阅读说明：本技术 用于在水下使用的具有液压伺服驱动装置的液压系统 (Hydraulic system with hydraulic servo drive for underwater use ) 是由 A·奥尔特 G·亨德里克斯 S·卡尔 O·格哈德 于 2019-10-02 设计创作，主要内容包括：本发明涉及一种用于在水下使用的液压系统(7),具有液压伺服驱动装置,其中存在一个液压缸(15)和至少一个液压机(48、49),其中,为了共同旋转运动,至少一个旋转驱动装置(54、55)和液压机(48、49)机械耦联并且液压机(48、49)至少调节液压缸(15),其中,液压缸(15)具有至少三个缸腔室(32、33、34、35、36),并且其中,存在第一液压回路(68)和第二液压回路(69)。此外,本发明包括用于在水下布置和用于控制能够输送的体积流的装置。用于在水下使用的液压系统尤其设置有用于手动的(机械的)操纵的冗余的液压伺服驱动装置。(The invention relates to a hydraulic system (7) for use underwater, having a hydraulic servo drive, wherein one hydraulic cylinder (15) and at least one hydraulic machine (48, 49) are present, wherein, for a common rotational movement, the at least one rotational drive (54, 55) and the hydraulic machine (48, 49) are mechanically coupled and the hydraulic machine (48, 49) adjusts at least the hydraulic cylinder (15), wherein the hydraulic cylinder (15) has at least three cylinder chambers (32, 33, 34, 35, 36), and wherein a first hydraulic circuit (68) and a second hydraulic circuit (69) are present. The invention further comprises a device for arrangement under water and for controlling the transportable volume flow. Hydraulic systems for use underwater are provided in particular with redundant hydraulic servodrives for manual (mechanical) actuation.)

1. A hydraulic system (7) for use underwater, having a hydraulic servo drive, wherein one hydraulic cylinder (15) and at least one hydraulic machine (48, 49) are present, wherein, for a common rotational movement, the at least one rotational drive (54, 55) and the hydraulic machine (48, 49) are mechanically coupled and the hydraulic machine (48, 49) at least adjusts the hydraulic cylinder (15), wherein the hydraulic cylinder (15) has at least three cylinder chambers (32, 33, 34, 35, 36), and wherein a first hydraulic circuit (68) and a second hydraulic circuit (69) which open into different cylinder chambers (32, 33, 34, 35, 36) are present.

2. The hydraulic system (7) of claim 1, wherein the first hydraulic circuit (68) comprises a hydraulic cylinder (15) and a first hydraulic machine (49), and the second hydraulic circuit (69) comprises a hydraulic cylinder (15) and a second hydraulic machine (48), wherein the hydraulic cylinder (15) and the at least one hydraulic machine (48, 49) are each part of a hydrostatic transmission.

3. The hydraulic system (7) as claimed in claim 1 or 2, wherein the first hydraulic circuit (68) is provided with at least one cylinder chamber (32, 33, 34) in the hydraulic cylinder (15) as a normal working-servo drive and the second hydraulic circuit (69) is provided with two further cylinder chambers (35, 36) in the hydraulic cylinder (15) as an emergency-servo drive.

4. The hydraulic system (7) according to any one of the preceding claims, wherein the hydraulic cylinder (15) has at least four or at least five cylinder chambers (32, 33, 34, 35, 36).

5. The hydraulic system (7) according to any one of the preceding claims, wherein both cylinder chambers (35, 36) are decoupled from the working movement of the piston rod (23) of the hydraulic cylinder (15).

6. The hydraulic system (7) according to any one of the preceding claims, wherein the hydraulic cylinder (15) is a differential cylinder or a synchronous cylinder.

7. The hydraulic system (7) as claimed in one of the preceding claims, wherein the hydraulic cylinder (15) is configured with a movable first piston (19) for adjusting the process valve (1).

8. The hydraulic system (7) according to any one of the preceding claims, wherein the hydraulic cylinder (15) comprises a pressure spring (38) for resetting the hydraulic cylinder (15).

9. The hydraulic system (7) as claimed in claim 8, wherein the pressure spring (38) is supported with its one end on the cylinder head (18) and with its other end on the first piston (19) or on one piston element (29).

10. The hydraulic system (7) according to any one of the preceding claims, wherein the hydraulic cylinder (15) is configured as a series cylinder.

11. The hydraulic system (7) according to any one of the preceding claims, wherein there is a container (9) in the inner space (10) of which a hydraulic cylinder (15) and at least one hydraulic machine (48, 49) are arranged.

12. The hydraulic system (7) according to any one of the preceding claims, wherein at least one rotary drive (54, 55) is arranged outside the container (9) and is provided for coupling to and decoupling from the hydraulic machine (48, 49).

13. The hydraulic system (7) according to claim 12, wherein two rotary drives (54, 55) are arranged outside the container (9), wherein a second rotary drive (55) is provided for normally operating the hydraulic cylinder (15) and a first rotary drive (54) is provided for operating the hydraulic cylinder (15) in an emergency.

14. The hydraulic system (7) according to any one of the preceding claims, wherein the remotely controlled underwater vehicle (72) comprises a rotary drive (54, 55).

15. Device for arrangement under water and for controlling a transportable volume flow of a gaseous or liquid medium, having a process valve (1) which has a process valve housing (2) and a process valve slide (5) with which the volume can be controlled, and having a hydraulic cylinder (15) which is assigned to the process valve housing (2) and can be moved together with the process valve slide (5), wherein the device has a hydraulic system (7) with a hydraulic servo drive and at least one rotary drive (54, 55) which drives at least one hydraulic machine (48, 49) which regulates the hydraulic cylinder (15) is arranged on a remotely controlled underwater vehicle (72), wherein the hydraulic cylinder (15) has at least three cylinder chambers (32, 33, 34, 35, 36), wherein there are cylinder chambers (32, 36) which open into different cylinder chambers (32, 36), 33. 34, 35, 36) and a second hydraulic circuit (69).

Technical Field

The invention relates to a hydraulic system for use underwater, in particular at great water depths, having a hydraulic servo drive. Hydraulic servo drives are used in particular for operating underwater equipment. The system preferably comprises a container having an inner space arranged for forming a volume closed with respect to the environment and for containing hydraulic pressure fluid. Furthermore, the system comprises a hydraulic cylinder and at least one hydraulic machine, which are arranged inside the container. Hydraulic systems for use underwater are provided in particular with redundant hydraulic servodrives for manual (mechanical) actuation.

Background

Hydraulic systems of this type are mainly used for moving elements underwater at deep water depths up to several kilometers in connection with oil and gas transport, mining, natural science research, infrastructure projects or renewable energy projects. For example, in oil or gas installations, at great depths at sea, process valves (prozessventils) are therefore present, by means of which the volumetric flow of the medium to be transported can be regulated or shut off.

The electrohydraulic system can be designed with an electrohydraulic actuator which comprises a container in the interior of which a hydrostatic machine which can be operated at least as a pump and an electric motor which is mechanically coupled to the hydrostatic machine are arranged. The main drive of the servo drive is realized here by an electric motor which drives a pump and thus adjusts the hydraulic cylinder with a linear movement. The electric motor consumes a large amount of electric energy, which has to be obtained, for example, by deep sea cables. The servo drive regulates large production equipment such as oil or gas drilling that regulates the delivery rate. In order to also be able to actuate the process valve manually by means of a robot, for example in an emergency, such as, for example, by means of a Remotely Operated Vehicle (ROV) or an Autonomous Underwater Vehicle (AUV), a manual interface is present on the container, from which a rod is coupled to a piston in a cylinder. In the interface, the stem may have a moving thread and cooperate with a nut provided with an internal thread and axially fixed, which is rotated to operate the process valve. A disadvantage of this arrangement is the outlay on equipment. A large installation space is required here. Furthermore, the limited service life generates interference. Furthermore, manual manipulation of frequent adjustments of the process valve during operation can be inconvenient. Furthermore, the mechanical assembly is sensitive to shocks and vibrations that can be generated by the underwater vehicle.

Disclosure of Invention

Starting from this, the object of the invention is to provide a hydraulic system and a device which alleviate or even avoid the disadvantages mentioned. In particular, a compact design, i.e. a small installation space, and an increased service life should be achieved in a structurally simple manner. Furthermore, frequent adjustment of the servo drive should be possible in a simple manner. Furthermore, reliable handling should be achieved in emergency situations by e.g. external robots.

These objects are solved with a hydraulic system and a device according to the independent claims. Further embodiments of the invention are given in the dependent claims. It should be noted that the description particularly in connection with the figures sets out further details and refinements of the invention, which may be combined with the features of the claims.

This is facilitated by a hydraulic system for use underwater with a hydraulic servo drive, wherein there is a hydraulic cylinder and at least one hydraulic machine. At least one rotary drive and the hydraulic machine are mechanically coupled to achieve a common rotary motion. The hydraulic machine also adjusts at least the hydraulic cylinder. The hydraulic cylinder has at least three cylinder chambers. Furthermore, there are a first and a second hydraulic circuit which open into different cylinder chambers.

The hydraulic system with a hydraulic actuating drive proposed here has the advantage that a small installation space is combined with an increased service life in a structurally simple manner. In particular, frequent adjustments are made by means of underwater vehicles, such as robots. Finally, undesired shocks and vibrations to the hydraulic cylinder, which may occur by underwater vehicles, are avoided. Advantageously, the two hydraulic circuits are combined with a plurality of cylinder chambers of the hydraulic cylinder. Since the hydraulic cylinder has at least three cylinder chambers, two separate hydraulic circuits are associated with a hydraulic cylinder in a structurally elaborate manner, so that different functions of the two circuits can be realized by the same hydraulic cylinder.

Preferably, the first hydraulic circuit comprises a hydraulic cylinder and a first hydraulic machine and the separate second hydraulic circuit comprises a hydraulic cylinder and a second hydraulic machine, wherein the hydraulic cylinder and the at least one hydraulic machine are each part of a hydrostatic transmission. The hydrostatic transmission operates according to the displacement principle. Typically in this case there is a driven hydraulic pump and cylinder.

Preferably, the first hydraulic circuit is provided with at least one cylinder chamber in the hydraulic cylinder as a normal working-servo drive and the second hydraulic circuit is provided with two further cylinder chambers in the hydraulic cylinder as emergency-servo drives. The rotary drive can thus be used not only for mechanically emergency adjustment of the hydraulic cylinder, but also for continuous adjustment of the hydraulic cylinder in normal operating mode.

Preferably, the same piston of the hydraulic cylinder can be moved back and forth along its axis of movement (individually or independently) with each hydraulic circuit. This embodiment is particularly such that for the case where one (first) hydraulic circuit does not function (correctly), the other (second or further) hydraulic circuit can effect the movement.

Suitably, the hydraulic cylinder has at least four or five cylinder chambers. In this case, it can be provided that a (first) hydraulic circuit with (first) two cylinder chambers and a (second) hydraulic circuit with (second) two cylinder chambers interact, and that a pretensioning or resetting unit for the piston rod of the hydraulic cylinder is also arranged in the fifth cylinder chamber.

Preferably, the two cylinder chambers are decoupled from the working movement of the piston rod and of the hydraulic cylinder. In this way, wear of the seal is reduced.

Advantageously, the hydraulic cylinder is a differential cylinder or a synchronous cylinder (gleichagangzylinder). For a differential cylinder, the two pressure-loaded active surfaces on the piston are of different sizes. In this way, different forces are generated with the same operating pressure and different velocities are generated with constant volume flow during the insertion and removal. Differential cylinders are inexpensive and have a high power density, which results from the large forces that can be achieved and the large stroke relative to the size of the cylinder.

The hydraulic cylinder is expediently designed with a longitudinally displaceable piston for adjusting the process valve. Preferably, the hydraulic cylinder comprises a pressure spring, for example a helical pressure spring, for resetting the hydraulic cylinder. Advantageously, the pressure spring is supported with its one end on the cylinder head and with its other end on the first piston or the movable piston element.

In a preferred embodiment, the hydraulic cylinders are configured as tandem cylinders. The hydraulic cylinder is designed such that the two cylinders are connected to one another in such a way that the piston rod of one cylinder acts on its piston surface via the base of the second cylinder.

Preferably, there is a container in the inner space of which a hydraulic cylinder and at least one hydraulic machine are arranged. The container is in particular designed such that it is also sealed against seawater over a large depth and is durable.

The rotary drive is advantageously arranged outside the container and is provided for coupling to and decoupling from the hydraulic machine.

Two rotary drives are expediently arranged outside the container, wherein the second rotary drive is provided for normal actuation of the hydraulic cylinder and the first rotary drive is provided for emergency actuation of the hydraulic cylinder (bridging, Ü berbr ü ckung).

Advantageously, the remotely controlled underwater vehicle comprises a rotary drive. The rotary drive is preferably a torque tool of the underwater robot. Suitably, the rotary drive means comprises an electric motor. The motor may be located outside the vessel (in the sea area). A separate motor may be provided as the working drive in the container. Preferably, there is a coupling between the rotary drive and the hydraulic machine.

With the hydraulic system proposed here, a mechanically driven, hydraulic emergency servo drive is advantageously integrated into a 3-chamber or 5-chamber cylinder. The 3-chamber or 5-chamber cylinder has at least one hydraulic safety unlocking function (three chambers) and optionally one hydrostatic drive (five chambers). In addition, two chambers are provided for a hydraulic emergency servo drive that can be actuated mechanically from the outside.

In larger variants, a compact solution for manual override (override) is needed (by the robot manipulating the cylinder via an external mechanical interface). With the hydraulic system proposed here, a complete independent hydraulic circuit is achieved. The details of the hydraulic cylinder with the individual chambers are particularly advantageously suitable for this.

According to a further aspect, a device for arrangement underwater and for controlling a transportable volume flow of a gaseous or liquid medium is proposed, which device is configured with a process valve. The process valve has a process valve housing and a process valve slide, with which a volume can be controlled.

Furthermore, a hydraulic cylinder is provided, which is assigned to the process valve housing and can be moved together with the process valve slide. Furthermore, the device has a hydraulic system with a hydraulic servo drive, wherein a rotary drive is arranged at the remotely controlled underwater vehicle, which rotary drive drives a hydraulic pump, which regulates a hydraulic cylinder. The hydraulic cylinder has at least three cylinder chambers, wherein there are a first and a second hydraulic circuit which open into different cylinder chambers. Reference may be made to further description regarding the structure or function of the hydraulic system.

Drawings

The invention and the technical field are explained in detail below with the aid of the figures. Here, the same members are identified by the same reference numerals. The drawings are schematic and are not provided to illustrate scale. The explanations set forth in the individual details with reference to one drawing are extractable and can be freely combined with the explanations from the other drawings or the preceding description, unless other results must be derived by the person skilled in the art or such combinations are explicitly prohibited here. Shown schematically in the drawings:

fig. 1 shows a side view of a device with a closed process valve, which has a hydraulic cylinder with three cylinder chambers, wherein one cylinder chamber is assigned to a movable piston and two cylinder chambers are assigned to a stationary piston;

fig. 2 shows an enlarged detail of the hydraulic cylinder according to fig. 1;

fig. 3 shows an embodiment of a hydraulic cylinder with five cylinder chambers, wherein two cylinder chambers are assigned to a movable first piston, one cylinder chamber is assigned to a movable piston element, and two cylinder chambers are assigned to a stationary piston;

FIG. 4 shows the embodiment as shown in FIG. 3, but with two cylinder chambers associated with a movable second piston;

FIG. 5 shows the embodiment as shown in FIG. 3, but with two cylinder chambers associated with one movable piston member;

FIG. 6 shows the embodiment as shown in FIG. 3, but with two cylinder chambers each assigned to a movable sealing sleeve;

FIG. 7 shows the embodiment as shown in FIG. 3, but with two cylinder chambers each assigned to a movable sealing disk;

FIG. 8 shows the embodiment as shown in FIG. 3, but with two cylinder chambers associated with a movable third piston;

FIG. 9 shows a circuit diagram of a hydraulic system with one hydraulic cylinder configured as a tandem cylinder having three cylinder chambers and two hydraulic circuits; and is

Fig. 10 shows an enlarged detail of the hydraulic cylinder according to fig. 9.

Detailed Description

The exemplary embodiment of the hydraulic system shown in the drawing has a process valve 1 according to fig. 1, which has a process valve housing 2, through which a process valve channel 3 runs, which continues at its opening through a pipe, not shown, and in which the gaseous or liquid medium flows from the undersea flow to the part of the drilling tower protruding from the sea or to the drilling vessel. The flow direction is indicated by arrow 4.

A hollow space is formed in the process valve housing 2, which hollow space is oriented transversely to the process valve channel 3 and in which the process valve slide 5 can be moved transversely to the longitudinal direction of the process valve channel 3 by means of the through-flow opening 6. In the state shown in fig. 1, the process valve channel 3 and the throughflow opening 6 in the process valve slide 5 do not overlap. The process valve 1 is thus closed. In the state (not shown), the through-flow opening 6 and the process valve channel 3 overlap to a large extent. The process valve 1 is almost fully open. A process valve of the type shown and of the described application should on the one hand be able to be actuated in a controlled manner and on the other hand should also contribute to safety in that, in the event of a malfunction, the process valve is quickly and reliably in a position corresponding to a safety state. This safety state is referred to herein as a closed process valve.

The process valve 1 is actuated by a compact hydraulic system 7 which is arranged directly on the process valve 1 underwater. Starting from the hydraulic system 7, it is sufficient for only one cable 8 to be routed, for example, to the sea surface or to other higher-level electrical control devices located under water.

The hydraulic system 7 shown as an example has a container 9 which is fastened on the open side to the process valve housing 2, whereby an interior space 10 closed off from the environment is present which is filled with hydraulic pressure fluid as the working medium. For fastening to the process valve housing 2, the container 9 has an inner flange on its open side, with which it is screwed to the process valve housing 2. Radially outside the threaded connection, a circumferential seal 11 is arranged between the inner flange of the container 9 and the process valve housing 2, said seal engaging in a circumferential groove of the process valve housing 2.

The container 9 is pressure compensated with respect to the ambient pressure prevailing under the water (sea area 12). For this purpose, in the case of the pressure compensator 13, the membrane 14 is tightly clamped in the opening in the container wall. There is a hole in the cover so that the space between the membrane 14 and the cover is part of the surrounding environment and is filled with seawater. The interior space 10 is therefore separated from the surroundings by the membrane 14. The membrane 14 is loaded on its first side facing the interior space 10 by the pressure in the interior space 10 and on its second side facing the lid (which is approximately as large as the first side) by the pressure existing in the surroundings and always seeks to occupy a position and shape in which the sum of all forces acting on the membrane is zero.

In the interior 10 of the container 9 there is a hydraulic cylinder 15 with a cylinder housing 16 which is closed at the end by a cylinder bottom 17 and a cylinder head 18, and with a piston 19 which is movable in the interior of the cylinder housing 16 in the longitudinal direction of the cylinder housing 16 as shown in fig. 2, and a movable first piston rod 24 which is fixedly connected to the piston 19 and projects from the piston 19 on one side and which is guided through the cylinder head 18 in a sealing manner and in a manner not shown in detail. The gap between piston rod 24 and cylinder head 18 is sealed by two seals (not shown) arranged axially spaced apart from one another in cylinder head 18. The process valve slide 5 is fastened on the free end of the piston rod 24. Furthermore, a second movable piston rod 25 is fixedly connected to the piston 19 and projects from the piston 19 to the other side, said second piston rod being guided in a sealing manner and passing through the first cylinder inner wall 39.1 and the second cylinder inner wall 39.2. The interior of the cylinder housing 16 is divided by the piston 19 into a first cylinder chamber 32 on the cylinder bottom side and a spring chamber 37 on the cylinder head side, the volumes of which are dependent on the position of the piston 19. A first end face of the piston 19 is denoted by 19.1 and a second end face of the piston 19 is denoted by 19.2. A first end face of the piston rod 23 is denoted by 23.1 and a second end face of the piston rod 23 is denoted by 23.2.

A pressure spring 38 is accommodated in the spring chamber 37, which pressure spring coaxially surrounds the piston rod 24 and is clamped between the cylinder head 18 and the piston 19, i.e., loads the piston 19 in the direction in which the piston rod 24 is moved in and the process valve slide 5 is moved to close the process valve 1.

According to fig. 2, the end region 25.1 of the movable second piston rod 25 facing the cylinder bottom 17 is (partially) designed as a hollow cylinder with a hollow cylinder wall 25.2 and a hollow cylinder bottom 25.3, opposite which a closed first cover element 42 with a circular cross section is arranged. A stationary piston 22 (connected to the cylinder housing 16) is located in the interior hollow space of the hollow cylinder, the stationary piston rod 28 extending from its first end face 22.1 to the cylinder bottom 17 through an opening in the cover element 42. The first cylinder interior hollow space is indicated at 65 and the second cylinder interior hollow space is indicated at 66.

The hydraulic cylinder 15 has three cylinder chambers, namely a first cylinder chamber 32, a fourth cylinder chamber 35 and a fifth cylinder chamber 36. The two cylinder chambers 35 and 36 are part of a hydraulic bridging assembly for emergency situations, while the cylinder chamber 32 is used for normal working operation of the hydraulic cylinder 15. In this way, the emergency servo drive is integrated into the 3-chamber cylinder. Two cylinder chambers 35 and 36 in addition to cylinder chamber 32 are provided for a hydraulic emergency servo drive which can be actuated mechanically from the outside. The passages in the stationary piston rod 28, which convey hydraulic fluid into the cylinder chamber 35 or 36 or out of the cylinder chamber 35 or 36, are designated by 44 and 45. Directional arrows indicating the direction of movement of the piston rod 23 are indicated by a and B. The directions of movement a and B apply in the same way to the displaceable piston 19 which is fixedly connected to the piston rod 23 and to the end region 25.1 which is fixedly connected to the piston rod 23.

A hydraulic machine 48, which can be operated as a pump with two conveying directions, is also arranged in the interior space 10 of the container 9. The hydraulic machine 48 has a first pressure or suction connection 52 and a second pressure or suction connection 53. Pressure fluid which is pumped in operation as a pump can be supplied by the hydraulic machine 48 via the pressure connection 52 to the cylinder chamber. Instead, the pressure fluid can be sucked out of the cylinder chamber by means of the hydraulic machine 48 (see fig. 9 for this purpose).

The rotary drive 54 is mechanically coupled for common rotary movement with the hydraulic machine 48, for example by a shaft 56. The shaft 56 transfers torque from the rotary drive 28 to the hydraulic machine 48. The rotary drive 54 is located outside the container 9. The rotary drive is comprised, for example, by a remotely controlled underwater vehicle 72 (ROV) or a robot and preferably has an electric motor as the rotary drive 54.

In order to be able to actuate the process valve 1 by means of a robot, such as, for example, an ROV, a connection 57 is present on the container 9, from which a shaft 56 is coupled to the hydraulic machine 48 in the interior 10.

Fig. 1 shows a simplified illustration of the separate second hydraulic circuit 69, shown in detail in fig. 9, as an emergency servo drive. In the embodiment according to fig. 1, the first hydraulic circuit 68 shown in fig. 9 can be used as a normal operating servo drive. Alternatively, the work-servo drive can be realized in a manner not shown by a combination of a hydraulic pump and an additional electric motor not shown.

In the embodiment according to fig. 3 to 8, there are five cylinder chambers, namely a first cylinder chamber 32, a second cylinder chamber 33, a third cylinder chamber 34, a fourth cylinder chamber 35 and a fifth cylinder chamber 36, respectively. The two cylinder chambers 35 and 36 are part of a hydraulic bridging assembly for emergency situations, while the cylinder chambers 32, 33 and 34 are provided for normal working operation of the hydraulic cylinder 15. All variants of five cylinder chambers can be used for a hydraulic cylinder 15 with three cylinder chambers (see fig. 2 and 9). In all embodiments according to fig. 1 to 9, there is a first cylinder chamber 32, a fourth cylinder chamber 35 and a fifth cylinder chamber 36, respectively. In the exemplary embodiments according to fig. 3 to 8, a second cylinder chamber 33 and a third cylinder chamber 34 are additionally present in each case, which are used for normal operating operation of the hydraulic cylinder 15.

Fig. 3 shows an embodiment of a hydraulic cylinder 15 with five cylinder chambers 32, 33, 34, 35, 36, two cylinder chambers 32, 33 being assigned to a first movable piston 19, one cylinder chamber 34 being assigned to a movable piston element 29, and two cylinder chambers 35, 36 being assigned to a stationary piston 22. The cylinder chamber 34 is delimited by the first hollow piston 29.2 and the third cylinder inner wall 39.3. The movable piston element 29 is formed by a hollow-cylindrical composite element 29.1, on both end regions of which a first hollow piston 29.2 or a second hollow piston 29.3 is respectively mounted, the opening of which is coaxially penetrated by the movable first piston rod 24. The piston element 29 is movable in a sealing manner in the directions of arrows C and D on the piston rod 24. A flange-like projection is indicated at 24.1 on the piston rod 24, which (when the piston rod 24 is moved in the directions a and B) can move the piston element 29 in the directions C and D by engagement with the hollow pistons 29.1 and 29.2.

Fig. 4 shows an embodiment in which two cylinder chambers 35, 36 are assigned to a movable second piston 20. In this way, a differential cylinder is formed, for which the two active surfaces, i.e. the first end surface 20.1 and the second end surface 20.2, which are acted upon by pressure on the piston 20 are of different sizes.

Fig. 5 shows an embodiment in which two cylinder chambers 35, 36 are assigned to a movable piston element 29. In order to form the cylinder chambers 35, 36, a cylinder interior chamber partition wall 40 is provided, which is present between the housing wall of the cylinder housing 16 and the composite element 29.1 and the hollow pistons 29.2 and 29.3. A third cylinder interior hollow space 67 is formed on the bottom-side end of the piston rod 23, which is surrounded by the cup-shaped second cover element 43.

Fig. 6 shows an embodiment in which two cylinder chambers 35 and 36 are each associated with a sealing sleeve 30.1 or 30.2 which can be moved in the direction of arrow E, F. The sealing sleeves 30.1 and 30.2 are arranged coaxially and sealingly relative to the first piston rod 24 or relative to the second piston rod 25. The cylinder chambers 35 and 36 are formed between the sealing sleeve 30.1 or 30.2 and the opposite cylinder inner wall 39 or 39.2.

Fig. 7 shows an embodiment similar to fig. 6, in which, however, two hollow-cylindrical sealing disks 31.1 and 31.2 which can be moved in the direction of the arrows G and H are present instead of the sealing sleeves 30.1 and 30.2.

Fig. 8 shows an embodiment in which two cylinder chambers 35 and 36 are assigned to a movable third piston 21. A movable fourth piston rod 27 connected to the second hollow piston 29.3 starts from the piston 21 on one side. In the spring chamber 37, a cylinder 41 is arranged, in the interior hollow space of which the piston 21 is movable together with the piston element 29 in the direction of the arrows C and D. The passages for the throughflow of hydraulic fluid in the cylinder chambers 35 and 36 are designated by 46 and 47.

Fig. 9 shows a circuit diagram of a hydraulic system with a hydraulic cylinder 15 and three cylinder chambers 32, 35 and 36 (see fig. 10) configured as series cylinders and two hydraulic circuits 68 and 69. The circuit 68 is an open circuit with a second hydraulic machine 49 configured as a pump with a constant displacement volume in the conveying direction and in the direction of rotation. The pump has a pressure connection 50 and a suction connection 51. Directional seat valves (Wegesitzventil) are denoted by 61 to 64 and check valves without pressure drop are denoted by 70.1 and 70.2. The circuit 69 is a closed circuit with a first hydraulic machine 48 configured as a pump with two directions of delivery. The pump has a first pressure or suction connection 52 and a second pressure or suction connection 53. Hydraulic shut-off valves are indicated by 58 and 59, and hydraulic accumulators, for example piston accumulators, are indicated by 60. The non-pressure-drop check valves are denoted by 70.3 and 70.4 and the check valves with pressure drop are denoted by 71.1 and 71.2. A movable third piston rod is indicated by 26.

In the first (open) circuit 68, the volume flow flows from the outflow side of the hydraulic cylinder 15 to the container (not shown). In the second (closed) circuit 69, the volume flow is again conveyed directly from the outflow side of the hydraulic cylinder 15 to the suction line of the pump; the return volume flow is equal to the inflow volume flow. The two circuits 68 and 69 each form a hydrostatic transmission which comprises a hydraulic cylinder and a hydraulic machine 48 or 49 in the form of a pump.

Two rotary drives 54, 55 are arranged outside the container 9, wherein the second rotary drive 55 is provided as a normal working servo drive for the hydraulic cylinder 15 and the first rotary drive 54 is provided as an emergency servo drive for the hydraulic cylinder 15.

In the embodiment variant shown in fig. 3 to 8, there are five cylinder chambers 32, 33, 34, 35, 36 and one spring chamber 37 with a pressure spring 38. In the configuration shown in fig. 10, three cylinder chambers 32, 35, 36 and a spring chamber 37 with a pressure spring 38 are provided. According to one embodiment (not shown), the configuration according to fig. 10 can be modified such that there are four cylinder chambers, i.e. the spring chamber 37 is provided without the pressure spring 38 as a further (fourth) cylinder chamber.

List of reference numerals

1 Process valve

2-process valve housing

3 Process valve passage

4 arrow head

5 Process valve slide

6 through-flow opening

7 hydraulic system

8 cable

9 Container

109 of the inner space

11 seal

12 sea water area

13 pressure compensator

14 film

15 hydraulic cylinder

16 cylinder housing

17 bottom of cylinder

18 cylinder cover

19 a first movable piston

19.119 first end face

19.219 second end face

20 second movable piston

20.120 first end face

20.220 second end face

21 movable third piston

22 fixed position piston

22.122 first end face

22.222 second end face

23 piston rod

23.123 first end face

23.223 second end face

24 movable first piston rod

24.124 on the base plate

25 movable second piston rod

25.125 end region

25.2 hollow cylinder wall

25.3 hollow Cylinder bottom

26 movable third piston rod

27 displaceable fourth piston rod

28 position fixed piston rod

29 movable piston element

29.1 composite element

29.2 first hollow piston

29.3 second hollow piston

30.1 removable first sealing Sleeve

30.2 removable second sealing Sleeve

31.1 removable first seal disc

31.2 removable second seal disc

32 first cylinder chamber

33 second cylinder chamber

34 third cylinder chamber

35 fourth cylinder chamber

36 fifth cylinder chamber

37 spring chamber

38 pressure spring

39 inner wall of cylinder

39.1 first Cylinder inner wall

39.2 second Cylinder inner wall

39.3 inner wall of third cylinder

40 cylinder internal chamber divider wall

41 cylinder barrel

42 first cover element

43 second cover element

44 first channel

45 second channel

46 third channel

47 fourth channel

48 first hydraulic press

49 second hydraulic press

50 pressure joint

51 suction joint

52 first pressure or suction connection

53 second pressure or suction connection

54 first rotary drive

55 second rotary drive device

56 shaft

57 interface

58 first valve which can be hydraulically shut off

59 second valve capable of hydraulic cut-off

60 hydraulic accumulator

61 first direction seat valve

62 second direction seat valve

63 third direction seat valve

64 fourth direction seat valve

65 first Cylinder interior hollow space

66 second Cylinder interior hollow space

67 third Cylinder interior hollow space

68 first circuit

69 second circuit

70.1 first non-return valve without pressure drop

70.2 second non-return valve without pressure drop

70.3 third non-return valve without pressure drop

70.4 fourth check valve without pressure drop

71.1 first check valve with pressure drop

71.2 second check valve with pressure drop

72 remotely controlled underwater vehicle.