WO2006105764A1

WO2006105764A1 - Hydraulic heave compensation system

Info

Publication number: WO2006105764A1
Application number: PCT/DE2006/000567
Authority: WO
Inventors: Martin Fluks; Charles A. Simons
Original assignee: Bosch Rexroth Ag
Priority date: 2005-04-04
Filing date: 2006-03-30
Publication date: 2006-10-12
Also published as: EP1869282A1; EP1869282B1; DE502006005035D1; NO332099B1; NO20075563L; DE102005058952A1; ATE445081T1

Abstract

The invention relates to a heave compensation system, wherein the relative motion, caused by rough sea, of a load (L) relative to a desired position is compensated by means of a passive hydropneumatic accumulator (6) and an actively controlled active cylinder (8). The invention is characterized in that the active cylinder is integrated into the hydropneumatic accumulator, which allows for an extremely compact and simple design of the compensation device (4).

Description

description

Hydraulic sea state compensation device

The invention relates to a hydraulic sea state compensation device according to the preamble of claim 1.

Such sea state compensation devices are used, for example, in naval technology, when a load is to be deposited by a ship on an object supported on the seabed, for example a platform, wherein, for example, a crane is arranged on the ship. Conversely, the crane can also be arranged on a platform supported on the seabed, so that the load can be placed on a ship or a corresponding floating object. A similar task is also present when, for example, a drill string is lowered from a floating platform and it is raised and lowered by the sea. In research, for example, heavy measuring devices or supply stations for robots or the like are lowered from a ship via a winch to great depths, the sea cable causing the holding cable to be subjected to considerable tensile loads. In some applications, it may also happen that both the target object and the load due to the sea run movements, but then in principle the same conditions as in the cases described above.

The movements of the load caused by the swell are to be compensated for by wave compensation devices, which ensure that the relative position of the load to the target object is kept substantially constant. US Pat. No. 3,946,559 discloses a sea compensation system in which the load, in the present case a drill string, is fastened to an actuator embodied as a cylinder, which in turn is mounted on a ship or a platform. A pressure chamber of the actuator is subjected to the pressure of a passive hydropneumatic storage which has a piston, via which a gas space is separated from a pressure medium space. The piston can be moved by means of an active cylinder. This has two control chambers, which can be acted upon in response to a control signal via a control valve device and a pressure medium source with a flow to control the change in position in the actuator. A similar solution is also disclosed in US 5,209,302. In such systems, the static load is compensated by the hydropneumatic accumulator while the position and pressure changes due to the sea are compensated by the active cylinder. It has been shown that such systems have a much better sea state compensation behavior than systems in which the static load is supported only by a comparatively simple passive system (hydropneumatic accumulator).

In the subject matter of US 3,946,559 the load (drill string) via a linear actuator (actuator) is held - in principle, the load can also be held by a winch, in which case the winch must be controlled in a suitable manner to compensate for the sea state. For example, in the region between the winch and the load, a hydraulically displaceable roller may be arranged, which is moved in dependence on the sea state, in order to keep the position of the load to the target object constant. Such solutions are, for example, in the printing "Efficient Heave Motion Compensation For Cable-Suspended Systems" (www.oceanworks.ee).

A problem with the known solutions is that the systems are comparatively complex and have a large footprint.

The invention has for its object to provide a sea state compensation device, which allows a simple compensation of a reliable compensation caused by sea conditions movements.

This object is achieved by a hydraulic sea state compensation device having the features of patent claim 1.

According to the invention, the sea state compensation device (Heave Compensation System) has a compensation system, which consists in principle of a hydropneumatic storage (passive cylinder) and an active cylinder device. The active cylinder device is integrated in the hydropneumatic accumulator, wherein a common piston arrangement is arranged within a common cylinder housing. By the two outer piston bottom surfaces and the adjacent housing end faces in each case a pressure chamber is limited, one of which is preferably a gas space of the hydropneumatic accumulator.

In the prior art according to US Pat. No. 3,946,559, by contrast, the active cylinder device is attached to the hydropneumatic accumulator, so that such a solution requires considerably more space and device complexity. The unit of hydropneumatic accumulator with integrated therein active cylinder device can be operated in operative connection with a linear actuator (hydraulic cylinder) or a winch, of which the load is held.

In the first-mentioned alternative, the load is thus supported by the actuator designed as a hydraulic cylinder, whose pressure chamber, which is effective in the supporting direction of the load, is connected via a pressure line to the second pressure chamber of the common cylinder housing. This working space forming a pressure chamber and the above-mentioned gas space then form the two end portions of the common cylinder housing.

The guided in this common cylinder housing piston assembly has two piston bottom surfaces forming piston collars, which are connected by a piston land. This passes sealingly through a partition wall of the cylinder housing, so that the two control chambers of the active cylinder device are formed by the annular end faces of the piston collars on the one hand and the housing partition on the other hand.

To seal these two control chambers with each other and the control chambers to the adjacent gas space or working space seals are arranged on the outer circumference of the annular collars and in Durchgangsδffnung the housing partition.

In the second alternative mentioned above, the load is supported on a winch. This is preferably driven by a hydraulic motor whose pressure side is connected to a working space of the cylinder housing, so that there is a pressure medium connection between the hydraulic motor and the active cylinder device. The unit of hydrodynamic storage and active cylinder device in this embodiment preferably has a piston assembly with two end piston collars and a central annular collar, which are connected to each other via two piston webs. Each of these piston webs passes through a housing partition wall of the cylinder housing, so that in addition to the two outer cylinder chambers (one of which is the gas space) in the cylinder housing by two adjacent annular end faces of the above piston collars and the housing partition between them, the two control chambers of the active cylinder device and by the other two annular end faces the piston collars and the intermediate housing partition of the working space and another working space are formed.

According to the above statements, a gas space and a further pressure chamber are delimited on the front side in the cylinder housing, the latter can be acted upon in a preferred embodiment, with ambient pressure.

The provided for driving the winch hydraulic motor can be performed in a closed or open pressure fluid circuit.

In the former case (closed pressure medium circulation), the hydraulic motor is supplied with pressure medium via a variable displacement pump driven by a motor, wherein a suction port of the pump via a suction line with a low pressure port of the hydraulic motor and a pressure port of the pump via a high pressure line with a pressure port connected to the hydraulic motor. In this embodiment, the high-pressure line via a pressure line with the first-mentioned working space and the suction line via a Nieder- pressure line connected to the other working space, so that the hydraulic motor can be supplied with pressure medium either over or over the pump or work spaces.

Both the collars of the common piston and the piston webs can be designed with different diameters.

To secure a fast-switching shut-off valve (isolation valve) can be arranged in the pressure line between the pressure chamber of the actuator (hydraulic cylinder) and the working space of the cylinder housing or between the working space and the pressure line of the hydraulic winch drive, so that the connection between the actuator or the Winch drive and the compensation system (hydropneumatic storage / active cylinder device) can be interrupted in no time.

The piston assembly may be formed integrally or from a plurality of pistons.

Other advantageous developments of the invention are the subject of further subclaims.

In the following preferred embodiments of the invention will be explained in more detail with reference to schematic drawings. Show it:

Figure 1 shows a hydraulic sea state compensation device for a load held on a linear actuator;

Figure 2 is a sea state compensation device for a load held on a winch and Figure 3 shows a concrete application of the sea state compensation device according to Figure 1 in a drilling device.

1 shows a functional diagram of a sea state compensation device (Heave Compensation System) 1, in which a load L is movable by means of a designed as a hydraulic cylinder 2 linear drive. It is assumed that this hydraulic cylinder 2 is stationarily mounted on a ship or a floating platform and the load L is to be held in a predetermined relative position with respect to a fixed target, for example a platform supported on the seabed. The compensation of the static load and the sea state via a dot-dash line indicated compensation system 4 with hydropneumatic memory, via which the hydraulic cylinder 2 is controlled such that the load L retains the predetermined relative position to the target object.

The designed as a differential cylinder hydraulic cylinder 2 has a differential piston 35, which divides the hydraulic cylinder 2 in a penetrated by the piston rod annular space 36 and a bottom-side cylinder chamber. At least the annular space 36 is connected via a pressure medium supply, not shown, for extending and retracting the piston rod 39 with a pump or a tank to raise or lower the load L. Such a linear drive is designed only for relatively small strokes.

The compensation system 4 consists essentially of a hydropneumatic accumulator 6 and an active cylinder 8 designed as a synchronous cylinder, which is integrated in the hydropneumatic accumulators. The unit of hydropneumatic accumulator 6 and active cylinder 8 is referred to as an active storage. Of the Hydropneumatic accumulator 6 is designed to be able to support load L statically, ie without supporting the dynamic cycling due to sea state, while the active cylinder is intended to balance the dynamic alternating loads such as friction and other parasitic factors and to provide position control to enable the load at high speed.

The existing from the memory 6 and the active cylinder 8 active storage has a common cylinder housing 10 in which a piston 12 is guided axially displaceable. This has two outer piston collars 14, 16, which are interconnected by a piston web 18. This passes through a housing partition 20 of the cylinder housing, so that it is divided by the bottom of the piston collar 16 in a gas space 22 and the bottom of the piston collar 14 in a working space 24. By the annular end face of the piston collar 16 and the partition wall 20, a first control chamber 26 and the second annular space 28 is limited by the annular end face of the piston collar 14 and the housing partition 20. In the area of the passage of the piston rod 18 through the housing partition wall 20 and on the outer circumference of the two piston collars 14, 16 not shown seals are arranged in the illustration of Figure 1, via which the aforementioned spaces of the cylinder housing are separated from each other. The gas space 22 is connected via a gas line 30 to a gas reservoir 32, so that acts on the bottom surface of the piston collar 16 of the gas pressure. The two control chambers 26, 28 can be connected via connections A, B to a control valve device described in more detail below and to a pressure medium source or a tank, so that the annular end face of the piston collar 16 or the annular end face of the piston collar 14 can be actively pressurized. around the piston 12 in response to the movement of the load L. slide. The terminals A, B can also be short-circuited to put the active cylinder in "clearance"; then the system works as a passive memory.

The working space 24 is connected via a pressure line 34 to an annular space 36 of the hydraulic cylinder 2 in order to prevent shock loads when lifting loads from a movable location (eg deck of a ship in sea state), in the pressure line 34 a dashed line indicated fast switching Shut-off valve 38 may be provided, via which the oil side of the active storage of the hydraulic cylinder 2 is separable. About this shut-off valve 38 and the memory function can be disabled.

In the embodiment according to FIG. 1, the passive hydropneumatic accumulator is thus formed by the gas accumulator 32, the gas space 22 and the working space 24, while the active cylinder is formed by the two annular control spaces 26, 28 which are separated from one another by the housing dividing wall 20 which can be acted upon via the connections A, B with pressure medium.

It is now assumed that the load L moves due to the seaway relative to the cylinder housing 2 supported on the ship to the right (view of Figure 1). As a result, pressure medium from the annular space 36 is displaced via the pressure line 34 into the working space 24, so that the piston 12 of the active storage is moved to the left in the representation according to FIG. 1, the pressure in the gas space 22 and thus in the gas storage 32 being shifted the load L counteracts. In the case where the two working ports A, B are connected to each other, the active reservoir acts as a passive, conventional hydro-pneumatic accumulator. The load position can not be influenced directly here. In the case in which the compensation control is active, the control chambers 26 and 28 in Figure 1 can be acted upon via the ports A and B with pressure medium. By the displacement of the piston 12 to the left or right of the working space 24 is actively enlarged or reduced, so that the pressure medium flows from the annular space 36 and the load L maintains its desired relative position. The regulation of the pressure medium supply and pressure medium discharge to and from the two control chambers 26, 28 takes place in such a way that the load L is moved according to a predetermined velocity profile or held in its relative position.

The solution shown in Figure 1 shows over the aforementioned prior art, in particular US 3,946,559 significant advantages. Thus, in the prior art four seals are required (two on the piston collars, one on a partition and a fourth on the passage of a piston rod of the piston through the end face of the active cylinder housing), while in the solution shown in Figure 1 only three seals

(Piston collars 16, 14 and partition 20) must be provided. Since no piston rod projects out of the cylinder, the solution according to the invention also builds up considerably shorter. The piston is guided in the prior art along four sliding guides (two piston collars, passage through the housing partition wall and passage through Aktivzylinder- end face), while in the embodiment shown in Figure 1, only three sliding guides

(Piston collars 14, 16, housing partition 20) are provided. Another advantage is that in the prior art according to the US patent an external movable part (piston rod) is provided, while in the solution according to Figure 1, the active storage requires no external moving parts. The above-described embodiment with a linear drive is designed for comparatively small paths of the load L. In the event that the load L is to be moved over long distances, a winch is used instead of a linear drive. Such an embodiment is shown in FIG.

In this case, the load L is moved by means of a winch 40, which is driven via one or more hydraulic motors 42. In the illustrated embodiment, the hydraulic motor 42 is arranged in a closed circuit and is supplied via a driven by a motor M variable 44 with pressure medium. In this case, a pressure port P of the variable displacement pump 44 is connected via a high pressure line 47 to a pressure port P 'of the hydraulic motor and a suction port S of the variable displacement pump 44 via a suction line 49 to a low pressure port T of the hydraulic motor 42.

Of course, instead of the closed circuit and an open pressure fluid circuit can be used, wherein the variable pressure sucks pressure medium from a tank T and the pressure medium via the low pressure port T of the hydraulic motor 42 is returned to the tank T.

The compensation system 4 essentially consists in turn of a hydropneumatic accumulator 6 and a synchronous cylinder 8 formed as a synchronous cylinder, which in turn are designed as a unit (active accumulator). In the common cylinder housing 10, a piston 12 is guided, which in the illustrated embodiment has two outer piston collars 14, 16 and a central annular collar 46. The annular collar 46 and the piston collar 14 are of a first piston ridge 48 and the annular collar 46 and the piston collar 16 connected to each other via a second piston ridge 50, which, for example, has a smaller diameter than the first piston ridge 48. The piston web 48 passes through a first housing partition wall 52 and the second piston web 50 passes through a further housing partition 54. The cylinder housing 10 is thus subdivided into six pressure chambers by the piston 12, which is designed with three collars, the pressure chamber being the gas chamber 22 in FIG. The two control chambers 26, 28 are limited by the housing partition wall 52 and the annular collar 46 and the piston collar 14. Another working space 56 is limited by the further housing wall 54 and the middle annular collar 46 and the working space 24 through the housing partition wall 54 and the right piston collar 16. The gas space 22 is connected to the gas reservoir 32 via a gas line 30, as in the previously described embodiment, so that the gas pressure acts on the bottom surface of the piston collar 16. By the bottom surface of the further piston collar 14 and the inner end face of the housing 10, a space 58 is limited, the z. B. connected to the environment or the low-pressure room or can be completed.

According to FIG. 2, the working space 24 is connected via the pressure line 34 to the high-pressure line 47 and the further working space 56 is connected via a low-pressure line 60 to the suction line 49. In the low-pressure line 60 and / or the pressure line 34 in turn fast closing check valves 38 may be provided. By these check valves 38, the transmission of shock loads (shock loads) can be prevented, which can occur, for example, when picking up a load from a moving deck. About the shut-off valves 38 and the memory function can be disabled. The two control chambers 26, 28 can in turn, as in the above embodiment via the terminals A, B and a control valve assembly, not shown, connect to a pressure medium source or a tank to perform an active position control of the accumulator piston, and thus the load.

To raise or lower a load under normal operating conditions, i. without swell compensation these two ports A, B are closed and / or the shut-off valves 38 are closed, so that the active cylinder 8 is ineffective and the speed and direction of rotation of the winch is determined by the pivot angle of the variable 44.

In the case in which no lifting or lowering of the load is required, but a sea state compensation is required to hold the load in a predetermined relative position to a target object, the variable displacement pump 44 does not promote pressure means to the hydraulic motor 42. However, the piston 12 is the control of the active cylinder 8 is shifted as a function of the vertical movement of the ship, so that correspondingly from the working spaces 24 or 56 pressure medium to the motor 42 is guided so that it drives the winch 40 accordingly to allow the compensation movement. The load L is supported by the pressure in the hydropneumatic accumulator 6. The active cylinder must apply pressure differences due to gas characteristics, friction and dynamic influences.

In the case in which the sea state compensation is to be carried out simultaneously with a raising or lowering of the load - this is the most frequent application case - the control of the variable-displacement pump 44 superimposes the Control of the active accumulator (active cylinder 8, hydropneumatic accumulator 6) and vice versa.

As mentioned above, the gas pressure should be designed so that it can support the load. In the case where highly different loads are to be handled, it may be advantageous if the gas pressure in the gas storage 32 is variable in dependence on this load. For this purpose, for example, a compressor with the associated control devices for adjusting the gas pressure should be provided.

Alternatively or additionally, the adjustment of the compensation force to the load to be handled can also take place in that the hydraulic motor 42 of the winch 40 is designed with a variable displacement volume or in that a plurality of hydraulic motors 42 with variable displacement volume are connected in parallel. The displacement volume is then adjusted as a function of the load, the pressure at the gas side of the active reservoir, i. the pressure in the gas space 22 and in the gas storage 32 can be kept constant, so that no separate compressor and no gas pressure regulating device are required.

The hydraulic circuit containing the pump 44 and the hydraulic motor 42 is still performed with all conventional devices, such as pressure relief valves, rinse cycle, coolers, filters, as used in conventional closed circuits. Leakage can be compensated in the same way as conventional systems.

In principle, the functions of the individual pressure chambers of the active storage can be exchanged. So can For example, the control chamber 28 are interchanged with the working space 24.

In the above-described embodiment, the piston 12 is made in one piece, in principle, this piston could also be designed in several parts.

FIG. 3 shows a concrete application of the sea state compensation device shown in FIG. 1 for a drill string forming the load L, wherein a drill head is to be lowered from a ship 62 to the ocean floor in order, for example, to remove a seabed sample or to drill for oil. In the concrete embodiment example, a hydraulic cylinder arrangement 2 is formed by two or more hydraulic cylinders connected in parallel, wherein the piston rods 39 are mounted on a drilling stand 64 supported on the ship 62 and the load L (drill string) is fastened to the vertically displaceable cylinders. On the drill frame 64, a laser measuring device 66 is arranged in the illustrated embodiment, via which the position of the ship can be detected. The position of the cylinder 2 is detected by displacement transducer 68.

Figure 3 shows the essential components of the control unit for controlling the active cylinder 8, over which the movements, or the pressure fluctuations on the hydraulic cylinders 2 are actively compensated due to the sea state. As mentioned in connection with Figure 1, the load L, ie the weight of the cylinder and the drill string is statically supported by the hydropneumatic storage 6 by the gas pressure in the gas chamber 22 and thus in the gas storage 32 is set accordingly. The setting of the gas pressure in the gas reservoir 32 via a gas pressure regulating unit 70, via which the gas storage 32 with a storage 72nd is connectable, which in turn can be charged via a compressor assembly 74. Of course, the gas storage 32 can also be charged directly via the compressor unit 74 and the gas pressure control unit 70, wherein the gas pressure is variable depending on the weight of the drill string and possibly the sea state.

The pressure medium supply of the active cylinder 8, the hydraulic cylinder 2 and the working chamber 24 via a variable displacement pump 76, can be sucked via the pressure medium from a tank T and conveyed into the pressure line 34. This pressure line 34 is connectable via a lifting valve 78 with a pump line 80 connected to the pump 76 and via a drain valve 82 with a tank line 84 connected to the tank T. Both valves 78, 80 are biased leak-free in a blocking position. The lifting valve 78 is a switching valve, while the lowering valve 82 is a continuously variable directional control valve, in which a drain aperture is proportionally adjustable.

A feed line 86 branches off from the pump line 80 and a drain line 88 branches off from the tank line 84, leading to two input connections P, T of a proportionally adjustable active storage control valve 90. Two working ports A, B of the active storage control valve 90 are connected via a supply line 92 and a drain line 94 to the working ports A and B of the active cylinder 8. The supply line 92 and the drain line 94 can be switched via a bypass valve 97, so that the active cylinder 8 is then ineffective and the memory 4 only works as a passive memory. About the proportionally adjustable active storage control valve 90, the two control chambers 26, 28 of the active cylinder 8 in response to the ship movement with pressure medium be charged or connected to the tank T. The Aktivspeicherregelventil 90 is executed in its spring-biased home position with a floating position and can be adjusted via proportionally adjustable electromagnets so that either the control chamber 26 or the control chamber 28 is connected to the variable displacement 76, while the pressure medium from the other pressure chamber to the tank T displaces becomes.

The filling of the working space 24 of the hydropneumatic accumulator 6 and the annular spaces 36 of the hydraulic cylinder arrangement 2 takes place via a filling control valve 96 whose single working port A is connected via a filling line 98 to a connecting line 100 between the working space 24 and the pressure line 34. In this connection line 100, the above-described check valve 38 is arranged, via which the connection between the working space 24 and the hydraulic cylinder assembly 2 can be shut off or opened. A pressure port P of the Füllregelventils 96 is connected via a pump branch line 102 to the pump line 80 and a tank port T of the Füllregelventils 96 via a tank branch line 104 with the tank line 84, in which further means for cooling, filtering, etc. of the pressure medium are provided.

For a better understanding, the lowering and catching up of a drill head are explained below.

In a first preparatory phase, the hydropneumatic accumulator 6 is first moved to a starting position and the gas pressure in the gas space 22 is set as a function of the weight of the drill string, this setting being set proportionally to the expected weight to be lowered minus the desired feed force acting on the drill head. These Setting of the active accumulator 8 via the filling control valve 96, via which the working space 24 is supplied with pressure medium, while the check valve 38, the lifting valve 78, the drain valve 82 are closed and the bypass valve 97 is opened, so that the two control chambers 26 and 28 of the Active cylinder 8 are connected.

In a second phase, the drill head is lowered to the seabed. The shut-off valve 38 remains closed and the valves 78 and 82 are used to allow by retracting and extending the hydraulic cylinder assembly 2, the assembly of the drill string and lower the drill head. When the drill head is lowered, the hydraulic cylinder arrangement 2 should be adjusted in such a way that there is still sufficient travel path for the sea state compensation. During this lowering process, the pressures in the gas space 22 and in the working space 24 can still be adjusted correspondingly via the filling valve 96 or the gas pressure regulating unit 70 in order to compensate for the weight of the drill string.

At the moment when the drill head reaches the seabed, a passive sea state compensation is first switched on, whereby the load pressure of the hydraulic cylinder arrangement 2 is detected. During this passive control, the valves 78, 82 are moved to their locked position, the active storage control valve 90 is still in its home position and the check valve 38 is open. The active storage 8 is still ineffective, since the bypass valve 97 still remains in its passage position.

In actual drilling, three methods are distinguished.

1. In so-called normal drilling, the drilling pressure is passively "regulated". There are drilling pressure fluctuations due to the ship movements and therefore cylinder movements and accumulator piston movements and gas pressure fluctuations deliberately allowed. In this type of drilling the active cylinder is short-circuited, in which the bypass valve 97 are brought into its passage position and the Aktivspeieherregelventil 90 in its neutral position (up).

2. "Improved normal drilling" is the Bohrdruckschwankungen and according to torque and rotational speed fluctuations and the

Drill head wear and a Bohrkopfabheben reduced or largely avoided, in which the pressure in the working chamber 24 or, preferably, in the annular space 36 is kept constant. This is done by a pressure control of the active cylinder 8, wherein the bypass valve 97 is brought into its blocking position and the Aktivspeicherregelventil 90 is driven on the basis of a suitable control process so that the pressure in said pressure chambers 24 or, 36 remains practically constant.

3. In so-called "core drilling", soil samples are drilled using a special device attached to the drill string. In this process, the positions must be controlled with relatively high accuracy to compensate for the sea state and possible ship movements. The total weight of the drill string is, as already explained, compensated approximately by the gas pressure in the gas space 22. The position of the hydraulic cylinder 2 is controlled by the active cylinder 8 so that the ship's motion is compensated, while the bypass valve 97 is in its blocking position and the active storage control valve 90 is controlled accordingly. After completion of the drilling operation, the drill head is pulled out of the ground and lifted. This extraction can also be done in principle according to the three methods described above. In the case where continuous extraction of the drill bit or the attached equipment is desired, the active swell compensation control can be switched to a position control to compensate for the ship movements.

This controlled extraction of the drill head from the ground is effected in that via the fill control valve 96 when the bypass valve 97 is open, pressure medium is conveyed into the annular spaces 36 of the hydraulic cylinder arrangement 2, so that the drill head is pulled out of the ground at a constant speed. As mentioned, an active sea state compensation takes place by means of the setting of the active storage control valve 90, via which the pressure required for sea state compensation in the control chambers 26, 28 is adjusted in order to pull the drill head out of the ground at a constant speed.

After the drill head is pulled out of the ground, can be prevented on the above-described types of control that this is raised in an uncontrolled manner. The time of extraction of the drill head from the ground can be very easily detected, since then the required pull-out force drops abruptly. In order to prevent a collision of the drill head with the ground, this is then brought relatively quickly in a distance to the ground. Once the piston 12 of the active storage has reached its default starting position, the

Seegangskompensation off, while the check valve 38 is closed and the filling control valve 96 and how the Aktivspeicherregelventil 90 in their Move back to basic positions. The bypass valve 97 is brought into its passage position, so that the active cylinder 8 is turned off. The two valves 78, 82 remain closed.

The drill string is then removed and the drill head is raised back to the ship. During this lifting, the check valve 38 remains closed, the bypass valve 97 is open and the two control valves 96, 90 are still in their basic position. During the lifting of the drill head and the disassembly of the drill string, the required raising and lowering of the attached to the cylinder jackets of the hydraulic cylinder assembly 2, the drill string carrying guide bar via the lifting valve 78 and the drain valve 82. In this case, the gas pressure in the gas chamber 22 again via the gas pressure regulating unit 70 adapted to the decreasing weight of the drill string.

Disclosed is a Seegangskompensationseinrichtung (Heave Compensation System), in which the compensation of a generated by the sea relative movement of a load with respect to a desired position via a passive hydropneumatic storage and an actively controlled active cylinder takes place. According to the invention, the active cylinder is integrated in the hydropneumatic accumulator, so that the compensation device is constructed extremely compact and simple. LIST OF REFERENCE NUMBERS

1 sea state compensation device

2 hydraulic cylinders

4 compensation system

6 hydropneumatic storage

8 active cylinders

10 cylinder housing

12 pistons

14 piston collar

16 piston collar

18 piston ridge

20 housing partition

22 gas room

24 workroom

26 tax area

28 tax area

30 gas line

32 gas storage

34 pressure line

35 differential pistons

36 annulus

38 check valve

40 winds

42 hydraulic motor

44 variable pump

46 ring collar

47 high pressure line

48 1. Piston ridge

49 suction line

50 2nd piston ridge

52 1. Housing partition

54 2. Housing partition

56 more working space

58 room

60 low pressure line Ship Drilling rig Laser measuring device Displacement sensor Gas pressure regulating unit Storage tank Compressor unit Pump Lifting valve Pump line Sink valve Tank line Supply line Drain line Active storage control valve Inlet line Drain line Fill control valve Bypass valve Fill line Connecting line Pump branch line Tank branch line

Claims

claims

A hydraulic sea state compensating device for compensating for relative movements between a load (L) and a target position caused by sea conditions, comprising a compensation system (4) having a hydropneumatic accumulator (6) supporting the load (L) and an active cylinder device (8) operatively connected thereto ) having two control spaces (26, 28) connected to

Actuating the active cylinder device (8) can be acted upon with a pressure, characterized in that the active cylinder device (8) in the hydropneumatic accumulator (6) is integrated, wherein a common piston assembly (12) in a common cylinder housing (10) is accommodated with its two-sided housing end faces and adjacent piston bottom surfaces bounded in each case a pressure chamber, one of which is a gas space (22) of the hydropneumatic accumulator (6).

2. Seegangskompensationseinrichtung according to claim 1, comprising a hydraulic cylinder (2) for moving the load (L) having at least one pressure chamber (36) via a pressure line (34) with the second, a working space (24) forming the pressure chamber in the cylinder housing connected is .

3. Seegangskompensationseinrichtung according to claim 2, wherein the piston assembly (12) has two end, the piston bottom surfaces forming piston collars (14, 16), which are connected by a piston web (18) which passes through a housing partition (20) sealingly, so that through the Ring end faces of the piston collars (14, 16) on the one hand and the housing partition (20) on the other hand the both control spaces (26, 28) of the active cylinder (8) are limited.

4. Seegangskompensationseinrichtung according to claim 3, wherein at the two piston collars (14, 16) and the housing partition wall (20) seals are arranged.

5. Seegangskompensationseinrichtung according to claim 1, with one of a hydraulic motor (42) driven, the load (L) supporting the winch (40), wherein a pressure side of the hydraulic motor (42) having a working space

(24) is connected in the cylinder housing.

6. Seegangskompensationseinrichtung according to claim 5, wherein the piston assembly (12) has two end piston collars (14, 16) and a central annular collar (46), which via two piston webs (48, 50) are interconnected, each having a housing partition (52, 54) pass through, so that by a housing partition (52) and the adjacent annular end faces of the piston assembly

(12) the two control chambers (26, 28) of the active cylinder (8) and by the further Gehäusetrennwand (54) and the adjacent annular end faces of the working space (24) and a further working space (56) are limited.

7. Seegangskompensationseinrichtung according to claim 8, wherein the from the gas space (22) remote pressure chamber (58) is acted upon by ambient pressure.

8. Seegangskompensationseinrichtung according to one of the claims 5 to 7, wherein the hydraulic motor (42) is designed with a constant or variable displacement volume.

9. Seegangskompensationseinrichtung according to claim 8, wherein the hydraulic motor (42) in a closed NEN or open pressure fluid circuit is arranged.

10. Seegangskompensationseinrichtung according to claim 9, the first alternative, wherein a pump (44) with a variable displacement of an electric motor (M) is driven and a suction port (S) of the pump (44) via a suction line (49) with a low-pressure connection (T) the hydraulic motor (42) and a pressure port (P) of the pump via a high pressure line (47) with a pressure port (P ¹ ) of the hydraulic motor (42) is connected.

11. Seegangskompensationseinrichtung according to claim 10, wherein the working space (24) via a pressure line (34) to the high pressure line (47) and the further working space (56) via a low pressure line (60) to the suction line (49) are connected.

12. Seegangskompensationseinrichtung according to any one of the preceding claims, wherein the piston collars

(14, 16) and piston webs (48, 50) are each designed with different diameters.

13. Seegangskompensationseinrichtung according to one of the claims 5 to 12, wherein the two control chambers (26, 28) by means of a bypass valve (97) are connectable or separable from the hydraulic motor circuit.

14. Seegangskompensationseinrichtung according to claim 2 or 11, wherein in the pressure line (34) or the high-pressure / suction lines (47, 49) fast-switching shut-off valves (38) are arranged.