Abstract: The disclosure relates to a transmission unit, having (i) a housing for the fluid-tight encapsulation of at least one part of the transmission unit, (ii) a rack and pinion transmission which is arranged in the housing and has at least one gear rack, (iii) a hydraulic drive system, which is arranged in the housing, has at least one displacer unit for increasing the energy of a pressurizable working fluid of the hydraulic drive system, and has at least one chamber in which a piston, operatively connected to a gear rack of the rack and pinion transmission, can be moved using the working fluid in order to effect a linear movement of the gear rack, and (iv) a rotatable mechanical actuator, which is operatively connected to the pinion of the rack and pinion transmission and is arranged outside the housing at least in portions.

Abstract: An electrohydraulic system includes an output shaft, a hydraulic piston, and a preload device. The output shaft rotationally drives the valve and extends along a first axis. The hydraulic piston extends along a second axis perpendicular to the first axis, is actuated by a pressure medium, and rotates the output shaft. The preload device stores energy via preloading of an elastic element, which extends along a third axis, by a hydraulic cylinder and to transmit the energy to the output shaft in the event of a fault. The hydraulic piston is guided into first and second cylinder housings, and at least one of the cylinder housings is connected to the hydraulic cylinder. A check valve is arranged between the cylinder housing and the hydraulic cylinder, and is configured to decouple the preload device from the hydraulic piston, the blocking direction going from the hydraulic cylinder to the cylinder housing.

Abstract: A system filled with a fluid, designed for underwater applications, in which the interior of a housing and/or tank forms a fluid region which is sealed with respect to the surrounding seawater region, includes at least one hydraulic pressure compensation device, which at least raises the pressure level of the fluid region to the ambient pressure prevailing in the seawater region. The pressure compensation device is constructed in two stages in such a way that at least one store having a flexible wall region and at least one piston store having a displaceable piston are arranged in series. The use of the pressure compensation device to pressurize at least one housing filled with fluid for a hydraulic actuating shaft is also proposed.

Abstract: An electrohydraulic system includes an output shaft, a hydraulic piston, and a preload device. The output shaft rotationally drives the valve and extends along a first axis. The hydraulic piston extends along a second axis perpendicular to the first axis, is actuated by a pressure medium, and rotates the output shaft. The preload device stores energy via preloading of an elastic element, which extends along a third axis, by a hydraulic cylinder and to transmit the energy to the output shaft in the event of a fault. The hydraulic piston is guided into first and second cylinder housings, and at least one of the cylinder housings is connected to the hydraulic cylinder. A check valve is arranged between the cylinder housing and the hydraulic cylinder, and is configured to decouple the preload device from the hydraulic piston, the blocking direction going from the hydraulic cylinder to the cylinder housing.

Abstract: An electrohydraulic system for use under water includes an electrohydraulic actuator and a container. A hydraulic cylinder or a hydraulic motor and a hydraulic machine are arranged in an internal space of the container. The hydraulic machine is mechanically coupled to a rotary drive unit for a common rotary movement, and the hydraulic machine adjusts the hydraulic cylinder or the hydraulic motor. The rotary drive unit is arranged outside the container and is configured to couple to and decouple from the hydraulic machine. A device in one embodiment includes the electrohydraulic system.

Abstract: A hydraulic system, for use under water with a hydraulic actuating drive, includes a hydraulic cylinder and at least one hydraulic machine. At least one rotary drive device and the hydraulic machine are coupled mechanically for a common rotating movement, and the hydraulic machine adjusts at least the hydraulic cylinder. The hydraulic cylinder has at least three cylinder chambers, and the hydraulic system includes a first hydraulic circuit and a second hydraulic circuit. The hydraulic system for use under water is set up, in particular, with a redundant hydraulic actuating drive for manual (mechanical) actuation.

Abstract: An electrohydraulic system having an adjustment device for a valve includes a drive apparatus, a control apparatus, and a preloading apparatus. In the event of a fault, the energy stored in the preloading apparatus can be transferred to the control apparatus such that a rotational motion of the control apparatus begins, which leads to the adjustment of the valve. The preloading apparatus comprises at least one elastic element, which is arranged adjacent to a control shaft of the control apparatus, is stationarily connected to the control shaft, and applies a torque to the control shaft.

Abstract: A hydraulic system, for use under water with a hydraulic actuating drive, includes a hydraulic cylinder and at least one hydraulic machine. At least one rotary drive device and the hydraulic machine are coupled mechanically for a common rotating movement, and the hydraulic machine adjusts at least the hydraulic cylinder. The hydraulic cylinder has at least three cylinder chambers, and the hydraulic system includes a first hydraulic circuit and a second hydraulic circuit. The hydraulic system for use under water is set up, in particular, with a redundant hydraulic actuating drive for manual (mechanical) actuation.

Abstract: An electrohydraulic system for use under water includes an electrohydraulic actuator and a container having an internal space provided for forming a volume which is enclosed from the environment and which is provided for receiving a hydraulic pressurized fluid. A hydraulic cylinder is provided in the internal space of the container, the inside of which is divided into a first cylinder chamber and a second cylinder chamber by a piston to which a first piston rod and a second piston rod are connected. The two active surfaces of the piston are the same or approximately the same size.

Abstract: An electrohydraulic system for use under water includes an electrohydraulic actuator and a container. A hydraulic cylinder or a hydraulic motor and a hydraulic machine are arranged in an internal space of the container. The hydraulic machine is mechanically coupled to a rotary drive unit for a common rotary movement, and the hydraulic machine adjusts the hydraulic cylinder or the hydraulic motor. The rotary drive unit is arranged outside the container and is configured to couple to and decouple from the hydraulic machine. A device in one embodiment includes the electrohydraulic system.

Abstract: A system filled with a fluid, designed for underwater applications, in which the interior of a housing and/or tank forms a fluid region which is sealed with respect to the surrounding seawater region, includes at least one hydraulic pressure compensation device, which at least raises the pressure level of the fluid region to the ambient pressure prevailing in the seawater region. The pressure compensation device is constructed in two stages in such a way that at least one store having a flexible wall region and at least one piston store having a displaceable piston are arranged in series. The use of the pressure compensation device to pressurize at least one housing filled with fluid for a hydraulic actuating shaft is also proposed.

Abstract: An electrohydraulic system for use under water includes an electrohydraulic actuator and a container having an internal space provided for forming a volume which is enclosed from the environment and which is provided for receiving a hydraulic pressurized fluid. A hydraulic cylinder is provided in the internal space of the container, the inside of which is divided into a first cylinder chamber and a second cylinder chamber by a piston to which a first piston rod and a second piston rod are connected. The two active surfaces of the piston are the same or approximately the same size.

Abstract: An electro-hydraulic compact drive for underwater use and for driving an output element includes a hydraulic motor, a hydraulic pump, and an electric motor as components of the electro-hydraulic compact drive. The hydraulic motor has an output shaft. The hydraulic pump supplies the hydraulic motor with hydraulic fluid via a working line. The hydraulic pump is driven by the electric motor. The components of the electro-hydraulic compact drive are located in a closed container filled with a hydraulic fluid. The container has an opening for coupling the output shaft of the hydraulic motor to the output element. The electro-hydraulic compact drive forms a closed unit that contains the complete electric motor/hydraulic pump/hydraulic motor arrangement. The compact drive combines the advantages of the high power density of hydraulics with a decentralized electric direct drive. The handling of the drive is simplified, thus also simplifying the control of underwater vehicles and machines.

Abstract: An electrohydraulic system for use at great water depths includes a vessel, a hydrostatic machine, and an electric machine. The vessel has an interior space configured to form a volume that is closed off with respect to the surroundings and that accommodates a hydraulic pressure fluid. The vessel includes a compensation piston configured to subject the hydraulic pressure fluid in the interior space to at least approximately the pressure prevailing in the surroundings. The hydrostatic machine is configured to be operated as a pump. The electric machine is mechanically coupled to the hydrostatic machine and operates as an electric motor in order to operate the hydrostatic machine as a pump. The hydrostatic machine and the electric machine are arranged in the interior space of the vessel. The compact electrohydraulic system fits on existing installations and on new installations. The electrohydraulic system also includes a compact process valve.

Abstract: An electro-hydraulic compact drive for underwater use and for driving an output element includes a hydraulic motor, a hydraulic pump, and an electric motor as components of the electro-hydraulic compact drive. The hydraulic motor has an output shaft. The hydraulic pump supplies the hydraulic motor with hydraulic fluid via a working line. The hydraulic pump is driven by the electric motor. The components of the electro-hydraulic compact drive are located in a closed container filled with a hydraulic fluid. The container has an opening for coupling the output shaft of the hydraulic motor to the output element. The electro-hydraulic compact drive forms a closed unit that contains the complete electric motor/hydraulic pump/hydraulic motor arrangement. The compact drive combines the advantages of the high power density of hydraulics with a decentralized electric direct drive. The handling of the drive is simplified, thus also simplifying the control of underwater vehicles and machines.

Abstract: An electrohydraulic system for use at great water depths includes a vessel, a hydrostatic machine, and an electric machine. The vessel has an interior space configured to form a volume that is closed off with respect to the surroundings and that accommodates a hydraulic pressure fluid. The vessel includes a compensation piston configured to subject the hydraulic pressure fluid in the interior space to at least approximately the pressure prevailing in the surroundings. The hydrostatic machine is configured to be operated as a pump. The electric machine is mechanically coupled to the hydrostatic machine and operates as an electric motor in order to operate the hydrostatic machine as a pump. The hydrostatic machine and the electric machine are arranged in the interior space of the vessel. The compact electrohydraulic system fits on existing installations and on new installations. The electrohydraulic system also includes a compact process valve.