An actuator, such as a pressure actuator or a vacuum actuator, has a housing and a plunger that is guided through the housing. A diaphragm is connected to the housing and to the plunger and forms a gas-tight pressure chamber with the housing. A pressure medium connector is provided on the housing and communicates with the pressure chamber to pressurize the pressure chamber. A braking element is provided on the plunger and enables a braking force can be exerted on the plunger.

A hydraulic fluid system is disclosed herein. The hydraulic fluid system includes a hydraulic motor including an output shaft, a reduction gear box having a first side and an opposing second side, the reduction gear box being coupled to the output shaft at the first side and coupled to a reduction shaft at the second side, and a magneto-rheological fluid brake (MRF) brake coupled to the reduction shaft.

In a cushion mechanism of a gas cylinder, when the pressure of a gas in a first pressure chamber is less than or equal to a prescribed pressure, a valve body cuts off communication between the upstream side and downstream side of a discharge flow passage by mean of the biasing force of a spring member. In addition, when the pressure of the gas exceeds the prescribed pressure, the valve body is displaced to the downstream side of the discharge flow passage against the biasing force, thereby enabling communication between the upstream side and the downstream side of the discharge flow passage.

A pneumatic artificial muscle (PAM) actuator includes first and second end caps, an elastic bladder connected to the end caps, and a covering around the elastic bladder and connected to the end caps. At least one of the first and second end caps is configured to move and narrow a distance between the end caps in response to inflation of the elastic bladder by a fluid. At least one of the end caps includes a vent configured to allow the fluid to exit the elastic bladder and collapse the covering after activation of the PAM actuator. At least the covering is configured to provide braking for the PAM actuator. The covering may be configured to collapse at least partially between the first and second end caps to provide at least some of the braking for the PAM actuator.

Systems and methods are provided for a hydraulic stabilizer trim actuator (HSTA). The HSTA may operate one or more movable control surfaces. The HSTA operate responsive to commands issued by the pilot and/or by a controller and may include hydraulic architecture that minimizes the probability of an un-commanded movement or movement in the opposite direction of such commands.

A hydraulic system for an aircraft. The hydraulic system can include a hydraulic actuator that is operatively coupled to a flight control member. Hydraulic fluid is moved through the hydraulic system by an engine driven pump that delivers hydraulic fluid to the actuator at a first pressure, and a boost pump that delivers hydraulic fluid to the actuator at a second pressure that is higher than the first pressure. The hydraulic system is configured such that the hydraulic fluid returning from the actuator to the engine driven pump can be delivered to the boost pump prior to reaching the engine driven pump.

The hydraulic system can include a control member that is operatively coupled to a member. The control member can include a hydraulic control member and an integrated inerter. Hydraulic fluid at variable pressures is moved through the hydraulic system by pumps. The hydraulic system can be configured for hydraulic fluid returning from the control member to the first pump to be delivered to the second pump prior to reaching the first pump. A dual-spool valve is positioned between the pumps and the control member to control the flow of the hydraulic fluid. The dual-spool valve is movable to move the hydraulic fluid at variable pressures into and out of first and second chambers of the control member. The dual spool valve can also be configured to operate the control member when a spool is not operational.

A hydraulic power drive unit (PDU) for a transmission system includes a hydraulic motor for converting hydraulic pressure into torque and rotation; a hydraulic brake system for applying a braking force to the hydraulic motor to prevent rotation of the hydraulic motor, wherein the hydraulic brake system is biased to apply the braking force to the hydraulic motor to prevent rotation of the hydraulic motor, and configured to remove the braking force in response to a supply of hydraulic fluid; and a hydraulic circuit for supplying a flow of hydraulic fluid to the hydraulic motor to pressurise and thereby operate the hydraulic motor and for supplying hydraulic fluid to the hydraulic brake system to pressurise the hydraulic brake system and thereby remove the braking force; wherein the hydraulic circuit comprises a brake supply line for supplying the hydraulic fluid to the hydraulic brake system.

A directional control system of a marine vessel includes a steering control member manually operated by a user and operationally connected to a direction-variation member acting on or in the water, such as at least one rudder blade or at least one outboard engine, the direction-variation member having an angular position that is controlled by the steering control member; and a locking system locking the free variation of the angular position of the direction-variation member, which can be activated and deactivated to allow the variation of angular position and carry out a directional change, the locking system including a hydraulic cylinder having a piston dividing the cylinder into two chambers, which are connected by a bypass circuit that can be opened and closed by a switching member. According to the invention, the fluid in the hydraulic circuit is a magnetorheological fluid, and a magnetic field generator, which can be activated and deactivated by the switching member, is combined with the bypass circuit, the magnetorheological fluid changing viscosity depending on the generated magnetic field, switching from a fluid condition to a substantially solid condition or viscosity that prevents flow in the bypass circuit.

A hydraulic system for a working machine includes a first hydraulic apparatus to be activated by the operation fluid, a second hydraulic apparatus being configured to be activated by the operation fluid, a first operation valve to control the operation fluid to be supplied to the first hydraulic apparatus, a second operation valve to control the operation fluid to be supplied to the second hydraulic apparatus, a first fluid tube connecting the first operation valve to the first hydraulic apparatus, a second fluid tube connecting the first operation valve to the second hydraulic apparatus, a third fluid tube connecting the first fluid tube to the second fluid tube, and an outputting fluid tube connected to any one of the first operation valve and the second operation valve and configured to output the operation fluid supplied from any one of the first fluid tube and the second fluid tube.