A hydraulic actuator includes a hydraulic cylinder; a piston within the hydraulic cylinder and movable in response to movement of hydraulic fluid in a hydraulic circuit coupled to the hydraulic cylinder; a synchronisation connection for receiving an input from a simultaneous transmission line; and a valve for controlling the flow of hydraulic fluid in the hydraulic circuit. The valve is a rotary valve comprising: a first valve section arranged to rotate in either a first rotational direction or a second rotational direction in response to input from the simultaneous transmission line in order to open a hydraulic flow path to the cylinder and urge the piston to move along the hydraulic cylinder in a corresponding first linear direction or second linear direction; and a second valve section arranged to rotate in either the first or second rotational direction.

The present invention relates to a system preventing the pressured oil leakage in a cylinder line enabling very low leakage rates without using the valve or the system, or without reducing the diametrical space between the housing and spool.

The present invention relates to a system preventing the pressured oil leakage in a cylinder line enabling very low leakage rates without using the valve or the system, or without reducing the diametrical space between the housing and spool.

An apparatus and methods for limiting the return stroke and modifying the extension stroke of a log splitter. A control rod is translated in the direction of the return stroke of the log splitter. An effort end of a trip arm coupled to the control rod is moved in the direction of the translation and a load end of the trip arm is moved in the opposite direction. The rotation of the load end causes a control lever of the log splitter to move from its rearward position to an intermediate position thereby stopping the return stroke.

A rotary actuator includes a central housing; an output shaft that extends through the central housing; a vane that is mechanically coupled to the output shaft and divides the central housing into a first chamber and a second chamber; and a flow control mechanism that is moveable within the central housing and including a high pressure port and a low pressure port for communicating hydraulic fluid into and from the first and second chambers. The flow control mechanism is moveable to position the high pressure port and low pressure port relative to the first chamber and the second chamber for communication of the hydraulic fluid, thereby generating a pressure differential across the chambers. The vane rotates within the central housing in response to the pressure differential, and rotation of the vane drives the output shaft. A motor is configured to receive control signals to drive the movement of the flow control mechanism.

An actuating system comprising a hydraulic actuator provided with a cylindrical cavity containing a piston configured to slide within the cylindrical cavity and a rod. The piston separates the cylindrical cavity into a first actuating chamber and a second actuating chamber. A first servo valve comprises a sheath including a first slider configured to slide within a cavity of the sheath on the basis of command signals from a command system. The cavity of the sheath comprises a first command chamber and a second command chamber on either side of the first slider. The first actuating chamber is fluidically connected to the first command chamber, and the second actuating chamber is fluidically connected to the second command chamber.

Apparatus for providing mechanical feedback of a position of an actuator to a controller in a high vibration environment. The apparatus includes a member that contacts a cam surface of the actuator such that movement of the actuator and cam surface causes the member to move. The apparatus also includes a spring that exerts a force on the member toward the cam surface to maintain contact between the member and the cam surface. The apparatus also includes a damper that dampens motion of the member, thereby eliminating resonant movement of the spring and member caused by vibrations.

Apparatus for providing mechanical feedback of a position of an actuator to a controller in a high vibration environment. The apparatus includes a member that contacts a cam surface of the actuator such that movement of the actuator and cam surface causes the member to move. The apparatus also includes a spring that exerts a force on the member toward the cam surface to maintain contact between the member and the cam surface. The apparatus also includes a damper that dampens motion of the member, thereby eliminating resonant movement of the spring and member caused by vibrations.

An actuator is driven even if a jammed state, a motor stop, or the like occurs. An electromechanical actuator includes: an electric motor attached to a housing; a conversion mechanism portion having a drive portion that is driven to rotate by the electric motor and a driven portion that is driven by the drive portion and advances and withdraws in a predetermined advancing and withdrawing direction, the conversion mechanism portion being accommodated in the housing; a sliding support mechanism that transmits rotational force of the electric motor to the drive portion and allows the drive portion to slide in the advancing and withdrawing direction with respect to the electric motor; and a piston portion controlled so as to be at a predetermined position in the advancing and withdrawing direction with respect to the housing by means of pressure of a fluid supplied to and discharged from the housing.

An actuator is driven even if a jammed state, a motor stop, or the like occurs. An electromechanical actuator includes: an electric motor attached to a housing; a conversion mechanism portion having a drive portion that is driven to rotate by the electric motor and a driven portion that is driven by the drive portion and advances and withdraws in a predetermined advancing and withdrawing direction, the conversion mechanism portion being accommodated in the housing; a sliding support mechanism that transmits rotational force of the electric motor to the drive portion and allows the drive portion to slide in the advancing and withdrawing direction with respect to the electric motor; and a piston portion controlled so as to be at a predetermined position in the advancing and withdrawing direction with respect to the housing by means of pressure of a fluid supplied to and discharged from the housing.