A piston ring includes a first ring portion which is fitted onto an outer circumferential portion of a piston and which is capable of sliding relative to an inner wall surface of a cylinder, and a second ring portion which is fitted onto the outer circumferential portion of the piston, arranged side-by-side with the first ring portion in the axial direction, and which is capable of sliding relative to the inner wall surface of the cylinder. The second ring portion is fitted onto the outer circumferential portion of the piston in such a way as to be positioned on a side opposite to a compression chamber inside the cylinder, relative to the first ring portion, and has a greater hardness than the first ring portion has.

A gas compression system may include a gas compressor having a compressor rod, a piston, and an interior chamber. The gas compressor may receive a process gas at a first pressure, pressurize the process gas via the piston, and output the process gas at a second pressure higher than the first. Additionally, an internal combustion engine coupled to the gas compressor may, during operation, actuate the compressor rod and generate exhaust gas. The gas compression system may also include a packing case, disposed around the compressor rod and fluidly coupled to the interior chamber. The packing case may receive and direct the exhaust gas to counter a flow of the process gas through the packing case from the interior chamber.

The present invention discloses a compressor configured to compress gas. The compressor includes: a cylinder part; a piston disposed in the cylinder part to form in the cylinder part a compression chamber in which the gas is compressed, the piston being configured to compress the gas in the compression chamber; a first sealing part located adjacent to the compression chamber and attached to an outer circumference of the piston, and formed mainly containing at least one type of component that is selected from a group of polyetheretherketone, polyimide, and polybenzimidazole; and a second sealing part located more separated from the compression chamber than the first sealing part is from the compression chamber and attached to the outer circumference of the piston, the second sealing part having a hardness equal to or smaller than that of the first sealing part.

A cylinder coupling structure of a small air compressor according to the present invention, in which a cylinder is integrally coupled to a block by which a crankshaft is shaft-supported, wherein the block is provided with a supporting end by which the cylinder is pressed to be supported; a latching end is formed on the outer surface of the cylinder; and a press bolt is fastened to the block and a valve cover so that the valve cover presses the front end of the cylinder while the latching end of the cylinder is latched and supported on the supporting end.

A portable pump is provided including an electric motor having a drive shaft connected to a gear assembly to drive a reciprocating air compressor arrangement. The reciprocating air compressor arrangement includes a crank that drives a connecting rod and a piston within a cylinder. The connecting rod has a first end and a second end and the first end of the rod is connected to the crank while the second end of the rod connected to the piston (to drive the piston in the cylinder and provide compression). The second end of the connecting rod is connected to the piston via a pin. The piston includes a sealing arrangement. A control unit is provided which is in electrical communication with the electric motor and the air compressor to control the operation of the pump arrangement. A power supply is also provided in electrical communication with the control unit to supply power to the control unit and electric motor. The pump is provided within a housing which accommodates the electric motor, the gear assembly, the reciprocating air compressor, the control unit and the power supply. A outlet connected to the reciprocating air compressor is also provided so as to engage with an object to be pumped.

A pumping device for processing a liquid comprises: a plurality of pistons, each of which is slidable along a movement direction in order to vary the volume of a corresponding chamber; a casing inside of which a driving device is housed for moving each piston of the plurality of pistons along the movement direction; a head inside of which the chambers are at least partially obtained; a plurality of suction valves, each one of which is associated with a chamber and is operable for enabling the liquid to enter the chamber; a plurality of delivery valves, each one of which is associated with a chamber and is operable for enabling the liquid to exit the chamber.

Each suction valve has an axis arranged transversely with respect to a further axis of the delivery valve associated with the same chamber. The pumping device further comprises an intermediate body interposed between the casing and the head. The intermediate body is provided with a guide device for guiding each piston along the movement direction.

Various assemblies that can be used in a mud pump with a plunger-style piston to reduce seal failures, to offer control in variability of the circumference of the piston to thereby control fluid pressure, and to provide visibility into seal condition during operation. In one embodiment, a sleeve that can vary the overall effective circumference of the piston enables fluid pressure control. In some embodiments, seal failure within a pump can be monitored via a drain port that would receive drilling fluid leaking past a seal during operation of the pump. A discharge valve can be provided between an inlet and an outlet of the mud pump to reduce the load on pump components during start-up. Additional systems, devices, and methods are also disclosed.

A cylinder coupling structure of a compact air compressor includes a block, a tubular-shaped cylinder assembled to the block, a valve cover which covers the valve assembly, at least one pressurized bolt which assembles the valve cover and the block, a piston which is reciprocated inside the cylinder, a stator which is assembled to the block, a rotator which is located to relatively rotate as to the stator, a crank axis which is assembled to the rotator to integrally rotate with the rotator to be axially supported in the block to be rotatable, and a connecting rod, each of both ends thereof is connected to the crank axis and the piston, respectively.

Piston ring having a first annular body and a second annular body, which annular bodies, are arranged adjacent to and concentric with one another in the axial direction (A), the first annular body having a radially outwardly directed outer side, an upper and a lower flank and a radially inwardly directed inner side, the second annular body being designed as a segmented sealing ring having a plurality of sealing ring segments, which sealing ring segments each have a radially outwardly directed sealing surface, an up-per and a lower sealing ring segment flank and a radially inwardly directed inner side, the sealing ring segments each being guided on the first annular body by means of at least one guide means, which guide means substantially prevent twisting of the sealing ring segments against the first annular body in the circumferential direction (U) and permit displacement of the sealing ring segments transversely to the axial direction (A).

A throttle arrangement for sealing a sliding surface of a body in a piston compressor the throttle arrangement having annular sealing discs and a sealing disc holder having an L-shaped radial section having a first leg running in the axial direction and a second leg running transversely, the second leg being annular and having a bearing surface pointing in the direction of the high-pressure side, the sealing discs are stacked one on top of one another axially, the first leg being cylindrical extending from the bearing surface toward the high-pressure side, the axial height of the first leg H4 allow bearing surface to have axial play, the first leg gas passage openings, the first leg having a boundary surface facing in the sealing discs, aligned coaxially with the first limb and the body, a first annular gap RS1 is formed between the boundary surface and the sealing discs.