EP3290383A1 - Device for lifting, lowering or holding a load - Google Patents

Abstract

Disclosed is a sea state compensation device, in which a load is supported via a passive compensation device and an active compensation unit is designed as a linear actuator.

Description

The invention relates to a device for lifting, lowering or holding a load according to the preamble of claim 1.

Swell or swell compensation devices (Heave Compensation System) - hereinafter also referred to as HCS - are used, for example, in offshore / marine technology when a load from a ship by means of a crane to an object supported on the seabed, for example, a platform to be discontinued. Such a task is in the assembly of rigs or offshore wind turbines before or when a drill string is lowered from a floating platform and this is raised and lowered by the sea. In research, heavy measuring devices or supply stations for robots or the like are lowered from a ship via a winch to great depths, in which case the tether, caused by the sea state, is exposed to considerable tensile loads.

To compensate for such caused by swell or swell relative movements of the load to the respective predetermined target position passive compensation systems and active compensation systems are known. In a passive system, as for example in the introduction to the description of US 4,121,806 is described, a linearly adjustable unit, such as a Hydrozylin- or a rotationally operated unit, for example, a hydraulic motor in the support direction via a hydropneumatic storage unit is applied, the pressure is designed so that the load is supported without sea state in a central position - the hydropneumatic Storage unit thus acts as a kind of gas spring.

Such passive compensation systems are designed to match the particular application and the associated loads, so that an adaptation to different loads is possible only with great effort. Passive compensation systems are often located between the actual crane hook and the load and are thus located below the sea level when lowered.

A problem with such passive systems is that the charging of the hydro-pneumatic storage unit must be adjusted depending on the load and the sea state and also on the immersion depth. In the US Pat. No. 7,934,561 B1 is a passive system with a water depth compensation shown, over which the influences of the water depth when lowering the load can be compensated something.

For applications in which a very precise guidance of the load when lowering is important, active compensation systems are preferably used in which a linear drive, primarily a hydraulic cylinder, or a rotary drive, primarily a hydraulic motor, is designed with a position control system, through which Last by driving the drive can always be kept at the predetermined position. Such a device with active and passive compensation device is in the US 4,121 . 806 described.

Such active compensation systems are usually placed on the ship so that they also have to move the weight of the crane cable, the crane blocks (pulley) and the crane hook, so that the payload is reduced by the additional weight of these components.

For larger loads usually a combination of active and passive compensation system is used, as for example in the EP 1 869 282 B1 is explained.

On the one hand, the load is compensated via a passive hydro-pneumatic storage system and, on the other hand, the setpoint position of the load is kept constant via an active control system. Such a system has the advantage that only the compensating movement of the load must be effected via the active system, while the actual support is carried out via the passive system. Such combination systems are particularly required when lifting a load at a predetermined speed from the seabed or from an anchored on this platform or lowered to this. A similar system is also mentioned in the beginning US 4,121,806 explained. In this arrangement, passively acting, over a hydropneumatic storage unit biased hydraulic cylinder and active hydraulic cylinders are arranged with a position control parallel to each other in a compensation unit to which the actual crane hook is attached, which in turn is connected via a crane cable to the load.

The US 4,021,019 shows a system in which an active hydraulic cylinder is integrated into a passive hydraulic cylinder.

Such systems have a relatively complex structure and are integrated by the manufacturer in the design of the crane. Retrofitting the active system to existing cranes using only a passive compensation system is only possible with great effort, as it requires intervention in the crane structure of the existing design and also provides additional hydraulic power. In addition, existing crane designs due to restrictions in terms of maximum rope speed, weight and the diameter of the sheaves / blocks and the rigidity of the construction are subject, so that retrofitting with an active system is almost impossible.

In the pamphlets DE 10 2015 225 936 A1 and EP 2 896 589 A1 In each case, systems are shown in which an active compensation unit and a lifting device provided with a passive compensation device act separately on the load. Due to the separate power flow lines of the active and passive part existing systems can be retrofitted with an active compensation unit.

In these systems, the active compensation unit is each implemented with a winch arrangement, wherein a winch cable or the like acts on the load to assist the lifting device and the passive compensation device on lowering, by controlling the fibrillation of the winch cable by corresponding activation of the active winch. The disadvantage of such solutions is that support for the lowering movement, that is, an active lowering by "pressing" is not possible.

In contrast, the invention has for its object to provide a device in which the lowering of the load is actively supported.

This object is achieved by a device with the combination of features of claim 1.

Advantageous developments of the invention are the subject of the dependent claims.

According to the invention, the device for lifting, lowering or holding a load has a compensating device which is designed to compensate for the relative movements of the load, in particular caused by swell, with reference to a target position. The load is movable by means of a lifting device in the direction of the target position or away. The lifting device is assigned to a passive compensation device on the one hand. Furthermore, an active compensation unit is provided which can be controlled via a control unit as a function of a relative movement of the load or an effective force. The passive compensation device is designed so that it supports the weight of the load at least partially. According to the invention, the active compensation unit is designed as a linear actuator, for example as an active cylinder or as a linear motor, whose actuating element engages the load parallel to the passive compensation device. The linear actuator is associated with an active drive for actuating the control element.

With such a solution, the load can be acted upon actively, that is to say by suitable actuation of the linear actuator both in the lowering direction and in the lifting direction, so that the lowering movement takes place even under complex swell or complex swell according to the specifications.

In the case where the linear actuator is an active cylinder, it is preferably designed as a hydraulic cylinder.

In a variant of the invention, the hydraulic cylinder is a synchronous cylinder, which is arranged in a closed hydraulic circuit.

The passive compensation device is preferably designed with a hydraulic cylinder. This has a piston which limits a pressure chamber effective in the direction of support. This pressure chamber is in operative connection with a hydropneumatic storage unit and thus forms a kind of gas spring.

The active drive of a hydraulic actuator designed as a linear actuator of the active compensation device, also called active cylinder, may be a hydraulic pump with two flow directions, the terminals are connected in a closed circuit, each with a pressure chamber of the active cylinder.

The drive of the hydraulic pump can again take place via an electric drive motor or a winch drive. The conveying direction is then controlled simply by reversing the drive motor or winch drive.

The delivery volume of the hydraulic pump is easily adjustable when the drive motor is designed frequency-controlled.

In a particularly compact solution, the hydraulic pump and the drive motor with the active cylinder form a structural unit, with a signal and power supply via an active line whose immersion length is adjustable via an active wind on the deck, so that practically the active line with the change in position the load is lengthened or shortened.

In one embodiment, in which the hydraulic pump is driven by a winch drive, this is carried out with one or two active winches, which is associated with a winch cable or the like, which is deflected by means of a deflecting wheel. The winch cable thus extends from an active winch via the deflection wheel to the other winch or other active winch, so that the rotational speed and direction of rotation of the deflection wheel is determined by corresponding activation of the active winch or active winches, via which the hydraulic pump is then driven.

The hydraulic pump and the deflection wheel can be mounted on a roller block on which the loose / movable rollers of a pulley of the lifting device are mounted.

The device technical effort is particularly low when an active winch is a component of the pulley, which is provided as part of the lifting device for raising and lowering a load.

According to the invention it is particularly preferred if the passive compensation device is biased, wherein the bias voltage is designed so that a resulting force acting in the support direction corresponds approximately to the weight of the load.

Preferred embodiments of the invention are explained in more detail below with reference to schematic drawings. In the concrete embodiments, the device is designed with compensation devices for compensating for sea-induced relative movements of the load with respect to a target position.

Figur 1

eine als Seegangskompensationseinrichtung ausgeführte Einrichtung mit einer passiven Kompensationseinrichtung und einer aktiven Kompensationseinheit, wobei letztere als Hydrozy-linder ausgeführt ist und

Figuren 2 bis 4

Varianten des Ausführungsbeispiels gemäß Figur 1.

Show it

FIG. 1

a designed as a sea state compensation device with a passive compensation device and an active compensation unit, the latter being designed as a Hydrozy-linder and

FIGS. 2 to 4

Variants of the embodiment according to FIG. 1 ,

FIG. 1 shows a greatly simplified schematic diagram of a running with a device according to the invention for sea state compensation (HCS Heave Compensation System) 1 vessel or floating crane 2, via which a load L on another ship or the seabed 4 or a platform anchored on this is to be discontinued. The device 1 (motion compensation device, HCS) has a passive compensation device 6 and an active compensation unit 8, the concrete structure of which is explained below. On the indicated floating crane 2, a loading crane 10 is mounted, which in a conventional manner a plurality of stationary rollers 14 (discs) and moving rollers (discs) 16 which form a pulley 20 together with a support cable 18. The movable rollers 16 (loose part) are mounted on a roller block 22. The fixed with an end on deck support cable 18 can be obtained by means of a winch 21 of the loading crane 10 or gefiert / omitted to raise the load L or lower. The effective force of the winch 21 is then translated according to the pulley 20.

According to the embodiment FIG. 1 is on the roller block 22, a passive hydraulic cylinder 24 is held, which is designed as a differential cylinder with only one piston rod. A piston 26 divides the Cylinder 24 in a direction effective in the direction of support pressure chamber 28 and an effective in Absenkrichtung pressure chamber 30. The pressure chamber 28 is connected to a hydropneumatic storage unit 32, which may be formed as usual as a hydropneumatic piston accumulator with one or more downstream gas cylinders and through which the pressure chamber 28 with a biasing pressure is applied. The force resulting from this bias in the illustrated embodiment corresponds approximately to the load L to be moved. This is thus compensated for approximately 100%. The pressure chamber 28 and the storage unit 32 form a kind of gas spring, the pressure of which changes with increasing water depth. To compensate for this change, for example, the pressure chamber 30 may be associated with a device for compensation of the water depth. The pressure chamber 30 may also be connected to a pressure medium expansion tank.

As explained, the hydraulic cylinder 24 is designed as a differential cylinder. An in FIG. 1 load-side piston rod 34, which passes through the pressure chamber 28, carries the load L, which is attached to the piston rod 34, for example via a crane hook or the like. The passive hydraulic cylinder can also be designed as a synchronous cylinder with two piston rods, so that the forces generated by the pressure of the water are compensated.

At the in FIG. 1 illustrated embodiment, the active compensation unit 8 also acts on the load L. The compensation unit 8 has an active cylinder 36, which is connected via a bridge 38 to the hydraulic cylinder 24 of the passive compensation device 6. The active cylinder 36 is designed as a synchronous cylinder, wherein an active piston 40 two pressure medium-filled annular spaces 42, 44 of the active cylinder 40 separates from each other. A load-side piston rod 46 engages directly or via an extension of the load L. It is also conceivable that the load-side piston rod 46 of the active cylinder 36 acts like the piston rod 34 of the passive hydraulic cylinder via the crane hook on the load, as in FIG. 1 is shown. The other piston rod 48 is led out of the Zylinderge-housing, so that the two annular spaces 42, 44 in the middle position of the active piston 40 have equal volumes. These two annular spaces 42, 44 are arranged with a hydraulic pump 50, whose connections are connected via pressure lines 52, 54, each with an annular space 42 and 44, in a closed hydraulic circuit. Depending on the direction of conveyance of the hydraulic pump 50, pressure medium can thus be displaced / conveyed out of one of the annular spaces, for example the annular space 42, via the hydraulic pump 50 into the other annular space 44 which enlarges. The hydraulic pump 50 is a constant pump and forms a structural unit with the active cylinder 36 and is thus also arranged when lowering the seabed 4 below the water level. The drive of the hydraulic pump 50 takes place directly via a shaft 56 or via a transmission by a deflecting wheel 58, which is part of a winch drive 60. This has two active winches 62, 64, each having an electric or hydrostatic drive, via a control unit (see FIG. 3 ) is controllable.

About the active winches 62, 64 a winch rope 66 can be gefiert or caught (unwound / wound), which is partially rolled onto the one active winch, leads from this active winch to the guide wheel 58, deflected via the guide wheel 58 is guided by the guide wheel 58 to the other active winds and partly rolled up on the other active winds. Thus, the speed of the guide wheel 58 and thus the speed of the hydraulic pump and the per unit time funded by the hydraulic pump pressure medium flow depends on how the speeds of the two active winches 62 and 64 behave to each other, the simplicity is assumed that the winding radius for the Winch rope 66 on one active winch is just as big as on the other active winch.

• Beim Absenken der Last L ohne Wellengang werden die beiden Aktivwinden mit gleicher Drehzahl angetrieben, so dass pro Zeiteinheit von beiden Aktivwinden 62, 64 dieselbe, auf die Senkgeschwindigkeit der Last abgestimmte Strecke Windenseil 66 abgerollt wird. Das Umlenkrad 58 dreht sich nicht.

Beim Heben der Last L ohne Wellengang werden die beiden Aktivwinden mit gleicher Drehzahl in umgekehrter Richtung wie beim Absenken angetrieben, so dass pro Zeiteinheit von beiden Aktivwinden 62, 64 dieselbe, auf die Hubgeschwindigkeit der Last abgestimmte Strecke Windenseil 66 aufgerollt wird. Wiederum dreht sich das Umlenkrad 58 nicht.
Soll die Last L weder abgesenkt noch gehoben werden, sondern in Bezug zur Erde auf einer festen Höhe gehalten werden, und ist ein Wellengang auszugleichen, so werden die beiden Aktivwinden 62, 64 derart angesteuert werden, dass je nachdem, ob der Schwimmkran gerade auf einen Wellenberg angehoben oder in ein Wellental abgesenkt wird, entweder die Aktivwinde 62 oder die Aktivwinde 64 Windenseil abgibt und die jeweils andere Aktivwinde Windenseil aufnimmt. Die abgerollte Seillänge und die aufgerollte Seillänge sind dabei gleich, da sich der Abstand zwischen dem Schwimmkran und dem Rollenblock nicht ändert.
Soll während eines Heben- oder eines Senkenvorgangs der Wellengang ausgeglichen werden, so ist der durch die Heben- oder Senkbewegung der Last bedingten Drehbewegung einer Aktivwinde 62, 64 eine Drehbewegung zu überlagern, die zu einer Drehung des Umlenkrades 58 und damit zu einem Antrieb der Hydropumpe 50 führt. Beim Absenken einer Last und Anheben des Schwimmkrans durch einen Wellenberg muss die Hydropumpe 50 in den Ringraum 44 fördern. Dazu möge die Drehzahl der Aktivwinde 62 erhöht und die Drehzahl der Aktivwinde 64 verringert werden. Beim Absenken des Schwimmkrans muss die Hydropumpe 50 in den Ringraum 42 fördern und in umgekehrter Drehrichtung angetrieben werden. Es wird dazu die Drehzahl der Aktivwinde 64 erhöht und die Drehzahl der Aktivwinde 62 verringert. Beim Heben einer Last und Anheben des Schwimmkrans durch einen Wellenberg wird dann die Drehzahl der Aktivwinde 64 erhöht und die Drehzahl der Aktivwinde 62 verringert. Beim Absenken des Schwimmkrans wird die Drehzahl der Aktivwinde 62 erhöht und die Drehzahl der Aktivwinde 64 verringert. Die unterschiedlichen Drehzahlen der Aktivwinden führen dazu, dass ein Seilabschnitt von dem Trum zwischen der schneller drehenden Aktivwinde und dem Umlenkrad 58 über das Umlenkrad 58 zu dem Trum zwischen dem Umlenkrad 58 und der langsamer drehenden Aktivwinde gelangt und sich das Umlenkrad dreht. Insbesondere wenn die Hydropumpe 50 schnell gedreht werden muss, um die notwendige Fördermenge zu liefern, oder insbesondere bei einer kleinen Geschwindigkeit der Last wird sich die Drehrichtung der verlangsamten Aktivwinde sogar umkehren, wie dies in dem oben geschilderten Fall, in dem die Last weder gehoben noch abgesenkt werden soll, besonders deutlich wird. Von der einen Aktivwinde wird dann Seil abgerollt und von der anderen Aktivwinde Seil abgerollt, wobei aber die Länge des abgerollten Seilabschnitts eine andere als die Länge des aufgerollten Seilabschnitts ist.To explain the mode of operation, various states of the lifting device are considered below:

• When lowering the load L without swell the two active winches are driven at the same speed, so that per unit time of both active winches 62, 64 the same, tuned to the lowering speed of the load line winch 66 is unrolled. The deflecting wheel 58 does not rotate.

When lifting the load L without swell the two active winches are driven at the same speed in the reverse direction as when lowering, so that per unit time of both active winches 62, 64 the same, tuned to the lifting speed of the load line winch 66 is rolled up. Again, the guide wheel 58 does not rotate.
If the load L is neither lowered nor raised, but held in relation to the earth at a fixed height, and is a swell compensate, so the two active winches 62, 64 are controlled such that, depending on whether the floating crane just to a Wellenberg raised or lowered into a trough, either the active winch 62 or the active winch 64 gives winch rope and receives the other active winch winch rope. The unrolled rope length and the rolled rope length are the same, because the distance between the floating crane and the roller block does not change.
If the swell is to be compensated during a lifting or lowering operation, the rotational movement of an active winch 62, 64 due to the lifting or lowering movement of the load is to superimpose a rotary movement which leads to a rotation of the deflecting wheel 58 and thus to a drive of the hydraulic pump 50 leads. When lowering a load and lifting the floating crane by a wave crest, the hydraulic pump 50 must promote in the annular space 44. For this purpose, the speed of the active winch 62 may be increased and the speed of the active winch 64 reduced. When lowering the floating crane, the hydraulic pump 50 must promote in the annular space 42 and be driven in the reverse direction. For this purpose, the rotational speed of the active winch 64 is increased and the rotational speed of the active winch 62 is reduced. When lifting a load and lifting the floating crane through a wave crest then the speed of the active winch 64 is increased and the speed of the active winch 62 is reduced. When lowering the floating crane, the speed of the active winch 62 is increased and the speed of the active winch 64 is reduced. The different speeds of the active winches cause that a cable section passes from the strand between the faster rotating active winds and the guide wheel 58 via the guide wheel 58 to the strand between the guide wheel 58 and the slower rotating active winds and rotates the guide wheel. In particular, when the hydraulic pump 50 needs to be rotated quickly to provide the necessary flow rate, or particularly at a low speed of load, the direction of rotation of the decelerated active winch will even reverse, as in the above case where the load is neither lifted nor lifted is lowered, is particularly clear. From the one active winch then rope is unrolled and unrolled from the other active winch rope, but the length of the unrolled rope section is different than the length of the rolled up rope section.

The winch cable 66 must be under a certain tension in order to turn the deflection wheel 58 and the hydraulic pump 50. However, the hydraulic pump does not have to promote excessively high pressures, since the weight of the load L is to be carried by the passive compensation device to approximately 100 percent. The active cylinder 36 therefore has to apply only a force which compensates for the change in the pressure in the pressure chamber 28 caused by the movement of the piston 26 and by the change in volume of the pressure chamber 28. The pressures in the annular spaces 42 and 44 are therefore low and the drive torque to be applied to the hydraulic pump 50 is low.

Corresponding to the circumferential speed and the direction of rotation of the deflecting wheel 58, the hydraulic pump 50 is activated and actuated in accordance with the active cylinder 36, the piston rod 46 either extending or retracting.

The winch cable 66 may also be designed as a chain or the like in the region of the deflection over a length. The deflection wheel can be designed as a gear, with which the chain interacts.

Based on FIGS. 2 to 4 Further embodiments of the sea state compensation device according to the invention will be explained. Here, the basic structure of the passive compensation device 6 corresponds to that of the embodiment in FIG FIG. 1 , so that with regard to the construction of the compensation device 6 for the sake of simplicity to the corresponding embodiments in FIG. 1 reference is made and only the essential differences to the described active compensation unit 8 is discussed.

In the embodiment described above, the hydraulic pump 50 and the deflection wheel 58 are arranged with the drive shaft 56 or a transmission active cylinder side. According to the embodiment FIG. 2 the deflection wheel 58, the shaft 56 or instead of the shaft, a transmission and the hydraulic pump 50, which together form the pump unit, are mounted on or on the roller block 22, wherein the storage takes place for example via support brackets or the like. That is, the guide wheel 58 is supported on the roller block 22 corresponding to the movable / loose rollers 16. The axes of the rollers and the deflection wheel can be arranged parallel to each other. Due to the greater distance of the hydraulic pump 50 to the active cylinder 36, more precisely to the annular spaces 42, 44, the pressure lines 52, 54 are longer than in the embodiment according to FIG. 1 educated. In principle, these pressure lines can also be designed as channels through the roller block 52 and the bridge 38. Otherwise, this corresponds to FIG. 2 illustrated embodiment that in FIG. 1 , so that further explanations are dispensable.

FIG. 3 shows a variant in which no winch drive 60 but an electric drive is used to drive the hydraulic pump 50. Accordingly, the hydraulic pump 50 is driven via the shaft 56 or a transmission by an electric drive motor 68. This forms a structural unit with the hydraulic pump 50 and the again designed as a synchronous cylinder active cylinder 36, the annular spaces 42, 44 are arranged with the hydraulic pump 50 in a closed hydraulic circuit.

The structural unit can be attached, for example, as a pump block to the housing of the active cylinder 36. The drive and power supply of the drive motor 68 via a loose electrical line 70, which is unrolled according to the movement of the roller block 22 by a drum 71 or rolled onto the drum 71. The immersion length of the conduit 70 thus changes with the movement of the roller block. The control of the electric motor 68 via the already mentioned electrical control unit 72nd

The drive motor 68 may be frequency-controlled or regulated in any other way, so that the hydraulic pump 50 is designed in principle as a variable displacement pump.

The electrical line 70 is used only for signal transmission and the power supply of the electric motor 68th

Of course, the positioning of the hydraulic pump 50 with the drive motor 68 also correspondingly FIG. 2 respectively. The drive motor 68 and the hydraulic pump 50 can therefore also be located on or on the roller block 22.

In the embodiment according to FIG. 4 are the hydraulic pump 50 and the guide wheel 58 and the shaft 56 as in the embodiment according to FIG. 2 stored on or on the roller block 22. However, the guide wheel 58 forms one of the loose / movable rollers 16 and is thus a part of the pulley 20, the example on the one hand by two fixed rollers 14, 14 'and on the other hand by two loose rollers 16, 16' and also as "movable Roller "acting deflecting wheel 58 is formed, which are looped by the common support cable 18. The fetching and retrieving of the support cable 18 takes place in this embodiment, two synchronously operating winches 62, 64, wherein the first-mentioned wind 62 and the function of the winch 21 from FIG. 1 Has. The reference numeral 21 is therefore in FIG. 4 additionally added in brackets. This in FIG. 1 Accordingly, the "fixed end" of the winch cable 18 is in operative connection with the active winch 64.

According to the embodiment FIG. 4 However, it is not absolutely necessary that the winch 62 is also designed as an active winch. It is also sufficient that these winds only the function of the winds 21 according to the FIGS. 1 and 2 Has.

The length of rope wound on the active winch 64 is substantially less than the length of rope wound on the winches 21, 62. The inertial mass of the active winch 64 is therefore low, so that the power to be installed for driving the active winch 64 is low.

• Beim Absenken der Last L ohne Wellengang wird von der Winde 62 und von der Winde 64 Seil abgerollt, wobei die Länge der von der Winde 64 abgerollten Seilstrecke gleich dem Weg der Last und die Länge der von der Winde 62 abgerollten Seilstrecke unter Berücksichtigung der Weguntersetzung des Flaschenzugs ebenfalls gleich dem Weg der Last ist. Das Umlenkrad 58 dreht sich deshalb nicht, Beim Heben der Last L ohne Wellengang wird auf die Winde 62 und auf die Winde 64 Seil aufgerollt, wobei die Länge der auf die Winde 64 aufgerollten Seilstrecke gleich dem Weg der Last und die Länge der auf die Winde 62 aufgerollten Seilstrecke unter Berücksichtigung der Weguntersetzung des Flaschenzugs ebenfalls gleich dem Weg der Last ist. Das Umlenkrad 58 dreht sich deshalb wiederum nicht.

Für den Fall, dass die Last L weder abgesenkt noch gehoben werden, sondern in Bezug zur Erde auf einer festen Höhe gehalten werden soll, und ein Wellengang auszugleichen ist, sei davon ausgegangen, dass die Winde 21 keine Aktivwinde ist. Diese bleibt also in Ruhe. Es wird nur die Aktivwinde 64 angesteuert. Und zwar wird die Aktivwinde 64 derart angesteuert, dass das Seil 18 von ihr abgerollt wird, wenn der Schwimmkran gerade auf einen Wellenberg angehoben wird. Das Umlenkrad 58 dreht sich also und treibt die Hydropumpe 50 in eine solche Richtung an, dass die Hydropumpe Druckmittel dem Ringraum 42 entnimmt und in den Ringraum 44 fördert. Aufgrund des Abrollens des Seils 18 von der Aktivrolle 64 vergrößert sich auch der Abstand des Rollenblocks 22 und damit der Last L vom Schwimmkran 2. Die Last bewegt sich aufgrund der Bewegung des Rollenblocks 22 also in dieselbe Richtung, in die auch die aktive Kompensationseinrichtung die Last bewegt, so dass die Bewegung des Rollenblocks 22 die Kompensation der Bewegung des Schiffskrans unterstützt. Taucht der Schwimmkran in ein Wellental ein, so wird die Aktivwinde 64 derart angesteuert, dass das Seil 18 aufgerollt wird. Das Umlenkrad 58 dreht sich in die entgegengesetzte Richtung wie vorher und treibt die Hydropumpe 50 in eine solche Richtung an, dass die Hydropumpe Druckmittel dem Ringraum 44 entnimmt und in den Ringraum 42 fördert. Aufgrund des Aufrollens des Seils 18 von der Aktivrolle 64 verkleinert sich auch der Abstand des Rollenblocks 22 und damit der Last L vom Schwimmkran 2. Die Last bewegt sich aufgrund der Bewegung des Rollenblocks 22 also wiederum in dieselbe Richtung, in die auch die aktive Kompensationseinrichtung die Last bewegt, so dass die Bewegung des Rollenblocks 22 die Kompensation der Bewegung des Schiffskrans unterstützt.
Soll während eines Heben- oder eines Senkvorganges der Wellengang ausgeglichen werden, so ist der durch die Heben- oder Senkbewegung der Last bedingten Drehbewegung der Aktivwinde 64 eine Drehbewegung zu überlagern, die zu einer Drehung des Umlenkrades 58 in die richtige Richtung führt.To explain the operation of the lifting device according to FIG. 4 In the following, different states of the lifting device are again considered:

• When lowering the load L without swell of the winch 62 and the winch 64 rope is unrolled, the length of the unrolled from the winch 64 rope route equal to the path of the load and the length of the unrolled from the winch 62 cable line, taking into account the Weguntersetzung of Pulley is also equal to the way the load is. The deflection wheel 58 therefore does not rotate. When lifting the load L without swell, the rope 62 and the winch 64 rope are rolled up, the length of the rope stretch wound on the winch 64 being equal to the path of the load and the length of the winch 62 rolled up cable route, taking into account the Weguntersetzung the pulley is also equal to the path of the load. The deflection wheel 58 therefore does not turn again.

In the event that the load L is neither lowered nor lifted, but is to be kept in relation to the earth at a fixed height, and a swell is to be compensated, it is assumed that the winch 21 is not an active wind. So it stays calm. Only the active winch 64 is activated. Namely, the active winch 64 is driven such that the rope 18 is unrolled from it when the floating crane is being raised to a wave crest. The deflection wheel 58 thus rotates and drives the hydraulic pump 50 in such a direction that the hydraulic pump removes pressure medium from the annular space 42 and conveys it into the annular space 44. Due to the unwinding of the rope 18 from the active roller 64, the distance between the roller block 22 and thus the load L from the floating crane 2. The load moves due to the movement of the roller block 22 in the same direction, in which the active compensation device, the load moves, so that the movement of the roller block 22 supports the compensation of the movement of the ship's crane. If the floating crane dives into a trough, the active winch 64 is activated in such a way that the rope 18 is rolled up. The guide wheel 58 rotates in the opposite direction as before and drives the hydraulic pump 50 in such a direction that the hydraulic pump takes pressure medium from the annular space 44 and conveys into the annular space 42. Due to the reeling of the rope 18 of the active roller 64, the distance between the roller block 22 and thus the load L from the floating crane 2. Also reduces the load due to the movement of the roller block 22 in the same direction, in which the active compensation device Moving load, so that the movement of the roller block 22 supports the compensation of the movement of the ship's crane.
If the swell should be compensated during a lifting or lowering operation, the rotational movement of the active winch 64 caused by the lifting or lowering movement of the load is to be superimposed by a rotational movement which leads to a rotation of the deflecting wheel 58 in the correct direction.

When lowering a load and lifting the floating crane by a wave crest the speed of the active winch 64 is lowered, so that a lack of rope in the strand between the guide wheel 58 and the active winch 64 occurs and this deficiency is compensated by the running of the rope over the guide wheel 58 becomes. As a result, the hydraulic pump 50 is driven in such a direction that the hydraulic pump 50 draws pressure medium from the annular space 42 and conveys it into the annular space 44. When lowering a load and lowering the floating crane, the speed of the active winch 64 is increased, so that an excess of rope length is unwound from her. The deflection wheel 58 thus rotates and drives the hydraulic pump in such a direction that the hydraulic pump 50 withdraws pressure medium from the annular space 44 and conveys it into the annular space 42.

When lifting a load and lifting the floating crane by a wave crest, the speed of the active winch 64 is increased so that it rolls up more rope distance than the lifting speed of the load corresponds. As a result, the deflection wheel 58 and thus the hydraulic pump 50 are driven in such a direction that the hydraulic pump 50 draws pressure medium from the annular space 42 and conveys it into the annular space 44. When lifting a load and lowering the floating crane, the speed of the active winch 64 is lowered so that it rolls up too little rope length. The deflection wheel 58 thus rotates in the opposite direction and drives the hydraulic pump in such a direction that the hydraulic pump 50 takes pressure medium from the annular space 44 and conveys it into the annular space 42.

The speed of the active winch 64 is possibly lowered so far that it reverses its direction of rotation.

If the winch 21 is also used as the active winch 62, it can be avoided by activating the winch 21, 62 that the active compensation affects the movement of the roller block 22. Incidentally, the function corresponds to taking into account the translation of the guide roller 58 to the winch 21 of the function of the embodiments of the FIGS. 1 and 2 ,

In the embodiments according to the FIGS. 1 . 2 and 4 the drives of the hydraulic pump are designed with winches (winch 21, active winches 62, 64). In principle, other actuators, for example linear drives or the like, can be used instead of such winches.

As described, the winch cable 66 can be designed in the region of the deflection around the deflection wheel 58 as a chain or other wear-resistant traction means and, for example, made of high-strength plastic, for example. Dyneema ^® exist. The active compensation unit can be retrofitted with little effort, since the active and passive systems are essentially independently operable. As explained, the application of the device is not limited to the compensation of movements caused by swellings but is generally applicable where relative movements of a load due to external circumstances are to be compensated. The active compensation unit can also be designed as a mobile solution.

Disclosed is a sea state compensation device, in which a load is supported via a passive compensation device and an active compensation unit is designed as a linear actuator.

LIST OF REFERENCE NUMBERS

1

Facility

2

floating crane

4

Seabed

6

passive compensation device

8th

active compensation unit

10

ladekran

14

solid role

16

loose roll

18

supporting cable

20

pulley

21

winch

22

pulley block

24

cylinder

26

piston

28

pressure chamber

30

pressure chamber

32

storage unit

34

piston rod

36

active cylinder

38

bridge

40

active piston

42

annulus

44

annulus

46

piston rod

48

piston rod

50

hydraulic pump

52

pressure line

54

pressure line

56

wave

58

guide wheel

60

wind power

62

active winds

64

active winds

66

winch rope

68

electric drive motor

70

electrical line

71

drum

72

control unit

Claims (12)

Device for lifting, lowering or holding a load (L) with a compensating device for compensating, in particular, rough motion of the load (L) with respect to a target position, wherein the load (L) is from a lifting device towards or away from the target position is movable and the lifting device is associated with a passive compensation device (6) which at least partially supports the weight of the load (L), wherein an active compensation unit (8) is provided which in response to a relative movement of the load (L) or the effective force can be controlled, characterized in that the active compensation unit (8) has a linear actuator, the actuating element parallel to the passive compensation device (6) acts on the load (L), wherein the active compensation unit (8) an active drive for actuating the linear actuator having. Device according to claim 1, wherein the linear actuator is an active cylinder (36), preferably a hydraulic cylinder. Device according to claim 1 or 2, wherein the active cylinder (36) is designed as a synchronous cylinder. Device according to claim 2 or 3, wherein the passive compensation device (6) has a cylinder (24) with a piston (26) which delimits an effective in the direction of support pressure chamber (28) which is in operative connection with a hydropneumatic storage unit (32), wherein the active cylinder (36) is arranged approximately parallel to the cylinder (24). Device according to one of the preceding claims, wherein the active drive has a hydraulic pump (50) with two conveying directions, whose connection is connected to a respective pressure chamber of the active cylinder (36). Device according to one of the claims 1 to 4, wherein the active drive is an electric drive motor (68) or a winch drive (60). Device according to claim 6, wherein the drive motor (68) is frequency-controlled. Device according to claim 6 or 7, wherein the hydraulic pump (50) and the drive motor (58) with the active cylinder (36) form a structural unit, wherein the signal transmission and power supply via an active line (70), the immersion length via an active winch (64 ) is adjustable. Device according to claim 6, wherein the winch drive (60) has two active winches (62, 64), to which a winch cable (66) or a suspension cable (18) is deflected, which is deflected by means of a deflecting wheel (58) via which the hydraulic pump (58) 50) is driven. Device according to one of the claims 6 to 9, wherein the hydraulic pump (50) and the deflection wheel (58) are mounted on a roller block (22) on which loose rollers (16) of a pulley (20) of the lifting device are mounted. Device according to claim 10, wherein an active winch (64) is a component of the pulley (20). Drive according to one of the preceding claims, wherein the passive compensation means (6) is biased such that the resulting from the compensation support force is about as large as the weight of the load (L).

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