Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
  • B66C13/00—Other constructional features or details
  • B66C13/02—Devices for facilitating retrieval of floating objects, e.g. for recovering crafts from water

Definitions

• the invention relates to controlling the vertical position of a load (by decoupling, stabilizing, balancing or moving the load).
• the invention relates to a heave compensation device for decoupling a load to be lifted by a hoisting device.
• the heave compensation device is to be connected to a hook of the hoisting device.
• the invention further relates to a hoisting system, preferably controlling the vertical position of the load during heaving motions, more preferably a spring balanced hoisting system.
• the invention also relates to a method of heave compensated hoisting.
• the load By controlling the vertical position of a load (by decoupling, stabilizing, balancing or moving the load), the load can be transferred from a heaving object to a fixed object, from a fixed object to a heaving object, or between two heaving objects.
• springs have been used to decouple a vertical movement of the load from the hoisting device, which could be a crane on a ship. In prior art, the spring is coupled linearly to the load.
• EP 3 653 561 A spring-balanced decoupling device is known from EP 3 653 561 , the content of which is fully incorporated here.
• EP 3 653 561 discloses examples of balanced heave compensation devices.
• heave compensation devices comprise passive heave compensation devices (with or without active components), which comprise a spring placed in line with a load path.
• a gas spring comprises a gas volume acting on a cylinder directly.
• a hydro-pneumatic spring comprises a medium separator in between the cylinder and the gas: an oil volume acts on the cylinder and the gas acts on a piston between the gas and the oil volume.
• (Gas- or) hydro-pneumatic springs can be configured.
• a (gas- or) hydro-pneumatic spring can comprise a configuration set up to increase or reduce the volume and/or the filling amount of the oil and/or the gas volume of the spring, thereby configuring the spring and adapting its spring behavior.
• the gas cylinders containing such gas volumes and medium separators according to the prior art are made of steel. Steel is known to be heavy, but according to the prior art it is the only material with properties suitable for heave compensation.
• Heave compensation devices that are coupled to the hook or hoisting wire of an existing hoisting system can be very heavy. Therefore, the net load that can be suspended by the hoisting wire is decreased. It is thus a goal to decrease the weight of such heave compensation devices. For higher loads and higher heaving motions a larger gas volume is beneficial to control the load. When made of steel such large gas volumes become cumbersome: the net load is reduced too much by the own weight of the heave compensator. It is an object of the invention to provide a large gas volume suitable for heave compensation at relevantly reduced weight when compared to traditional gas cylinders made of steel.
• a heave compensation device for decoupling a load.
• the heave compensation device has a first frame and a second frame that can be coupled to the load.
• the first frame and the second frame can move with respect to each other, resulting in the decoupling of the load.
• the heave compensation device comprises a preferably configurable (gas- or) hydro-pneumatic spring system, preferably coupled to first and second frame.
• a pressure vessel is provided to configure the (gas- or) hydro-pneumatic spring system.
• That vessel has a fiber layer for weight reduction, while retaining high strength and other properties required for heave compensation.
• the fiber layer provides strength and has little wear even though the vessel is at least partially filled and emptied at high frequencies, such as every 6-12 seconds, and at very high repetitions, such as >30.000 and even up to >1.000.000 times during its service life.
• the heave compensation device is arranged to be deployed in a hoisting device.
• the heave compensation device has on the first frame a connection unit for connection to a hoisting device.
• the heave compensation device has on the second frame a carrying or support unit that can be coupled to the load.
• a transmission is provided between the first and second frame, which guides first and second frames and which provides a force transmission between the two frames.
• the configurable (gas- or) hydro-pneumatic spring is preferably part of the force transmission.
• the transmission is arranged to at least partially, preferably fully, decouple movement of the load connected to the second frame from movement of the first frame.
• the pressure vessel with fiber layer is a fiber overlayed pressure vessel.
• the fiber layer is an outer layer of the vessel. This results in a high reinforced structure able to resist high pressures by the gas in the vessel.
• the fiber layer is the only layer of vessel. The fiber layer is then resistant to gas penetration, preferably resistant to N2.
• the pressure vessel comprises an inner liner, which is partially, substantially or fully covered by a fiber layer or more preferably a layer of fiber composite.
• the liner provides the gas-penetration prevention.
• the inventors found the combination of a fiber layer combined with an inner layer provides a relevant weight reduction when compared with steel. Compared to embodiments with an only-fiber layer, a combination of liner with fiber layer for the pressure vessel provides a further weight reduction.
• the inner liner of the pressure vessel consists of one or multiple layers of metal, preferably aluminum or steel and/or plastic, preferably HDPE or Polyamide, more preferably PA11.
• the fiber composite of the pressure vessel comprises or consists of carbon fiber.
• the pressure vessel has an access point and a connection for connecting the pressure vessel to a piston type accumulator of the (gas- or) hydro-pneumatic spring system.
• the transmission comprises at least one pivoting arm, with the (gas- or) hydro-pneumatic spring system coupled to the pivoting arm, wherein the transmission is preferably arranged as a spring-balanced system.
• a hoisting device is provided with the heave compensation device as disclosed herein.
• the connection unit of the heave compensation device is connected to a hoisting wire of the hoisting device.
• a ship comprising a hoisting device as disclosed herein.
• the vessel according to the invention can be used in any weight balancing system.
• An embodiment disclosed here is a device comprising a first frame and second frame moveable with respect to the first frame and a configurable (gas- or) hydro-pneumatic spring, which includes at least one pressure vessel that has a fiber layer. This embodiment can have any of the other features disclosed herein.
• FIG. 1 is a schematic diagram showing a detailed embodiment of a hook-based heave compensation device 1.
• a heave compensation device can be arranged in a hoisting device.
• the heave compensation device comprises a fiber overlayed pressure vessel 405.
• the pressure vessel is shown in more detail in FIG. 3 .
• the heave compensation device 1 can be used in an existing non-motion compensated crane.
• the heave compensation device 1 will convert the existing non-motion compensated crane into a crane that operates with the load decoupled, e.g. using balanced heave compensation.
• the heave compensation device 1 of this embodiment allows to add the decoupling feature to existing high-load cranes without having to make costly adaptations to the existing crane equipment.
• the heave compensation devices according to the invention are suitable for offshore transfers of large loads. Transfers can include feeder barge operations for transferring loads such as wind-turbine components between a heaving vessel and a fixed of floating crane vessel. Transfers can also include floating installation, wherein loads are transferred from a floating crane vessel to a fixed or floating landing target.
• the heave compensation device 1 could also be easily connected and disconnected to any type of mechanical support or suspension system which is mounted on the ground or for example onto an off-shore platform.
• the heave compensation device 1 is suitable for deployment below the hook of a crane on a floating or fixed (jacked up) offshore crane vessel.
• the heave compensation device is lifted by a hook connected to a hoisting wire, the hook engaging connection unit 22.
• the heave compensation device 1 is lifted by a crane with a wire and hook.
• a crane is used to illustrate the invention, clearly any kind of support structure can be used.
• the crane or support structure could be placed on a floating vessel.
• the vessel can be a heaving ship or platform.
• a heave compensation device 1 can be a device that decouples, preferably balances, a load 35 at different positions or can be a device that generally balances the load, preferably by spring loaded means.
• Embodiments of the heave compensation device comprise balancing a load at different positions of the heave compensation device, the balancing force being provided for the most part by spring loaded means, preferably (gas- or) hydro-pneumatic spring systems.
• spring loaded means preferably (gas- or) hydro-pneumatic spring systems.
• loads of over 10 tons, preferably over 20 tons, and more preferably over 30 tons are supported and balanced using a heave compensation device 1.
• the heave compensation device 1 comprises a first frame 2 having the connection unit 22.
• the connection unit 22 is a ring, which, in this embodiment, forms an integral part of a first frame 2.
• the heave compensation device 1 further comprises a second frame 3 having a carrying unit 32 for suspending a load 35.
• a load 35 can be supported by carrying unit 32.
• the first frame 2 and second frame 3 can move with respect to each other.
• the connection unit 22 and carrying unit 32 move with respect to each other along a linear guideline 209.
• the connection unit 22 and/or the carrying unit 32 are positioned on the guideline 209.
• the guideline 209 is generally parallel to the gravitational force, although in some embodiments, as result of heaving and other movements of a ship offshore, this can change.
• a transmission couples the moving frame parts 2,3.
• the transmission allows moving connection unit 22 with respect to carrying unit 32, resulting in an increase or reduction of the distance between the two suspension points 22,32.
• the suspension points are oriented along the vertical line, here the guide line 209, thereby thus controlling the vertical position of the load.
• a linear guide is provided in the heave compensation device 1, which guides the moving frame parts 2,3 with respect to each other.
• the linear guide is part of the transmission.
• the linear guide is arranged such that the connection unit 22 and carrying unit 32 move along the straight guideline 209.
• the transmission comprises one or more arms or beams 6,7 for transferring forces between the suspension points, the arm being positioned non-parallel, preferably at an angle between 2-178 degrees, with respect to the guideline 209 / the direction of the guide.
• the arms are at an angle with the vertical direction.
• one or more arms are pivotable with respect to a first frame 2 or second frame 3.
• the transmission comprises one or more beams 6,7 connected via one or more pivot connections 21,31,41.
• the beams and pivot connections transfer forces between the first and second frame.
• the transmission comprises two leverage units in the form of arms assemblies 50, 51 positioned on opposite sides of the linear guideline 209.
• the arm assemblies allow providing a force at arm length, corresponding to a lever.
• Arm assemblies 50,51 work simultaneously and identically.
• the mechanical parts are labelled only on the left-hand side.
• Left-hand arm assembly 50 comprises an arm part 7 and a balancer arm 6.
• Arms 6,7 are connected to each other via a pivot point 41 that can comprise a bearing.
• Arm 6 is connected to the second frame 3 via pivot point 31.
• Arm 7 is connected to the first frame 2 via pivot point 21.
• the second frame 3 has pivot points. Pivot point 31 is connected to the balancer arm 6 of arm assembly 50. Balancer arm 6 can pivot with respect to pivot point 31. Arms 6 and 7, part of the transmission, are connected at pivot point 41.
• the transmission comprises force application points 41,42. At least one force application point 41 is positioned away from the linear guideline 209.
• the force application points are preferably arranged symmetrically around the guideline.
• Force application points are preferably arranged so the carrying/supporting/suspension forces are guided symmetrically around the guideline.
• forces transmitted through said one or more force application points are not in line with, that is non-parallel to, the guideline 209.
• the transmission comprises a (gas- or) hydro-pneumatic spring system 4.
• the application points of the transmission are such that the orientation of the (hydro-) pneumatic spring changes and that a direction of said forces changes when frames 2 and 3 move with respect to each other and/or when the distance between the connection unit and the carrying unit changes. This will allow using the (gas- or) hydro-pneumatic springs as a spring in a spring-balanced system.
• pivot point 41 also forms a point of force application for (gas- or) hydro-pneumatic spring system 4.
• the (gas- or) hydro-pneumatic spring system 4 is arranged as a pulling device. The spring force is applied between application points 41 and 42.
• the (gas- or) hydro-pneumatic spring system comprises cylinder 401 that is connected to first frame 2 via pivoting connection point 42 and to beams 6,7 in pivot point 41. As point 41 is on arm 7 at a distance from pivot point 21, the distance between the two points 21,31 acts as a lever.
• the (gas- or) hydro-pneumatic spring system 4 comprises cylinder 401, a first hydraulic connection 402, a second hydraulic connection 403, a piston type accumulator 404 and pressure vessel 405.
• the (gas- or) hydro-pneumatic spring system 4 allows setting the spring force of the (gas- or) hydro-pneumatic cylinder 401.
• One chamber of cylinder 401 is connected to the piston type accumulator 404 and will have a relatively high pressure.
• the other chamber 43, on the opposite side of the piston of cylinder 401, may have a limited, relatively low pressure at minimum compression of the spring. When compressed, the gas pressure in chamber 43 increases. This helps to prevent the heave compensation device to suddenly reach the end of the stroke and it allows for better balance given the non-linear and adiabatic characteristics of a gas spring.
• the heave compensation device can comprise an actuator.
• the actuator can be part of the (gas- or) hydro-pneumatic spring. Such an actuator is arranged to move the spring.
• the actuator can be part of the transmission between first and second frames 2,3. The actuator can be used to move the first with respect to the second frame / move the connection unit 22 with respect to carrying unit 32.
• the actuator is connected between the first and second frames 2,3 directly via a toothed gear 82 on one frame and a toothed track 81 on the other frame.
• the actuator can comprise a drive that drives the gear wheel 82.
• the actuator acts on the piston of the (gas- or) hydro-pneumatic spring.
• the actuator is coupled to a leverage unit, preferably the same leverage unit as the pneumatic spring.
• the actuator can provide an additional force to compensate for non-ideal spring balance behavior of the spring balance arrangement.
• the actuator can further be used to drive the system, e.g. lift or lower the load.
• FIG. 1 is an example embodiment of a heave compensation device 1 suspended by a hoisting device to carry or suspend a load.
• the combination of connection unit and carrying unit allows to hoist the heave compensation device by existing hoisting devices and pick up and drop offloads while in operation.
• the heave compensation device of FIG. 1 allows decoupling, preferably complete decoupling, of that load suspended by a hoisting device.
• the invention is not limited to 100%, e.g. spring-balanced, decoupling.
• a significant decoupling e.g. of at least 40% of the weight, preferably at least 50%, more preferably at least 60%, and even more preferably at least 80% decoupling of the weight.
• FIG.1 shows an example of a heave compensation device 1 that comprises a transmission.
• the transmission comprises a pivoting arm loaded by a configurable spring, such as a gas- or hydro-pneumatic spring.
• the transmission comprises a spring force balancing arrangement.
• the spring does not have to be a (perfect) linear spring. Additional decoupling can be provided by an actuator.
• FIG. 2 shows an embodiment of a passive heave compensation (PHC) device 4.
• PHC passive heave compensation
• the PHC 4 decouples at least partially the load 35.
• the PHC 4 can be connected to a hoisting device via a connection unit 22.
• PHC 4 also comprises a support or carrying unit 32, that can suspend or support the load 35. Both the connection unit 22 as the carrying unit 32 are shown schematically as rings. Other connections units are possible too.
• Connection unit 22 is connected to a first frame formed by the body of cylinder 400.
• Carrying unit 32 is connected to the rod of cylinder 400, which forms a second frame.
• the first and second frames can move with respect to each other along a guideline, preferably a vertical line in operation. Moving the first and second frames allows decoupling of the load 35.
• the cylinder 400 is the guide for guiding the movement.
• the cylinder is in this arrangement in line with the guideline and vertical direction in use.
• the PHC 4 comprises a hydro-pneumatic spring system 401 that comprises one or more cylinders.
• a hydraulic connection 402 connects the cylinder 400 to a piston type accumulator (PTA) 404.
• PTA piston type accumulator
• a pneumatic connection 403 connects the PTA 404 to a pressure vessel 405.
• PTA 404 is in fluid communication with the rod side chamber 45 of cylinder 400.
• the fluid can be a mineral oil or a glycol-water fluid, but not limited only thereto.
• the PTA piston 406 therein displaces (in FIG. 2 ) upwards and compresses the gas in the chamber (in FIG. 2 ) above the PTA piston 406.
• the gas can normally be nitrogen or air, but not limited only thereto. The compression of gas in chamber creates an effective spring.
• Pressure vessel 405 is used as a gas reservoir. Gas from the pressure vessel 405 is used to increase or decrease pressure inside chamber through the pneumatic connection 403.
• the heave compensation device of FIG. 1 or FIG. 2 or any other heave compensation device for at least partially decoupling a load in a hoisting device, has one or more fiber overlayed pressure vessels 405, which will be discussed in more detail with reference to FIG. 3 .
• FIG. 3A and FIG. 3B show respectively a schematic drawing of a cross-sectional (A) and non-cross-sectional (B) view of a fiber overlayed pressure vessel 405.
• the vessel comprises a liner 60 that is fully or partially covered by a fiber composite 61.
• the inner aluminium liner 60 acts as a gas barrier, preventing any unwanted escaping of gas from the pressure vessel to the outside of the vessel.
• the liner 60 can consist of a metal, preferably aluminum or steel, and / or a plastic, preferably HDPE or Polyamide, more preferably PA11, or another material that can act as a sufficient gas barrier.
• the liner 60 may consist of one or multiple layers of the aforementioned materials, including a combination of layers of different materials.
• the liner 60 can be cylindrical.
• the liner can comprise a top and bottom part.
• the cylinder can have rounded edges near the top and bottom ends.
• the liner 60 and vessel 405 are ball-shaped or cubic.
• the liner 60 of vessel 405 comprises one or several access points 407.
• the access point can be part of a bottleneck of the vessel.
• Access point 407 allows filling and emptying of the pressure vessel.
• the access point can have a sealed opening with a removable cover.
• the access point can have a flanged or threaded connection or other type of closure mechanism that ensures a leak proof seal when the vessel is pressurized.
• At least one of the access points 407 of each vessel 405 of the balanced heave compensator of FIG. 1 or the passive heave compensator of FIG.2 is connected to the cylinder 401 through connection 403, which enables the increase and/or decrease of the pressure inside the cylinder, increasing/decreasing the pulling force.
• the pressure in the cylinder 401 can be changed using the vessel 405 and the PTA 404 to set/configure/operate the (gas- or) hydro-pneumatic spring dependent on the weight of the load that is to be decoupled.
• the pneumatic connection between vessel 405 and PTA 404 also provides a driving force for moving first frame 2 with respect to second frame 3 and thus allows using the (gas- or) hydro-pneumatic spring system 4 as an actuator for the heave compensation device 1.
• the settings for the actuating function can be super-positioned over the settings for the spring balance function of the (gas- or) hydro-pneumatic spring system 4.
• the pressure in the vessel 405 varies significantly and repeatedly, often at high frequencies and at very high repetitions over its service life. This results in high stress and can create wear.
• the liner 60 is covered by a fiber composite 61.
• the fiber composite 61 may consist of one or multiple layers of fiber material, preferably carbon.
• a pressure vessel consisting of only a fiber composite material 61 can also be envisioned.
• the fiber composite material acts as both the gas barrier as well as the load bearing structure.
• FIG.4 shows another embodiment.
• the vessels can be interconnected via their access points 407 through interconnections 408, wherein at least one access point 407 of at least one of these vessels is connected to the PTA 404 through connection 403. It can also be envisioned that the pressure vessel is directly connected to the cylinder by connection 403.
• FW filament winding
• the benefit of the current invention over heavier state of the art vessels made of steel only, is not only the reduction of weight, but also the superior properties of the fiber overlayed pressure vessels.
• the strength of the fiber allows for a higher gravimetric storage density for overlayed pressure vessels compared to all metal vessels. Overlayed pressure vessels furthermore show an increased fatigue performance and corrosion resistance.
• For the application in heave compensation devices a high frequency and high repetition of emptying and filling of the vessels is required and increased fatigue performance reduces long-term costs.
• the overlayed pressure vessels weigh significantly less than the vessels employed in the state of the art. Since the pressure vessels are present in line on hook, this reduction in weight allows suspending a higher load from the crane.
• overlayed pressure vessels can provide a much larger gas volume at the same weight when compared to steel pressure vessels according to the prior art.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Load-Engaging Elements For Cranes (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)

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Citations (3)

• 2024
  • 2024-07-05 EP EP24186925.4A patent/EP4674800A1/de active Pending
• 2025
  • 2025-07-04 WO PCT/EP2025/069228 patent/WO2026008880A1/en active Pending

Patent Citations (3)

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