A two-stage compressor of a compressed air supply device includes a low pressure stage having a low pressure cylinder, a high pressure stage having a high pressure cylinder, a low pressure piston guided in an axially movable manner in the low pressure cylinder, a high pressure piston guided in an axially movable manner in the high pressure cylinder, a piston rod rigidly connecting the low pressure piston and the high pressure piston, and a sliding block guide. The sliding block guide includes a recess arranged in the piston rod and further includes two substantially parallel sliding block tracks. One of the sliding block tracks has an arc-shaped indentation in a central portion. The sliding block tracks are constructed and such that a movement of the low pressure piston and of the high pressure piston follows a piston stroke curve that deviates from a regular sinusoidal stroke curve.

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 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 valve plate assembly for a compressor according to the principles of the present disclosure includes a valve plate and a suction valve retainer. The valve plate is configured to separate suction-pressure working fluid entering a cylinder of the compressor from discharge-pressure working fluid exiting the cylinder of the compressor, the valve plate defining a discharge valve seat. The suction valve retainer is configured to retain a suction valve within a suction valve seat disposed about a central longitudinal axis of the cylinder and to extend radially outward from the central longitudinal axis of the cylinder without extending beyond a suction passage of the compressor.

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.

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.

The present invention relates to a breathing air charger for detecting a tank state, capable of providing air properly adjusted in the concentration of oxygen and nitrogen to a breathing air tank used by a firefighter or a scuba diver, and of effectively discharging air from the breathing air tank.

The present invention relates to a breathing air charger for detecting a tank state, capable of providing air properly adjusted in the concentration of oxygen and nitrogen to a breathing air tank used by a firefighter or a scuba diver, and of effectively discharging air from the breathing air tank.

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 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.