A drive control system of a hydraulic excavator includes a control device. When accelerating a turning body to a target turning speed, the drive control device controls an operation of the electric motor driving device such that the electric motor outputs high efficiency torque by which a highest electric power efficiency is obtained at the target turning speed. The control device controls an operation of an oil pressure supply device such that residual torque obtained by subtracting the high efficiency torque from target torque is output from an oil-pressure motor.

A fluid pressure actuator including a fluid pressure cylinder having a first position detector and a second position detector, a piston body having a piston head and a rod, the piston head mounted on the rod and slidably accommodated in the fluid pressure cylinder, the rod including a first scale and a second scale, the first scale facing the first position detector and the first position detector configured to detect a position in a sliding direction of the piston body, the second scale facing the second position detector and the second position detector configured to detect a position of the rod in a rotation direction of the piston body, and a controller configured to perform a first positioning control of a position of the rod in the sliding direction and a second positioning control of the rod in the rotation direction may be provided.

An electrohydraulic device includes an extender which is arranged to be actuated by hydraulic fluid, and a rotor of an electric motor, the rotor being arranged to rotate about a part of the extender. The rotor may have an annular body which encircles or surrounds part of the extender. There is also described a related method of use and a marine vessel or platform where the device may be applied.

A method and a system are disclosed for detecting, isolating and estimating a degradation of a corresponding component of an actuator controlled by an actuator command signal, the method comprising obtaining a control signal of the actuator; obtaining a signal indicative of a displacement of the actuator; computing an envelope of admissible values for the displacement of the actuator; determining if the displacement of the actuator is outside the computed envelope and in the case where the displacement of the actuator is outside the computed enveloped computing an estimation of each parameter and state of the actuator; identifying at least one corresponding parameter responsible for causing the actuator displacement to be outside the computer envelope and providing an indication of the at least one corresponding parameter.

An actuator according to an aspect of the present invention includes: a driving body including a plurality of conductive grains, a chamber configured to confine the plurality of conductive grains, and two or more electrodes disposed on a surface of the chamber; and a controller configured to obtain, through the two or more electrodes, a change in an electric signal, in response to a load applied to the chamber, and to adjust the load applied to the chamber based on the change in the electric signal.

An aircraft landing gear actuation system which uses two separate actuation forces to retract aircraft landing gear is disclosed. One of the actuation forces may be provided by an actuator, such as a hydraulic actuator. Another of these actuation forces may be provided by a pressurized fluid that is directed into the actuator through a conduit that extends into a hollow interior of an actuator rod of the actuator. The pressurized fluid may be provided from a pressurized fluid source that contains a fixed volume of pressurized fluid. This pressurized fluid may exert a force on an actuator piston of the actuator or the actuator rod. The pressurized fluid may also be used to dampen the deployment of the landing gear.

A device for amplifying a force includes a prime mover configured to receive a first force, and a secondary mover configured to generate a second force that is greater than the first force in response to the prime mover receiving the first force. The prime mover includes an output that, in response to the first force, rotates about a first axis through a power stroke defined by an angular displacement that is less than ninety degrees. The prime mover's output includes a first end that revolves about the first axis during the power stroke. The secondary mover includes an input, an output, and a body. The input includes a second end that is coupled with the first end of the prime mover's output, and that, as the first end of the prime mover's output revolves about the first axis through the power stroke, the second end of the secondary mover's input also revolves about the first axis and moves relative to the secondary mover's body. The secondary's mover's output is configured to apply the second force to an object. The secondary mover's body is releasably and pivotally anchored at a position such that as the first end of the prime mover's output revolves about the first axis through the power stroke, the body of the secondary mover pivots about a second axis that passes through the position, and such that as the first end approaches the end of the power stroke, the first end of the prime mover's output accelerates, without an additional force applied to the prime mover's output.

[Object] To provide a compact, high-output actuator device allowing force control. [Solution] An actuator device 1000 includes an electromagnetic coil member 110 provided over a prescribed width on an outer circumference of a cylinder 100, and a movable element 200 slidable as a piston in the cylinder 100. The movable element 200 has a magnetic member 202, and is moved relatively by excitation of the electromagnetic coil member 110. Fluid is supplied to first and second chambers 106a and 106b such that when the movable element 200 is to be moved relatively, the movable element 200 is driven in the same direction.

A device for amplifying a force includes a prime mover configured to receive a first force, and a secondary mover configured to generate a second force that is greater than the first force in response to the prime mover receiving the first force. The prime mover includes an output that, in response to the first force, rotates about a first axis through a power stroke defined by an angular displacement that is less than ninety degrees. The prime mover's output includes a first end that revolves about the first axis during the power stroke. The secondary mover includes an input, an output, and a body. The input includes a second end that is coupled with the first end of the prime mover's output, and that, as the first end of the prime mover's output revolves about the first axis through the power stroke, the second end of the secondary mover's input also revolves about the first axis and moves relative to the secondary mover's body. The secondary's mover's output is configured to apply the second force to an object. The secondary mover's body is pivotally anchored at a location such that as the first end of the prime mover's output revolves about the first axis through the power stroke, the body of the secondary mover pivots about a second axis that passes through the location. The position of the device's secondary mover relative to the first end of the prime mover's output is such that, as the first end approaches the end of the power stroke, the first end of the prime mover's output accelerates, without an additional force applied to the prime mover's output.

An asymmetric linear actuator is provided which integrates a hydraulic dissipater and an electric motor and power screw which generates small forces. The actuator is configured so that an electric motor drives a power screw which drives a rod through a cylinder to provide linear actuation. The cylinder is fluid-filled and incorporates a piston that separates the cylinder into a first and second fluid chamber which are filled with a first and second volume of working fluid. Movement of the piston and rod assembly results in fluid movement between the first and second volumes of working fluid and through the fluidic restriction. The fluidic restriction can be proportionally controllable via an electric motor which enables controllable power dissipation via control of the fluidic restriction motor and controllable power generation via control of the power screw motor.