A hermetic compressor may include a crankshaft having an input shaft rotatably supported on the cast-iron block along the crankshaft axis and connected to the electric motor rotary output, and an eccentric crankpin orbitally rotating about the axis as the crankshaft is rotated. A pair of opposed pistons may lie on the common plane. Each piston may be pivotably connected to one of the connecting rod piston ends to drive the pistons in an oscillatory manner within the cylinders as the crankshaft rotates. The piston and cylinder pairs may cause fluid to be pumped from the inlet port to the outlet port as the piston oscillates varying the volume of the enclosed space bound by the piston and the cylinder pairs.

A piston and cylinder assembly of an axial piston machine is disclosed which includes a cylinder having a uniform internal diameter, a cylindrical bushing press-fit against the inner surface of the cylinder and extending at least partially therein, the bushing comprising at least one circumferential groove formed on an outer surface of the bushing against the inner surface of the cylinder, a piston reciprocably disposed within the cylindrical bushing, generating a piston-bushing-interface, the piston and the bushing defining a diametrical clearance therebetween, the diametrical clearance defining a lubrication gap and a fluid-dynamic seal between the piston and the cylindrical bushing.

Systems and methods are described for a reciprocating mechanism. The system includes at least one axially translating y-axis component configured to reciprocate substantially along a y-axis with a reciprocating motion of a piston assembly relative to a base. The system also includes at least one x-axis component slidingly coupled via at least one bearing assembly to and translating with the at least one y-axis component along the y-axis. The at least one x-axis component is configured to reciprocate substantially perpendicularly to the y-axis relative to the at least one y-axis component, and includes an orbital output component and an orbital linking component disposed substantially concentric with the orbital output component. The system also includes a stationary output component rotatably attached to the base in a direction that is substantially perpendicular to both the x-axis and y-axis, and a stationary linking component rotatably attached to the base in a direction that is substantially concentric with the stationary output component.

A cam driven compressor includes a cam coupled to a plurality of cylinder and piston assemblies. Each cylinder and piston assembly comprises a piston located and movable within a respective cylinder. Each cylinder has a cylinder head. The compressor comprises a housing defining a cavity configured to receive a portion of a source gas from one or more of the cylinders in order to maintain a positive gas pressure within the cavity.

A hermetic compressor may include a crankshaft having an input shaft rotatably supported on the cast-iron block along the crankshaft axis and connected to the electric motor rotary output, and an eccentric crankpin orbitally rotating about the axis as the crankshaft is rotated. A pair of opposed pistons may lie on the common plane. Each piston may be pivotably connected to one of the connecting rod piston ends to drive the pistons in an oscillatory manner within the cylinders as the crankshaft rotates. The piston and cylinder pairs may cause fluid to be pumped from the inlet port to the outlet port as the piston oscillates varying the volume of the enclosed space bound by the piston and the cylinder pairs.

A reciprocating type compressor may include a crank shaft that is coupled to a rotor of a motor to receive a rotational force and a connecting rod that is coupled to a pin of the crank shaft and converts a rotational force of the crank shaft into a linear motion of a piston. The connecting rod may include a first end having a tubular body that includes a pin insertion hole into which the pin of the crank shaft is inserted and a socket that projects from the tubular body, a second end coupled with the piston, and a main body that extends between the first end and the second end and having a ball that is received inside of the socket.

An oil wiper packing for a piston rod of a crosshead piston compressor, and corresponding assembly method. The oil wiper packing has at least one chamber disc having a chamber disc cutout, wherein a wiper ring arranged in the chamber disc cutout. At least two chamber discs, each having a chamber disc cutout, are arranged in succession in a direction of extent (L), and a single wiper ring is in each chamber disc cutout. Each wiper ring has no play or only negligible play in the direction of extent (L) in the operating state but is movable in the radial direction. It is necessary to set the play in in the cold state during the assembly of the wiper rings. Such an arrangement allows advantageous wiping of oil, preventing oil from spreading in the direction of extent of the piston rod.

A compressor (20) has a case (22) and a crankshaft (38). The case has a number of cylinders (30-32). For each of the cylinders, the compressor includes a piston (34) mounted for reciprocal movement at least partially within the cylinder. A connecting rod (36) couples each piston to the crankshaft. A pin (44) couples each connecting rod to the associated piston. Each pin has first (52) and second (53) end portions mounted to first (56) and second (57) receiving portions of the associated piston and a central portion (48) engaging the associated connecting rod. For each of the pistons a pair of first and second at least partially non-metallic plugs have respective stems received in the pin first and second end portions and respective heads facing a wall surface of the associated cylinder.

A compressor (20) has a case (22) and a crankshaft (38). The case has a number of cylinders (30-32). For each of the cylinders, the compressor includes a piston (34) mounted for reciprocal movement at least partially within the cylinder. A connecting rod (36) couples each piston to the crankshaft. A pin (44) couples each connecting rod to the associated piston. Each pin has first (52) and second (53) end portions mounted to first (56) and second (57) receiving portions of the associated piston and a central portion (48) engaging the associated connecting rod. For each of the pistons a pair of first and second at least partially non-metallic plugs have respective stems received in the pin first and second end portions and respective heads facing a wall surface of the associated cylinder.

A piston ring is used for a reciprocating compressor. In the piston ring, polytetrafluoroethylene and polyetheretherketone or polyimide account for 50% or more by mass in total. The piston ring does not contain polyphenylene sulfide. The piston ring has a tensile strength within a range of more than 15 MPa and less than 100 MPa.