An accumulator includes a housing having a sealing face and a fluid inlet/outlet passage, a bellows fixed at least one end to the housing such that an inner space of the housing is hermetically partitioned by the bellows into an interior and an exterior of the bellows, the bellows including a bellows main body capable of expanding and contracting and a bellows cap including an annular seal holder, and a sealing member formed by covering a disc-shaped substrate with an elastic body that is opposed to and capable of being closely attached to the sealing face of the housing, the sealing member is held by a holding portion of the annular seal holder on an inner diameter side of the annular seal holder, the fluid inlet/outlet passage of the housing being closed upon a close attachment of the elastic body to the sealing face.

An accumulator includes a pressure container, a tubular bellows, a bellows cap divisionally defining a liquid chamber and a gas chamber in cooperation with the bellows. A stay provided with a through hole partitions the liquid chamber into a closed liquid chamber on a side of the bellows and an open liquid chamber on a side of the liquid pressure port. The bellows cap includes an elastic abutment part provided with an annular sealing part positioned around the through hole to face the through hole, a buffering part is positioned on a radially inner side of the sealing part, and communication passages always communicating with the through hole are formed in the buffering part of the elastic abutment part.

The invention provides a metal bellows type accumulator having an outer shell provided in its one end with a pressure introducing passage in an opening manner, an axially expandable metal bellows including peak portions directed to an outer side in a radial direction and trough portions directed to an inner side alternately in an axial direction, having an axially fixed end to the outer shell and separating an inner chamber of the outer shell into a pressure introducing chamber and a gas chamber charged with cushion gas, and a support member arranged in an inner periphery of the metal bellows, fixed to the outer shell and constructed by a cushioning member. A clearance in a radial direction between the trough portions of the metal bellows and the support member is smaller than a clearance in a radial direction between the peak portions of the metal bellows and the outer shell.

An accumulator has a pressure vessel, a partition portion comparting an internal space of the pressure vessel into a gas chamber having sealed gaseous matter and a liquid chamber having introduced liquid, and a bellows connected to the partition portion. The partition portion is provided with a bellows connection portion connected to the bellows, a seal arranged in a liquid chamber side of the bellows connection portion, and a seal retention portion fixed to the bellows connection portion and retains the seal. The seal retention portion is constructed by a leaf spring which is elastically deformable in a part thereof, and is structured by integrally forming a fixed portion fixed to the bellows connection portion, and a retention portion retaining the seal. Accordingly, the accumulator can reduce the number of parts of a pressure fluctuation absorbing mechanism, can be easily assembled, and can reduce a parts cost.

The invention provides a metal bellows type accumulator having an outer shell provided in its one end with a pressure introducing passage in an opening manner, and a metal bellows repeatedly formed peak portions directed to an outer side in a radial direction and trough portions directed to an inner side, capable of expanding and contracting in an axial direction and separating an inner chamber of the outer shell into a pressure introducing chamber communicated with the pressure introducing passage and a gas chamber charged with cushion gas. A tubular portion is provided at a position where an amplitude of vibration in a radial direction becomes maximum in the metal bellows, has a greater diameter than a maximum diameter portion of each of the peak portions and is in contactable with an inner peripheral surface of the outer shell at a predetermined width in the axial direction.

The invention relates to a tensioning cylinder device, comprising a housing (2) and and at least partly longitudinally movable piston-rod unit (30, 34) arranged therein, and comprising a compensating element in the form of a bellows body (18) having bellows folds, which is longitudinally variable and has a media-carrying connection to a compressible medium accommodated in a medium chamber (12) in the housing (2).

A shell member 10 constituting an accumulator 100 including a cover member 30, a shell member 10 having a cylindrical portion 11, an opening portion 13 formed at one end of the cylindrical portion 11 and welded to the cover member 30, and a closed portion 12 formed at another end of the cylindrical portion 11, and an accumulation part 70 accommodated in the shell member 10. The cylindrical portion 11 includes an upper end portion 11a, and a protruding portion 11c having the opening portion 13. The protruding portion 11c is thicker than the upper end portion 11a.

A center biased actuator having an outer cylinder, a slave cylinder linearly transposed within the outer cylinder, a rod assembly with a piston linearly transposed within the slave cylinder and a rod extending from the outer cylinder, one or more first dynamic seals arranged to act on a sidewall of the rod to inhibit hydraulic fluid leaking from the outer cylinder, one or more second dynamic seals arranged to act on a sidewall of the slave cylinder or an inner surface of the outer cylinder to inhibit hydraulic fluid leaking from the outer cylinder, and a gas chamber comprising a sealed expandable chamber containing gas. The expandable chamber is arranged to act on hydraulic fluid within the center biased actuator to bias the center biased actuator to assume an intermediate condition which lies between a compressed condition and an extended condition.

An accumulator is provided, which is aimed at stabilization in mounting state of a damping member while diminishing the impact on a metal bellows. In an accumulator (100), a damping member (190) formed slidably at the inner circumferential surface of a pressure vessel (110) and suppressing the oscillation of a metal bellows (130) while keeping a gap between the metal bellows (130) and the inner circumferential surface of the pressure vessel (110) is mounted at at least one site of a plurality of annular valley parts of the metal bellows(130) including a plurality of annular crest parts and the plurality of annular valley parts alternately formed therein. In the damping member (190), a radially inward tip is fitted with the valley part, and a radially outward tip is longer than the crest part of the metal bellows radially and outwardly.

In general, certain embodiments of the present disclosure provide an electro-hydrostatic actuator comprising a piston assembly and a hydraulic cylinder. The piston assembly, having a piston head and a piston rod extending from the piston head, is located and movable within the hydraulic cylinder. The hydraulic cylinder includes a hydraulic fluid chamber region including a piston side chamber and a rod side chamber, a reservoir for storing hydraulic fluid located within the hydraulic cylinder which is in fluid communication with the hydraulic fluid chamber region. The electro-hydrostatic actuator includes a hydraulic pump system for moving hydraulic fluid in the reservoir and the hydraulic fluid chamber region, the hydraulic pump system in fluid communication with a flow control network in a hydraulic cylinder boss for controlling a direction and flow magnitude of hydraulic fluid within the hydraulic fluid chamber region, and an electric motor for driving the hydraulic pump system.