EP3152107B1 - Driving and guidance system of a rotating joint - Google Patents

Description

The invention relates to the field of systems for driving and / or guiding rotary joints. These are used for any type of use and preferably but not limited to in connection with fixed or mobile platforms and floating production, storage and unloading units, in the offshore sector.

An oil platform is a unit enabling the exploitation of offshore oil fields, that is to say extracting, producing or storing petroleum and / or other gases, such as, for example non-limiting, hydrocarbons, said products being located on the high seas at sometimes very great depths.

• tout d'abord, des plateformes fixes qui s'appuient sur les fonds marins et peuvent ainsi être reliées de façon rigide à des têtes de puits pétroliers et à des canalisations subaquatiques, encore appelées « pipelines » selon une terminologie anglo-saxonne ;
• ensuite, des unités flottantes de production, de stockage et de déchargement, généralement connus sous l'appellation anglo-saxonne « Floating Production Storage and Offloading », ci-après désignées FPSO.

There are two types of offshore oil and / or gas field platforms:

• firstly, fixed platforms which rest on the seabed and can thus be rigidly connected to oil well heads and underwater pipelines, also called “ pipelines ” according to Anglo-Saxon terminology;
• then, floating production, storage and unloading units, generally known by the Anglo-Saxon name " Floating Production Storage and Offloading ", hereinafter designated 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 at the bottom of the sea by a system, permanent or disconnectable, allowing, depending on environmental conditions, the rotation of floating supports around the central point of mooring, in in principle a mooring turret. The document WO 99/65762 shows such a mooring turret.

• de traiter les hydrocarbures venant d'un réservoir sous-marin et de séparer le pétrole des autres composants tels que, à titre d'exemples non limitatifs, les gaz, l'eau et le sable ;
• de stocker le pétrole et/ou autres gaz au préalable, afin de pouvoir, par la suite, les exporter en utilisant des bateaux navettes, également connus sous l'appellation anglo-saxonne « Shuttle tanker » ;
• de réinjecter dans le réservoir l'eau et/ou le gaz extraits du pétrole et/ou autres gaz, qui ne peuvent pas être stockés sur les supports flottants ;
• d'injecter dans des têtes de puits pétroliers des produits chimiques servant à protéger lesdits puits contre des phénomènes de corrosion et la formation de différents sous-produits susceptibles de perturber le fonctionnement desdits puits ;
• de commander au moyen de commandes hydrauliques et/ou électriques des installations sous-marines.

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

• to treat the hydrocarbons coming from an underwater tank and to separate the oil from the other components such as, by way of nonlimiting examples, gases, water and sand;
• to store petroleum and / or other gases beforehand, in order to be able to export them later using shuttle boats, also known by the Anglo-Saxon name " Shuttle tanker ";
• re-injecting the water and / or gas extracted from petroleum and / or other gases into the tank, which cannot be stored on the floating supports;
• injecting into petroleum well heads chemicals used to protect said wells against corrosion phenomena and the formation of various by-products capable of disturbing the operation of said wells;
• control underwater installations by hydraulic and / or electrical controls.

A mooring turret is connected to a floating support by a bearing system, said bearing system allowing the ship to pivot around the geostatically fixed part of the turret, said turret being attached to an anchoring system. A turret can advantageously be located inside, that is to say by being inserted at the bow of the ship, or outside, that is to say by constituting an additional part at the bow of said ship, its position depending mainly on the structure of the ship's hull 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 the underwater pipes to the floating production unit. Indeed, within the turret, a rotary joint, also designated by the term "rotary joint", or an assembly of rotary joints, also known by the Anglo-Saxon names " swivel " or " swivel stack ", allows to put implement a fluid transfer between the geostatic part and the free system of the vessel which revolves around the turret.

• les joints tournants tubulaires, également connus sous les appellations anglo-saxonnes « pipe swivel » et « in-line swivel » ;
• les joints tournants toroïdaux, également connus sous l'appellation anglo-saxonne « toroidal swivel ».

Thus rotary joints ensure that all fluids, whether gaseous or liquid, are transferred safely from geostatic parts, such as, by way of nonlimiting examples, oil wells, submerged pipes in the seabed, collectors, hoses, to the system allowing movements. There are two main types of rotary joints:

• tubular rotary joints, also known by the Anglo-Saxon names " pipe swivel " and " in-line swivel ";
• toroidal rotary 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, the toroidal rotary joints are recommended 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 rotary joints.

An example of a "classic" toroidal rotary joint has a number of main components. It includes a male member, also referred to as "internal member" or "fixed member", and a female member, also referred to as "external member" or "rotary member", movable relative to the other and kept concentric and coaxial using a mechanical bearing. By way of nonlimiting example, such a bearing is advantageously a bearing with three rollers, also known under the Anglo-Saxon 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 slip 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 fluid transfer takes place. A plurality of chambers can be present within the same rotating joint to ensure the passage or transfer of one or more fluids. To ensure tightness within a rotating 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 can advantageously but not limitatively result from open toric recesses, arranged on the surface in the internal wall of one or the other of the male and female members.

• un connecteur rotatif optique 13 et un connecteur rotatif éléctrique 14, également connus sous les appellations anglo-saxonnes « Optical Swivel » et « Electric Swivel », qui permettent les transferts de puissance et d'informations ;
• d'autres raccords rotatifs 15 et 16, également connus sous l'appellation anglo-saxonne « Utility Swivel », permettant le transfert de tous les produits et additifs nécessaires au transfert et au bon fonctionnement du système de transfert, tels que des agents chimiques, des agents hydrauliques, de l'air ou autre gaz, les eaux de lutte contre les incendies ou bien des évacuations ;
• des systèmes d'entraînement et/ou de guidage des modules de joints tournants 17, 17' et 17" permettent d'assister le système de transfert de fluide 12 et assurent le maintien des joints tournants 1, 1' et 1".

Such rotary joint modules are integrated within a fluid transfer system, consisting of an assembly of rotary joint modules. The figure 1 presents such an assembly of rotary joint modules. The assembly of rotary joints includes in particular rotary joints 1, 1 'and 1 ", suitable for the transfer of fluids. However, other modules of rotary joints can be used to allow other transfers. By way of examples non-limiting, we can notably cite:

• 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 the products and additives necessary for the transfer and for the proper functioning of the transfer system, such as chemical agents, hydraulic agents, air or other gases, firefighting or evacuation water;
• drive and / or guide systems for the rotary joint modules 17, 17 'and 17 "make it possible to assist the fluid transfer system 12 and maintain the rotary joints 1, 1' and 1".

Advantageously, such drive and / or guide systems are used to rotate the female members of the rotary joints, serving to transfer the various fluids between the male member, in other words the fixed part, and the female member, in other words the rotating part of a mooring system for a floating production unit, also known as "FPSO". This clever rotation drive takes place through the transmission of mechanical torque. Such a drive and / or guide system is designed to support the friction loads generated by the various rotary joints, said joints sliding on their respective friction surfaces, in particular the grooves where the seals take place. Such a drive and / or guide system does not affect the variation in the seal extrusion clearance. Each rotary joint module is equipped with an independent drive and / or guidance system, designed to allow relative linear movements of all the rotary joint modules, 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. Therefore, such a drive and / or guidance system allows to drive the female member of rotating rotating joints. The drive and / or guide system is such that the only degree of freedom existing is rotation around the axis of revolution of the mooring system, and consequently the assembly of rotary 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 couple 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 cooperating with the female member of a rotary joint. The female member may advantageously be integral with one or more, advantageously, protruding drive ears, said ears themselves comprising openings or recesses. The drive and / or guide system comprises one or more protrusions, advantageously two. The ear recesses are advantageously sized to receive said protuberances and thus ensure cooperation between the rotary joint and the drive and / or guide system. In addition, such a drive and / or guidance system may include additional attachment and / or attachment means to guarantee the assembly and cohesion of the system and of the rotary joint.

Such drive and / or guide systems cooperate with gantries, also known by the English name " gantry structures ", mooring systems and in particular mooring turrets. As a variant, they can be directly integrated into said gantries within the mooring turrets and constitute a single and same entity.

• un anneau d'entraînement, également connu sous l'appellation anglo-saxonne « Ring type », illustré en liaison avec la figure 2a ;
• une poutre en torsion, également connue sous l'appellation anglo-saxonne « Torsion Beam type », décrite en liaison avec la figure 2b ;
• une poutre articulée, également connue sous l'appellation « Articulated Beam type », illustrée en liaison avec la figure 2c ;
• une poutre en tension/compression, également connue sous l'appellation « Tension-Compression Beam type », décrite en liaison avec la figure 2d.

Among the known drive and / or guidance systems, there are four mainly used systems, described in relation to the figures 2a to 2d :

• a training ring, also known by the Anglo-Saxon name " Ring type", illustrated in conjunction with the figure 2a ;
• a torsion beam, also known by the Anglo-Saxon name " Torsion Beam type ", described in conjunction with the figure 2b ;
• an articulated beam, also known under the name " Articulated Beam type " , illustrated in connection with the figure 2c ;
• a tension / compression beam, also known under the name “ Tension-Compression Beam type ”, described in conjunction with the figure 2d .

According to figure 2a , the drive and / or guide system, commonly called “drive ring” comprises a floating ring 20, made from a material having the resistance necessary to support the load imposed by a rotary joint module. The term "ring" means any quadrilateral with rounded or non-rounded angles, which may be oblong, ellipse or ovoid. The definition of the term "ring" would not be limited to the examples given above in the document. The floating ring 20 comprises one or more, advantageously two, protrusions 20p, dimensioned to cooperate advantageously with the driving ears 21 projecting from a female member of a rotating joint. In addition, such a ring cooperates with a mooring system, such as by way of nonlimiting example, a gantry 30, with articulation means allowing the implementation of sliding pivot connections. Such sliding pivot connections allow two degrees of freedom, translation and axial rotation. The ring can thus move laterally and longitudinally relative to the system. The rotational drive is finally performed when a torque is transmitted to the system.

According to figure 2b , drive ears 21 are advantageously fixed to a drive and / or guide system 17 by any means, using the distal parts 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 part and dimensioned to fit into a recess arranged within each protruding drive ear 21 of a female member 3 and ensure cooperation of the arm 22 and of the female member 3. At the other end, the proximal parts of the two drive arms 22 cooperate with each of the ends of an articulated beam 23 by means of two articulations 23a allowing the implementation of ball joints or pivots. Such ball joint connections ensure complete connection in translation between the drive arms and the articulated beam 23, but the leave free to rotate. They thus comprise three degrees of connections, the three translations, and three degrees of freedom, the three rotations. Thus, the rotational drive is finally carried out by a torsion of the articulated beam 23. The term “torsion” is understood to mean the stress suffered by the beam, said beam being subjected to the action of a couple acting in parallel planes. .

According to figure 2c , like the torsional beam device described in connection with the figure 2b , drive ears 21 are advantageously fixed to the drive and / or guide system 17 by any means, using the distal parts of two drive arms 22, said arms being substantially parallel and integrated into the system 17 Each arm 22 advantageously comprises a protuberance 22e, said protuberance being positioned substantially around its distal part and dimensioned to fit into a recess formed in each protruding drive ear 21 of a female member 3 and ensure the cooperation of the arm 22 and of the female member 3. At the other end, the proximal parts of the two drive arms 22 cooperate with a hinged beam by means of two articulations 23a allowing the implementation of ball joints, at least connections pivots. In this embodiment, the proximal parts of the arms 22 no longer cooperate with the ends of said articulated beam 23, but with a central part of the articulated beam. The articulated beam 23 cooperates itself, by means of articulations 23b, allowing the implementation of ball or pivot connections, 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 blocking the articulated beam 23, when a torque is transmitted to the system 17.

According to figure 2d , like the torsional beam and articulated beam devices described respectively in conjunction with the Figures 2b and 2c , the drive ears 21 are advantageously fixed to the drive and / or guide system 17 by any means, using the distal parts 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 part and dimensioned to fit into a recess made within each protruding drive ear 21 of a female member 3 and ensure cooperation arm and female member. At the other end, the proximal parts of the two arms 22 each cooperate with a triangular support 24 by means of a joint 23a allowing the implementation of a ball joint, at least a pivot link. The two triangular supports 24 are themselves linked together by means of a beam 23, said beam being transverse with respect to the two drive arms 22. The connections between the beam 23 and the supports 24 are in principle ball joints or pivots, materialized by means of adapted joints 23b. Furthermore, the two triangular supports 24 also cooperate with a drive structure, such as by way of nonlimiting example, a gantry 30, by means of articulations 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 in compression when a torque is transmitted to the system. “Tension” means any stress which 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 different ball joints present in the system. In contrast, “compression” means any stress 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 and / or guidance system is described in connection with the figure 2e . Like the torsional beam, articulated beam and tension / compression beam devices described respectively in conjunction with the figures 2b to 2d , drive ears 21 are advantageously fixed to the drive and / or guide system by any means, using the distal parts of two drive arms 22, said arms being substantially parallel and integrated into the system 17. At the other end, the proximal parts of the two drive arms 22 cooperate with an articulated beam 23 via triangular plates 26, by means of two articulations 23a allowing the implementation of ball joints. In this embodiment, the proximal parts no longer cooperate with the ends of said articulated beam, but with a central part of the articulated beam 23. The articulated beam 23 cooperates itself, by means of articulations 23b allowing the setting in work of pivots or ball joints, at its ends with a drive structure, such as a non-limiting example, a gantry. In addition, the beam 23 comprises a link 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 'a hinge allowing the implementation of a first pivot link 23c.

• tout d'abord, une déformation élastique : le matériau ou l'élément se déforme proportionnellement à l'effort appliqué et reprend sa forme initiale lorsque la contrainte sollicitation disparaît. Il s'agit d'un changement temporaire et réversible ;
• suivie parfois d'une déformation plastique ou permanente : le matériau ne reprend pas sa forme initiale lorsque la contrainte ou sollicitation disparaît, il subsiste une déformation résiduelle. Il s'agit d'un changement irréversible.
• et enfin la rupture : la contrainte ou sollicitation dépasse la résistance intrinsèque du matériau ou seuil de résistance de l'élément et entraîne sa rupture.

Although the drive and / or guidance systems, described in conjunction with the 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 and / or guidance system is a mechanical system and therefore requires the application of constraints, such as non-limiting examples, torsion, compression and / or tension, on the system. and more particularly on beams and arms. Although these elements, more specifically the beams and arms, are made of materials adapted to withstand the stresses applied and / or applicable, under the effect of the sudden stresses, a material and subsequently the beams and arms of the system drive and / or guidance, can undergo different consequences, that is to say that they can present three different types of deformations. “Deformation” is understood to mean any substantial change or modification 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 while it is permanent when it remains even in the absence of constraints. However, all materials, beams and arms have a limit to be able to deform. When the stresses exerted are too great, they cause the material to rupture. Each material has a specific resistance threshold which corresponds to the limit threshold of the stress level that it can undergo without breaking. Thus, three types of deformations are to be counted:

• first of all, an elastic deformation: the material or the element deforms in proportion to the force applied and resumes its initial shape when the stress stress disappears. It is a temporary and reversible change;
• sometimes followed by a plastic or permanent deformation: the material does not return to its initial shape when the stress or stress disappears, there remains a residual deformation. It 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 leads to its rupture.

When a material or an element is subjected to repetitive or variable stresses over time, it can become more fragile. This phenomenon is called "mechanical fatigue". In this case, instead of simply being deformed, the material or the element will end up having cracks and possibly breaking. Fatigue is notably characterized by a range of stress variation which can be much lower than the resistance threshold of a material or element.

The invention makes it possible to respond to all or part of the drawbacks raised by known solutions.

• d'éviter la déformation des matériaux composant le système d'entrainement et/ou de guidage, d'assouplir les déplacements ;
• de supprimer les contraintes de torsion, tension et/ou compression appliquées sur les différents membres d'un système d'entrainement et/ou de guidage ;
• d'assurer une plus longue durée de vie d'un système d'entrainement et/ou de guidage ;
• de réduire le poids et le coût d'un système d'entraînement et/ou de guidage et ainsi simplifier le nombre d'éléments composant le système ;
• d'alléger la structure des systèmes d'entraînement et/ou de guidage et ainsi diminuer le dimensionnement de tels systèmes ;
• de remplacer un système mécanique par un système mixte combinant mécanique et hydraulique, voire parfois pneumatique.

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

• to avoid the deformation of the materials making up the drive and / or guide system, to soften the movements;
• to remove the torsional, tension and / or compression constraints applied to the different members of a drive and / or guide system;
• ensure a longer service life of a drive and / or guidance system;
• reduce the weight and cost of a drive and / or guide system and thus simplify the number of elements making up the system;
• to lighten the structure of the drive and / or guidance systems and thus reduce the dimensioning of such systems;
• replace a mechanical system with a mixed system combining mechanical and hydraulic, and sometimes even pneumatic.

• des premier et deuxième bras coplanaires, les parties distales desdits premier et deuxième bras coopérant avec un membre femelle d'un joint tournant à l'aide de moyens d'accroche et/ou d'attache ;
• une poutre étant sensiblement transversale et coplanaire et coopérant avec les parties proximales des premier et deuxième bras ;

Pour supprimer les contraintes de torsion, flexion ou compression appliquées sur la poutre, les premier et deuxième bras ou le portique, les premier et deuxième bras comportent respectivement des premier et deuxième vérins à double tige. En outre, le premier vérin comprend un piston, une chambre postérieure et une chambre antérieure de part et d'autre dudit piston, lesdites chambres étant de même section. De même, le deuxième vérin comprend un piston, une chambre postérieure et une chambre antérieure de part et d'autre dudit piston, lesdites chambres étant de même section que les chambres postérieure et antérieure du premier vérin. Par ailleurs, pour permettre une alimentation croisée des vérins, la chambre postérieure du premier vérin coopère avec la chambre antérieure du deuxième vérin au moyen d'un premier conduit. De la même façon, la chambre postérieure du deuxième vérin coopère avec la chambre antérieure du premier vérin au moyen d'un deuxième conduit.To this end, provision is made in particular for a drive and / or guide system for 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 attachment and / or attachment means;
• a beam being substantially transverse and coplanar and cooperating with the proximal parts of the first and second arms;

To remove the torsional, 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 a front chamber on either side of said piston, said chambers being of the same section. Likewise, the second cylinder comprises a piston, a rear chamber and a front 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 cylinders, the rear chamber of the first cylinder cooperates with the front chamber of the second cylinder by means of a first conduit. Similarly, the rear chamber of the second cylinder cooperates with the front 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 within the first and second conduits and thus avoid any accumulation of fluid, the first and second conduits are rigid.

To absorb movements due to small angles, the proximal parts of said arms cooperate with the female member by means of a ball joint.

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

According to a last variant, the proximal parts of said arms cooperate with the female member by means of an embedding 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 and / or guide system, said drive and / or guide cooperating with a gantry. To optimize the transfer of fluid and reduce the fatigue loads on the system, said fluid transfer system comprises a drive and / or guidance system 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 to an oil platform, the mooring system advantageously includes a fluid transfer system according to the invention.

According to a fourth object, the invention relates to a floating unloading, production and storage unit. Said unit advantageously comprises a mooring system according to the invention.

• la figure 1, précédemment décrite, illustre un assemblage de modules de joints tournants connu ;
• les figures 2a à 2e, précédemment décrites, présentent cinq systèmes d'entraînement et/ou de guidage connus ;
• les figures 3a et 3b décrivent schématiquement un système d'entraînement et/ou de guidage selon l'invention ;
• les figures 3c et 3d illustrent des exemples de vérins utilisés dans des systèmes d'entraînement et/ou de guidage.

Other characteristics and advantages will appear more clearly on reading the following description and on examining the accompanying figures, among which:

• the figure 1 , previously described, illustrates an assembly of known rotary joint modules;
• the Figures 2a to 2e , previously described, present five known drive and / or guidance systems;
• the Figures 3a and 3b schematically describe a drive and / or guidance system according to the invention;
• the figures 3c and 3d illustrate examples of cylinders used in drive and / or guidance systems.

• une liaison encastrement, qui empêche tout mouvement des bras par rapport aux oreilles d'entraînement,
• une liaison pivot, qui garantit la libre rotation des bras, selon leurs axes de révolution.
• une liaison rotule, également connue sous la dénomination « liaison sphérique », solution préférée, qui lie complétement les oreilles d'entraînement et les parties distales des bras, mais laisse lesdits bras et oreilles complétement libres en rotation. Une telle liaison rotule permet à chacune des parties distales des deux bras de se mouvoir selon des petits angles dans toutes les directions et permet de diminuer la sollicitation des bras au niveau du membre femelle 3 du joint tournant. La charge de fatigue est ainsi grandement diminuée.

The Figures 3a and 3b schematize a drive and / or guide system for 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 rotating joint. The arms 22 are advantageously made of a material capable of withstanding the stresses applied to the arms. The term “stress” is understood to mean the tendency of a material to deform under the effect of external forces exerted on said arms. As described in relation to the Figures 3a and 3b , the arms 22 are preferably two in number, to allow the transmission of the torque and consequently the rotary drive of the rotary joint 1. They will be called in the following document "first and second arm". The first and second arms of a drive and / or guide system according to the invention are at least coplanar and preferably parallel. The distal parts 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 in rotation relative to the male member 2. Such cooperation can be done using attachment and / or attachment means 21, said means being able to be integral with or integrated into the female member 3. Such attachment and / or attachment means 21 may preferably be in the form of two protruding drive ears , one for each arm, or any equivalent support, said ears being advantageously welded, bolted or fixed by any other means The distal parts 22d can cooperate with the drive ears according to different mechanical connections, in particular:

• a built-in link, which prevents any movement of the arms relative to the drive ears,
• a pivot link, which guarantees the free rotation of the arms, along their axes of revolution.
• a ball joint, also known under the name "spherical link", preferred solution, which completely links the drive ears and the distal parts of the arms, but leaves said arms and ears completely free to rotate. Such a ball joint connection allows each of the distal parts of the two arms to move at small angles in all directions and makes it possible to reduce the stress on the arms at the female member 3 of the rotary joint. The fatigue load is thus greatly reduced.

Furthermore, the proximal parts 22p of the first and second arms 22 'and 22 "advantageously cooperate with a beam 23, substantially transverse to the first and second arms. As a variant, the proximal parts 22p of each arm could directly cooperate with a gantry 30. Analogously to the distal parts of the first and second arms 22, this cooperation can be organized around different mechanical connections, by way of preferred but nonlimiting examples, pivot, ball or embedding 23a connections. Furthermore, as a variant, the beam 23 can be directly integrated into 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 can be integrated within such an arm or constitute the whole of the 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 which transforms the energy of a pressurized fluid into mechanical energy. A cylinder is characterized by its stroke, that is to say the length of the movement to be ensured, by the diameter of its piston and by the pressure of the fluid, said diameter and said pressure depending on the force developed. There are two main types of cylinders, depending on the fluid used: pneumatic cylinders, in which the fluid used is mainly compressed air, advantageously but not limited to between 2 and 10 bars, and hydraulic cylinders, in which the fluid used is mainly pressurized oil, up to 350 bars. Preferably, the first and second arms 22 'and 22 "include first and second cylinders 28' and 28". A cylinder generally consists of a cylinder closed at both ends, defining one or more cavities. Inside said cavity, a movable part, in principle a piston 28p, is mounted on a first rigid rod 28t1, and makes it possible to separate the volume of the cavity into two chambers 28c1 and 28c2, isolated one from the other. The two rooms are preferably of the same section. According to a conventional embodiment, the term "anterior chamber" 28c2 is used, the chamber not containing the first rod 28t1 of the jack and "posterior chamber" 28c1 the chamber containing the first rod 28t1 of the jack. The proximal part of the first rod 28t1 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 part of the first rod 28t1 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. Furthermore, the first rod 28t1 guarantees the transmission of a force in the form of pressure and by way of consequence of a displacement. Such a jack 28 can advantageously have a damper (not shown in figures 3a to 3d ) in order to obtain a slowdown at the end of 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 body of the cylinder. The first rod 28t1 advantageously cooperates with the distal part 22p of the arm, while the end of the body of the jack, opposite to said first rod, advantageously cooperates with the proximal part 22p of the arm 22. Similarly, the first rod 28t1 can advantageously cooperate with the proximal part 22p of the arm, while the end of the cylinder body, opposite to said first rod, can advantageously cooperate with the distal part 22d of the arm. Said cooperation is done using any known attachment and / or attachment means allowing the materialization of a mechanical connection, by way of preferred but nonlimiting examples, pivot connections, ball joint or embedding.

A jack 28 can also be characterized by its mode of action. Two types of action are distinguished in particular: single-acting cylinders, known under the name "VSE", and double-acting cylinders, known under the name "VDE". As illustrated in connection with the figure 3c , a cylinder 28 is said to have a single effect when the cylinder only works in one direction, that is to say that only one chamber is supplied with fluid, preferably the anterior chamber, and consequently, the arrival of the pressure is done only through a single opening 28o, driving the piston 28p in one direction. The return of the piston 28p is achieved under the action of a spring 28r, an equivalent system or an external force. As described in connection with the 3d figure , a jack is said to have a double effect when the jack works in two directions, that is to say that the VDE jack has two possible feeds, by the anterior chamber 28c2 or by the posterior chamber 28c1: the pressurized fluid is thus sent on either side of the piston 28p depending on the desired work. Such a jack 28 has two openings 28o1 and 28o2 for supplying the device with fluid. Furthermore, pressure is applied alternately on each side of the piston 28p, said piston thus moving in one direction then in the other. When supplying pressure to the anterior chamber 28c2, the piston 28p moves to reduce the posterior chamber 28c1, said piston compressing or "driving out" the fluid from the posterior chamber 28c1. When the posterior chamber 28c1 is supplied with pressure, the piston 28p moves in the opposite direction, said piston 28p compressing or "driving out" the fluid from the anterior chamber 28c2. The effort in pushing, that is to say when the first rod 28t1 leaves the cylinder cavity, is slightly greater than the force in pulling, that is to say that the first rod 28t1 penetrates the actuator cavity 28: in fact, the pressure does not act on the surface of the piston 28p occupied by the first rod 28t1 fixed to said surface, generally opening into the rear chamber 28c1 of the cavity. The pressure and the effort are therefore not identical in the two chambers anterior 28c2 and posterior 28c1 since the entry of material, represented by the entry of the first rod 28t1, is accomplished within the posterior chamber 28c1 only.

To overcome this drawback, double rod cylinders 28 are used. The principle of said double rod cylinders, illustrated in conjunction with the 3d figure is as follows: the first rod 28t1 enters and leaves the jack 28 within the rear chamber 28c1. As explained above, in this configuration, certain problems appear, particularly concerning the pressure and the force to be applied, but also the guiding in translation of the jack. The proximal part 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 part is fixed to said surface by any means. Said second rod 28t2 advantageously has a section substantially identical to the first rod, but can be of different length. Furthermore, the distal part of said second rod may advantageously be free. The first and second rods are advantageously parallel, but not necessarily mirrored to each other, that is to say that their respective points of attachment to the piston are not necessarily substantially identical. Preferably, the longitudinal axes of the first and second rods 28t1 and 28t2 are coincident 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 embodiment, illustrated by Figures 3a and 3b , a drive system and / or guide 17 according to the invention comprises a double rod cylinder 28 in each arm 22.

As explained above, the first and second arms 22 'and 22 "advantageously comprise first and second cylinders 28' and 28" respectively, advantageously with double rod and with double effect. Each cylinder has two openings, a 28o2 in the anterior chamber 28c2 and a 28o1 in the rear chamber 28c1, said openings alternately supplying and discharging the fluid within the anterior and posterior chambers. Thus, the first jack 28 'has an opening 28o2 in its anterior chamber 28c2 and a 28o1 in its rear chamber 28c1, said rear chamber 28c1 allowing the insertion of the first rod 28t1 within it. Similarly, the second cylinder 28 "has an opening 28o2 in its anterior chamber 28c2 and a 28o1 in its rear chamber 28c1, said rear chamber allowing the insertion of the first rod 28t1 therein. When the first rod 28t1" "inside" the cylinder, the opening 28o1 within the rear chamber 28c1 ensures the supply of pressurized fluid, while the opening 28o2 within the anterior chamber 28c2 guarantees the escape of the fluid. , when the first rod "leaves" inside the cylinder, the opening 28o1 within the rear chamber 28c1 ensures the escape of the fluid, while the opening 28o2 within the anterior chamber 28c2 guarantees the supply in pressurized fluid.

• la chambre postérieure 28c1 du premier vérin 28' coopère avec la chambre antérieure 28c2 du deuxième vérin 28" au moyen d'un premier conduit 27', c'est-à-dire que les ouvertures au sein de la chambre postérieure 28c1 du premier vérin 28' et au sein de la chambre antérieure 28c2 du deuxième vérin 28" sont connectées l'une par rapport à l'autre au moyen d'une première ligne fluidique.
• la chambre postérieure 28c1 du deuxième vérin 28" coopère avec la chambre antérieure 28c2 du premier vérin 28' au moyen d'un deuxième conduit 27"", c'est-à-dire que les ouvertures au sein de la chambre postérieure 28c1 du deuxième vérin 28" et au sein de la chambre antérieure 28c2 du premier vérin 28' sont connectées l'une par rapport à l'autre au moyen d'une deuxième ligne fluidique.

In order to compensate for the deformation constraints of the structure of the drive and / or guide system, as examples, the torsional, bending or compressive stresses applied to the known and previously described drive and / or guide systems in conjunction with the Figures 2a to 2e , the first and second jacks 28 ′ and 28 "present in said system are supplied by means of crossed connections, advantageously in a closed circuit, that is to say that:

• the rear chamber 28c1 of the first cylinder 28 'cooperates with the front chamber 28c2 of the second cylinder 28 "by means of a first conduit 27', that is to say that the openings within the rear chamber 28c1 of the first cylinder 28 'and within the anterior chamber 28c2 of the second cylinder 28 "are connected relative to each other by means of a first fluid line.
• the rear chamber 28c1 of the second cylinder 28 "cooperates with the front chamber 28c2 of the first cylinder 28 'by means of a second conduit 27"", that is to say that the openings within the rear 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 cross connections allow the first and second cylinders 28 'and 28 "to be controlled by means of which the first and second arms 22' and 22" are stretched in the same direction and thus reduce the deformation 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 are made of a material capable of withstanding the pressure imposed by the fluid. Preferably, the first and second conduits are rigid to avoid any swelling and / or any accumulation due to the pressure.

As previously described in connection with the figure 1 , a drive and / or guide system 17 for a rotary joint is in principle used within a fluid transfer system 12. Such a fluid transfer system generally comprises at least two modules of rotary joints, chosen from , by way of nonlimiting examples, rotary joints for fluid transfer, rotary optical and electrical connectors. At least one drive and / or guide system according to the invention is used within such a fluid transfer system. All or part, that is to say at least the ends, of the beam 23 of a drive and / or guide system 17 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.

• un certain nombre de lignes d'ancrages pour permettre une certaine stabilité de l'unité flottante ;
• une structure tourelle, pour garantir la connexion entre l'unité flottante et les lignes d'ancrage ;
• un roulement mécanique support pour permettre à l'unité flottante de pivoter autour de la partie fixe de la tourelle d'un point de vue géostatique ;
• une structure d'unité flottante pour supporter ledit roulement mécanique ;
• un système de transfert de fluide, consistant en un système de transfert sous-marin, un collecteur, un assemblage de joints tournants et un arrangement de conduits. Le système de transfert de fluide est avantageusement conforme à l'invention.

Transfer systems, by means of a gantry, are generally introduced into rotary mooring systems at sea, as for example, without limitation, within a mooring turret. “Mooring” means the action of connecting a floating unit to another system, such as, for example not restrictive, another floating unit, a platform or even a pontoon. Said turret is generally composed of five main elements:

• a number of anchor lines to allow a certain 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 pivot 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, an assembly of rotary joints and an arrangement of conduits. The fluid transfer system is advantageously in accordance with the invention.

The mooring systems are in principle rotary and generally introduced within a floating production, storage and unloading unit, also known by the Anglo-Saxon name " Floating production storage and offloading ". Said units are generally in the form of a vessel cooperating with a drilling platform and at least one fluid transfer system, said system being able to be included within a mooring turret, a pivoting system allowing the vessel to s '' orient freely from so as to offer less resistance to sea currents. Advantageously, the floating unit includes a mooring system according to the invention.

The invention has been described during its operation in relation to rotary joints for ensuring the transfer of fluids within floating unloading, production and storage units comprising a mooring turret. It can also be implemented for any type of rotary joints or any type of mobile platforms combined with an adequate 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 in rotation 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 capable of performing an action equivalent to that performed by the jack, for example a gear and rack assembly, the two elements being motorized.

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

Claims (11)

1. Drive and/or guidance system (17) for a rotary joint (1), comprising:

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

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

   said system being characterized in that:

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

   - the first cylinder (28') comprises a piston (28'p), a posterior chamber (28'c1) and an anterior chamber (28'c2) on either side of said piston (28'p), said chambers having the same cross section;

   - the second cylinder (28") comprises a piston (28"p), a posterior chamber (28"c1) and an anterior chamber (28"c2) on either side of said piston (28p), said chambers having the same cross section as the posterior chamber (28'c1) and anterior chamber (28'c2) of the first cylinder (28');

   - the posterior chamber (28'c1) of the first cylinder (28') engages with the anterior chamber (28"c2) of the second cylinder (28") by means of a first pipe (27');

   - the posterior chamber (28"c1) of the second cylinder (28") engages with the anterior chamber (28'c1) of the first cylinder (28') by means of a second pipe (27").
2. Drive and/or guidance system (17) according to the preceding claim, wherein the first and second arms (22', 22") are substantially parallel.
3. Drive and/or guidance system (17) according to either of the preceding claims, wherein the first and second pipes (27', 27") are rigid.
4. Drive and/or guidance system (17) according to any of the preceding claims, wherein the proximal portions (22'p, 22"p) of said arms (22', 22") engage with the female member (3) by means of a ball joint connection.
5. Drive and/or guidance system according to any of claims 1 to 3, wherein the proximal portions (22'p, 22"p) of said arms (22', 22") engage with the female member (3) by means of a pivot connection.
6. Drive and/or guidance system according to any of claims 1 to 3, wherein the proximal portions (22'p, 22"p) of said arms engage with the female member (3) by means of an embedding connection.
7. Drive and/or guidance system according to any of the preceding claims, wherein the first and second cylinders (28', 28") are pneumatic.
8. Drive and/or guidance system according to any of claims 1 to 6, wherein the first and second cylinders (28', 28") are hydraulic.
9. Fluid transfer system, comprising a rotary joint module (1), said rotary joint module (1) engaging with a drive and/or guidance system (17), said drive and/or guidance system (17) engaging with a gantry structure (30), characterized in that said fluid transfer system comprises at least one drive and/or guidance system (17) according to any of claims 1 to 8.
10. Mooring system, comprising a mooring turret within which a fluid transfer system is arranged, characterized in that said mooring system comprises a fluid transfer system according to claim 9.
11. Floating offloading, production and storage unit, characterized in that said unit comprises a mooring system according to claim 10.

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