A fail-safe actuation system comprising an actuator having first and second chambers, a working circuit with a motor/pump device configured to actuate the actuator in an operative state, and a safety circuit configured to move the actuator into the safety position in a failure state, the safety circuit having a tank that holds pressurized fluid and that, in the failure state, is automatically connected to the first chamber via a switching valve, and having a drain valve that, in the failure state, is moved into a through-flow position in order to drain fluid out of the second chamber, the safety circuit configured such that, in the operative state, an inflow into the actuator—in a manner that is decoupled from the tank—is established by the working circuit, and, in the failure state, an inflow from the tank into the first chamber—in a manner that is completely decoupled from the working circuit—is created by the safety circuit, whereby a short-circuit fluid connection is provided between the first and second chambers that, in the failure state, is through-connected in order to generate a short-circuit flow between the first and second chambers.

A soft actuator is described, including: a rotation center having a center of mass; a plurality of bucklable, elastic structural components each comprising a wall defining an axis along its longest dimension, the wall connected to the rotation center in a way that the axis is offset from the center of mass in a predetermined direction; and a plurality of cells each disposed between two adjacent bucklable, elastic structural components and configured for connection with a fluid inflation or deflation source; wherein upon the deflation of the cell, the bucklable, elastic structural components are configured to buckle in the predetermined direction. A soft actuating device including a plurality of the soft actuators and methods of actuation using the soft actuator or soft actuating device disclosed herein are also described.

A closed loop, self-priming hydraulic system comprising a reciprocating, hydraulic piston pump, a high pressure loop and a low pressure loop is disclosed. The reciprocating, hydraulic piston pump comprises a first piston operating in a first piston bore and a second piston operating in a second piston bore. The high pressure loop is defined by a high pressure accumulator that is fluidly connected to an inlet of the first piston bore and an outlet of the second piston bore. The low pressure loop is defined by a low pressure accumulator that is fluidly connected to an inlet of the second piston bore and an outlet of the first piston bore. The closed-loop, self-priming hydraulic system manipulates a hydraulic fluid to convert energy from one form to another.

In a hydraulic drive system performing the load sensing control by using a pump device having two delivery ports whose delivery flow rates are controlled by a single pump controller, surplus flow is prevented and energy loss at an unload valve and a pressure compensating valve is reduced in combined operations in which two actuators are driven at the same time while producing a relatively large supply flow rate difference therebetween. A boom cylinder 3a is connected so that the hydraulic fluids delivered from delivery ports P1 and P2 of a pump device 1a are merged and supplied to the boom cylinder 3a. An arm cylinder 3h is connected so that the hydraulic fluids delivered from delivery ports P3 and P4 of a pump device 1b are merged and supplied to the arm cylinder 3h. A travel motor 3d is connected so that the hydraulic fluid delivered from one (delivery port P2) of the delivery ports of the pump device 1a and the hydraulic fluid delivered from one (delivery port P4) of the delivery ports of the pump device 1b are merged and supplied to the travel motor 3d. A travel motor 3e is connected so that the hydraulic fluid delivered from the other (delivery port P1) of the delivery ports of the pump device 1a and the hydraulic fluid delivered from the other (delivery port P3) of the delivery ports of the pump device 1b are merged and supplied to the travel motor 3e.

The invention relates to a method for operating a vibrating ram arrangement comprising a hydraulic assembly with a hydraulic pump driven by an internal combustion engine, a vibrator connected to the hydraulic assembly in a hydraulic circuit, a hydraulic clamping device connected to the vibrator for a material to be rammed, and a controller, with which a fluid flow through a hydraulic motor of the vibrator can be activated and deactivated and with which the hydraulic clamping device can be closed and opened. According to the invention, the controller requests at least one operating state value during a pause in the operation when the vibrator is deactivated and automatically stops the internal combustion engine if the operating state value corresponds to a specified value. Additionally, the controller automatically starts the internal combustion engine in order to resume the vibrating ram operation in the event of a user signal.

An automobile or other wheeled vehicle includes various hydraulic components, including a hydraulic gearbox, transmission, clutch, and brake energy recovery system. Such hydraulic components supplement or replace traditional mechanical components of the automobile or other wheeled vehicle to improve the overall operational efficiency thereof.

An object of the invention is to achieve a travel speed known in the art during travelling operation, improve energy efficiency by reducing energy loss, and obtain favorable travel operability less susceptible to effects from variations in a travel load and changes in a pump delivery pressure when travelling operation is performed through operation of a travel lever over a half stroke range or less. A variable restrictor valve 80 is disposed in parallel with a flow sensing valve 50 of an engine speed sensing valve unit 13. A travel pilot pressure is adapted to act in an opening direction of the variable restrictor valve 80. The variable restrictor valve 80 is set to have a continuously increasing opening area from a full closure to a maximum with an increasing travel pilot pressure. Travel flow control valves 6d and 6e have an opening area that allows a predetermined flow rate QT required for traveling to be obtained even when a target LS differential pressure is decreased to a second specified value Pa3 when the travel lever is fully operated. In a first half of a spool stroke, the travel flow control valves 6d and 6e have an opening area approximate to an opening area of comparative example 1.

A hydraulic flushing system comprises a hydraulic machine including a case drain, a gearbox having a cavity, and a flushing valve. The case drain is included in a hydraulic pump or a hydraulic motor. The flushing valve is fluidly connected to the case drain, fluidly connected to the cavity, and fluidly positioned between the case drain and the cavity. The flushing valve is configured to selectively allow hydraulic fluid to flow from the case drain to the cavity.

A system is provided. The system includes a body having at least two surfaces. The body is configured to be located at least partially below a surface of a body of water moving in a first direction. The system includes a mechanical system connected to the body. The mechanical system is configured to allow the movement of the body of water in the first direction to move the body back and forth in a plane parallel to the surface of the body of water in a second direction and a third direction. The second and the third directions are substantially perpendicular to the first direction. The mechanical system is configured to translate the movement of the body to a rotor of an electrical generator.

The present invention relates to a hydraulic valve arrangement for controlling/regulating at least one hydraulic consumer of a mobile machine, with a summation interconnection of at least two hydraulic valves and at least one consumer interconnection of hydraulic valves, wherein the outputs of the summation interconnection are hydraulically connected with the inputs of the consumer interconnection, wherein at least one backflow valve is provided in the consumer interconnection. According to the invention, the at least one backflow valve for throttling a consumer return volume flow opens or closes in dependence on a consumer inflow pressure and comprises at least one main piston arranged in a bushing and at least two further pistons arranged in a lid separate from the bushing.