A fluid pressure cylinder which has a head cover and a rod cover provided on both ends of a cylinder tube, wherein the head cover and the rod cover are formed by casting such as die-casting. A first connecting channel which recesses in a groove shape in the outward radial direction is formed in the outer-circumferential surface of a first concave section of the head cover. A ring-shaped first holder is pressed into the first concave section, causing the formation of a cross-sectionally rectangular first connecting channel, the opening region of which is sealed. In addition, the first connecting channel connects a cylinder chamber of the cylinder tube and a first cushion chamber of the head cover.

A hydraulic assembly includes a barrel having a head port disposed proximate an end of the barrel, a piston assembly disposed within the barrel and movable relative thereto, the piston assembly including a bore terminating at a back wall, the bore defining a longitudinal axis, and a plunger at least partially received within the bore and translatable along the longitudinal axis. The plunger includes a main body having an end facing the head port, a shoulder extending radially-outwardly from the main body, and a passageway extending through the main body. A spring is disposed in a first region defined between the shoulder and the back wall, the spring configured to exert a biasing force on the shoulder.

Described is a modular linear actuator for use in an aerospace application, comprising: a piston housing having a closed end and an open end; a piston rod slideable within an interior of the piston housing between an extended position and a compressed position, the piston rod having a first end proximal to the closed end of the piston housing and a second end distal to the closed end of the piston housing; an attachment mechanism for removably attaching a lug end to the closed end of the piston housing, the lug end for attaching the actuator to a first component; an attachment mechanism for removably attaching a rod end to the second end of the piston rod, the rod end for attaching the piston rod to a second component; and, a piston head removably attached to the first end of the piston rod, the piston head for providing a snubbing engagement with the closed end of the piston housing.

A fluid pressure cylinder includes a cushion bearing provided movably on an outer periphery of the piston rod; a flange portion provided on the piston rod by facing the piston with the cushion bearing between them; and a collar provided movably in a radial direction on the outer periphery of the piston rod between the cushion bearing and the flange portion. End surfaces of the cushion bearing and the collar are inclined symmetrically to a center axis of the piston rod, and end surfaces of the flange portion and the collar are formed having plane shapes crossing the center axis.

A rod for a piston and cylinder device has a rod spud having a spiral channel in an outer surface thereof. The spiral channel spirals around the rod spud in a longitudinal direction. The spiral channel provides a hydraulic fluid flow path between an internal volume of a barrel and an internal volume of a spud receiver of the piston and cylinder device when the rod spud is in the spud receiver. At least a portion of the spiral channel has a cross-sectional area that decreases continuously and gradually as the spiral channel spirals longitudinally away from a distal end of the rod spud. The spiral channel provides more controlled deceleration of the hydraulic cylinder rod until the end of the retraction stroke.

A drive unit of a fluid-actuated linear drive includes a piston rod, an annular drive piston seated coaxially on the piston rod and a buffer sleeve which is likewise seated coaxially on the piston rod. These components are secured to one another by one and the same common welded joint. Furthermore, a method for the manufacture of such a drive unit and a fluid-actuated linear drive equipped with such a drive unit is proposed.

A helically shaped dynamic seal ring is provided. The helically shaped dynamic seal ring includes a spirally wound body and a snubbing orifice area formed in the spirally wound body. The spirally wound body is configured to expand in response to contacting a snubbed stroke range of an actuator piston. The spirally wound body is configured to contract in response to distancing from the snubbed stroke range of the actuator piston.

A hydraulic system for supplying fluid to an actuator comprising a variable speed prime mover drivingly coupled to a variable displacement hydraulic pump. The system is configured to deliver hydraulic fluid via fluid conduits to an actuator. It may deliver hydraulic fluid to an actuator at a first hydraulic pressure at a first rate of pressure rise; and at a second hydraulic pressure at a second rate of pressure rise. The first hydraulic pressure may be greater than the second hydraulic pressure; and the first hydraulic rate of pressure rise may be lower than the second hydraulic rate of pressure rise.

A hydraulic cylinder includes: a cylindrical cushion bearing that is clamped between a piston and a step portion of a piston rod; a cushion passage that is formed between the cushion bearing and a bearing receiving portion and that imparts resistance to the flow of the working oil passing therethrough; and a check seal that is provided between the inner circumference of the cushion bearing and the outer circumference of the piston rod. The check seal shuts off the flow of the working fluid from a connection gap between the piston rod and the piston towards the rod side chamber through the annular gap and allows the flow of the working fluid from the annular gap towards the bottom-side chamber through the connection gap.

The present application discloses a hydraulic oil cylinder, of which a piston rod (3) is provided with at least two cushion collars (4, 11) which are axially slidable along the piston rod (3). Axial throttle oil channels (301a, 301b) are provided between the cushion collars (4, 11) and a piston (6). A first cushion collar (4) is provided with a sealing end face (401), and an end cover of a rod cavity (1) is provided with a sealing end face (101). The sealing end face (401) of the first cushion collar contacts with the sealing end face (101) of the end cover of the rod cavity to form a seal. Hydraulic oil within the rod cavity is discharged through one axial throttle oil channel (301a) to an oil passage B.