally introduced into offshore mooring systems, such as, for example, without limitation, within a mooring turret. "Docking" means the action of connecting a floating unit to another system, such as, for example, not limitative, another floating unit, a platform or a pontoon. The turret is generally composed of five main elements:

a number of anchor lines to allow some stability of the floating unit;

a turret structure, to guarantee the connection between the floating unit and the anchor lines;

a mechanical bearing support to allow the floating unit to rotate around the fixed part of the turret from a geostatic point of view;

a floating unit structure for supporting said mechanical bearing;

a fluid transfer system, consisting of an underwater transfer system, a manifold, a rotating joint assembly and a conduit arrangement. The fluid transfer system is advantageously in accordance with the invention.

In principle, the mooring systems are rotary and generally introduced in a floating production, storage and unloading unit, also known as "Floating production storage and offloading". Said units are generally in the form of a ship cooperating with a drilling platform and at least one fluid transfer system, said system being able to be included in a mooring turret, pivoting system enabling the ship to 'orient freely from to offer less resistance to ocean currents. Advantageously, the floating unit comprises a docking system according to the invention. The invention has been described in its operation in connection with rotating joints to ensure the transfer of fluids within floating unloading units, production and storage comprising a mooring turret. It can also be implemented for all types of rotating joints or any type of mobile platforms combined with a suitable mooring system.

Within the meaning of the document, the expression "rotary joint" can be applied to a rotary joint or to any other system more generally comprising a female member rotated relative to a male member, said female member being subjected to the transmission of a couple. In addition, the invention could be implemented using any actuator that can perform an action equivalent to that performed by the cylinder, for example a gear and rack assembly, the two elements being motorized.

Other modifications may be envisaged without departing from the scope of the present invention defined by the appended claims.

Claims

System (17) for driving and / or guiding a rotary joint (1), comprising:

first and second coplanar arms (22 ', 22' '), the distal portions (22d) of said first and second arms (22', 22 '') cooperating with a female member (3) of a rotary joint (1) by hooking and / or fastening means (21);

a beam (23) being substantially transverse and coplanar and cooperating with the proximal portions (22 ', 22' 'p) of the first and second arms (22', 22 ''),

said system being characterized in that:

the first and second arms (22 ', 22' ') respectively comprise first and second double rod cylinders (28', 28 '');

the first jack (28 ') comprises a piston (28' '), a rear chamber (28' ') and an anterior chamber (28' '' ') on either side of said piston (28' '), said chambers being same section;

the second cylinder (28 '') comprises a piston (28 '' p), a rear chamber (28 '' cl) and an anterior chamber (28 '' c2) on either side of said piston (28p), said chambers being of the same section as the posterior (28 'cl) and anterior (28' c2) chambers of the first cylinder (28 '); the rear chamber (28 'cl) of the first jack (28') cooperates with the anterior chamber (28 '' c2) of the second jack (28 '') by means of a first duct (27 ');

the rear chamber (28 '' cl) of the second cylinder (28 '') cooperates with the anterior chamber (28 'cl) of the first cylinder (28') by means of a second conduit (27 '').

System (17) for driving and / or guiding according to the preceding claim, wherein the first and second arms (22 ', 22' ') are substantially parallel.

Drive and / or guide system (17) according to any one of the preceding claims, wherein the first and second conduits (27 ', 27' ') are rigid.

A drive and / or guide system (17) as claimed in any one of the preceding claims, wherein the proximal portions (22'p, 22 '' p) of said arms (22 ', 22' ') cooperate with the limb female (3) by means of a ball joint.

Drive and / or guide system according to any one of claims 1 to 3, wherein the proximal portions (22'p, 22 '' p) of said arms (22 ', 22'') cooperate with the female member (3) by means of a pivot connection. A drive and / or guide system according to any one of claims 1 to 3, wherein the proximal portions (22'p, 22 '' p) of said arms cooperate with the female member (3) by means of a flush connection.

7. Drive system and / or guide according to any one of the preceding claims, wherein the first and second cylinders (28 ', 28' ') are pneumatic.

Drive and / or guide system according to any one of claims 1 to 6, wherein the first and second cylinders (28 ', 28' ') are hydraulic.

A fluid transfer system comprising a rotary joint module (1), said rotary joint module (1) cooperating with a drive and / or guide system (17), said drive system (17) and / or guiding cooperating with a gantry (30), said fluid transfer system being characterized in that it comprises at least one system (17) for driving and / or guiding according to any one of claims 1 to 8 .

10. Mooring system, comprising a mooring turret, within which is arranged a fluid transfer system, characterized in that it comprises a fluid transfer system according to claim 9.

11. floating unit unloading, production and storage, characterized in that it comprises a docking system according to claim 10.