Locking mechanism for a telescopic crane system

Abstract

The invention relates to locking means and a locking method for a lifting system (1) which comprises a tower having two segments T3, T4, which are telescopically movable relative to each other, one T3 of the segments having an upper pin (31) which engages with an upper end of an oblong hole in the other segment T4, and a lower pin (32) which simultaneously engages with a lower end of said hole, such that the strike plate is substantially immobilized vertically by the pins.

Description

Lock for telescopic crane system

[0001] The present invention relates to the field of lifting loads to great heights, in particular for the assembly, maintenance and disassembly of fixed or floating offshore wind turbines.

[0002] The assembly, maintenance or disassembly of a wind turbine requires significant lifting equipment, both in terms of lifting capacity and working height. The problem is greater for offshore wind turbines. Thus, for maintenance of a wind turbine, for example to replace a blade, a gearbox or an alternator, these lifting equipment can be brought out to sea, to the location where the wind turbine is installed; such lifting equipment is difficult to mobilize and the intervention is particularly expensive. A second solution, when the wind turbine is floating, is to bring it back to a port to use a land-based crane.

[0003] If the wind turbine is brought back to a port, the cranes that are generally available do not allow for working at great heights on the moving parts of a wind turbine or its nacelle. A land-based mobile crane must then be used.

[0004] However, such a crane has many disadvantages: - such a crane is rare and its mobilization time can be several months; - it is particularly bulky; it requires a large footprint, particularly during its assembly and disassembly; - its assembly and disassembly time is more than a week for each operation; - a high cost; and, - a usefulness limited to intervention on the wind turbine.

[0005] For example, in 2021, to install a blade of the "Haliade-X" wind turbine prototype at a height of nearly one hundred and fifty meters above the ground, this blade weighing two hundred tons with its lifting tool, it was necessary to use a "Liebherr 11350" crane which costs several hundred thousand euros to mobilize.

[0006] The aim of the invention is to propose lifting means allowing the assembly, maintenance or disassembly of a floating wind turbine at dock or an offshore wind turbine, fixed or floating, and which anticipates the continuous increase in the size of wind turbines.

[0007] According to a first object of the invention, a lifting system comprises a tower comprising at least two sections which can be telescoped together so that the tower can take at least one retracted position, in which the tower has a minimum height, and a deployed position, in which the tower has a maximum height, and, hauling means for a cable provided for the deployment of an upper section relative to a lower section, among the at least two sections.

[0008] Preferably:- the upper section comprises a lower set of low pulleys arranged near a lower end of this section;- the lower section comprises an upper set of high pulleys arranged near a high end of this lower section;- the hauling being carried out between these two sets of pulleys.

[0009] The upper pulleys are preferably double pulleys. The lower pulleys are preferably arranged in a herringbone pattern.

[0010] According to a second object of the invention, a lifting system comprises a tower comprising at least two sections which can be telescoped together so that the tower can take at least one retracted position, in which the tower has a minimum height, and one deployed position, in which the tower has a maximum height, and means for locking said two telescopable sections together.

[0011] Preferably:- the upper section comprises a striker having a substantially oblong hole extending vertically;- the section comprises a latch having a high pin and a low pin both adapted to engage the striker in the hole;so that, in a locked position, the high pin is in substantially fitted engagement with an upper end of the oblong hole, and, the low pin is in substantially fitted engagement with a lower end of the oblong hole, so that the striker is substantially immobilized vertically relative to the latch

[0012] Advantageously, the locking means comprise two strikers, one for engaging the lock in a retracted position of the upper section relative to the lower section, the other striker being provided for engaging the lock in a deployed position of the upper section relative to the lower section.

[0013] According to a third object of the invention, a method for locking a system according to the invention comprises the following steps: - the striker is positioned at a height greater than a locking height provided for the locking position, so that the upper pin can penetrate with clearance between the upper and lower ends of the oblong hole; then, - the upper pin is penetrated into said oblong hole; then, - the upper section is lowered until it rests on the upper pin; then, - the lower pin is penetrated into the oblong hole. Brief description of the figures

[0014] Several embodiments of the invention will be described below, by way of non-limiting examples, with reference to the appended drawings in which:

[0015] is a schematic elevational view of a telescopic lifting system according to, on the right in retracted configuration, on the left in fully extended configuration;

[0016] is a top-down, isometric perspective view of the lifting system used to manipulate a blade of an offshore wind turbine;

[0017] Illustrates four stages of system deployment, from the retracted configuration on the left to the fully deployed configuration on the right;

[0018] is a half view, from above, of the system, illustrating in particular a telescoping device according to the invention;

[0019] schematically illustrates a hauling system for deploying a telescoping section of the lifting system;

[0020] is a schematic elevation view, three-quarter view and isometric perspective from above, of the telescoping section of the;

[0021] illustrates several partial views of the section of the, including a truncated and elevational half-view of this section, a quarter top view according to 7A illustrating locking means, a quarter horizontal section according to 7B illustrating a set of pulleys, at the base of the section, an isometric view 7C of the locking means, and, a detail 7D of these means; and,

[0022] illustrates four steps for locking together neighboring sections of the lifting system according to the invention. Detailed description

[0023] The figures illustrate a lifting system 1 according to the invention.

[0024] The lifting system 1 comprises a telescopic tower 11 and a crane 12 mounted on top of the tower 11. The crane 12 comprises a lifting jib 14. The crane illustrated is of the PC400 type, supplied by Favel-Favco-Berhad (Malaysia).

[0025] In the illustrated example, tower 11 comprises a base 10 and four elements T1-T4 designed to slide vertically relative to each other. Each element has a substantially square horizontal section, symmetrical about a tower axis X11; the tower is mainly made of a lattice of metal beams.

[0026] A first section T1 is rigidly fixed to the base 10 and extends upwards from the base 10; a second section T2, of reduced section, is slidably mounted inside the first; a third section T3, of smaller section, is slidably mounted inside the second; the fourth section T4, of even smaller section, is slidably mounted inside the third element. The fourth section is the upper section and supports, at its top, the crane 12. The crane is mounted so that it can rotate around the axis X1 of the tower relative to the upper section T4.

[0027] Illustrates two configurations of Tower 11, on the left in its fully extended configuration, in its maximum height H11D, and, on the right in its retracted configuration, in its minimum height H11R.

[0028] In the example illustrated, the maximum height H11D of the tower, measured from the top of the base, i.e. from the lowest section of the first section T1, to the top of the fourth section is one hundred and ten meters, H11D = 110 m. Measured in the same way, the minimum height H11R of tower 11 is forty meters, H11R = 40 m. Thus, when the boom of crane 12 is fully erected, the height under hook HC can reach more than one hundred and seventy-five meters above the base 10.

[0029] The, illustrates the system 1 in use for handling, here the installation of a blade 2 of a wind turbine 3 at sea. In this example, the wind turbine 2 is fixed to the seabed. The system 1 is fixed on a self-elevating platform 4, of the jack-up type, resting by feet 5 on the seabed. A stock 6 of blades is arranged on the platform 4, ready to be installed on other wind turbines of the same farm, currently being assembled.

[0030] Illustrates, from left to right, four stages 3A-3D of the telescoping of Tower 11.

[0031] In a first step 3A, the tower is in its retracted configuration.

[0032] In a second step 3B, a T2-T4 assembly consisting of the second section T2, the third section T3 and the fourth section T4 was lifted as a unit, relative to the first section T1. As illustrated in, the T2-T3 assembly was lifted to a height H3B which corresponds to the position of the second section T2 in the fully deployed configuration (see).

[0033] In a third step 3C, an assembly T3, T4, consisting of the third section T3 and the fourth section T4, was lifted as a unit relative to the second section T2. ​​As illustrated in, the assembly T3-T4 was lifted to a height H3C which corresponds to the position of the second section T2 in the fully extended configuration (see).

[0034] In a fourth step 3C, the fourth section T4 was lifted relative to the third section T2. ​​As illustrated in, the fourth section T4 was lifted to a height H3D so that the tower 11, hence the lifting system 1, is in its fully extended configuration.

[0035] Preferably, during the deployment operations of the system 1, the boom 14 of the crane 12 is straightened so that the loads are lowered as close as possible to the axis X1 of the tower. Typically, in the example illustrated, the boom 14 forms an angle A14 of around eighty degrees.

[0036] The sequence described above is recommended but not mandatory. The sections may be deployed in a different order. Sections may be left retracted if the height to be reached does not justify their extension. Lifting operations may be carried out with retracted sections as long as they are locked together, as will be explained with reference to the.

[0037] Illustrates a half-top view of the tower 11. It shows the four sections T1-T4 nested within each other, above the base 10. It also shows elements of telescoping systems 2, in particular pulleys 16, winches 17. In the example illustrated, each of the four faces of the tower 11 comprises its own telescoping system 2. Each telescoping system comprises three winches 17: - a first winch 171 for telescoping the second section T2 or the set of three sections T2-T4; - a second winch 172 for telescoping the third section T3 or the set of two sections T3-T4; and,- a third winch 173 for telescoping the fourth section T4. The first, second and third sections T1-T3 each comprise locking means 18.

[0038] Illustrates the third section T3. Each of its faces includes a lower set JBT3 of 16 pulleys and an upper set JHT3 of 16 pulleys.

[0039] As particularly illustrated in the, a high clearance JH of a section is reeved with a low clearance JB of a higher level section. In the illustrated example, the high clearance THT3 of the third section T3 is reeved with the low clearance of the fourth section T4. As a result, only the first, second and third sections T1-T3 have high clearances JH, and only the second, third and fourth sections T2-T4 have low clearances JB. The first section does not have a low clearance; the upper section, here the fourth section T4, does not have a high clearance.

[0040] We will now describe, with reference to the, the pulley which allows the fourth section T4 to slide inside the third section T3.

[0041] On one of the faces of tower 11, one of the upper sets JHT3 of the third section T3 and the corresponding lower set JBT4 of the fourth section T4 can be seen. There is also a cable 20 which, hauled onto these sets JHT3, JBT4 and driven by the corresponding third winch 173, allows the deployment or retraction of the fourth section T4 relative to the third section T3.

[0042] The high set JHT3 comprises, in addition to the input pulley 16E, two double pulleys 16H. The low set JBT4 comprises five single pulleys. Thus, the cable 20, coming from the winch is first received by the input pulley 16E, returned downwards onto a low pulley 16B, then returned to a first groove G1 of a first high pulley 16H, then returned downwards to a second low pulley 16B, then upwards onto the second groove G2 of the same first high pulley, then downwards to a third low pulley 16B, then upwards into a first groove G1 of the second high pulley, then downwards onto a fourth low pulley 16B, then upwards into the second groove G2 of the same second high pulley, then downwards onto the fifth low pulley 16B, then finally upwards to a fixed point PF of the fourth section T4.Thus reeved, the cable 20 forms ten strands which connect, on each face of the tower 11, the fourth section T4 to the third section T3, i.e. forty strands in total.

[0043] We will now describe section T3 in more detail, with reference to the.

[0044] Section T3 comprises a metal lattice structure, which comprises four vertical uprights 21. The locking means 18 comprise four locks 22, each arranged at the top of a respective upright 21.

[0045] Each upright 21 further comprises two latches 23 for engaging with a lock of the lower section. Thus, the latches 23 of the third section T3, illustrated in FIGS. 6 and 7, are provided to engage with locks of the second section T2. ​​One of the latches 23, arranged near the top of the section, is provided to lock the section there in its retracted position, for example in configurations 3A and 3B of the. The second latch 23, located lower on the upright 21, is provided to lock the section there in its deployed position, for example in configurations 3C and 3D of the.

[0046] The strike plates are identical to each other; each has substantially the shape of a vertical plate which extends diagonally from the upright 22 to which it is fixed away from the axis X1 of the tower. As particularly illustrated in details 7C and 7D of the, each strike plate is pierced with an oblong hole 24 which extends vertically, the lower and upper ends of which have substantially the shape of a semicircle of radius R24; the axis X24H of the upper semicircle and the axis X24B of the lower semicircle are distant from each other by a spacing distance D24 greater by a non-zero value J24 than the sum of these radii, that is to say that D24 = 2 x R24 + J24.

[0047] The oblong hole 24 widens slightly between the two axes X24H, X24B, so that at mid-height it has a greater width L24.

[0048] Rollers 26 serve as guides for the upper section. Thus, the rollers of the third section T3, visible in view 7A, are arranged to serve as guides for the fourth section T4. The rollers are arranged to be able to roll on the outer faces 21E of the uprights 21.

[0049] Elevation wedges 27 extend from the lattice structure. They constitute a safety feature; they are designed to abut against the structure of the lower section, to prevent the section being deployed from rising beyond a limit height relative to this lower section. Thus, the wedges 27 visible on the third section T3 are designed to abut against the second section T2.

[0050] As shown in view 7A, the pulleys 16 of the high set JH include an input pulley 16E and double pulleys 16H. As shown in view 7B, the pulleys 16B of the low set JB are arranged in a herringbone pattern. This herringbone pattern allows each strand extending between a groove G1, G2 to a corresponding low pulley to be vertical, as much as possible.

[0051] We will now describe a locking procedure according to the invention, with reference to the. This figure illustrates, in section, three steps 8A-8D for locking in the deployed position of the fourth section T4 of the third section T3.

[0052] The lock 22 comprises a yoke 30, formed of two vertical flanks 300. A top pin 31 and a bottom pin 31. The pins 31, 32 are movable horizontally relative to the yoke 30, under the action of a respective double-acting cylinder 33. Each pin is fixed, with its cylinder, on a respective side of the yoke. Thus, at, the top pin 31 is fixed on the left on the yoke, and, the bottom pin 32 is fixed on the right on the yoke 30. The pins are substantially identical to each other. Each pin has a cylindrical shape around a respective axis X31, X32. It has a radius R312, substantially equal to the radius R24 of the oblong hole 24 of the strikers. The axes of the pins are in the same vertical plane; this plane of axes X31, X32 is the cutting plane of the.

[0053] In the first step 8A of the, each of the pins 31, 32 is engaged in a respective flank 300, on the side of the yoke to which it is fixed. One of the strikers 23 of the fourth section T4 is arranged between the two flanks 300 of the yoke 30; the striker is arranged so that the axis of the upper pin 31 of the third section T3 extends substantially between the two ends, upper and lower, of the oblong hole 24 of the striker 23; thus, the upper pin is facing the region of greatest width L24 of the oblong hole. Since the section T4 may not be totally aligned with the section T3, it is thus ensured that each of the four upper pins 31 of the third section is indeed facing a corresponding oblong hole 24 and can penetrate therein easily due to the play in height and width which compensates for the misalignment.This effect is due to the oblong shape of the hole and its greater width L24, which is greater than twice the diameter of the radius R24 of the ends of the hole.

[0054] In the second step 8B, the high pin 31 is advanced so that it is engaged in the oblong hole, and beyond, into the opposite flank 300.

[0055] In the third step 8C, the fourth section T4 is lowered until the striker rests by its upper end on the upper pin 31. The set of four strikers 23 of the sections T4 resting on a respective upper pin, it is thus ensured that the fourth section T4 is suitably aligned with the third section T3 which carries it; in this position, the axis X32 is substantially aligned with the lower axis X24B of the oblong hole 24.

[0056] In the fourth step 8D, the lower pin 32 is advanced so that it is engaged in the oblong hole 24, and beyond, into the opposite flank 300. In this position, the fourth section T4 is aligned and secured to the third section T3. If the action of a load lifted by the system 1 tended locally to lift the fourth section relative to the third, it would be prevented from doing so by the support of the lower pin 32 on the latch 23; If the action of a load lifted by the system 1 tended locally to lower the fourth section, it would also be prevented from doing so by the support of the upper pin 31 on the latch 23.

[0057] Such a locking method is useful for locking each of the telescoping sections, in the retracted position or in the deployed position.

[0058] It will indeed appear to those skilled in the art that various modifications can be made to the embodiments described above, in light of the teaching which has just been disclosed to them.

[0059] Thus, the number of sections of the tower may be other than four; for example, the tower may have three or five sections. Each or all may have a section that is not square but, for example, form a polygon with more than four sides; each or all may also be formed by something other than a lattice of girders, for example, by solid sheets.

[0060] The number of tower sections and their respective heights are preferably calculated so that in the retracted position the system has optimal dimensions for use as a harbor crane and in the deployed position the system has optimal dimensions for use in the maintenance of a floating wind turbine.

[0061] The number of winches can vary. There is not necessarily one winch per side and per telescoping section. However, increasing the number of winches limits their capacity as well as the size of the cables and pulleys.

[0062] Unlike existing cranes, a system according to the invention makes it possible to achieve very high lifting heights by means of a rotating crane mounted on a telescopic tower with high vertical slenderness. Since the load passes substantially through the neutral fiber of the mast, or at least in the envelope of the support base, the problems of bending moments are reduced and controlled.

[0063] A system according to the invention may comprise a gantry and the tower is mounted on this gantry. The gantry being arranged on rails, it allows the tower and the entire lifting system to be moved parallel to the edge of the quay.

[0064] Being able to leave the system stationary in the retracted position eliminates the risks caused by strong winds, which are significant at the seaside.

[0065] The dual-use capability of the system, both for loading and unloading ships and for installing and removing wind turbine parts from the quayside, is a real added value for a port with a construction vocation.

[0066] Furthermore, since a system according to the invention remains stationary on its platform, its footprint is reduced. It requires neither assembly time nor space, apart from the very short time required to deploy or fold the tower.

[0067] The system replaces a pre-existing quayside crane for loading or unloading ships without penalty, based on the principle that less is more. The system is and remains versatile for use between conventional heights for vessels of all sizes and, for example, up to 200 meters for current high-capacity floating wind turbines.

[0068] A system according to the invention can be used to install the blades of floating wind turbines. This limits the use of a giant, high-capacity crane to the installation of masts and nacelles. It is then possible, for example, to store the floats without blades, which takes up much less space than with the blades. The blades can then be installed with the lifting system according to the invention just a few days before towing the assembly out to sea, which is a real advantage.

[0069] A system according to the invention can be used elsewhere than in a port. For example, it can be mounted on a jack-up barge to maintain offshore wind turbines fixed to the seabed. The compactness of the system allows the use of much smaller and much less expensive jack-up platforms than the ships currently used to install very large wind turbines.

[0070] The system, mounted on a standard jack-up platform, can also be used to install blades for a wind farm under construction. This limits the time required for a large vessel to operate and reduces the overall duration of the offshore campaign. This installation option can be very cost-effective, especially in locations where installation periods are short, for example, only a few months per year.

[0071] A system according to the invention can also be used temporarily on a floating wind turbine to carry out a heavy maintenance operation such as changing a blade or a gearbox, directly at sea.

[0072] With regard to the two-stage locking principle, it will be apparent to those skilled in the art that the striker and its oblong hole could be replaced by another form of part which would first rest on the lower pin before being capped by the upper pin, or any other arrangement which first makes it possible to ensure the correct alignment of the sections before locking them. The retractable parts, here called pins, could not be cylindrical. Also, instead of moving in translation, these parts could be mounted to rotate.

Claims

Lifting system (1), comprising a tower (11) comprising at least two sections (T1-T4) which can be telescoped together so that said tower can take at least one retracted position, in which the tower has a minimum height (H11R) and one deployed position, in which the tower has a maximum height (H11D), and means (18) for locking said two telescopable sections (T3, T4) together, characterized in that: - the upper section (T4) comprises a latch (23) having a substantially oblong hole (24) extending vertically; - the section (T3) comprises a lock (22) having a high pin (31) and a low pin (32) both provided to engage with said latch (23) in said hole (24);such that, in a locked position, the upper pin (31) is in substantially fitted engagement with an upper end of said oblong hole, and, the lower pin (32) is in substantially fitted engagement with a lower end of said oblong hole, such that said striker (23) is substantially immobilized vertically relative to said latch (22; System according to claim 1, characterized in that the locking means comprise two latches (23), one for engaging the lock in a retracted position of the upper section (T4) relative to the lower section (T3), the other latch being provided for engaging the lock in a deployed position of the upper section (T4) relative to the lower section (T3). Method for locking a system according to one of claims 1 and 2, characterized in that the following steps are carried out: - the strike plate is positioned at a height greater than a locking height provided for the locking position, so that the upper pin (31) can penetrate with clearance between the upper and lower ends of the oblong hole (24); then, - said upper pin (31) is made to penetrate into said oblong hole; then, - the upper section (T4) is lowered until it rests on said upper pin; then, - the lower pin (32) is made to penetrate into said oblong hole.

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