A hydraulic strut assembly, for use in a semi-levered landing gear in an aircraft, comprising an actuator and a manifold associated with the actuator. The actuator comprises a housing, a first piston, a second piston, and a third piston. The first piston is positioned between outer and inner cylindrical structures of the housing. The outer and inner cylindrical structures and first piston form an outer chamber that receives a first fluid. The inner cylindrical structure, the first piston, and the second piston, which is nested within the first piston, form an inner chamber, which holds a second fluid comprising a gas. A volume of the inner chamber changes when at least one of the first and second pistons moves. The third piston is positioned between the outer cylindrical structure and the first piston. The first, second, and third pistons move in a direction parallel to an axis through the housing.

There are provided a piston rod having one end portion attached to a marine vessel propulsion machine main body; an inner cylinder; an inner piston mounted in the other end portion of the piston rod, dividing a space in the inner cylinder into a fourth chamber and a fifth chamber; an outer cylinder accommodating the inner cylinder therein; a cap covering an opening portion of one end portion of the outer cylinder; and an outer piston dividing a space in the outer cylinder into a second chamber and a first chamber, is formed with a through hole that allows the fourth chamber and the second chamber to communicate with each other, comes into contact with the cap to divide the third space into an inner space on a more inner side than the through hole and an outer space on a more outer side than the inner space.

There are provided a piston rod having one end portion attached to a marine vessel propulsion machine main body; an inner cylinder; an inner piston mounted in the other end portion of the piston rod, dividing a space in the inner cylinder into a fourth chamber and a fifth chamber; an outer cylinder accommodating the inner cylinder therein; a cap covering an opening portion of one end portion of the outer cylinder; and an outer piston dividing a space in the outer cylinder into a second chamber and a first chamber, is formed with a through hole that allows the fourth chamber and the second chamber to communicate with each other, comes into contact with the cap to divide the third space into an inner space on a more inner side than the through hole and an outer space on a more outer side than the inner space.

There are provided a bar-shaped piston rod having one end portion attached to a marine vessel propulsion machine main body; an inner cylinder; an inner piston mounted in the other end portion of the piston rod, is accommodated in the inner cylinder, and divides a space in the inner cylinder into a fourth chamber on the one end portion side and a fifth chamber on the other end portion side; an outer cylinder accommodating the inner cylinder therein; and an outer piston covering an opening portion of one end portion of the inner cylinder in a state where the piston rod is exposed, divides a space in the outer cylinder into a second chamber on one end portion side and a first chamber on the other end portion side, and is formed with a through hole that allows the fourth chamber and the second chamber to communicate with each other.

There are provided a bar-shaped piston rod having one end portion attached to a marine vessel propulsion machine main body; an inner cylinder; an inner piston mounted in the other end portion of the piston rod, is accommodated in the inner cylinder, and divides a space in the inner cylinder into a fourth chamber on the one end portion side and a fifth chamber on the other end portion side; an outer cylinder accommodating the inner cylinder therein; and an outer piston covering an opening portion of one end portion of the inner cylinder in a state where the piston rod is exposed, divides a space in the outer cylinder into a second chamber on one end portion side and a first chamber on the other end portion side, and is formed with a through hole that allows the fourth chamber and the second chamber to communicate with each other.

A tilting pump apparatus includes a pump operation unit arranged between a mudguard, which is configured to obstruct foreign objects entering from a front side, and a tilting pump, which is configured to be rotated for generating hydraulic pressure to transmit movement of the mudguard generated by depressing the mudguard as rotational force for rotating the tilting pump.

An easy extention of a telescopic rod. The telescopic rod extends in the axial direction by a gas forcibly fed to the inside and is provided with a posture control means.

An easy extention of a telescopic rod. The telescopic rod extends in the axial direction by a gas forcibly fed to the inside and is provided with a posture control means.

A device and a system for controlling the turning of an object includes a shaft enclosing a first space, and a sleeve forming a second space between the shaft and the sleeve. Movement of the sleeve is transmitted to movement of the object. The device further comprises a housing comprising means for rotating the shaft and at least one inlet for a lubricant, and a lubricant collector. The shaft has a first through hole extending from the first space to the second space, and the sleeve has at least a second through hole for providing the second space in fluid communication with the lubricant collector. The housing is in fluid communication with the second space, and the first space is pressurizeable for causing the lubricant in the second space to be displaced through the second through hole and collected in the lubricant collector.

A hydraulic cylinder (1) which acts as a cylinder hollow rod in an outer hydraulic cylinder (10) is disclosed comprising an inner rod (4) with a piston (2) and piston-gland (3) wherein the cylinder hollow rod (1) is held longitudinally displaceably in the cylinder housing (10). The system additionally has a cylinder base (5) and a fibre cover (14) on the outer casing of hydraulic cylinder (10). The system also has ports for fluid (11, 12 and 13) corresponding to four chambers, (67, 8 and 9 respectively). According to the invention, when pressure is applied to chamber (7), the internal rod (4) extends into the chamber (6), displacing its mass and dramatically increases the pressure in Chamber (6). This displacement is effectively an internal pump which can be activated multiple times within a given stroke of rod (1).