A shovel may be provided with a swing hydraulic motor, a relief valve provided on the swing hydraulic motor, and an accumulator part that supplies to the swing hydraulic motor a working oil having a pressure lower than a relief pressure of the relief valve. The accumulator part may accumulate the working oil on a braking side of the swing hydraulic motor. The accumulator part may discharge the working oil to an upstream of a main pump.

A medical fluid delivery machine including: a medical fluid pump including a pneumatically actuated pump chamber and first and second pneumatically actuated medical fluid valve chambers located respectively upstream and downstream of the pneumatically actuated pump chamber; a compressor for creating positive pressure air; and an accumulator storing the positive pressure air for delivery to at least one of the pneumatically actuated pump chamber, the first pneumatically actuated medical fluid valve chamber, or the second pneumatically actuated medical fluid valve chamber, the accumulator holding an elastic bladder that inflates under positive pressure air from the compressor, creating additional positive pressure that increases the amount of positive pressure air that the accumulator can provide.

The invention relates to a hydraulic accumulator, especially a piston accumulator, in which a piston part (27) separates from each other two media spaces (23, 25) inside a storage housing (1), characterized in that the piston part (27) is designed as a deep-drawn part.

A hydraulic accumulator includes a shell, a bellows, and a self-seal stay disposed at a hydraulic-fluid inlet and including a cylindrical body portion open to a hydraulic chamber and a lid-shaped head portion defining a through hole. The self-seal stay includes a first weakened portion for deforming the body portion when a pressure of the gas chamber is more than a given threshold. The first weakened portion includes a first recessed portion formed in a circumferential direction of the body portion. The first recessed portion includes a bottom surface of a plane surface or a circular arc shaped curved surface which is convex toward outside of the body portion from inside thereof. At least one of both end portions of the bottom surface in the circumferential direction is joined with an outer circumferential surface of the body portion.

A metal bellows (110) for an accumulator (100) into which a hydraulic fluid is drawn in, has a bellows-shape in which ridge fold portions (110a) and valley fold portions (110b) are formed repeatedly with slope portions (110c) in between, wherein two of the slope portions (110c) that are adjacent to each other via a common ridge fold portion (110a) have: first slope portions (110c1) which extend from the common ridge fold portion (110a) and second slope portions (110c2) each of which extends from each of the first slope portions (110c1) such that a distance therebetween becomes much greater than the first slope portions (110c1) as the second slope portions (110c2) extend toward the adjacent valley fold portions (110b), wherein the first slope portion (110c1) and the second slope portion (110c2) are connected at an inflection point (P).

An actuator according to the present invention includes a cylinder, a piston inserted into the cylinder to be free to slide, a rod that is inserted into the cylinder and connected to the piston, a rod side chamber and a piston side chamber defined by the piston within the cylinder, a tank, a first opening/closing valve provided in a first passage that connects the rod side chamber to the piston side chamber, a second opening/closing valve provided in a second passage that connects the piston side chamber to the tank, a pump that supplies a working fluid to the rod side chamber, a motor that drives the pump, an exhaust passage that connects the rod side chamber to the tank, and a passive valve that is provided in the exhaust passage and has a predetermined pressure/flow rate characteristic.

A hydraulic accumulator includes an accumulator housing (1), in which a bellows (21) having a selectable number of pleats (23) forms a mobile separation element between the gas side (25) and the fluid side (13). A distancing device (33) is arranged inside the accumulator housing (1), and is fluidically connected to the inside of the bellows (21) or abuts the bellows (21), forming an additional medium chamber.

A low-pressure liquid inlet manifold and a fracturing apparatus are disclosed. The low-pressure liquid inlet manifold includes a main liquid inlet pipe and N liquid feeding pipes; the N liquid feeding pipes are arranged in sequence; each of the liquid feeding pipes includes a third end and a fourth end, the third end is communicated with the main liquid inlet pipe, and the fourth end is configured to provide low-pressure liquid to a plunger pump; and the low-pressure liquid inlet manifold further includes at least one auxiliary accumulator, which is connected with the main liquid inlet pipe and is arranged corresponding to at least one of the N liquid feeding pipes, an orthographic projection of the auxiliary accumulator on an axis of the main liquid inlet pipe overlaps with an orthographic projection of a corresponding liquid feeding pipe on the axis.