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.

A hydropneumatic pressure accumulator, in particular a pulsation damper, includes an accumulator housing (2) and a movable separating element (20), which separates a pressurized working gas-containing gas working space (24) from a fluid chamber (22) in the accumulator housing (2). A gas storage chamber (12) is provided, which contains an additional volume of the pressurized working gas, and is connected via a connecting path (30) having a throttle point to the gas working space.

A hydropneumatic pressure accumulator, in particular a pulsation damper, includes an accumulator housing (2) and a movable separating element (20), which separates a pressurized working gas-containing gas working space (24) from a fluid chamber (22) in the accumulator housing (2). A gas storage chamber (12) is provided, which contains an additional volume of the pressurized working gas, and is connected via a connecting path (30) having a throttle point to the gas working space.

A fluid system includes a reservoir having a first reservoir chamber and a second reservoir chamber separated by a movable barrier, the first reservoir chamber being configured to contain a working fluid. The fluid system includes a piston housing defining an internal volume and a piston movable within the internal volume, the piston separating the internal volume into a first piston chamber and a second piston chamber, the second piston chamber being fluidly coupled to the second reservoir chamber. The fluid system includes a fluid supply configured to provide a control fluid to the first piston chamber.

Disclosed is an expansion tank having an internal cavity separated by a flexible diaphragm to form an upper pressurized gas portion and a lower pressurized fluid portion, and an indicator positioned at an upper part of the expansion tank in communication with the contents of the upper pressurized gas portion. The indicator is configured so as to display a first color if the operating conditions are normal in the pressurized gas portion, and a second color if the amount of moisture detected in the pressurized gas portion greater than or equal to a predetermined amount. Further disclosed is a method for detecting whether there is an excessive amount of moisture in a pressurized gas portion of an expansion tank by allowing pressurized gas from the pressurized gas portion to come into contact with the indicator, and viewing the color displayed by the indicator. As such, the tank can be simply visually inspected to determine whether there is a potential failure in the tank.

Disclosed is an expansion tank having an internal cavity separated by a flexible diaphragm to form an upper pressurized gas portion and a lower pressurized fluid portion, and an indicator positioned at an upper part of the expansion tank in communication with the contents of the upper pressurized gas portion. The indicator is configured so as to display a first color if the operating conditions are normal in the pressurized gas portion, and a second color if the amount of moisture detected in the pressurized gas portion greater than or equal to a predetermined amount. Further disclosed is a method for detecting whether there is an excessive amount of moisture in a pressurized gas portion of an expansion tank by allowing pressurized gas from the pressurized gas portion to come into contact with the indicator, and viewing the color displayed by the indicator. As such, the tank can be simply visually inspected to determine whether there is a potential failure in the tank.

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 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.

Disclosed is an expansion tank having an internal cavity separated by a flexible diaphragm to form an upper pressurized gas portion and a lower pressurized fluid portion, and an indicator positioned at an upper part of the expansion tank in communication with the contents of the upper pressurized gas portion. The indicator is configured so as to display a first color if the operating conditions arc normal in the pressurized gas portion, and a second color if the amount of moisture detected in the pressurized gas portion greater than or equal to a predetermined amount. Further disclosed is a method for detecting whether there is an excessive amount of moisture in a pressurized gas portion of an expansion tank by allowing pressurized gas from the pressurized gas portion to come into contact with the indicator, and viewing the color displayed by the indicator. As such, the tank can be simply visually inspected to determine whether there is a potential failure in the tank.