A linear compressor includes a cylinder that defines a compression space of a refrigerant and has a cylindrical shape, and a piston disposed in the cylinder and reciprocating along an axis of the cylinder. The cylinder includes a supply port radially passing through the cylinder, and a recess formed on an inner circumferential surface of the cylinder and communicating with the supply port. The supply port includes a first supply port and a second supply port disposed in a rear of the first supply port, and the recess includes a first recess and a second recess disposed in a rear of the first recess. The first recess and the second recess are formed in different shapes.

A lubricating oil supply apparatus may include a rotational portion that rotates together with a rotational shaft and a fixed portion that maintains a fixed location thereof and supplies oil through a space that circles with respect to a rotational center of the rotational portion, thereby supplying oil regardless of a rotational direction of the rotational shaft.

A high-pressure pump includes a pump cover, an air cylinder, a piston, a water cooling device, and a pump seat. The air cylinder is formed by a first air cylinder, a second air cylinder and a third air cylinder whose diameters are progressively reduced and that are coaxially disposed. The piston is also formed by a first piston, a second piston and a third piston whose diameters are progressively reduced and that are respectively disposed in the first air cylinder, the second air cylinder and the third air cylinder. A water cooling device is disposed between the second air cylinder and the third air cylinder.

In order to prevent working medium from accumulating in the compressor housing (2) of a piston compressor (1) in a simple manner by means of a sealing of the piston rod (7) in the form of sealing medium barrier supplied by a hydraulic unit (12), it is provided that a ventilator (32) and a sealing medium container (37), which is partially filled with sealing medium, are provided in the hydraulic unit (12), wherein the ventilator (32) suctions air from the free space of the sealing medium container (37), and the free space (45) in the sealing medium container (37) is connected via a line (15, 17) to the compressor housing (2), and an opening (16) is provided at the compressor housing (2) for connecting the interior of the compressor housing (2) to a purge gas reservoir (18).

A linear compressor is provided, The linear compressor may include a cylinder; a frame coupled to an outer side of the cylinder; a cylinder groove defined on an outer circumferential surface of the cylinder; and a sealing member provided in the cylinder groove. The sealing member may be provided between the outer circumferential surface of the cylinder and an inner circumferential surface of the frame.

A linear compressor is provided. The linear compressor may include a cylinder including a cylinder body that defines a compression space for a refrigerant and a cylinder flange that extends from the cylinder body in a radial direction; a piston that reciprocates within the cylinder in an axial direction; and a frame coupled to the cylinder. The frame may include a frame body into which the cylinder body may be inserted and a first press-fitting portion press-fitted into the cylinder flange.

A linear compressor is provided. The linear compressor may include a frame coupled to a cylinder, a gas hole defined in the frame, and a gas pocket that communicates with the gas hole and transfers a refrigerant gas to the cylinder.

A pumping system utilizes a linear actuator to move a shaft attached to two pistons within cylinders to pump a working fluid. A housing is designed with coolant passageways and one-way valves such that movement of the shaft also pumps coolant past cooling fins and over a motor. The shaft is formed of several sections joined by couplers which slide within a bore of the housing. The couplers have a non-round shape and the bore has a complimentary non-round cross section such that rotation of the shaft is prevented.

A compressor, which includes a cylinder block and a piston assembly arranged inside the cylinder block; the piston assembly comprises a first piston, a second piston arranged inside the first piston, and a movable assembly connected to the first piston, and the movable assembly is configured to drive the first piston and the second piston to reciprocate; the cylinder block is provided with a first compression chamber that defines a space for the first piston to move up and down; the cylinder block is provided with a gas storage chamber for storing the gas after the first compression, and the gas storage chamber is connected to the first compression chamber; and the cylinder block is also provided with a second compression chamber that defines a space for the second piston to move up and down, and the second compression chamber is connected to the gas storage chamber.

An eccentric sleeve for a crankshaft of a compressor, a crankshaft, a crankshaft assembly, and a compressor are provided. The crankshaft has a main shaft, a counterbalance and an eccentric shaft. The main shaft and the eccentric shaft are provided at two sides of the counterbalance and arranged eccentrically. The main shaft is internally provided with a main lubrication oil passage. An outer circumferential wall of the eccentric shaft is provided with an oil leakage hole in fluid communication with the main lubrication oil passage. The eccentric sleeve is fitted over the eccentric shaft. An outer circumferential wall of the eccentric sleeve is provided with a shaft flow hole extending through the outer circumferential wall in a thickness direction of the eccentric sleeve.