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.

A linear compressor includes a cylinder that defines a compression chamber configured to accommodate refrigerant and that includes a cylinder nozzle configured to receive refrigerant, and a piston provided in the cylinder and configured to be pressed by refrigerant in the cylinder. The piston includes a piston body configured to move forward and backward within the cylinder, a piston front part located on a front surface of the piston body, the piston front part comprising a suction port through which refrigerant is supplied into the compression chamber, and a refrigerant collection part that is recessed from an outer circumferential surface of the piston front part, that extends to a front surface of the piston front part, and that is configured to receive at least a portion of refrigerant compressed in the compression chamber.

A method for operating a linear compressor includes establishing a set of predictors, and establishing a model for an estimated head clearance of the linear compressor with the set of predictors. Coefficients of the model for the estimated head clearance of the linear compressor may also be established. The model for the estimated head clearance of the linear compressor may be used to calculate an estimated head clearance during operation of the linear compressor.

A reciprocating pump includes a first manifold which includes a pump chamber, a second manifold which is connected to the first manifold, and seal means which is disposed inside the second manifold and comes into slidable contact with a plunger. A communication pipe which extends across an inside of the first manifold and an inside of the second manifold comes into contact with the seal means. Additionally, the reciprocating pump includes a collar which is disposed inside the first manifold and comes into contact with the communication pipe through which the plunger is inserted. The collar, the communication pipe, and the seal means are sandwiched between the inside of the first manifold and the inside of the second manifold.

The present invention relates to a piston assembly for pumping a liquid, in particular in a bottle filling system. The object of the invention is to propose a piston assembly for pumping a liquid, which can be cleaned and/or disinfected without dismantling of the piston or performing any other external interventions into the assembly. The object is achieved by a piston assembly for pumping a liquid, which comprises a piston 1 that travels within a cylinder 2 and has a working path A between a first inversion point U1 and a second inversion point U2, with the piston 1 forming a tight seal with respect to the cylinder 2 in the region of the working path. The assembly is characterized in that beyond one of the two inversion points U1, U2, outside of the working path A, the diameter of the cylinder 2 is enlarged in one section 8 such that the sealing closure is eliminated there, and the piston 1 can be moved into this area for a cleaning and/or disinfection process.

An implantable infusion device includes a reservoir for housing an infusion medium and a drive mechanism having an inlet chamber, a piston and a piston channel. The inlet chamber is in fluid communication with the reservoir. The piston channel is in fluid communication with the inlet chamber, and has a distal end and a proximal end, the proximal end being closer to the inlet channel than the distal end. The piston is axially moveable within the piston channel to drive infusion medium out of the distal end of the piston channel. The clearance between the piston and the channel is sufficiently small to prevent undissolved gas in the inlet chamber from passing through the clearance. The inlet chamber may be sufficiently large to allow undissolved gas to accumulate without adversely affecting the performance of the infusion device.

A compressor includes a plurality of gas bearing conduits and a plurality of gas bearing control valves. Each gas bearing control valve of the plurality of gas bearing control valves is coupled to a respective one of the plurality of gas bearing conduits. The gas bearing control valves are configured for permitting fluid flow through the gas bearing conduits when a piston of the compressor is positioned adjacent the gas bearing conduits in a chamber of the compressor.

In some aspects, waterjet cutting pressurization systems can include a water pump: (i) having a pressurization chamber and (ii) having a high-pressure water seal maintaining water pressure within the chamber; and a leak detector in fluid communication with the high-pressure water seal and configured to monitor a leak rate of a fluid from the high-pressure water seal.

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 at one side of the cylinder to selectively discharge the refrigerant compressed in the compression space, and at least one nozzle, through which at least a portion of the refrigerant discharged through the discharge valve may flow, the at least one nozzle being disposed in the cylinder. The at least one nozzle may include an inlet, through which the refrigerant may be introduced, and an outlet having a diameter less than a diameter of the inlet.

Systems and methods for operating a linear motor (e.g., for an ESP), where the motor's mover moves in a reciprocating motion within a bore of the stator. Hard stops are located at the ends of the bore. The motor has a first set of sensors in the stator positioned proximate to the bore. When the mover moves in the bore, the sensors produce corresponding output signals, except when the mover is in a position near, but not in contact with a hard stop. While the sensors produce output signals, the motor is driven in a first direction toward the hard stop. When the sensors stop producing the output signals, the mover has reached the first position, and the motor is controlled to reverse the direction of the mover.