Telescopic rotary rigging

Abstract

The invention relates to telescopic Fettner rotary rigging comprising a number of embodiments, suitable for various applications and constructed on the same base which makes it possible, in particular, to prevent the transmission of a rotational torque from the rigging via the central mast or by the skins of the tubular sections making up the surface of the cylindrical sail, to limit weights suspended at great height when the rigging is in a deployed position and their resulting effect on the righting torque of a ship, and to limit a bending torque generated by the sail thrust that is taken up by the bearings guiding the tubular sections.

Description

Telescopic rotating rigging

[0001] The invention belongs to the field of sail propulsion devices. More particularly, the invention relates to a rotating cylindrical rig of the telescopic Flettner type, capable of being deployed and retracted.

[0002] A Flettner type rotating rig constitutes a sail propulsion device for a ship, and comprises a rigid cylindrical rotating sail, the diameter of which is several meters, extending vertically from a deck of the ship to a height equal to several times its diameter.

[0003] This sail is set in rotation, typically at a speed of a few hundred rpm, so when it is subjected to the wind, this sail produces, by an aerodynamic effect known as the Magnus effect, a thrust perpendicular to the direction of the wind and to its axis of rotation.

[0004] The aspect ratio of such a sail, the ratio H / D of its height H by its diameter D, is typically between 4 and 9, i.e. for a sail with a diameter of 5 meters, a height between 20 m and 45 m.

[0005] The presence of one or more sails of this type on a ship does not pose some difficulties, particularly when the ship is not offshore or when the sail propulsion device is not in use.

[0006] Indeed, the sail produces an air draft, a capsizing moment, reduces the righting moment, reduces visibility, hinders the passage of engineering structures as well as the transshipment of equipment, particularly by means of a crane.

[0007] Also, several techniques have been used to allow a Flettner sail to be lowered.

[0008] US patent 4,401,284 describes a vessel equipped with a drop sail, consisting of a waterproof, inflatable fabric tarpaulin, stiffened by an internal structure comprising mast rings mounted on a cable and connected to the waterproof tarpaulin by flexible straps. Inflating and deploying the tarpaulin puts tension on the cable and the straps.

[0009] Such a prior art device has the disadvantage of requiring the maintenance of internal pressure within the tarpaulin at a level sufficient to ensure its rigidity, which consumes additional energy and makes the device susceptible to malfunctions or adverse sea conditions. Therefore, such a device cannot constitute the primary means of propulsion for a ship.

[0010] US patent 4,602,584 describes a vessel equipped with a Flettner-type rotating sail, which includes at its base, approximately at deck level, a hinge mechanism allowing the rotating sail to be lowered by tilting it onto the deck. This type of mechanism is also difficult to adapt to large rotating sails weighing several tens of tons; it also requires additional stays to hold the rotating sail in position, which clutter the deck.

[0011] Document EP 4 568 884 describes a Flettner-type rotating sail with a hinge that allows an upper segment of the sail to be tilted approximately halfway up. While this device is satisfactory, it does increase the lateral bulk of the rotating sail when it is lowered. This lowering system can also be difficult to operate in strong winds or rough seas.

[0012] Document WO 2019 / 157483 describes a Flettner-type telescopic rotating rig comprising two tubular sections: a fixed lower section and an axially movable upper section. The two sections are rotationally linked to a central mast. The central mast drives the two sections in the deployed position. Because this central mast must absorb the sail thrust, this configuration requires a heavy rotating rig and complicates the connection of the central mast to the deck of a ship equipped with such a device.

[0013] The GB 2 187 154 standard describes a Flettner telescopic rig with a fixed central rotating mast, but does not specify how this rig is driven in rotation. The guide bearings are located at the base and top of the rig, far from the center of effort, which is located approximately at the center of the rig. This results in high stress on the bearings, which must withstand significant bending moments.

[0014] Document EP 2 723 632 describes a Flettner telescopic rotating rig, comprising a telescopic central mast and at least two tubular cylindrical sections capable of sliding relative to each other to deploy and retract the rig, the two sections being locked together in the deployed position. The rotation of the rig is driven by the lower tubular section at its base, which means that the portion of this section forming the cylindrical surface of the sail must be dimensioned to transmit the driving torque, thus increasing its mass and rotational inertia.

[0015] Document EP 2 536 624 describes a Flettner telescopic sail comprising a telescopic mast supporting a drive motor at the top of the telescopic mast so that the transmission of the motor torque between the cylindrical sections constituting the surface of the sail is carried out by these same tubular sections, which implies sizing them accordingly and increases the rotating mass, as well as the overall mass of the rigging.

[0016] The proposed device aims to resolve these drawbacks and concerns several embodiments of a Fettner-type rotating rig built on the same basis, notably allowing:

[0017] to avoid the transmission of a rotational torque of the rigging by a central mast or by the skins of the tubular sections constituting the surface of the cylindrical sail;

[0018] to limit the masses suspended at a great height in a deployed rigging position and their influence on a ship's righting moment; and

[0019] to limit a bending moment generated by the sail thrust to be taken up by the bearings guiding the tubular sections.

[0020] For these purposes, the proposed device concerns a Flettner-type rotating rig, configured to rotate around an axis of rotation and telescopic along the axis of rotation between a retracted height and a deployed height from a base, comprising:

[0021] a lower tubular section of a first outside diameter;

[0022] an upper tubular section of a second internal diameter, the second internal diameter being greater than the first external diameter;

[0023] a mast, fixed in rotation, comprising a tower extending from the base to a tower height;

[0024] a drive motor for rotating the lower tubular section positioned at the top of the tower;

[0025] a rotational guidance of the lower tubular section around the tower comprising at least one bearing combined with the torque motor;

[0026] a linear displacement device along the axis of rotation of the upper tubular section relative to the lower tubular section between a retracted position and a deployed position;

[0027] in which the motor is a direct drive torque motor whose stator is linked to the tower and leaving a free passage of a diameter of at least 700mm at the top of the tower.

[0028] The rotating rigging may include a transfer platform attached to a torque motor rotor, the transfer platform being configured to be rotationally linked with an internal ferrule connected to the upper tubular section when the latter is in the deployed position.

[0029] The transfer platform may include a conical portion configured to be rotationally linked with a conical portion of the inner shell when the upper tubular section is in the deployed position.

[0030] The linear displacement device of the upper tubular section may include at least one hoist cable and at least one sagging cable wound at one end around a winch connected to the transfer platform and connected to the upper tubular section at their other end.

[0031] The rotating rigging may include a fixed, rotating telescopic section configured to slide along the axis of rotation relative to the tower through the clear passage at the top of the tower. The upper tubular section is translationally fixed to the telescopic section and is guided in rotation by at least one upper bearing configured between the upper tubular section and one end of the telescopic section. The linear displacement device of the upper tubular section moves the telescopic section relative to the tower. The linear displacement device of the upper tubular section may be selected from a rack and pinion drive, a worm and nut drive, a linear motor, a hydraulic or pneumatic cylinder, a chain drive, and a cable device. The end of the telescopic section, when the upper tubular section is in the deployed position, may be located at a height less than or equal to 3 / 5 èmeof the deployed height or be located at a height equal to the deployed height, and may include a second torque motor, combined with the upper bearing, configured to drive the upper tubular section in rotation and a locking device for the telescopic part relative to the tower in the deployed position.

[0032] The telescopic rotating rigging can be implemented according to the embodiments presented below with reference to [reference to] in which: Fig.1

[0033] shows, in longitudinal section view, a schematic diagram of a first example of the realization of a telescopic rotating rigging; Fig. 2

[0034] represents, according to a longitudinal cross-sectional view, a schematic diagram of the basic structure common to all embodiments; Fig.3

[0035] represents a schematic detail view according to a cross-section of a sliding joint between the lower tubular section and the upper tubular section of the rigging shown; Fig. 4

[0036] shows, according to a schematic detail view in longitudinal section, an example of the implementation of a locking mechanism between the lower tubular section and the upper tubular section in a configuration applicable to the rigging shown; Fig. 5

[0037] represents, according to a partial longitudinal cross-sectional view, an example of the implementation of a rotational drive for the rotating rigging; Fig. 6A

[0038] represents, according to a profile view, an example of a ship equipped with rotating rigging in the deployed position; Fig. 6B

[0039] shows the ship with rotating rigging in the retracted position. Fig. 7A

[0040] shows, from a top view, the orientation of a sail propulsion force produced by a Flettner-type rotating rig subjected to a true starboard wind; Fig. 7B

[0041] shows from a top view the orientation of a sail propulsion force produced by a Flettner type rotating rig subjected to an apparent wind due to the forward movement of a ship under the effect of this force; Fig. 8

[0042] shows, in a longitudinal cross-sectional view, a schematic diagram of a first variant of a second implementation of the telescopic rigging; Fig. 8A

[0043] shows, according to a partial longitudinal cross-sectional view, an alternative way of coupling the lower tabular section and the upper tubular section in a configuration applicable to the rigging shown; Fig. 9

[0044] represents, in a schematic longitudinal cross-section, an example of a second variant of the second embodiment of the rotating rigging; and Fig. 10

[0045] shows, according to a partial longitudinal cross-sectional view, an example of the second embodiment of the telescopic rotating rigging comprising a locking device for a telescopic part of the mast.

[0046] Particularly when a Flettner type rig is fitted to an existing vessel, not originally intended to receive it, the presence of this rig modifies the capsizing moment and the righting moment of the vessel, in proportions which can reduce its navigational capabilities.

[0047] The aerodynamic capsizing moment is produced by the sail thrust which is a function, even if the rigging is not rotating, of the aerodynamic surface of the rigging and the height of the center of sail thrust, approximately at mid-height of the rigging.

[0048] The righting moment is the torque exerted by the hydrodynamic thrust on the hull when the ship is heeled over, opposing the weight of the crew to right the ship. Under these conditions, the ship's stability is all the more important as the distance between the center of hydrodynamic thrust and the center of mass is reduced. However, the installation of such a rig can increase this distance due to the mass of the rigging itself and the various crew members within it.

[0049] The ability to retract or lower the Flettner rig offered by a telescopic rig makes it possible to reduce the capsizing moment, by reducing the exposed rigging area and the height of the center of sail thrust, and also to increase the righting moment by bringing the centers of mass of the rigging crews closer to the deck.

[0050] In addition, the mass of the means used to take up the sail thrust (mast) as well as the means of deployment - retraction of the telescopic rigging can be reduced and the center of gravity of these means brought as close as possible to the deck of the ship so as to limit the adverse effect on the righting moment.

[0051] The embodiments described below allow for different compromises built on a similar basis.

[0052] According to one embodiment, a Flettner type rotating rig (300) comprises a mast (100) configured to be fixed to a base (105), in its lower part, to a deck of a ship (not shown), the mast extending perpendicularly to this base in a substantially vertical direction which corresponds to an axis of rotation (101) of the rotating rig.

[0053] The mast (100) can be fixed to the base (105) by bolting, welding, or any other suitable fastening method. The mast (100) is rotationally fixed and serves two functions: first, to guide the rotation of the cylindrical sail, and second, to transmit the sail thrust to the vessel for propulsion. Thus, the mast ensures the rigidity of the rigging.

[0054] The rotating rigging includes a lower tubular section (110) guided in rotation around the mast (100) along the axis of rotation (101), this guidance can be achieved by bearings (111, 112) configured to transfer a radial load and an axial load from the lower tubular section (110) to the mast (100).

[0055] A direct drive torque motor (130) can be used for the rotational drive of the lower tubular section around the axis of rotation (101) relative to the mast (100).

[0056] The rotating rigging includes an upper tubular section (120). This is able to slide relative to the lower tubular section (110) in a direction parallel to the axis of rotation (101) between a retracted position and a deployed position.

[0057] The lower and upper tubular sections are hollow cylinders with an outer and an inner diameter, designed to minimize weight. The inner diameter (191) of the upper tubular section (120) is larger than the outer diameter (190) of the lower tubular section to allow for relative sliding.

[0058] The mast (100) absorbs the entire sail thrust generated by the rotating section of the Flettner sail, comprising the lower tubular section (110) and the upper tubular section (120), via its connections to one or the other of these sections, and transfers this thrust to a vessel via the base (105). Therefore, when under sail thrust, the mast (100) is subjected primarily to bending stress at a moment perpendicular to the axis of rotation (101). To limit this bending moment and also ensure significant rigidity of the rigging, the connections between the mast (100) and the section(s) of the Flettner sail are preferably positioned as close as possible to the base (105), regardless of the specific design.

[0059] According to different embodiments: the rotational drive of the Flettner sail can be carried out on only one of the lower tubular section and the upper cylindrical section, and in this case the two sections are linked in rotation at least in the deployed position, or, the two sections can be driven individually in rotation.

[0060] According to embodiments: a deployment-retraction device can act directly on the upper tubular section (120) and in this case the mast can be of constant height, or the deployment-retraction device can act on the mast and in this case the mast includes a telescopic part.

[0061] Regardless of the embodiment, the mast (100) comprises a fixed, hollow tower (201) connected to the base (105). The fixed tower (201) can be made of steel, aluminum alloy, fiber-reinforced composite material, or a combination of these materials.

[0062] According to one embodiment, the fixed tower can be made, at least partially, by an assembly of beams or panels comprising wood fibers as described in document EP 4 538 167. This technical solution makes it possible to shift the natural frequencies of the tower towards frequencies higher than the rotation frequency of the Fletner rigging.

[0063] The lower tubular section (110) is guided in rotation and stopped in translation relative to the fixed tower (201) by at least one bearing, which may be a roller bearing (111, 112). The at least one bearing transfers to the fixed tower at least the weight of the lower tubular section (110) and at least a portion of the sail thrust.

[0064] The lower tubular section (110) can be connected to the bearings (111, 112) by bolting, for example via biconical flanges (211, 212).

[0065] Measured from the base (105), a height (210) of the fixed tower (201) can be substantially equal to a height of the lower tubular section (110) or even less.

[0066] A device for rotating the lower tubular section, for example in the form of a torque motor (130), can be installed at the top of the fixed tower (201) approximately halfway up the rotating rigging. The rotation of the lower tubular section can be driven via the upper biconical flange (212), which is itself connected to the rotor of the torque motor (130), so that at least one bearing (112) is combined with the torque motor (130). Thus, at least one bearing (112) is positioned at the top of the tower (201) near the center of effort of the rigging.

[0067] Positioning this bearing (112) at a height close to the center of effort reduces the bending stress it absorbs. This is especially true if the bearing is on roller bearings, allowing for a wider range of bearing selection. Bearing selection depends on its static and dynamic capacities, which increase with the size of the rolling elements, but also on the acceptable maximum tangential speed when the rigging is rotated, which is lower the greater the mass of the rolling elements.

[0068] This production base, adapted in terms of sizing, is essentially identical in principle regardless of the method of implementation and the variants described below, which allows for streamlining production while offering several possibilities depending on the performance or applications targeted.

[0069] , according to a first embodiment (300) the deployment-retraction device can act directly on the upper tubular section (120).

[0070] An inner diameter (191) of the upper tubular section is greater than an outer diameter (190) of the lower tubular section so that the upper tubular section can slide relative to the lower tubular section, between a deployed position as shown and a retracted position.

[0071] The transition from the retracted position to the deployed position and vice versa is achieved when the rotating rigging is not driven in rotation.

[0072] The lower tubular section (110) includes a transfer platform (140) fixed to an upper end of the lower tubular section (110), integral with an upper biconical flange (212) driven in rotation by the torque motor (130), so that the transfer platform (140) is driven in rotation when the rigging is in operation.

[0073] The upper tubular section (120) includes an inner ferrule (145) configured to cooperate with the transfer platform (140) when the upper tubular section (120) is in the deployed position, to achieve rotational locking (151) and axial locking (152) of the upper tubular section (120) relative to the lower tubular section (110)

[0074] The transfer platform (140) can also be a technical platform and can support a device for raising and lowering the upper tubular section (120), for its movement between the retracted position and the deployed position and vice versa.

[0075] The device for raising and lowering the upper tubular section (120) may include at least one hoisting cable (161) and at least one lowering cable (162), each associated with pulleys and wound around a single winch (160). The deployment and retraction device may include up to three hoisting cables and three lowering cables, depending on the rigging diameter, distributed around a circumference of the upper tubular section (120), with all six cables wound around a single winch.

[0076] According to this embodiment (300) the transfer platform (140) rotates with the Flettner rigging when the latter is in rotation.

[0077] An inner face of the upper tubular section may include a plurality of rails (121) configured to cooperate with a plurality of pads (115) linked to the lower tubular section (110), creating a sliding connection between the two sections, rotationally locking the upper tubular section (120) relative to the lower tubular section and ensuring alignment of the two sections during a deployment-retraction operation.

[0078] The rotation of the rigging is driven by a single torque motor (130), which drives the lower tubular section via the upper biconical flange (212). The rail (121) and slide (115) assembly does not transmit the rotational power generated by the torque motor (130) from one section to the other, but only maintains the two indexed sections in rotation relative to each other, regardless of their relative position.

[0079] The transmission of the rotary power to the upper tubular section (120) and the transmission of the sail thrust exerted on the upper tubular section (120) to the fixed tower (201) are carried out by the transfer platform (140) and the inner ferrule (145) joined in complete connection in the deployed position by a rotational lock (151) and an axial lock (151).

[0080] The use of a direct drive torque motor (130) for the drive of the rotating rigging allows the latter to be installed at the upper end of the tower (201), as close as possible to the transfer platform (140) while maintaining, at the top of the tower (201), a free passage with a diameter (192) of at least 700 mm to allow access, via the inside of the tower (201), to the transfer platform (140) in particular to carry out adjustment or maintenance operations.

[0081] The use of a torque (130) direct drive motor allows a high power / weight ratio of the motor without intermediate transmission which allows the motor to be placed approximately halfway up the rigging without unduly penalizing the righting moment, while avoiding the transmission of rotary power through the skin of the cylindrical sail or through the mast.

[0082] The skins of the upper and lower tubular sections can be made of stiffened panels (311, 312, 321, 322), the stiffeners of said panels not being shown to simplify the figure, which stiffened panels can be made, according to embodiment variants, of a composite material, an aluminum alloy, wood panels or a combination thereof.

[0083] The stiffened panels can be assembled onto longitudinal fittings (315, 325) by riveting or bolting.

[0084] The rails (121) of the sliding connections can be installed between the upper tubular section and the lower tubular section at the longitudinal fittings (315, 325).

[0085] A rail (121) can be connected to the upper tubular section (120) by bolting it to an intermediate fitting (326) inserted into a longitudinal fitting (325) fixed to the upper tubular section (120). This arrangement allows the radial position of the rail (121) to be adjusted by radially moving the intermediate fitting (326) relative to the longitudinal fitting (325) of the upper tubular section. Once the radial adjustment is complete, the intermediate fitting (326) is locked relative to the longitudinal fitting (325) of the upper tubular section, for example, by riveting.

[0086] A pad (115) can be linked to a longitudinal fitting (315) of the lower tubular section by elastic pads (316) of the "silent block" type.

[0087] The same rail (121) can be taken up on two pads (115) mounted on the same fitting (315) and spaced apart from each other, along the axis of rotation, by a distance between 1.5 and 2 times the outside diameter of the lower tubular section.

[0088] Adjusting the radial position of a rail (121), by the relative position of the longitudinal fitting (325) and the intermediate fitting (326) as well as the compliant mounting of the pad (115) by means of the elastic buffers (316) makes it possible to absorb the hyperstaticity of relative positioning of the sections.

[0089] Depending on the dimensions of the rotating rigging, 5 to 20 rail-shoe pairs are distributed over a circumference of the sections.

[0090] The relative locking of the upper tubular section and the lower tubular section can be achieved when the rotating rigging is in the deployed position.

[0091] The locking can be operated between the inner ferrule (145) fixed to the upper tubular section and the transfer platform (140) fixed to an upper end of the lower tubular section and guided in rotation relative to the fixed tower (201).

[0092] Thus, the transmission of the motor torque is achieved by the junction between the transfer platform (140) and the inner shell (145) of the upper tubular section (120) and not by the casing of the lower tubular section (110).

[0093] The locking mechanism may include rotational locking achieved by means of lugs (451) fixed to either the inner shell (145) or the transfer platform (140). These lugs extend substantially perpendicularly to an interface surface between the transfer platform and the inner shell and are configured to engage in angularly distributed peripheral bores (455) formed in either the transfer platform or the inner shell (145) opposite the lugs (451). These lugs (451) contribute, in particular, to the transmission of the rotational driving torque of the sections.

[0094] The locking may include axial locking of the sections. The locking may be achieved by studs (452) carried by either of the transfer platform (140) and the inner ferrule (145) and extending substantially perpendicularly to the interface surface between the transfer platform and the inner ferrule, studs which pass through either of the transfer platform or the inner ferrule when the rigging is in the deployed position, and which cooperate with nuts (465) so as to axially immobilize the lower tubular section and the upper tubular section relative to each other.

[0095] The rotational locking can include up to 6 studs (451) and the axial locking up to 24 studs (452) angularly distributed over circumferences of the transfer platform (140) and the inner ferrule (145) according to the diameter of the rigging.

[0096] According to alternative embodiments, the nuts (465) are installed and tightened onto the ends of the studs (452) manually or this connection can be made by automated means.

[0097] This embodiment (300) makes it possible to obtain a Flettner type telescopic rotating rig, light and including all its operating parts: torque motor (130), winch (160), cables (161, 162) inside the rig.

[0098] The deployment, retraction, locking and unlocking can be automated but can also be operated by operators from the transfer platform with a safety system prohibiting any rotation of the rigging during these maneuvers.

[0099] This embodiment also makes it possible to obtain, for the Flettner rig, a high deployed height / retracted height ratio, between 1.5 and 2. The majority of the mass being located in the lower part of the rig, its influence on the righting moment is reduced and the deployed height / retracted height ratios attainable are the highest among the different embodiments presented, so that the capsizing moment is reduced by 70% to 75% when the rig is in retracted configuration compared to the deployed configuration.

[0100] This lightweight embodiment also allows the natural modes of the rigging to be shifted towards higher frequencies far from the rigging's rotation frequency, enabling its integration into structures of medium stiffness at the base. Thus, a rotating Flettner-type rig in this embodiment is particularly well-suited to small vessels, less than 100 meters in length, or those with high stability requirements.

[0101] According to another embodiment (800, 900), the mast (100) may include a telescopic part (801) in sliding connection relative to the fixed tower (201), telescopic part around which the upper tubular section (120) is guided in rotation and stopped in axial translation relative to the telescopic part (801), by at least one upper bearing (811), for example by means of a biconical flange (821).

[0102] This embodiment is particularly, but not exclusively, suited to ships with a length exceeding 120 meters.

[0103] The deployment and retraction of the upper tubular section (120) relative to the lower tubular section (120) are carried out by the telescopic part (801) acting on the upper tubular section (120) by at least one upper bearing (811).

[0104] To this end, the telescopic part (801) can be linked to a trolley (850) in a sliding or helical connection with the tower (201), which trolley (850) can be moved relative to the tower parallel to the axis of rotation (101) by motorized means which may include, alone or in combination, a rack and pinion system, a lifting cable system, a linear motor, a worm nut drive system, one or more hydraulic cylinders, one or more chain cylinders.

[0105] According to a first variant (800), the Flettner rigging is driven in rotation by a single motor, for example by a torque motor (130) driving in rotation the lower tubular section (110) and placed at the top of the tower (201).

[0106] According to this first variant, the transfer platform (140) of the lower tubular section (110) may include a conical part (840) on its periphery, configured to cooperate with a conical ferrule (845) fixed inside the upper tubular section (120).

[0107] When the upper tube section reaches the deployed position, the conical ferrule (845) comes into contact with the conical part (840) of the transfer platform. The rotation imparted to the lower tube section by the torque motor (130) is transmitted to the upper tube section via the contact between the conical part (840) and the conical ferrule (845). This conical contact also ensures centering between the two sections.

[0108] The tapers of the conical part (840) and of the conical ferrule (845) are decreasing towards the base; alternatively, these tapers can be decreasing towards the top of the rigging.

[0109] The drive between the conical parts can be achieved by friction; for this purpose, the contacting faces can be given a suitable coating. Alternatively or additionally, the conical part (840) and the conical ferrule (845) can include grooves (not shown) so as to achieve a dog clutch and rotational connection by means of a barrier between the upper tubular section (120) and the transfer platform when the upper tubular section is in the deployed position.

[0110] An axial locking in the deployed position can, for example, be achieved between the tower (201) and the telescopic part (801).

[0111] The upper tubular section (120) may include in a lower part one or more elastomer skirts (860) to protect the interior of the Flettner rigging in particular from water spray.

[0112] The stroke of the telescopic section (801) and the position of the bearing linking the upper tubular section (120) and the telescopic section in translation result from a compromise between the bending moment resulting from the sail thrust applied to the mast, the achievable deployed height / retracted height ratio which conditions the reduction of the aerodynamic capsizing moment when changing from the deployed to the retracted configuration and the reduction of the righting moment in the deployed position.

[0113] According to an example embodiment, measured from the base, the height of the extended mast (810) is less than the height of the extended Flettner rigging (610). Since the stroke of the telescopic section (801) is less than or equal to the height of the tower (201), the height of the upper bearing (811), at the end of the telescopic section (801), is less than or equal to 3 / 5 èmeof the total height (610) of the Flettner rigging, an axial length (820) of the upper tubular section (120) being less than or equal to 2 times the total stroke of the telescopic part (801).

[0114] According to another embodiment, the upper bearing (811) of the upper tubular section is placed at the top of this section and the telescopic part (801) extends up to this bearing. This embodiment makes it possible to obtain a higher deployed height / retracted height ratio than the previous embodiment.

[0115] Regardless of the specific embodiment, variant (800) described above is capable of transmitting greater sail thrust to the vessel than the first embodiment, while maintaining reliable operation. It can be adapted to a Flettner rig with a diameter exceeding 5 meters and a sail area ratio (H / D) of approximately 5. The achievable deployed height / retracted height ratio is limited by the axial position of the bearing in the upper tubular section, which is between 1.3 and 1.6. This allows for a reduction in the capsizing moment of up to 60% between the deployed and retracted configurations.

[0116] According to a second embodiment (900), the upper bearing (811) located between the telescopic part (801) and the upper tubular section (120) includes a second torque motor (930) for the direct drive of the upper tubular section (120). The coupling of the motor to the upper tubular section via the biconical flange (821) can be achieved in a similar manner to the coupling of the torque motor (130) to the biconical flange (212) of the lower tubular section (110).

[0117] The drive system for rotating the entire rotating rigging or each of its sections is provided by a direct-drive torque motor (130, 930). The motor (130) comprises a stator (531) fixed to the tower (201) and a rotor (532) fixed to a biconical flange (212).

[0118] A combined bearing (530) allows the rotational guidance of the lower tubular section (110) or the upper tubular section (120) around the axis of rotation (101) relative to the mast (100) as well as the axial positioning of the section.

[0119] The use of two motors (130, 930) eliminates the need for the transfer platform and internal ferrule coupling devices at the top of the tower and also distributes the driving power between the two motors. This overall reduces the mass at the top of the tower without significantly increasing the mass at the upper bearing (811) of the upper section. Depending on the rigging configuration, this can be advantageous with regard to righting moment when the rigging is deployed, compared to the first variant (800). This second variant (900) can be adapted to a high-deployed Flettner rig with an H / D ratio greater than 5.

[0120] In addition, the use of two motors (130, 930) allows the lower tubular section and the upper tubular section to be driven at different rotational speeds, in particular to drive the upper tubular section (120) at a higher rotational speed than the lower tubular section (110), which can be advantageous when the deployed height of the rigging is significant.

[0121] Indeed, installed on a ship (600) a rotating rigging (601, 602) as described previously, extends from a deck of the ship (650) over a deployed height (610) between 4 and 9 times a maximum diameter (620) of the upper tubular section (excluding Tom's disk at the top).

[0122] Retracting the telescopic part allows the height of the rotating rigging, when not used for ship propulsion, to be reduced by at least 30% and up to nearly 50% depending on the embodiment, thus improving visibility, reducing the ship's aerodynamic drag, and reducing the capsizing moment generated by the rotating rigging, i.e. increasing the ship's stability, particularly with regard to rolling.

[0123] The maximum diameter corresponds to the outside diameter of the upper tubular section (120), the outside diameter of the lower tubular section (619) being less than the outside diameter (620) of the upper tubular section, so that the diameter of the rotating rigging is higher on its portion furthest from the deck (650) of the ship.

[0124] This configuration is advantageous because it allows you to take advantage of a more favorable sail thrust than if the rotating rigging had a constant diameter or a decreasing diameter from the deck towards its top.

[0125] Indeed, according to its operating principle, the rotating rigging (601) produces a sail thrust (710) that is both perpendicular to the relative wind (701) to which it is subjected and to its axis of rotation.

[0126] In the example, considering (in thought) the stationary ship (600) subjected to a starboard wind (701), the rotating rigging (601) produces a sail thrust (710) parallel to the longitudinal axis of the ship.

[0127] In practice, the ship moves forward in a propulsion direction (750), this propulsion being able to result from sail thrust alone or from the combination of this sail thrust with motorized means of propulsion of the ship.

[0128] Under these conditions, the rotating rigging is subjected to an apparent wind (702) resulting from the true wind (701) and the relative wind (703) produced by the displacement of the ship (600), and under these conditions the sail thrust (711) is no longer oriented in such a favorable manner.

[0129] However, the apparent wind perceived by the rotating rigging also varies in intensity with altitude according to a function of the type:

[0130]

[0131] With V(z) the apparent wind speed at altitude z measured from the ship's deck

[0132] Z0 is a reference altitude (for example, 10 m).

[0133] α an empirical coefficient α = 0.11

[0134] Thus the apparent wind speed (702) increases with altitude but moreover, this wind shear means that its direction gets closer to the direction of the true wind (701).

[0135] Also, using a diameter greater than that of the lower section for the upper section also presents an advantage with regard to the orientation of the sail propulsion force, particularly in crosswinds.

[0136] But moreover, the use of two drive motors, one for the lower tubular section (110) and one for the upper tubular section (120), makes it possible to take full advantage of this phenomenon by adjusting the rotation speeds of each section to obtain maximum sail thrust.

[0137] The upper tubular section may also not be fully deployed while still allowing the Flettner rig to function, thus allowing more flexibility in adapting to sailing conditions.

[0138] The telescopic section (801) may include a locking system with the tower (201) in the deployed position. The device is shown in cooperation with a cable-operated deployment-retraction device acting on the telescopic section but may be adapted to other deployment-retraction systems.

[0139] The tower (201) may include at its top a platform (1040) fixed to the tower and comprising a central passage for the telescopic part (801). The telescopic part (801) is attached at its lower end to a locking plate (1045) which comes into contact with the platform (1040) in the deployed position.

[0140] The locking plate (1045) includes a plurality of threaded studs (1052) distributed over a circumference of the locking plate (1045) and configured to enter into openings made in the platform (1040).

[0141] A plurality of pilot-operated tightening nuts (1065) on the platform, pivotally connected to it, are coaxial with an axis of slots and threaded studs (1052) when the locking plate (1045) approaches contact with the platform (1040). Tightening these nuts once the ends of the studs (1052) are engaged brings the locking plate (1045) into contact with the platform (1040), thus immobilizing both the locking plate (1045) and the platform (1040). The retraction process is reversed.

[0142] The extension and retraction of the telescopic section shown is operated by a cable system comprising a lifting cable (1061) and a lowering cable (1062), which are operated inside the tower (201) by a lifting winch (1060) and a lowering winch (1059) attached to the base (105). The cables are configured in loops and taken up by pulleys attached to the platform (1040). The two winches work together during both the lifting and lowering of the telescopic section. This system has the advantage of being inexpensive and lightweight.

Claims

Rotating rigging of the Flettner type (300, 800, 900), configured to rotate about an axis of rotation (101) and telescopic along the axis of rotation between a retracted height (611) and a deployed height (610) from a base (105), comprising: a lower tubular section (110) of a first outside diameter (190); an upper tubular section (120) of a second inside diameter (191), the second inside diameter (192) being greater than the first outside diameter (191); a mast, fixed in rotation, comprising a tower (201) extending from the base (105) to a tower height (210); a motor (130) for driving the rotation of the lower tubular section positioned at the top of the tower (201); a rotation guide for the lower tubular section around the tower comprising at least one bearing (112) combined with the torque motor (130);a linear displacement device along the axis of rotation (101) of the upper tubular section (120) relative to the lower tubular section between a retracted position and a deployed position; in which the motor is a direct drive torque motor (130) whose stator (531) is linked to the tower and leaving a free passage of a diameter (192) at least equal to 700mm at the top of the tower (201).; Rotating rigging of the Flettner type according to claim 1, comprising a transfer platform (140) integral with a rotor (532) of the torque motor (130), the transfer platform being configured to be rotationally linked with an internal ferrule connected to the upper tubular section when the latter is in the deployed position. Rotating rigging of the Flettner type according to claim 2, wherein the transfer platform (140) comprises a conical part (840) configured to be rotationally linked with a conical part (845) of the inner ferrule when the upper tubular section is in the deployed position. Felttner type rotating rigging according to claim 2, wherein the linear displacement device of the upper tubular section (120) comprises at least one hoist cable (161) and at least one lowering cable (162) wound at one end around a winch (160) connected to the transfer platform (140) and connected to the upper tubular section at their other end. Rotating rigging of the Flettner type according to claim 1, comprising a rotationally fixed telescopic part (801) configured to slide about the axis of rotation (101) relative to the tower (201) through the free passage at the top of the tower, wherein the upper tubular section (120) is translationally fixed to the telescopic part (801) and is guided in rotation by at least one upper bearing (811) configured between the upper tubular section and one end of the telescopic part, the linear displacement device of the upper tubular section moving the telescopic part (801) relative to the tower (201). Rotating rigging of the Flettner type according to claim 5, wherein the linear displacement device of the upper tubular section is selected from a rack and pinion pair, a worm and nut pair, a linear motor, a hydraulic or pneumatic cylinder, a chain cylinder and a cable device. Rotating rigging of the Flettner type according to claim 5, wherein the end of the telescopic part (801), when the upper tubular section is in the deployed position, is located at a height (810) less than or equal to 3 / 5 ème of the deployed height (610). Rotating rigging of the Flettner type according to claim 5, wherein the end of the telescopic part when the upper tubular section is in the deployed position is located at a height (810) equal to the deployed height (610). Rotating rigging of the Flettner type according to claim 5, comprising a second torque motor (930), combined with the upper bearing (811), configured to drive in rotation the upper tubular section (120). Rotating rigging of the Flettner type according to claim 5 comprising a locking device for the telescopic part relative to the tower (201) in the deployed position.

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