A linear compressor is provided. The linear compressor may include a shell including a suction inlet, a cylinder provided in the shell to define a compression space for a refrigerant, a piston reciprocated in an axial direction within the cylinder, a discharge valve provided on or at one side of the cylinder to selectively discharge the refrigerant compressed in the compression space, at least one nozzle disposed in the cylinder to introduce at least a portion of the refrigerant discharged through the discharge valve into the cylinder, and a passage to guide the refrigerant discharged from the discharge valve to the at least one nozzle.

A reciprocating pump includes a housing, a rod, a bellows, and a bearing. The housing surrounds a bellows chamber and a displacement chamber. A first portion of the rod extends into the bellows chamber. The bellows has a first end connected to the housing and a second end connected to the rod. The bellows surrounds a second portion of the rod. The bellows includes a plurality of convolutions. The bearing is disposed within the bellows between the bellows and the rod.

A pump system includes a housing, a lubricant system, and control circuitry. The housing includes a pump chamber defined by the housing and a throat seal. The lubricant system includes a lubricant pump, a lubricant gallery defined within the housing of the main pump, and a lubricant circuit fluidly connecting the lubricant pump and the lubricant gallery. The throat seal is disposed adjacent to and between the pump chamber and the lubricant gallery. The control circuitry is configured to cause the lubricant pump to pump a purge volume of lubricant through the lubricant system, cause the lubricant pump to stop pumping for a first time period after the lubricant pump has pumped the purge volume, and cause the lubricant pump to pump the purge volume of lubricant through the lubricant system after the first time period.

A flow restrictor (1) for application in bearing formation between a piston (2) and a cylinder (3) of a gas compressor (4). The gas compressor (4) includes a pad (5) externally surrounding the cylinder (3) and an inner cavity (6), arranged between the pad (5) and the cylinder (3), fluidly fed by a discharge flow arising from a compression movement exerted by the piston (2) within the cylinder (3). The gas compressor (4) includes a bearing formation gap (7) separating a piston outer wall (2) and an inner cylinder wall (3), and a flow restrictor (1) is provided with a housing (12) fluidly associating the inner cavity (6) to the bearing formation gap (7). The flow restrictor (1) includes a porous element (8), associated to the housing (12), provided with at least a restrictor part provided with a porosity sized to limit the gas flow flowing from the inner cavity (6) to the bearing formation gap (7).

A piston assembly for reducing clearance volume in a reciprocating compressor for compensating for piston tilt and improving the volumetric efficiency of the compressor includes a piston located within a piston cylinder, the piston having a first end and a second end, a wrist pin associated with the first end of the piston, and a cylinder head/valve assembly associated with the second end of the piston, wherein at least a portion of the second end of the piston includes an angled portion. The piston having the angled portion can be used with oil free cylinders and trunk type pistons. The piston can also be used in a multiple stage, multiple cylinder compressor including a series of piston assemblies. A method of increasing the volumetric efficiency of a reciprocating compressor can also be achieved using the piston having an angled portion.

Structural simplification and efficient injection state of high-pressure air from a nozzle are ensured. A foreign material removal device is provided with: a cylinder (18) into which air is caused to flow; a piston (22) which is movably supported in the cylinder and feeds the air introduced into the cylinder in a feeding direction as high-pressure air; and a nozzle (6) which injects the high-pressure air fed by the piston. Thus, the piston is moved relative to the cylinder, the high-pressure air is fed from the cylinder, and the high-pressure air is injected from the nozzle, whereby structural simplification and an efficient injection state of the high-pressure air from the nozzle can be ensured.

A gas bearing is disclosed. The gas bearing may include a cylinder with an inner cylinder radius. The gas bearing may include a piston with a piston radius, wherein the inner cylinder radius is larger than the piston radius, wherein the piston is located within the cylinder. The gas bearing may include a gas bearing radius, wherein the gas bearing radius is greater than the piston radius and less than the inner cylinder radius. The gas bearing may include a gap that exists between the cylinder and the piston, wherein the gap contains a pressurized gas, the pressurized gas configured to prevent contact between the cylinder and the piston. The gas bearing may include a gas bearing interface, wherein the gas bearing interface is positioned to control a size of the gap.