A bottom cylinder for a high-temperature and high-pressure environment simulator of a high-fidelity corer is provided. The bottom cylinder includes a cylinder barrel. The bottom of the cylinder barrel is provided with a cylinder base. The piston is provided inside the cylinder barrel and divides an inner cavity of the cylinder barrel into a rodless cavity and a rod cavity. The piston is provided with a piston rod. The outer wall of the cylinder barrel is provided with an oil inlet hole communicated with the rodless cavity, an oil outlet hole communicated with the rod cavity, and a reserved hole. The lower end surface of the piston is provided with a first buffer ring, and the upper surface of the cylinder base is provided with a second buffer ring mated with the first buffer ring. The bottom cylinder is applied to the simulator for oil and gas resource exploitation.

An apparatus for actuating a valve includes a first actuator having a first actuator housing and second actuator with a second actuator housing. A first plate is positioned within the first actuator housing and a second plate is positioned within the second actuator housing. An intermediate stem extends from a first pressure chamber of the first actuator housing to the second plate. A pressure media path extends through the intermediate stem and a second seal nut that extends into the second plate, the pressure media path providing fluid communication between the first pressure chamber, and a second pressure chamber of the second actuator housing. An injection port is open into one of the first pressure chamber and the second pressure chamber. The first plate and the second plate are movable in response to pressure media injected into the injection port, for actuating the valve.

An underwater actuator includes: a housing to be immersed under water; a cylinder chamber formed in the housing; a piston accommodated in the cylinder chamber so the piston is movable in a sliding manner in the cylinder chamber, the piston dividing the cylinder chamber into a first and a second pressure receiving chambers; a rod extending from the piston to the first pressure receiving chamber side, the rod penetrating the housing; a release chamber formed in the housing, having an internal pressure kept lower than a water pressure outside of the housing; and a switching mechanism including: a first switcher configured to switch a communication state between the second pressure receiving chamber and the outside of the housing to allow or block communication therebetween; and a second switcher configured to switch a communication state between the second pressure receiving chamber and the release chamber to allow or block communication therebetween.

A force limiting device comprises a housing defining an axially extending chamber containing a working fluid. A force transmitting member may be mounted for linear reciprocable movement inside the chamber under the action of external loads. An axial array of plates is floatingly disposed in the chamber between the force transmitting member and an end wall of the chamber. At rest, each plate is spaced from an adjacent plate by a gap occupied by the working fluid. When the force transmitting member is displaced towards the array of plates, the fluid in the chamber causes the plates to be successively pushed against each other, thereby causing some of the fluid to be squeezed out from between the plates.

A double-acting linear actuator includes a linear actuator, a receiving disk, a spring, and a piston rod having a piston rod extension fixed to the receiving disk. The spring's first end is supported on the linear actuator and it's second end is supported on the receiving disk. The spring is tensioned by a displacement of the piston rod extension when a pressure is applied to a side of the piston rod. A linear movement is triggered at a force transmission element with a maximum system force when a pressure is applied to a piston side of the linear actuator so that the spring is tensioned and presses against the receiving disk to thereby introduce a stored force of the spring, via the receiving disk being firmly connected to the piston rod extension, into the force transmission element in addition to a force of the linear actuator.

In a fluid pressure cylinder, a piston unit, which is displaced along an axial direction under the supply of a pressure fluid, is disposed in the interior of a cylinder tube of the fluid pressure cylinder. The piston unit includes a disk shaped plate body connected to one end of a piston rod, and a ring body connected to an outer edge portion of the plate body. The plate body is formed from an elastically deformable metal material, and by the plate body becoming elastically deformed and flexing when the ring body of the piston unit abuts against the head cover or the rod cover, shocks applied with respect to the piston unit are buffered.

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 force limiting device comprises a housing defining an axially extending chamber containing a working fluid. A force transmitting member may be mounted for linear reciprocable movement inside the chamber under the action of external loads. An axial array of plates is floatingly disposed in the chamber between the force transmitting member and an end wall of the chamber. At rest, each plate is spaced from an adjacent plate by a gap occupied by the working fluid. When the force transmitting member is displaced towards the array of plates, the fluid in the chamber causes the plates to be successively pushed against each other, thereby causing some of the fluid to be squeezed out from between the plates.

A mechanism to reduce load of a hydraulic cylinder having a body, a stem movable within the body, and a piston rod connected to the stem. The mechanism includes a mechanism body attached to the body and defining a recess, and a retainer attached to the mechanism adjacent the opening of the recess so that the retainer substantially fills the opening of the recess, and having an aperture that receives an end of the piston rod. The mechanism further includes a cap attached to the piston rod of the hydraulic cylinder within the recess, the cap having a diameter greater than the diameter of the aperture in the retainer, and a spring connected to the cap at a first end and to the retainer at a second end so that as the piston rod moves relative to the failsafe mechanism body, to reduce load transfer between the piston rod and the cylinder body.

An energy-saving pneumatic barrier gate device comprises a machine, having an actuating portion, an electronic control portion, and a gas supply portion connected to an air compressor; a shaft assembly and two switch components, installed on the actuating portion; a barrier component, installed on one end of the shaft assembly; and a driving assembly, installed on the other end of the shaft assembly. The shaft assembly controls execution of swinging of the barrier component. The two switch components control cessation of swinging of the barrier component. The driving assembly controls the movement of the shaft assembly and barrier component, and includes a linkage rod pivoted to the shaft assembly and two bellow pumps each having one end pivoted to a respective one of two ends of the linkage rod and the other end installed on a respective one of supports on an outer surface of the gas supply portion.