A method of mounting a bearing to an air compressor including a shaft element having a first end and a second is disclosed, which includes the steps of: fixing the second end of the shaft element to a center of a gear; inserting the first end of the shaft element through a central hole of a bearing to have an annular step of the shaft element abutted an inner ring of the bearing; and hitting the first end of the shaft element by a striking tool to form an expanded or flared edge on a top face of the first end of the shaft element. With the method, the bearing can be firmly fixed between the expanded or flared edge and the annular step of the shaft element.

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.

Hybrid thermodynamic compressor (8) for compressing a working fluid, the compressor comprising a volumetric cylinder (1) and a thermal cylinder (2) connected to one another mechanically by a connecting rod system (5) and pneumatically by a connecting circuit (12) optionally with a valve (4), a reversible electric machine (6), the volumetric cylinder comprising a first piston (81) that separates a first chamber (Ch1) from a second chamber (Ch2), the thermal cylinder comprising a second piston (82) which separates a third chamber (Ch3) from a fourth chamber (Ch4), which can be brought into thermal contact with a heat source (21) to thereby generate a cycled movement in the thermal cylinder, and concerning the connecting rod system (5), the first and second pistons are connected to a rotor (52) by first and second respective connecting rods (91,92), with a predetermined angular offset (θd), the volumetric cylinder being equipped with non-return valves (61,62), the power produced in the thermal cylinder being transmitted to the volumetric cylinder essentially via the connecting circuit and not via the rod system.

A crankshaft is provided. The crankshaft has a first shaft, a second shaft and a first crank arm. A first oil passage is formed in the first shaft along an axis direction of the shaft. A second oil passage is formed in the second shaft along an axis direction of the shaft. The first crank arm is configured to be connected between the first shaft and the second shaft. The first crank arm is provided with a third oil passage. The third oil passage is configured to communicate the first oil passage and the second oil passage. The second shaft is eccentrically provided relative to the axis of the first shaft. A compressor having the crankshaft and a refrigeration device having the compressor are also provided.

A hermetic compressor includes: a compression unit; a motor unit; a crankshaft that connects the motor unit and the compression unit; and a bearing member provided with a shaft receiving hole so as to support the crankshaft in a radial direction. An oil supply groove that defines a part of an oil supply passage is formed on an outer circumferential surface of the crankshaft, and the oil supply groove is provided between the outer circumferential surface of the crankshaft and an inner circumferential surface of the bearing member facing the outer circumferential surface of the crankshaft to be located out of pressed regions generated when the crankshaft rotates. As the oil supply groove that supplies oil to a bearing surface between the crankshaft and a main bearing is formed by avoiding the pressed regions, oil may be smoothly supplied to the bearing surface.

A multi-stage electric gas pump includes a driving mechanism and an eccentric shaft including a main body having a longitudinal axis, a first eccentric portion, and a second eccentric portion, wherein the first eccentric portion and the second eccentric portion are fixed on the main body. The eccentric shaft is driven by the driving mechanism to produce a first circular movement of the first eccentric portion around the longitudinal axis and a second circular movement of the second eccentric portion around the longitudinal axis, wherein the second circular movement is synchronized with the first circular movement. The multi-stage electric gas pump further includes a first cylinder, a second cylinder, and a third cylinder. The cylinders in three stages are driven by the eccentric shaft so as to achieve three-stage pressurization of gas.

An internal combustion engine system includes a reciprocating compressor for pressurizing a fluid medium and having a compressor cylinder for accommodating a compressor piston. The compressor cylinder has a main cylinder volume and a secondary adjustable volume in fluid communication with the main cylinder volume so as to provide a variable geometrical compression ratio.

A multi-stage compressor for compressing a fluid, the compressor comprising two or more cylinders each having a compression chamber and a piston, so that a fluid in each of the compression chambers can be com-pressed by the associated piston; the cylinders being connected in series such that a fluid entering an inlet of the compressor can be compressed to a first pressure in the compression chamber of a first cylinder and, then, enter into the compression chamber of a second cylinder where the compressed fluid is compressed to a second higher pressure and, before the fluid exits from an outlet of the com-pressor; wherein each piston is driven by one and the same crankpin of the compressor. Furthermore, a method for compressing a fluid, and a system for comprising the multi-stage stage compressor are disclosed.

Various embodiments of the present disclosure are directed to packing rings. In one example embodiment, a packaging ring is disclosed including a first axial ring end, a second axial ring end, at least three ring segments, a radial seal and at least one relief opening. Each of the at least three ring segments having a first segment end and a second segment end in a circumferential direction. A first segment end of one of the three ring segments including a first tangential contact surface and a first axial contact surface, the first axial contact surface facing towards the first axial ring end. A second segment end of another of the three ring segments including a second tangential contact surface and a second axial contact surface, the second axial contact surface facing towards the second axial ring end.

A hermetic compressor may include a frame, a crankshaft, and an oil pump. The crankshaft may be rotatably mounted to the frame. The oil pump may be mounted to a lower portion of the crankshaft to be rotatable together with the crankshaft. The oil pump may pump oil from a lower region to an upper region of a shell using centrifugal force. The crankshaft may be provided with a hollow hole therein that is inclined in two directions with respect to an axial direction of the crankshaft. This may result in increasing a dynamic pressure for scattering the oil to the upper region of the shell and an oil supply amount.