A diaphragm accumulator provided with a flexible diaphragm inside an accumulator housing has a stress relaxing member having a contact surface which the diaphragm deformed by a pressure fluctuation inside the accumulator housing contacts and regulating the deformed attitude of the diaphragm by the contact surface on the inner surface. When the diaphragm is deformed by the pressure fluctuation inside the accumulator housing, the stress relaxing member regulates the deformed attitude of the diaphragm to reduce a stress generated in the diaphragm.

A pressure accumulator having an accumulator housing (10) in which a movable separating element (16) separates a gas room (12) filled with a working gas from a fluid room (14) in a fluid-sealed manner, wherein a monitoring device (46) is provided, which, in the event of a fault impairing the sealing effect of the separating element (16), provides an optically discernible indication and which has an inspection window (54), through which an indicator can be observed, which is connected to the gas room (12) and whose optical properties change discernibly when wetted with the fluid, is characterized in that the indicator changing its optical properties is accommodated in a capsule (48), the capsule wall (50) of which is permeable to the passage of the fluid and which is arranged between the inspection window (54) and the separating element (16) in the accumulator housing (10).

A controller (45) is provided with an elapse time measuring section (47A) that measures an elapse time (tx) elapsed since an initial use of an accumulator (29) based upon a reset signal from a reset switch (44), a number-of-operations measuring section (47B) that measures a number of operations of the accumulator (29), that is, a number (N) of boom lowering operations after a reset, based upon a detection signal from an accumulator side pressure sensor (39), a gas permeation amount estimating section (47C) that estimates an estimation gas permeation amount (Qloss) of the accumulator (29), a sealed gas pressure estimating section (47D) that finds an estimation sealed gas pressure (Pgs) of a gas chamber (29B) of the accumulator (29), and an accumulator degradation determining section (47E) that determines a degradation condition of the accumulator (29) and outputs the determination result.

The accumulator includes a housing having a sealing face and a fluid inlet/outlet passage; and a bellows fixed at 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 includes a bellows main body capable of expanding and contracting and a bellows cap provided with a sealing member covered with an elastic body that is opposed to and capable of being closely attached to the sealing face of the housing. The fluid inlet/outlet passage of the housing is closed upon a close attachment of the elastic body to the sealing face. The accumulator further includes a spacer placed between the housing and the bellows cap so as to surround the sealing member. The spacer has a communication passage providing communication between an inside and an outside of the spacer.

A landing gear system for an aircraft includes a retractable landing gear assembly, a hydraulic actuator for actuating movement part, for example a bogie of the landing gear assembly, and an accumulator associated with the actuator. The accumulator comprises a volume of pressurised gas separated from hydraulic fluid by a separator piston. Travel of the separator piston beyond a certain position is indicative of a fault. The accumulator includes a snubbing device that acts to slow movement of the separator piston beyond that position. A monitoring system measures the time taken for the movement of the landing gear part effected by the hydraulic actuator. If the measured time is longer than a threshold time, that is indicative of a possible fault in the accumulator, that might, without the snubbing, remain undetected and/or hidden from view.

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.

A bootstrap hydraulic reservoir includes a bootstrap chamber to hold hydraulic fluid, a piston chamber fluidly connected to a pressure line of the hydraulic fluid system, a piston having a bootstrap end portion held within the bootstrap chamber and a pressure end portion held within the piston chamber, and a hydraulic accumulator fluidly connected to the pressure line of the hydraulic fluid system. The hydraulic accumulator accumulates pressurized hydraulic fluid from the pressure line. The bootstrap hydraulic reservoir also includes a valve fluidly connected to the pressure line of the hydraulic fluid system between the hydraulic accumulator and an outlet of a pump of the hydraulic fluid system. The valve includes an actuator selectively moves the valve to an open position when the pressure line of the hydraulic fluid system is de-pressurized.

An accumulator includes a bellows 3 having a plurality of outer ridge portions and a plurality of inner annular ridge portions and configured to be capable of expanding and contracting, and a housing having a fluid supply port and fixed to one end of the bellows serving as a fixed end. An interior of the housing is partitioned in a sealed state into an inside and an outside of the bellows. The outer annular ridge portions are divided into at least a first sector and a second sector which are distributed in an expansion and contraction direction of the bellows such that the second sector is positioned between the first sector and the fixed end. The outer annular ridge portions included in the first sector have an outer diameter smaller than an outer diameter of the outer annular ridge portions included in the second sector.

A damping device for fluids subject to pressure pulsations, having at least one hydraulic accumulator (2), the accumulator housing (4, 6) of which contains a movable separating element (18), which separates a gas side (14) from a fluid room (16) and can be pressurized by a fluid present in the fluid room (16), is characterized in that a damper housing (34) having a second fluid room (38) is provided as a component of the accumulator housing (4, 6), wherein through said second fluid room (38) the fluid subject to pressure pulsations can flow and the second fluid room (38) contains a second movable separating element (40), which separates the second fluid room (38) from the first fluid room (16) of the hydraulic accumulator (2) without dead space.

The present disclosure relates to a gas-charged hydraulic accumulator assembly of a work vehicle, which is hydraulically coupled to a cap side chamber of a hydraulic cylinder. The gas-charged hydraulic accumulator assembly absorbs an impact from a work tool which increases a pressure of a first fluid in the cap side chamber. The gas-charged hydraulic accumulator assembly may include a first accumulator and a second accumulator. The first accumulator has a first gas and is used to receive the first fluid. The second accumulator is coupled to the first accumulator and has a second gas. The pressure of the second gas in a second pre-charged status is higher than a pressure of the first gas in a first pre-charged status. The second accumulator is used to receive the first fluid.