Provided is a linear compressor including a linear motor having a mover reciprocating with respect to a stator; a piston coupled to the mover to reciprocate; a cylinder into which the piston is slidingly inserted, the cylinder having an inner circumferential surface forming a bearing surface together with an external circumferential surface of the piston, the cylinder forming a compression space together with the piston, and the cylinder having at least one first hole formed through the inner circumferential surface of the cylinder and an outer circumferential surface of the cylinder to guide refrigerant discharged from the compression space to the bearing surface; and a porous member inserted into the outer circumferential surface of the cylinder and configured to cover the first hole, the porous member having multiple micropores smaller than the first hole.

Disclosed herein is a linear compressor. The linear compressor includes a piston, a cylinder, a frame, a first bearing gap formed between an inner circumferential surface of the frame and the outer circumferential surface of the cylinder, a second bearing gap formed between an inner circumferential surface of the cylinder and the outer circumferential surface of the piston, a bearing inflow passage and a bearing side passage formed in the cylinder such that fluid flows from the first bearing gap to the second bearing gap.

A linear compressor is provided. The linear compressor may include a piston having a first piston groove and a second piston groove.

A hermetic compressor accommodates in hermetic container (101) electric motor element (102) and compression element (103) driven by electric motor element (102). Compression element (103) includes crankshaft (110) including main shaft (115), eccentric shaft (114), and flange (116), cylinder block (111) having cylinder bore (123) passing through cylinder block (111) in a cylindrical shape, and piston (112) configured to reciprocate in cylinder bore (123). Compression element (103) also includes connecting rod (113) connecting piston (112) and eccentric shaft (114) and bearing (124) formed on cylinder block (111) for pivotally supporting a radial load that acts on main shaft (115) of crankshaft (110). Crankshaft (110) further includes communicating oil supply passage (118) provided in flange (116), main shaft oil supply passage (119) configured for communication between communicating oil supply passage (118) and cylindrical surface (115a) of main shaft (115), and eccentric shaft oil supply passage (120) configured for communication between communicating oil supply passage (118) and cylindrical surface (114a) of eccentric shaft (114).

An improved air compressor includes a cylinder fitted with a piston body and an air storage container. The cylinder and the air storage container are detachably assembled to define an air chamber. A metal seat with a through hole is provided on top of the cylinder. A valve plug is spring-biased against the metal seat. The air storage container is provided with a pressure indicator, which includes a tube defining therein a first bore and a second bore, between which a tapered annular surface is formed. When the air pressure within the air storage container exceeds a predetermined pressure set for the air compressor, the pressure indicator allows excess air to flow into the first bore of the tube and sequentially pass through the tapered annular surface and an elongated opening to be released to the ambient environment, so that objects can be prevented from damages due to excessive inflations.

A pump barrel (70) for use in a hydrostatic pump assembly includes a barrel body (88) defining a plurality of piston bores (84) that receive a plurality of pistons moveable within the bores, and a porting face (74) that defines a plurality of ports (72) in fluid communication with the piston bores and providing fluid flow paths into and out from the barrel body. Each port (72) has a leading edge surface and a trailing edge surface relative to a direction of rotation of the pump barrel, said leading and trailing edge surfaces being oriented in a first direction (along line 6-6) at non-right angles relative to the porting face (74). Each port (72) has an inner edge surface (80) and an outer edge surface (82) relative to a radial direction of the pump barrel, said inner and outer edge surfaces (80,82) being oriented in a second direction (along line 9-9) comprising a tilt angle (90,92) relative to the porting face (74) that is different from the angles in the first direction. A hydrostatic pump assembly incorporating such a pump barrel (70) is also disclosed.

Provided is a linear compressor. Provided is a linear compressor. The linear compressor includes a shell defining an internal space, a compressor body disposed in the internal space, and a passage guide disposed between the shell and the compressor body. The passage guide may include a first guide part extending along an inner surface of the shell in an axial direction and a second guide part extending from the first guide part to the compressor body in a radial direction.

A fluid end (15) for a multiple reciprocating pump assembly (12) includes at least three plunger bores (61) or (91) each for receiving a reciprocating plunger (35), each plunger bore having a plunger bore axis (65) or (95). The fluid end (15) includes suction valve bores (59) or (89), each suction valve bore receiving a suction valve (41) and having a suction valve bore axis (63) or (93), and the fluid end further includes discharge valve bores (57) or (87), each discharge valve bore receiving a discharge valve (43) and having a discharge valve bore axis (63) or (93). The axes of at least one of the suction and discharge valve bores is inwardly offset in the fluid end from its respective plunger bore axis.

In order to prevent the leakage of a gas from an internal space communicating with a compression chamber inside a cylinder in a cylinder head of a compressor, the compressor includes a suction valve pressing portion that presses a suction valve so that the suction valve provided in the internal space of the cylinder head does not slip off through a suction-side head opening, the suction valve pressing portion includes a suction valve pressing and inserting portion that is inserted into the cylinder head through the suction-side head opening, the outer peripheral surface of the suction valve pressing and inserting portion is provided with an annular suction valve pressing groove portion, a suction-side O-ring is attached into the suction valve pressing groove portion, and a suction-side backup ring that suppresses the movement of the suction-side O-ring toward the suction-side head opening is disposed at a position near the suction-side head opening of the suction-side O-ring inside the suction valve pressing groove portion.

An improved air compressor generally includes a cylinder fitted with a piston body, a main frame for mounting a motor, and an air storage container. The cylinder defines at its top wall a plurality of exit holes, which are separated by a plurality of blocking walls and regulated by a control mechanism. When the compressed air is produced in the cylinder causing the control mechanism to open the exit holes, the instantaneous high-pressure air that flows through the exit holes can be restrained by the blocking walls to prevent the air from interfering with operation of the control mechanism, so that the piston body can conduct reciprocating motion more smoothly and thus the performance of the air compressor can be increased.