Jacking arrangement for lifting and lowering a self-elevating platform, use thereof, manufacturing thereof

Abstract

The invention provides a jacking arrangement for lifting and lowering a self-elevating platform, comprising a leg extending according to a jacking direction, a jacking unit configured for engaging with the leg, wherein the leg comprises a chord assembly, the chord assembly comprises a first rack and a second rack, and a rack spacer. The first rack is connected to the second rack via the rack spacer. The first rack comprises a first toothed rack face and the second rack comprises a second toothed rack face. The jacking unit comprises a first pinion, configured for meshing with the first toothed rack face, and a second pinion configured for meshing with the second toothed rack face, the first pinion and the second pinion jointly form a pinion set. The invention further provides for the use of a jacking arrangement and a manufacturing thereof.

Description

[0001] JACKING ARRANGEMENT FOR LIFTING AND LOWERING A SELF-ELEVATING PLATFORM, USE THEREOF, MANUFACTURING THEREOF

[0002] Technical field

[0003] The present invention relates to a jacking arrangement for lifting and lowering a self-elevating platform.

[0004] Background art

[0005] Self-elevating platforms, such as jack-up rigs or jack-up platforms, are known solutions for temporary off-shore activities, such as drilling or wind turbine installations. A typical jack-up rig includes a barge or hull equipped with jacking arrangements. The jacking arrangements contain legs that can be lowered and raised. When the legs are lowered, they engage with the seabed. Afterwards, the platform can raise itself above the water surface along the legs. Platforms and cargo require a joint load bearing capacity of the jacking arrangements of more than 50 000 metric tons, even more than 80 000 metric tons.

[0006] Solutions in the state of the art are known where the legs consist of trussed chords that are equipped with racks. Each rack engages with one or more jacking units through pinion gears, also called pinions, that are part of the jacking units and that mesh with the rack. A jacking unit consists of a motor, a gearbox and one or more pinions. The jacking unit is connected to the hull in a jacking house.

[0007] The pinions of the jacking units may be arranged such that the pinion teeth face the center of a trussed leg with multiple chords, or they may be oriented as opposing pinions with a toothed rack mounted on each side of a leg or leg chord to engage the opposing pinions. Multiple jacking units, and in particular multiple pinions, are often stacked vertically to provide enough force to lift the self-elevating platform and the load it is carrying. For example, jacking arrangements are described in US5915882 and FR2492029 A1 . They comprise a leg extending according to a substantially upright jacking direction and a jacking unit configured for engaging with the leg for moving the jacking unit to and fro along the leg according to the jacking direction, thereby moving a platform attached to the jacking unit. The leg comprises a chord assembly extending substantially according to the jacking direction. The chord assembly comprises a first rack extending substantially along the chord assembly according to the jacking direction. The first rack comprises a first toothed rack face extending substantially along the first rack according to the jacking direction, teeth protruding substantially perpendicular to the jacking direction. The jacking unit comprises a first pinion, the first pinion is configured for meshing with the first toothed rack face. Multiple pinions are stacked vertically to provide enough force to lift the desired loads.

[0008] The jacking arrangements known from the state of the art have the disadvantage that the upper pinions take on lower loads than the lower pinions, especially for absorbing dynamic forces exerted on the platform from waves, wind and activities on the platform. As a result, adding pinions does not linearly increase the load bearing capacity of the jacking arrangement.

[0009] Especially in wind turbine installation jack-up rigs, this is a major disadvantage. To increase the capacity of wind turbines, bigger turbines are developed. Accordingly, the required load bearing capacity of the jacking arrangement has to keep increasing as well. This required capacity increase cannot easily be provided by stacking more jacking units or pinions, even with racks made from the thickest commercially available high strength steel plate material (e.g. 250mm thick plates). Nor is this increase practically feasible by increasing rack and pinion sizes, because of manufacturing and installation constraints. Disclosure of the invention

[0010] It is an aim of the present invention to provide a solution for at least part of the disadvantages of the solutions known in the state of the art.

[0011] This aim is achieved with a jacking arrangement for lifting and lowering a self-elevating platform according to the first claim.

[0012] The jacking arrangement comprises a leg, by preference a trussed leg comprising braces and chords, by preference a three-chorded trussed leg, extending according to a substantially upright, preferably upright, jacking direction, and at least one jacking unit, by preference just one jacking unit, configured for engaging with the leg for moving the jacking unit to and fro along the leg according to the jacking direction, thereby lifting or lowering the self-elevating platform. The leg comprises a chord, in particular a chord assembly, extending substantially according to the jacking direction, preferably according to the jacking direction. The chord assembly comprises a first rack extending substantially along the chord assembly according to the jacking direction, preferably along the chord assembly according to the jacking direction, and the first rack comprises a first toothed rack face extending substantially along the first rack according to the jacking direction, preferably along the first rack according to the jacking direction, with the teeth of the first toothed rack face protruding in a first teeth protrusion direction, the first teeth protrusion direction being substantially perpendicular, preferably perpendicular, to the jacking direction. The chord assembly further comprises a second rack extending substantially along the chord assembly according to the jacking direction, preferably along the chord assembly according to the jacking direction, and the second rack comprises a second toothed rack face extending substantially along the second rack according to the jacking direction, preferably along the second rack according to the jacking direction, with the teeth of the second toothed rack face protruding substantially in the first teeth protrusion direction, preferably in the first teeth protrusion direction. The chord assembly further comprises a rack spacer extending substantially along the chord assembly according to the jacking direction, preferably along the chord assembly according to the jacking direction, the rack spacer also extending according to a spacing direction between a first rack spacer side and a second rack spacer side, the spacing direction being substantially perpendicular, preferably perpendicular, to a plane defined by the jacking direction and the first teeth protrusion direction. The rack spacer connects the first rack and the second rack. The first rack is connected to the rack spacer at the first rack spacer side and the second rack is connected to the rack spacer at the second rack spacer side. The at least one jacking unit comprises a first pinion configured for meshing with the first toothed rack face and a second pinion configured for meshing with the second toothed rack face. The first pinion and the second pinion jointly form a pinion set, in particular a dualpinion set, in particular the first pinion set, in particular the first dual-pinion set.

[0013] It is an advantage of the present invention, which we call the dualpinion jacking arrangement, that the load bearing capacity of a jacking arrangement with a single rack and pinion is increased without vertically stacking additional pinions. Adding a pinion on a second rack next to a pinion on a first rack, leads to a bigger dynamic load bearing capacity increase than adding a pinion on the first rack, above or below of the first pinion. This is due to the effect that under dynamic loads, the top pinion of a stack of pinions meshing with the same rack takes on less load than the bottom pinion. This effect is colloquially known in the industry as the Christmas Tree Effect. This advantage is especially important in dynamic offshore environments where jack-up platforms are operated.

[0014] An alternative solution known from the state of the art for increasing the load bearing capacity of a jacking arrangement is increasing the gear module, in particular increasing the diameter of the pinion and / or the size of its teeth. It is an additional advantage of the dual-pinion jacking arrangement, that it uses smaller pinions compared to this known alternative solution. As a result manufacturing and installation of pinions is easier. The manufacturing of the racks with a smaller gear module is easier as well. Also, the jack-up house, containing the jack-up unit attached to the hull, can be smaller, increasing the available deck or platform space. In addition, the surface area of the teeth of the dual-pinion jacking arrangement that absorbs the forces between the racks and pinions is bigger than in a single, large wheel jacking arrangement, lowering the pressure on the teeth of the racks and the teeth of the pinions and reducing the wear on the racks and pinions.

[0015] An alternative solution known from the state of the art for increasing the load bearing capacity of a jacking arrangement is increasing the thickness of the racks and pinions. It is another additional advantage of the dual-pinion jacking arrangement that it uses thinner racks and pinions compared to this known alternative solution. As a result, manufacturing and installation of the extra pinion pair is easier. In addition, any misalignments of the racks and pinions can be more easily absorbed or remedied when using two thinner pinions instead of a single thicker pinon, avoiding onesided wear on the thicker pinion.

[0016] Another additional advantage of the dual-pinion jacking arrangement is that the section modulus of the chord is optimized to absorb the different forces that affect the chord, by introducing a rack spacer. In addition, by introducing a second rack per chord, the stiffness and strength of the trussed legs is increased, enabling the legs to become longer and hence operate at larger sea-depths.

[0017] In a further embodiment according to the invention, the chord assembly comprises further racks (spaced by a rack spacer, analogously to the spacing of the first rack and the second rack) and the one or more jacking units comprise further pinions, that are part of the first pinion set. Hence, the first pinion set can comprise three, four or more pinions.

[0018] In an embodiment according to the invention, the first rack is a two- sided rack, comprising a third toothed rack face extending substantially along the first rack according to the jacking direction, preferably along the first rack according to the jacking direction, with the teeth of the third toothed rack face protruding in a second teeth protrusion direction, the second teeth protrusion direction being substantially opposite of the first teeth protrusion direction, preferably opposite of the first teeth protrusion direction. Preferably, the second rack is a two-sided rack, comprising a fourth toothed rack face extending substantially along the second rack according to the jacking direction, preferably along the second rack according to the jacking direction, with the teeth of the fourth toothed rack face protruding substantially in the second teeth protrusion direction, preferably in the second teeth protrusion direction. The at least one jacking unit, preferably two jacking units, further comprises a third pinion configured for meshing with the third toothed rack face, and, if the second rack is a two-sided rack, the at least one jacking unit further comprises a fourth pinion configured for meshing with the fourth toothed rack face. If the second rack is a two-sided rack, the third pinion and the fourth pinion jointly form a pinion set, in particular a dual-pinion set, in particular the second pinion set, in particular the second dual-pinion set.

[0019] In an embodiment according to the invention, the centers of the pinions of a pinion set are located on a single pinion set axis. This has the additional advantage that the pinons in a pinion set can be easily driven by a single axle or by the same jacking unit.

[0020] In an embodiment according to the invention, the centers of the pinions in a pinon set are not located on a single pinion set axis, but the centers of the pinions are pairwise separated in the jacking direction with a distance bigger than the outer radius of the pinions, but smaller than the outer diameter of the pinions. This way, the pinions can be driven by separate axles or even separate jacking units, while being closer to each other than the minimum required outer diameter of the pinions, if two pinions would mesh with the same rack, vertically next to each other. This has the additional advantage that the load experienced by the different pinons is more similar, as the so-called Christmas Tree Effect is bigger when pinions are spaced further apart vertically.

[0021] In an embodiment according to the invention, a jacking unit comprises one or more pinions, a gearbox connected to the one or more pinions and a motor connected to the gearbox. The motor and gearbox are configured for driving the one or more pinions for moving the jacking unit to and fro along the leg.

[0022] In a further embodiment according to the invention, a jacking unit comprises the pinions of a pinion set.

[0023] In a further embodiment according to the invention, a jacking unit comprises a pinion axle that connects all the pinions of the pinion set to the gearbox. This has the added advantage that the jacking unit is not required to control the pinons separately.

[0024] In an alternative embodiment according to the invention, a jacking unit comprises multiple pinion axles that connect the pinions of the pinion set to the respective gearbox, preferably a distinct pinion axle for some pinions in the pinion set, preferably a distinct pinion axle for every pinion in the pinion set. This has the added advantage that some or all of the pinions in a pinion set can be controlled separately, resulting in a better control of the lifting process and in the possibility to correct for differences in the required control, for example because of wear and tear.

[0025] In a further embodiment according to the invention, the distinct pinion axles are concentric. For example, one or more of the pinion axles can be hollow, enveloping one or more other pinion axles. This has the additional advantage that some or all of the pinions can be controlled separately, while the centers of the pinions of a pinion set are located on a single pinion set axis.

[0026] In an embodiment according to the invention, the first toothed rack face, the second toothed rack face, the third toothed rack face and the fourth toothed rack face are substantially in phase, preferably in phase. Two toothed rack faces are in phase if the location of the teeth tips and teeth roots from one of the toothed rack faces along the jacking direction respectively substantially match, preferably match, the location of the teeth tips and teeth roots from the other toothed rack face along the jacking direction. Note that at least the pitch of the teeth of the toothed rack faces needs to be substantially the same, preferably the same, for two toothed rack faces to be in phase. A set of more than two toothed rack faces are in phase if any combination of two rack faces from that set are in phase. This has the additional advantage that the rack faces can be applied during manufacturing of the chord assembly after the racks are connected using a rack spacer, for example by machining them with a CNC machine.

[0027] In an alternative embodiment according to the invention, the first toothed rack face is substantially in phase, preferably in phase, with the second toothed rack face.

[0028] In an alternative embodiment according to the invention, the third toothed rack face and the fourth toothed rack face are substantially in phase, preferably in phase.

[0029] In an alternative embodiment according to the invention, the first toothed rack face and the second toothed rack face are out of phase, preferably substantially counterphase, preferably counterphase, with each other, and I or the third toothed rack face and the fourth toothed rack face are out of phase, preferably substantially counterphase, more preferably counterphase, with each other. This has the added advantage that the gear contact stress is different in the multiple pinions of a pinion set while jacking unit is moving to and fro along the leg according to the jacking direction.

[0030] In an embodiment according to the invention, the rack spacer comprises a first rack spacer plate and a second rack spacer plate, both with their length direction extending substantially along the chord assembly according to the jacking direction, preferably along the chord assembly according to the jacking direction. Both the first rack spacer plate and the second rack spacer plate extend with their width direction along the spacing direction between respective first rack spacer plate sides and second rack spacer plate sides. The first rack spacer plate sides and the second rack spacer plate sides are part of the first rack spacer side and the second rack spacer side respectively. The first rack spacer plate is substantially parallel, preferably parallel, to the second rack spacer plate. The first rack spacer plate connects the first rack at the first rack spacer plate side of the first rack spacer plate to the second rack at the second rack spacer plate side of the first rack spacer plate. The second rack spacer plate connects the first rack at the first rack spacer plate side of the second rack spacer plate to the second rack at the second rack spacer plate side of the second rack spacer plate. This has the added advantage that the chord assembly has a better moment of inertia (synonymous with “the second moment of area”) compared to a solution with a chord assembly with less advantageous moment of inertia, increasing the resistance to bending.

[0031] An embodiment according to the invention, is a self-elevating platform, for example a jack-up rig, comprising at least one jacking arrangement according to the invention.

[0032] In a further embodiment according to the invention, the self-elevating platform further comprises a ship.

[0033] The invention also relates to a use of a jacking arrangement according to the invention, wherein the pinions, meshing accordingly with the racks, are driven by the jacking units, thereby moving the jacking units to and fro along the leg in the jacking direction.

[0034] The invention also relates to manufacturing a jacking arrangement according to the invention. The manufacturing of a jacking arrangement according to the invention comprises connecting the first rack to the rack spacer at the first rack spacer side, connecting the second rack to the rack spacer at the second rack spacer side, and, preferably after connecting the racks to the rack spacer, applying the first toothed rack face and the second toothed rack face, for example, by machining them onto the rack, by preference by a CNC machine. It optionally further comprises the manufacturing of the pinions, for example, by the process of casting. This manufacturing has the advantage that the application of the tooth rack faces can be done in a controlled way, allowing controlling the phase relation between the first toothed rack face and the second toothed rack face. It is harder to control this phase relationship if the tooth rack faces are applied to the racks before connecting the racks to the rack spacer.

[0035] In a further embodiment according to the invention, the manufacturing of a jacking arrangement according to the invention, in particular with two-sided racks, further comprises applying the third toothed rack face and the fourth toothed rack face, preferably after connecting the racks to the rack spacer. The application of the third toothed rack face and the fourth toothed rack face is done, for example, by machining them onto the rack, by preference by a CNC machine. This has a similar advantageous effect that the phase relation between the toothed rack faces can be controlled, in particular the phase relation between the third toothed rack face and the fourth toothed rack face.

[0036] Brief description of the drawings

[0037] The invention will be further elucidated by means of the following description and the appended figures.

[0038] Figure 1 a shows a top view horizontal section of a jacking arrangement according to the invention.

[0039] Figure 1 b shows a front view of a jacking arrangement according to the invention.

[0040] Figure 2a shows a front view of a jacking arrangement according to the invention.

[0041] Figure 2b shows a side view vertical section of a jacking arrangement according to the invention.

[0042] Figure 3a shows a front view of a jacking arrangement according to the invention.

[0043] Figure 3b shows a side view vertical section of a jacking arrangement according to the invention. Figure 4 shows an isometric view on a jacking arrangement according to the invention.

[0044] Figure 5 shows an isometric view on a self-elevating platform according to the invention.

[0045] Modes for carrying out the invention

[0046] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the invention.

[0047] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. The terms are interchangeable under appropriate circumstances and the embodiments of the invention can operate in other sequences than described or illustrated herein.

[0048] Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. The terms so used are interchangeable under appropriate circumstances and the embodiments of the invention described herein can operate in other orientations than described or illustrated herein.

[0049] The term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It needs to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

[0050] A first embodiment according to the invention is a jacking arrangement 101 for lifting and lowering a self-elevating platform, displayed in Figs. 1 a and 1 b. Fig. 1 a shows a top view horizontal section of the first embodiment of a jacking arrangement 101 according to the invention. Fig. 1 b shows a front view of the first embodiment of a jacking arrangement 101 according to the invention.

[0051] The jacking arrangement 101 for lifting and lowering a self-elevating platform of the first embodiment according to the invention comprises a leg 102, in particular a three-chorded trussed leg comprising braces 103 and chords 104, known from the state of the art. In an alternative embodiment according to the invention, the leg 102 is another type of trussed leg, for example a four-chorded trussed leg.

[0052] In the first embodiment according to the invention, a chord further comprises a chord assembly 105, extending according to a substantially upright, preferably upright, jacking direction j. In Figs. 1 a and 1 b, the leg 102 is not displayed fully. For clarity, a single chord assembly 105 and part of some of the braces 103 are shown. The jacking arrangement 101 further comprises at least one jacking unit 106, in particular two jacking units, in particular a first jacking unit 107 and a second jacking unit 108, configured for engaging with the leg 102 for moving the jacking unit 106 to and fro along the leg 102 according to the jacking direction j. The jacking arrangement 101 further comprises a jacking house 109, configured for holding the jacking units and connecting them to the self-elevating platform.

[0053] The chord assembly 105 comprises a first rack 1 10, in particular a two-sided rack, extending substantially along the chord assembly 105 according to the jacking direction j, preferably along the chord assembly 105 according to the jacking direction j, a second rack 1 1 1 , in particular a two- sided rack, extending substantially along the chord assembly 105 according to the jacking direction j, preferably along the chord assembly 105 according to the jacking direction j, and a rack spacer 1 12 extending substantially along the chord assembly 105 according to the jacking direction j, preferably along the chord assembly 105 according to the jacking direction j. The first rack 1 10 and the second rack 11 1 are racks known from the state of the art, for example racks made from 250mm thick high strength S690 plate steel material. The first rack 1 10 is connected to the second rack 1 11 via the rack spacer 112. The chord assembly 105 further comprises a half-chord plate 113, in particular two half-chord plates, extending along the chord assembly 105 in a semi-cylindrical shape. In an alternative embodiment according to the invention, the first two-sided rack and / or the second two-sided rack each comprise two one-sided racks that are connected to each other, jointly forming a two-sided rack. In an alternative embodiment according to the invention, the first rack 1 10 is a one-sided rack. In an alternative embodiment according to the invention, the second rack 1 1 1 is a one-sided rack.

[0054] In the first embodiment according to the invention, the first rack 110 comprises a first toothed rack face 114 extending substantially along the first rack 1 10 according to the jacking direction j, preferably along the first rack 1 10 according to the jacking direction j, with the teeth of the first toothed rack face 1 14 protruding in a first teeth protrusion direction p, the first teeth protrusion direction p being substantially perpendicular, preferably perpendicular, to the jacking direction j. The first rack 1 10 further comprises a third toothed rack face 1 15 extending substantially along the first rack 110 according to the jacking direction j, preferably along the first rack 1 10 according to the jacking direction j, with the teeth of the third toothed rack face 1 15 protruding in a second teeth protrusion direction p’, the second teeth protrusion direction p’ being substantially opposite of the first teeth protrusion direction p, preferably opposite of the first teeth protrusion direction p. The second rack 1 1 1 comprises a second toothed rack face 1 16 extending substantially along the second rack 1 11 according to the jacking direction j, preferably along the second rack 1 1 1 according to the jacking direction j, with the teeth of the second toothed rack face 1 16 protruding substantially in the first teeth protrusion direction p, preferably in the first teeth protrusion direction p. The second rack 1 1 1 further comprises a fourth toothed rack face 1 17 extending substantially along the second rack 1 11 according to the jacking direction j, preferably along the second rack 1 1 1 according to the jacking direction j, with the teeth of the fourth toothed rack face 1 17 protruding substantially in the second teeth protrusion direction p’, preferably in the second teeth protrusion direction p’.

[0055] The first toothed rack face 1 14, the second toothed rack face 1 16, the third toothed rack face 1 15 and the fourth toothed rack face 1 17 are substantially in phase, preferably in phase. In an alternative embodiment according to the invention, the first toothed rack face 1 14 and the second toothed rack face 1 16 are not in phase (synonymous with “are out of phase”) and / or the third toothed rack face 1 15 and the fourth toothed rack face 1 17 are not in phase. For example the first toothed rack face 1 14 and the second toothed rack face 1 16 are substantially counterphase, preferably counterphase, with each other.

[0056] In the first embodiment according to the invention, the rack spacer 112 also extends according to a spacing direction s between a first rack spacer side 1 18 and a second rack spacer side 119, the spacing direction s being substantially perpendicular, preferably perpendicular, to a plane defined by the jacking direction j and the first teeth protrusion direction p. In particular, the rack spacer 1 12 comprises a first rack spacer plate 120 and a second rack spacer plate 121 , both extending substantially along the chord assembly 105 according to the jacking direction j, preferably along the chord assembly 105 according to the jacking direction j, both also extending according to the spacing direction s between respective first rack spacer plate sides 122 and second rack spacer plate sides 123. The first rack spacer plate sides 122 and second rack spacer plate sides 123 are part of the first rack spacer side 1 18 and the second rack spacer side 119 respectively. The first rack spacer plate 120 is substantially parallel, preferably parallel, to the second rack spacer plate 121. Both the rack spacer plates 120 connect the first rack 1 10 to the second rack 1 1 1. The first rack spacer plate 120 connects the first rack 1 10 at the first rack spacer plate side 122 of the first rack spacer plate 120 to the second rack 1 1 1 at the second rack spacer plate side 123 of the first rack spacer plate 120. The second rack spacer plate 121 connects the first rack 1 10 at the first rack spacer plate side 122 of the second rack spacer plate 121 to the second rack 1 1 1 at the second rack spacer plate side 123 of the second rack spacer plate 121.

[0057] The at least one jacking unit 106, in particular the first jacking unit 107, comprises a first pinion 124. The first pinion 124 is a spur pinion configured for meshing with the first toothed rack face 114. The at least one jacking unit 106, in particular the first jacking unit 107, further comprises a second pinion 125. The second pinion 125 is a spur pinion configured for meshing with the second toothed rack face 1 16.

[0058] The at least one jacking unit 106, in particular the second jacking unit 108, comprises a third pinion 126. The third pinion 126 is a spur pinion configured for meshing with the third toothed rack face 1 15. The at least one jacking unit 106, in particular the second jacking unit 108, further comprises a fourth pinion 127. The fourth pinion 127 is a spur pinion configured for meshing with the fourth toothed rack face 1 17. In an alternative embodiment according to the invention, some or all of the pinions are helical pinions.

[0059] In the first embodiment, the pinions preferably have a gear module of 105 mm, more preferably greater than 105 mm, more preferably greater than 120 mm.

[0060] In an alternative embodiment according to the invention, the chord assembly 105 comprise more than two, for example three or four, racks. These racks are either one-sided or two-sided racks, with their toothed rack faces protruding substantially in the first teeth protrusion direction p, preferably in the first teeth protrusion direction p, in the case of one-sided racks and with their toothed rack faces either protruding substantially in the first teeth protrusion direction p, preferably in the first teeth protrusion direction p, or substantially in the second teeth protrusion direction p’, preferably in the second teeth protrusion direction p’, in the case of two- sided racks. The one or more jacking units comprise additional pinions configured for meshing with respective toothed rack faces. The pinions that mesh with toothed rack faces with their teeth protruding substantially in the first teeth protrusion direction p, preferably in the first teeth protrusion direction p, jointly form a pinion set 130, in particular the first pinion set 131 . The pinions that mesh with toothed rack faces with their teeth protruding substantially in the second teeth protrusion direction p’, preferably in the second teeth protrusion direction p’, form a pinion set 130, in particular the second pinion set 132.

[0061] In the first embodiment according to the invention, the pinions have a substantially identical, preferably identical, gear shape (among others identical diameter, thickness, number of teeth, pressure angle, addendum and dedendum ratios). In an alternative embodiment according to the invention, the pinions have different gear shapes.

[0062] In the first embodiment according to the invention, the jacking units, in particular the first jacking unit 107 and the second jacking unit 108, each comprise one or more pinions, in particular two pinions. The jacking units each further comprise a gearbox 128 connected to the one or more pinions, in particular to the two pinions, and a motor 129 connected to the gearbox 128, the motor 129 and the gearbox 128 being configured for driving the one or more pinions for moving the respective jacking unit 106 to and fro along the leg 102. The motor preferably is a 100 kW motor. In an alternative embodiment according to the invention, a jacking unit 106 comprises a single pinion. For example a jacking arrangement 101 according to the invention with the first pinion 124 and the second pinion 125 comprises two jacking units, each jacking unit 106 driving a single pinion. And for example a jacking arrangement 101 according to the invention with the first pinion 124, the second pinion 125, the third pinion 126 and the fourth pinion 127 comprises four jacking units, each jacking unit 106 driving a single pinion.

[0063] In the first embodiment according to the invention, the first pinion 124 and the second pinion 125 jointly form a pinion set 130, in particular a dualpinion set 130, in particular the first pinion set 131 , in particular the first dualpinion set 130. The third pinion 126 and the fourth pinion 127 jointly form a pinion set 130, in particular a dual-pinion set 130, in particular the second pinion set 132, in particular the second dual-pinion set 130.

[0064] A jacking unit 106 comprises the pinions of a pinon set, in particular the first jacking unit 107 comprises the first pinion 124 and the second pinion 125, both of which are part of the first pinion set 131 and the second jacking unit 108 comprises the third pinion 126 and the fourth pinion 127, both of which are part of the second pinion set 132. In an alternative embodiment according to the invention, a jacking unit 106 comprises pinions from multiple pinion sets. For example, a jacking arrangement 101 according to the invention with the first pinion 124, the second pinion 125, the third pinion 126 and the fourth pinion 127 comprises a single jacking unit 106 driving all pinions.

[0065] In the first embodiment according to the invention, the centers of the pinions of a pinion set 130 are located on a single pinion set axis a. In particular, the centers of the first pinion 124 and the second pinion 125 are located on a first pinon set axis a’, the centers of the third pinion 126 and fourth pinion 127 are located on a second pinion set axis a”. In an alternative embodiment according to the invention, the centers of the pinions of a pinion set 130 are located on different axes. For example, the center of the first pinion 124 is located on a first axis, the center of the second pinion 125 is located on a distinct, second axis. In the first embodiment according to the invention, a jacking unit 106 comprises a pinion axle 133 that connects all the pinions of a pinion set 130 to the respective gearbox 128. In particular, the first jacking unit 107 comprises a first pinion axle 134 that connects the first pinion 124 and the second pinion 125 to the gearbox 128 of the first jacking unit 107 and the second jacking unit 108 comprises a second pinion axle 135 that connects the third pinion 126 and the fourth pinion 127 to the gearbox 128 of the second jacking unit 108. In an alternative embodiment according to the invention, a jacking unit 106 comprises different axles that connect different pinons of a pinion set 130 to the respective gearbox 128. For example, a first jacking unit 107 comprises a first pinion axle that connects a first pinion 124 and a second pinion axle that connects a second pinion 125, the first pinion 124 and the second pinion 125 being part of a pinion set 130.

[0066] A second embodiment of a jacking arrangement 101 according to the invention is displayed in Figs. 2a and 2b. Fig. 2a shows a front view of the second embodiment of a jacking arrangement 101 according to the invention and Fig. 2b shows a side view vertical section of the second embodiment of a jacking arrangement 101 according to the invention.

[0067] The jacking arrangement 101 of the second embodiment according to the invention comprises a leg, in particular a three-chorded trussed leg comprising braces and chords. In Figs. 2a and 2b, the leg is not displayed fully. For clarity, only the racks are shown. In an alternative embodiment according to the invention, the leg is another type of trussed leg, for example a four-chorded trussed leg.

[0068] In the second embodiment according to the invention, a chord comprises a chord assembly according to the first embodiment of the invention. In an alternative embodiment according to the invention, the first two-sided rack and / or the second two-sided rack each comprise two onesided racks that are connected to each other, jointly forming a two-sided rack. In an alternative embodiment according to the invention, the first rack 1 10 is a one-sided rack. In an alternative embodiment according to the invention, the second rack is a one-sided rack. In an alternative embodiment according to the invention, the first toothed rack face 1 14 and the second toothed rack face are not in phase (synonymous with “are out of phase”) and / or the third toothed rack face 1 15 and the fourth toothed rack face 1 17 are not in phase. For example the first toothed rack face 1 14 and the second toothed rack face are substantially counterphase, preferably counterphase, with each other.

[0069] In the second embodiment according to the invention, the jacking arrangement 101 further comprises at least one jacking unit 106, in particular six jacking units, configured for engaging with the leg 102 for moving the jacking units 106 to and fro along the leg according to the jacking direction j.

[0070] The at least one jacking unit 106 comprises three first pinions, three second pinions, three third pinions 126 and three fourth pinions 127 according to the first embodiment of the invention, the respective first pinions and respective second pinions jointly forming respective first pinion sets, in particular dual-pinion sets, and the respective third pinions 126 and respective fourth pinions 127 jointly forming respective second pinion sets 132, in particular second dual-pinion sets, making up a total of three first pinion sets and three second pinion sets 132. The respective first pinion sets and the respective second pinion sets 132 jointly form respective pinion set layers 201 , making up a total of three pinion set layers 201 , a first pinion set layer 202, a second pinion set layer 203 and a third pinion set layer 204. The pinion set layers 201 are stacked according to the jacking direction j.

[0071] In an alternative embodiment according to the invention, the chord assembly comprises more than two, for example three or four, racks. These racks are either one-sided or two-sided racks, with their toothed rack faces protruding substantially in the first teeth protrusion direction p, preferably in the first teeth protrusion direction p, in the case of one-sided racks and with their toothed rack faces either protruding substantially in the first teeth protrusion direction p, preferably in the first teeth protrusion direction p, or substantially in the second teeth protrusion direction p’, preferably in the second teeth protrusion direction p’, in the case of two-sided racks. The one or more jacking units comprise additional pinions configured for meshing with respective toothed rack faces. Each pinion set 130 comprises additional pinions configured for meshing with the respective toothed rack faces. The pinion sets jointly form pinion set layers 201 according to the second embodiment of the invention, that are stacked according to the second embodiment of the invention. In an alternative embodiment according to the invention, some or all of the pinions are helical pinions. In an alternative embodiment according to the invention, the pinions have different gear shapes. In an alternative embodiment according to the invention, the jacking arrangement 101 comprises two or more pinion set layers 201 , for example two pinion set layers 201 and for example four pinion set layers 201 .

[0072] In the second embodiment according to the invention, the jacking units each comprise one or more pinions, in particular two pinions. The jacking units each further comprise a gearbox 128 connected to the one or more pinions, in particular to the two pinions, and a motor connected to the gearbox 128, the motor and the gearbox 128 being configured for driving the one or more pinions for moving the respective jacking unit 106 to and fro along the leg. In an alternative embodiment according to the invention, a jacking unit 106 comprises a single pinion. In the second embodiment according to the invention, a jacking unit 106 comprises the pinions of a pinon set, in particular each jacking unit 106 comprises the pinions of a distinct pinion set 130. In an alternative embodiment according to the invention, a jacking unit 106 comprises pinions from multiple pinion sets. For example, a single jacking unit 106 comprises pinions from a first pinion set 131 of the first pinion set layer 202 and pinions from a second pinion set 132 of the first pinion set layer 202. For example, a single jacking unit 106 comprises pinions from a pinion set 130 of the first pinion set layer 202 and pinions from a pinion set 130 of the second pinion set layer 203. The second pinion set layer 203 is preferably adjacent to the first pinion set layer 202.

[0073] In the second embodiment according to the invention, the centers of the pinions of a pinion set 130 are located on a single pinion set axis a according to the first embodiment of the invention. In an alternative embodiment according to the invention, the centers of the pinions of a pinion set 130 are located on different axes.

[0074] In the second embodiment according to the invention, a jacking unit 106 comprises a pinion axle 133 that connects all the pinions of a pinion set 130 to the respective gearbox 128 according to the first embodiment of the invention. In an alternative embodiment according to the invention, a jacking unit 106 comprises different axles that connect different pinons of a pinion set 130 to the respective gearbox 128.

[0075] A third embodiment of a jacking arrangement according to the invention is displayed in Figs. 3a and 3b. Fig. 3a shows a front view of the third embodiment of a jacking arrangement according to the invention and Fig. 3b shows a side view vertical section of the third embodiment of a jacking arrangement according to the invention.

[0076] The jacking arrangement of the third embodiment according to the invention comprises a leg, in particular a three-chorded trussed leg comprising braces and chords. In Figs. 3a and 3b, the leg is not displayed fully. For clarity, only the racks are shown. In an alternative embodiment according to the invention, the leg is another type of trussed leg, for example a four-chorded trussed leg.

[0077] In the third embodiment according to the invention, a chord comprises a chord assembly according to the first embodiment of the invention. In an alternative embodiment according to the invention, the first two-sided rack and / or the second two-sided rack each comprise two onesided racks that are connected to each other, jointly forming a two-sided rack. In an alternative embodiment according to the invention, the first rack 1 10 is a one-sided rack. In an alternative embodiment according to the invention, the second rack 1 1 1 is a one-sided rack. In an alternative embodiment according to the invention, the first toothed rack face 1 14 and the second toothed rack face are not in phase (synonymous with “are out of phase”) and / or the third toothed rack face 1 15 and the fourth toothed rack face are not in phase. For example the first toothed rack face 1 14 and the second toothed rack face are substantially counterphase, preferably counterphase, with each other.

[0078] In the third embodiment according to the invention, the jacking arrangement further comprises at least one jacking unit 106, in particular two jacking units, in particular a first jacking unit 107 and a second jacking unit 108, each configured for engaging with the leg for moving the at least one jacking unit 106 to and fro along the leg according to the jacking direction j.

[0079] The at least one jacking unit 106 comprises two first pinions, two second pinions, two third pinions 126 and two fourth pinions 127 according to the first embodiment of the invention, the respective first pinions and respective second pinions jointly forming respective first pinion sets, in particular dual-pinion sets, and the respective third pinions 126 and respective fourth pinions 127 jointly forming respective second pinion sets 132, in particular second dual-pinion sets, making up a total of two first pinion sets and two second pinion sets 132. The respective first pinion sets and the respective second pinion sets 132 jointly form respective pinion set layers 201 , making up a total of two pinion set layers 201 , a first pinion set layer 202 and a second pinion set layer 203. The pinion set layers 201 are stacked according to the jacking direction j.

[0080] In an alternative embodiment according to the invention, the chord assembly comprise more than two, for example three or four, racks. These racks are either one-sided or two-sided racks, with their toothed rack faces protruding substantially in the first teeth protrusion direction p, preferably in the first teeth protrusion direction p, in the case of one-sided racks and with their toothed rack faces either protruding substantially in the first teeth protrusion direction p, preferably in the first teeth protrusion direction p, or substantially in the second teeth protrusion direction p’, preferably in the second teeth protrusion direction p’, in the case of two-sided racks. The one or more jacking units comprise additional pinions configured for meshing with respective toothed rack faces. Each pinion set 130 comprises additional pinions configured for meshing with the respective toothed rack faces. The pinion sets jointly form pinion set layers 201 according to the second embodiment of the invention, that are stacked according to the second embodiment of the invention. In an alternative embodiment according to the invention, some or all of the pinions are helical pinions. In an alternative embodiment according to the invention, the pinions have different gear shapes. In an alternative embodiment according to the invention, the jacking arrangement comprises two or more pinion set layers 201 , for example four pinion set layers 201 .

[0081] In the third embodiment according to the invention, the jacking units each comprise one or more pinions, in particular four pinions. Each jacking unit 106 comprises pinions from multiple pinion sets. In particular, the first jacking unit 107 comprises pinions from the first pinion set 131 of the first pinion set layer 202 and pinions from the first pinion set 131 of the second pinion set layer 203. The second jacking unit 108 comprises pinions from the second pinion set 132 of the first pinion set layer 202 and pinions from the second pinion set 132 of the second pinion set layer 203. The second pinion set layer 203 is adjacent to the first pinion set layer 202. The jacking units each further comprise a gearbox 128 connected to the one or more pinions, in particular to the four pinions, and a motor connected to the gearbox 128, the motor and the gearbox 128 being configured for driving the one or more pinions for moving the respective jacking unit 106 to and fro along the leg. Each gearbox 128 comprises two connective gears 301 , one at each pinion set 130 layer, jointly configured for transferring a rotating movement from the first pinion set layer 202 to the second pinion set layer 203. The centers of the pinions of a pinion set 130 are located on a single pinion set axis a according to the first embodiment of the invention. In an alternative embodiment according to the invention, the centers of the pinions of a pinion set 130 are located on different axes.

[0082] In the third embodiment according to the invention, a jacking unit 106 comprises a pinion axle 133 that connects all the pinions of a pinion set 130 to the respective gearbox 128 according to the first embodiment of the invention. In an alternative embodiment according to the invention, a jacking unit 106 comprises different axles that connect different pinons of a pinion set 130 to the respective gearbox 128.

[0083] Fig. 4 shows an isometric view on a fourth embodiment of a jacking arrangement 101 according to the invention. The fourth embodiment according to the invention is a jacking arrangement 101 for lifting and lowering a self-elevating platform. The jacking arrangement 101 comprises a leg 102, in particular a three-chorded trussed leg 102 comprising braces 103 and chords 104, known from the state of the art. The leg 102 is not fully shown. In an alternative embodiment according to the invention, the leg 102 is another type of trussed leg, for example a four-chorded trussed leg.

[0084] The jacking arrangement 101 according to the fourth embodiment according to the invention in fact comprises three jacking arrangements according to the invention along the same leg 102, each interacting with one of the chords 104 of the leg 102. The chords 104 further comprise a chord assembly 105 according to the invention, in particular according to any of the other discussed embodiments. For details on the chord assembly 105, we refer to Figs. 1 a and 1 b. The jacking units 106 are attached to jacking houses that connect the jacking arrangement to the platform. The jacking units attached to jacking houses are conceptually represented in Fig 4. For details on the jacking units and the jacking houses, we refer to Figs. 2a and 2b.

[0085] Fig. 5 shows an isometric view of a fifth embodiment according to the invention in particular a self-elevating platform 501 . The self-elevating platform 501 comprises at least one jacking arrangement 101 according to the invention, in particular twelve jacking arrangements with jacking units 106 in jacking houses according to the second embodiment of the invention interacting with four three-corded trussed legs, each jacking arrangement 101 interacting with one of the chords 104. The trussed legs are conceptually represented by their chords. The braces are omitted in Fig. 5 for clarity. The self-elevating platform 501 further comprises a ship 502. The jacking units are attached to jacking houses that connect the jacking arrangements to the platform, in particular to the ship 502. In the state of the art, multiple ways exist for the jacking houses to connect the jacking units and jacking arrangements to the platform

Claims

Claims1. A jacking arrangement (101 ) for lifting and lowering a selfelevating platform, comprising:- a leg (102) extending according to a substantially upright jacking direction (j),- at least one jacking unit (106) configured for engaging with the leg for moving the jacking unit to and fro along the leg according to the jacking direction, wherein- the leg comprises a chord assembly (105) extending substantially according to the jacking direction,- the chord assembly comprises a first rack (1 10) extending substantially along the chord assembly according to the jacking direction,- the first rack comprises a first toothed rack face (1 14) extending substantially along the first rack according to the jacking direction, with the teeth of the first toothed rack face protruding in a first teeth protrusion direction (p), the first teeth protrusion direction being substantially perpendicular to the jacking direction,- the at least one jacking unit comprises a first pinion (124),- the first pinion is configured for meshing with the first toothed rack face, characterized in that,- the chord assembly further comprises- a second rack (1 1 1 ) extending substantially along the chord assembly according to the jacking direction,- a rack spacer (112) extending substantially along the chord assembly according to the jacking direction, the rack spacer also extending according to a spacing direction (s) between a first rack spacer side (1 18) and a second rack spacer side (1 19), the spacing direction being substantially perpendicularto a plane defined by the jacking direction and the first teeth protrusion direction,- the second rack comprises a second toothed rack face (116) extending substantially along the second rack according to the jacking direction, with the teeth of the second toothed rack face protruding substantially in the first teeth protrusion direction,- the first rack is connected to the second rack via the rack spacer,- the at least one jacking unit comprises a second pinion (125),- the second pinion is configured for meshing with the second toothed rack face,- the first pinion and the second pinion jointly form a pinion set (130), in particular a dual-pinion set, in particular the first pinion set (131 ), in particular the first dual-pinion set.

2. A jacking arrangement according to the previous claim, wherein:- the first rack is a two-sided rack, comprising a third toothed rack face (115) extending substantially along the first rack according to the jacking direction, with the teeth of the third toothed rack face protruding in a second teeth protrusion direction (p’), the second teeth protrusion direction being substantially opposite of the first teeth protrusion direction,- the at least one jacking unit further comprises a third pinion (126),- the third pinion is configured for meshing with the third toothed rack face,- the second rack is a two-sided rack, comprising a fourth toothed rack face (117) extending substantially along the second rack according to the jacking direction, with the teeth of the fourth toothed rack face protruding substantially in the second teeth protrusion direction,- the at least one jacking unit comprises a fourth pinion (127),- the fourth pinion is configured for meshing with the fourth toothed rack face,- the third pinion and the fourth pinion jointly form a pinion set, in particular a dual-pinion set, in particular the second pinion set (132), in particular the second dual-pinion set.

3. A jacking arrangement according to any of the previous claims, wherein the centers of the pinions of a pinion set are located on a single pinion set axis (a).

4. A jacking arrangement according to any of the previous claims, wherein a jacking unit comprises:- one or more pinions,- a gearbox (128) connected to the one or more pinions,- a motor (129) connected to the gearbox, wherein the motor and gearbox are configured for driving the one or more pinions for moving the jacking unit to and fro along the leg.

5. A jacking arrangement according to the previous claim, wherein a jacking unit comprises the pinions of a pinion set.

6. A jacking arrangement according to the previous claim, wherein a jacking unit comprises a pinion axle (133) that connects all the pinions of the pinion set to the gearbox.

7. A jacking arrangement according to any of the claims 2 to 6, wherein the first toothed rack face, the second toothed rack face, the third toothed rack face and the fourth toothed rack face are substantially in phase.

8. A jacking arrangement according to any of the previous claims, wherein the rack spacer comprises a first rack spacer plate (120) and a second rack spacer plate (121 ), both extending substantially along the chord assembly according to the jacking direction, both also extending substantially according to the spacing direction between respective first rack spacer plate sides (122) and second rack spacer plate sides (123), the first rack spacer plate sides and second rack spacer plate sides being part of the first rack spacer side and the second rack spacer side respectively, the first rack spacer plate being substantially parallel to the second rack spacerplate, and both the rack spacer plates connecting the first rack and the second rack.

9. A self-elevating platform (501 ) comprising at least one jacking arrangement according to any of the previous claims.

10. A self-elevating platform according to the previous claim, further comprising a ship (502).1 1 . The use of a jacking arrangement according to any of the claims 1 to 8, wherein the pinions, meshing with the racks, are driven by the jacking units, thereby moving the jacking unit to and fro along the leg in the jacking direction.

12. The manufacturing of a jacking arrangement according to any of the claims 1 to 8, comprising:- connecting the first rack to the rack spacer at the first rack spacer side,- connecting the second rack to the rack spacer at the second rack spacer side,- applying the first toothed rack face and the second toothed rack face.

13. The manufacturing of a jacking arrangement according to the previous claim, in combination with claim 2, further comprising:- applying the third toothed rack face and the fourth toothed rack face.

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