DE102017206590A1 - 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, wherein a pulley is associated with a lifting device of both the passive compensation device and the active compensation unit.

Description

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

Sea 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 on an object supported on the seabed, for example, a platform should 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 and active 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, for example, a hydraulic cylinder or a rotationally operated unit, for example, a hydraulic motor is acted upon in the support direction via a hydropneumatic storage unit whose pressure is designed so that the load is supported without swell in a central position - the 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. Such passive systems are often arranged between the actual crane hook and the load and thus are located when lowering below sea level.

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 shown a passive system with a water depth compensation, which can compensate for the effects of water depth when lowering the load something.

For applications in which a very precise guidance of the load when lowering is important, active 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 the 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 systems are usually placed on the ship, so they must also 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, a combination of an active and passive system is usually 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 is connected via the 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 on the maximum rope speed, the weight and the diameter of the sheaves / blocks and the rigidity of the construction, 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. A disadvantage of such solutions is that a relatively large device-technical effort for the realization of the passive compensation device and the active compensation unit is required.

In contrast, the present invention seeks to provide a device that allows the compensation of relative movements with low device complexity.

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 from it and has fixed and loose rollers, which together with a supporting cable form a pulley. The suspension cable can be caught or detended by means of an actuator to raise or lower the load. According to the invention, the lifting device is associated with a passive compensation device which at least partially supports the weight of the load L. Furthermore, an active compensation unit is provided, which can be controlled by a control unit as a function of a movement of the load caused by swell. According to the invention, the supporting cable of the pulley extends from the actuator via the rollers to an active actuator of the active compensation unit, wherein this active actuator can be controlled independently of the actuator. The pulley thus has a double function. It serves on the one hand to move the load and also to carry the passive compensation device and on the other hand is part of the active compensation unit. Thus, the device complexity compared to the above solutions is significantly reduced at least constant function, since no separate device, such as another winch rope is required to transmit the actuating movement of the Aktivaktors on a hydraulic cylinder of the active compensation unit.

In particular, in offshore conditions, it is advantageous if the actuator and the Aktivaktor are designed as winds. Such drives are inexpensive and robust.

In a particularly preferred embodiment, a brake is provided, which is arranged in particular on a roller of the pulley to hold the carrying cable, so that there is a passive part of the supporting cable from the roller to the actuator and the other, active part of the supporting cable from the roller to Aktivaktor extends. In other words, this brake the suspension cable and thus the pulley are divided into two functionally independently operable Parten.

According to the invention it is particularly preferred if the brake acts on one of the stationary rollers, which are usually arranged on the deck (above the water level).

According to a variant of the invention, the passive compensation device has a hydraulic cylinder whose piston defines a pressure chamber effective in the direction of support, which is in operative connection with a hydropneumatic storage unit, wherein a piston rod acts on the load, so that a kind of gas spring for passive support of the load is formed ,

The bias in the pressure space determined by the pressure in the hydropneumatic storage unit is preferably selected such that the weight of the load is approximately compensated for when the piston rod is extended (in the lowering direction). In the middle position, the load is then slightly undercompensated. As a result, for example, causes when the suspension of the suspension cable by means of the Aktivaktors the load-holding piston rod extends out of its central position, for example, to compensate for lifting a ship or floating crane due to a wave motion. Conversely, when lowering the floating crane of the Actuator actuated to catch up the carrying rope, so that the load remains in the predetermined target position.

The device complexity can be further reduced if the hydraulic cylinder is designed as a synchronous cylinder, wherein the active actuator associated part of the supporting cable engages the remote from the load piston rod. In this embodiment, the hydraulic cylinder is thus assigned to both the active compensation unit and the passive compensation device as an actuating element.

In a preferred embodiment of a device according to the invention, at least one loose roll of the first-mentioned part is arranged on a roller block carrying the hydraulic cylinder and at least one loose roller assigned to the active part engages the piston rod of the hydraulic cylinder facing away from the load.

The actuation of the actuators is simplified if facilities, in particular sensors for detecting the effective support rope length of Parten and the wind force are provided. Depending on the measurement signals of these devices then the actuation of the actuators by means of a control unit. Such a solution has the advantage that these devices / sensors can be provided on the cover side and it is not necessary to provide sensors for detecting the load conditions of the compensation device / compensation unit, in particular of the hydraulic cylinder below the water level.

For rapid pressure relief of effective in the direction of support pressure chamber of the hydraulic cylinder, the gas storage a bypass valve can be assigned.

The control unit mentioned above is designed to control the device according to the following modes:
On the one hand, a mode is provided in which the "simple" lifting or lowering of the load takes place by activating the actuator and stopping the active winch. The compensation of a relative movement of the load caused by swell or swell relative to the target position can be done by engaging the brake and driving the Aktivaktors and stopping the actuator. In a combination mode, the load is raised or lowered while actively compensating for a relative movement of the load relative to the target position caused by swell or swell by engaging the brake and driving the actuator and the active actuator.

A preferred embodiment of a device according to the invention for lifting, lowering or holding a load will be explained below with reference to a device shown in the drawing with compensation devices to compensate for caused by sea relative movements of a load with respect to a target position.

The sole figure of the drawing shows a schematic diagram of a device according to the invention for sea state compensation (HCS). 1 running ship or floating crane 2 over which a load L is on another ship or the seabed 4 or a platform anchored on it. The device 1 (Motion compensation device, HCS) has a passive compensation device 6 and an active compensation unit 8th whose concrete structure is explained below. On the indicated floating crane 2 is a loading crane 10 mounted, in a conventional manner, a plurality of stationary rollers (discs) 14a . 14b . 14c and a variety of moving rollers (discs) 16a . 16b . 16c has, in common with a carrying rope 18 a pulley 20 form. The moving rollers 16 (loose part) are on a roll block 22 stored. The fixed with one end on deck support rope 18 can by means of a winch 21 of the loading crane 10 be brought in or flocked / skipped to raise or lower the load L. The effective force of the winds 21 is then corresponding to the pulley 20 translated.

In the embodiment according to the figure is on the roller block 22 a hydraulic cylinder 24 held, which is designed as a synchronous cylinder. A piston 26 divides the interior of the hydraulic cylinder 24 in an effective in the direction of support pressure chamber 28 and an effective in Absenkrichtung pressure chamber 30 , The pressure room 28 is with a hydro-pneumatic storage unit 32 connected, 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 is subjected to a biasing pressure. The pressure room 28 and the hydro-pneumatic storage unit 32 form a kind of gas spring. The pressure chamber 30 may be filled with a gas, for example nitrogen, and may be associated with a gas cylinder to increase the volume of gas.

As explained, the hydraulic cylinder 24 designed as a synchronous cylinder. A load-side piston rod 34 carries the load L, for example, via a crane hook or the like on the piston rod 34 is attached. The resulting from the bias force corresponds to extended piston rod 34 about the weight of the load to be moved L. This is compensated in the final position about 100%, in the center position of the piston 26 if so the pressure room 28 the same size as the pressure chamber 30 is, there is an undercompensation.

A piston rod removed from the load L. 36 of the piston 26 passes through the pressure chamber 30 and is via a console 38 with another loose / moving role 40 connected, also from the suspension rope 18 is entwined. In the path of action of the pulley 20 adjacent to the other loose roll 40 Deck are two fixed roles 42 . 44 provided, the suspension cable 18 from the fixed roll 42 to the role 40 and from this to the role 44 passes over the the suspension rope 18 towards an active wind 46 is diverted.

The control of the two winches 21 and 46 takes place by means of a control unit 48 depending on measurement signals from sensors 50 . 52 , on which the force applied by the respective wind and the effective length of the supporting rope 18 or the change in length of the suspension rope 18 due to the felling or retrieval of the suspension rope 18 is detected. As indicated in the figure, the two winches 21 . 46 then via the control unit 48 triggered in response to these signals to control the explained compensation movements to compensate for the sea state.

The fixed role 42 is a brake 54 assigned over which the role 42 and also the suspension rope 18 can be held, so that then the continuous support cable 18 in one of the roles 40 . 44 wraparound, active part 56 and one the roles 14a . 16a . 14b . 16b . 14c . 16c wraparound, passive part 58 is divided. With the brake engaged 54 the role works 42 so to speak as a cover-sided fixed point for the respective part 56 . 58 , The active part 56 can then over the active winds 46 relative to the passive part be caught or fisted, the role 40 relative to the roles 16a . 16b and 16c is moved vertically. Meanwhile, the passive part 58 as a "normal" pulley - similar to the conventional solutions - over the winch 21 actuated. The activation of the brake 54 again takes place via the control unit 48 ,

As shown in the figure, the hydraulic cylinder can 24 a bypass valve 60 be assigned over which the pressure chamber 28 with the pressure chamber 30 can be connected, leaving only the active compensation unit 8th is effective.

In the illustrated embodiment, the hydraulic cylinder acts 24 as an actuating element for the passive compensation device 6 and the active compensation unit 8th , In principle, the console 28 Also attack on another active cylinder, the piston / piston rod then parallel to the hydraulic cylinder 24 at the load L attacks.

The control unit 48 is designed so that the device 1 can be controlled at least in three modes. In a first mode, in which the load L is lowered or raised only toward a target position and, for example, no sea state is present, the brake is 54 disengaged and the active winds 46 stopped / braked so that these are the fixed point of the suspension rope 18 forms. The raising and lowering movement then takes place by controlling the winch 21 , in which case the roles 14a . 14b . 14c . 42 . 44 fixed rollers of a pulley and the rollers 16a . 16b . 16c and 40 Train the loose pulley wheels.

In an operating mode in which the load L is to be held in a certain relative position at sea, the brake is 54 indented, leaving the suspension rope 18 or more precisely, the pulley 20 in the two parties 56 . 58 is divided. The winds 21 is stopped. Passive compensation is via the memory unit 32 formed gas spring and the active compensation by appropriate activation of the active winch 46 about the role 40 , the console 38 and the piston 26 together with the piston rods 34 and 36 by appropriate Fieren or catching / catching the active part 56 of the suspension rope 18 relative to the housing of the hydraulic cylinder 24 is raised or lowered, wherein the lowering movement is made possible substantially by the above-described under-compensating bias. The movement of the parts is in 1 by a double arrow 62 indicated.

In a third mode, the compensation of the sea state during the raising or lowering of the load L. For this mode of operation is also the brake 54 engaged and both winches 21 . 46 via the control unit 48 controlled so that on the one hand, the lowering / lifting movement takes place at the predetermined speed and on the other hand, the caused by the swell relative movements of the load L can be compensated. These relative movements are in turn by the double arrow 62 indicated.

Because the power flow of the active compensation unit 8th and the passive compensation device 6 runs parallel in the area of the pulley and then in a common path over the hydraulic cylinder 24 is transmitted to the load L, a swing or a rotation of the load L can be avoided, as may occur, for example, in solutions in which the active compensation unit and the passive compensation device along two separate force action paths on the load L attack.

Another advantage of the system described is that all fixed roles and all loose rollers are each substantially in the same plane, so that the dynamic loads in the pulley 20 are minimal, since all roles are more or less burdened in the same way.

The solution according to the invention can be achieved by replacing the carrying cable 18 and adding the active part 56 with the roles 42 . 44 . 40 be easily retrofitted to existing solutions.

In the embodiment, winches (winch 21 , Active winds 46 ) - in principle, other actuators, such as linear actuators or the like can be used instead of such winds.

The support cable can be designed in the region of the deflection as a chain or other wear-resistant traction means. The wound up on the winding section can also be made from high-strength plastic, for example. Dyneema ^®. The stroke of the above-described active compensation unit 8th preferably only corresponds to the ship movements caused by sea state / swell (+ approx. 10 m), so that the active actuator can be designed to be relatively small.

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 caused by 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, wherein a pulley is associated with a lifting device of both the passive compensation device and the active compensation unit.

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

hydraulic cylinders

26

piston

28

pressure chamber

30

pressure chamber

32

hydropneumatic storage unit

34

piston rod

36

piston rod

38

console

40

loose roll

42

solid role

44

solid role

46

active winds

48

control unit

50

sensor

52

sensor

54

brake

56

active part

58

passive part

60

bypass valve

62

double arrow

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 4,121,806 [0003, 0006, 0009]
• US 7934561 B1 [0005]
• EP 1869282 B1 [0008]
• US 4021019 [0010]
• DE 102015225936 A1 [0012]
• EP 2896589 A1 [0012]

Claims (10)

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 stationary and loose rollers ( 14 . 42 . 44 ; 16 . 40 ), which has a carrying rope ( 18 ) a pulley ( 20 ), wherein the supporting cable ( 18 ) can be obtained or gefiert by means of an actuator and wherein the lifting device is a passive compensation device ( 6 ) which at least partially supports the weight of the load (L), wherein an active compensation unit ( 8th ) provided by a control unit ( 48 ) in response to a relative movement of the load (L) is controlled, characterized in that the supporting cable ( 18 ) of the actuator ( 21 ) about the roles ( 14 . 42 . 44 ; 16 . 40 ) to an active actuator ( 46 ) of the active compensation unit ( 8th ), which is independent of the actuator ( 21 ) is controllable. Device according to claim 1, wherein the passive compensation device ( 6 ) as an actor a winch ( 21 ) and the active compensation unit ( 8th ) as Aktivaktor an active wind ( 46 ) and wherein a roll ( 42 ) a brake ( 54 ), over which the carrying cable ( 18 ), so that a passive part ( 58 ) of the suspension rope ( 18 ) of the role ( 42 ) to the winds ( 21 ) and an active part ( 56 ) of the suspension rope ( 18 ) of the role ( 42 ) to the active wind ( 46 ). Device according to claim 1 or 2, wherein the brake ( 54 ) on a stationary roll ( 42 ) attacks. Device according to any preceding claim, wherein the passive compensation device ( 6 ) a hydraulic cylinder ( 24 ) whose piston ( 26 ) an effective in the direction of support pressure chamber ( 28 ), which is connected to a memory unit ( 32 ) is in operative connection, wherein the load (L) on a piston rod ( 34 ) of the piston ( 26 ) attacks. Device according to claim 4, wherein the pressure in the memory unit ( 32 ) certain preload in the pressure chamber ( 28 ) is selected such that the weight of the load (L) when the piston rod is extended ( 34 ) is approximately compensated. Device according to claim 4 or 5, wherein the hydraulic cylinder ( 24 ) is designed as a synchronous cylinder and the active part ( 56 ) on the piston rod removed from the load (L) ( 36 ) attacks. Device according to claim 4, 5 or 6, wherein the at least the passive part ( 58 ) associated with loose rolls ( 16 ) on one of the hydraulic cylinders ( 24 ) carrying roll block ( 22 ) and the at least one of the active part ( 56 ) associated loose roll ( 40 ) on a piston rod ( 36 ) attacks. Device according to any preceding claim and with sensors ( 50 . 52 ) for detecting the effective support rope length and the wind force and with a control unit ( 48 ) for controlling the actuators as a function of the acquired measured values. Device according to any preceding claim and with a bypass valve ( 60 ) for pressure relief of the pressure chamber ( 28 ). Device according to any preceding claim, wherein a control unit ( 48 ) is designed to control the device according to at least the following operating modes: - raising or lowering the load (L) by activating the actuator and stopping the active actuator, - compensation of a relative movement of the load (L) caused by swell or swell to the target position by engagement the brake ( 54 ) and activation of the actuator and holding the actuator and - raising and lowering of the load (L) and thereby compensation of a caused by swell or swell relative movement of the load (L) to the target position by engaging the brake ( 54 ) and driving the actuator and the Aktivaktors.

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