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.

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.

A pressure accumulator includes a membrane (4) forming a movable separating element between media spaces (6, 8) and made of contiguous layers (16, 18, 20, 22, 24, 26) of different materials. At least one layer of a basic structure (16, 20) has filaments. A gas-tight impregnation (24) is disposed between layers (18) made of an elastomer.

A pressure accumulator includes a membrane (4) forming a movable separating element between media spaces (6, 8) and made of contiguous layers (16, 18, 20, 22, 24, 26) of different materials. At least one layer of a basic structure (16, 20) has filaments. A gas-tight impregnation (24) is disposed between layers (18) made of an elastomer.

An accumulator capable of suppressing collision of a metal bellows with a pressure vessel. A partition unit 300 includes: a tubular metal bellows 310, one end of which is side fixed to a pressure vessel 200 and which expands and contracts according to pressure in a fluid chamber and pressure in a gas chamber; and a bellows cap 320 which is fixed to another end side of the metal bellows 310, the partition unit 300 further including: a seal member 330 which is provided between the bellows cap 320 and a port 221 and seals a working fluid on the side of the fluid chamber via the metal bellows 310 when the metal bellows 310 contracts; and a sliding unit 350 which is fixed to the bellows cap 320 and slides in an expansion/contraction direction of the metal bellows 310 relative to a stay 400.

A method for manufacturing a hydraulic accumulator bladder includes the following steps: bonding a rubber sheet to the gas-filled air bladder to form a bladder blank; placing the bladder blank in a vulcanization device for vulcanization to form an initial bladder product; and releasing the gas in the gas-filled air bladder of the initial bladder product, taking the air bladder out, and naturally cooling the initial bladder product to a room temperature to form a finished bladder product. The bladder manufactured by the manufacturing method is integrally formed by one-step vulcanization, and has the advantages of uniform wall thickness, smooth inner and outer surfaces, long fatigue lifetime, a simplified process, high quality and good stability.

The invention provides an accumulator which can reduce the number of the parts of the pressure fluctuation absorption mechanism at the liquid expanding time, can simplify assembling and can reduce a cost of the parts. The accumulator has a seal holder which is provided in a bellows cap, and a plate-like seal which is retained by the seal holder. The seal holder is provided with an inward flange-like outer peripheral side engagement portion, and the seal is provided with an outward projection-like inner peripheral side engagement portion which is arranged in an outer peripheral surface of a seal main body and is made of a rubber-like elastic body engaging with the outer peripheral side engagement portion. The bellows cap moves to a position where liquid pressure and gas pressure are balanced with the seal seating on a seat surface due to difference in pressure receiving area.

A metal bellows of great durability capable of preventing breakage at both end portions of the metal bellows is provided. The metal bellows is annular-shaped and has, axially repeatedly, a structure in which, from an axial end portion 10c, a belly, a valley, a belly, a peak, and a belly are integrally formed in series sequentially in this order. The end portion 10c has a first connection belly 10d connected to a fitting member 15, and a connection valley 10e and a second connection belly 10f extending sequentially from the first connection belly 10d axially inward. The axial width b1 of the connection valley 10e in a free state is set larger than the axial width of valleys 10i, 10m, . . . or peaks 10g, 10k, . . . in a portion other than the end portion 10c.

A metal bellows of great durability capable of preventing breakage at both end portions of the metal bellows is provided. The metal bellows is annular-shaped and has, axially repeatedly, a structure in which, from an axial end portion 10c, a belly, a valley, a belly, a peak, and a belly are integrally formed in series sequentially in this order. The end portion 10c has a first connection belly 10d connected to a fitting member 15, and a connection valley 10e and a second connection belly 10f extending sequentially from the first connection belly 10d axially inward. The axial width b1 of the connection valley 10e in a free state is set larger than the axial width of valleys 10i, 10m, . . . or peaks 10g, 10k, . . . in a portion other than the end portion 10c.

An accumulator according to an embodiment includes, for example, a base member; a cover member welded to the base member, the cover member and the base member defining a pressure chamber therebetween; a stretchable partition member that partitions the pressure chamber into an inner chamber and an outer chamber; and a labyrinth structure provided in at least one of a first part of the base member and a second part of the cover member. The first part is located closer to the outer chamber than a welded part between the base member and the cover member. The second part is located closer to the outer chamber than the welded part, facing the first part.