A hermetic compressor includes an electric motor element driving a compression element that includes a crankshaft including a main shaft, an eccentric shaft, and a flange, a cylinder block having a cylinder bore, and a piston configured to reciprocate in the cylinder bore. The crankshaft further includes a communicating oil supply passage provided in the flange, a main shaft oil supply passage, and an eccentric shaft oil supply passage.

A closed compressor is provided with a flexible oil fence, of which a fixed portion as one end is fixed onto an upper surface of a cylinder between a shaft and a cylinder head and a free end as the other end extends toward an upper inner surface of a closed container. According to this configuration, a collision sound can be prevented from being generated even when the oil fence collides with the upper inner surface of the closed container and hot oil can be prevented from flowing along a surface of suction muffler.

A compressor includes a closed container housing a compression element driven by the shaft of a motor. The compression element includes a first and second bearings supporting first and second shaft portions, and at least one cylinder having at least one cylinder chamber disposed between the first and second bearings. At least one roller is fitted to the shaft in the at least one cylinder chamber. The first bearing is disposed closer to the motor than the second bearing. The first and second bearings have first and second annular grooves opened to the at least one cylinder chamber and first and second elastic portions provided in first and second opposing surfaces, respectively. A diameter of the second shaft portion is smaller than a diameter of the first shaft portion. A rigidity of the second elastic portion is smaller than a rigidity of the first elastic portion.

A lubricating oil supply apparatus having a structure in which a valve is forced in a direction for opening a bypass hole by a centrifugal force, and a spring presses the valve in a direction in which the valve closes the bypass hole. When the above-described structure is applied to an oil pump in which an oil (lubricating oil) supply amount increases in proportion to an operation speed, it is possible to secure a sufficient oil (lubricating oil) supply amount in a low speed operation mode, and prevent oil from being supplied more than necessary in a high speed operation mode.

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 compressor includes a casing having a cylindrical barrel, a compression mechanism, and an electric motor. The electric motor has a tubular stator, and a rotor disposed inside the stator. The stator has a back yoke forming an outer peripheral portion of the stator, a plurality of teeth extending radially inward, and slots. A fluid passage extends between an outer peripheral surface of the stator and an inner peripheral surface of the barrel. The fluid passage has a plurality of wide portions arranged in a circumferential direction of the stator, and a narrow portion provided between adjacent ones of the wide portions. The narrow portion has a smaller radial width than each of the wide portions. Each wide portion is provided in the outer peripheral surface of the stator and between a core cut having a recessed groove shape between the slots and the inner peripheral surface of the barrel.

A hermetic compressor includes an airtight case a lower portion of which oil is stored in; a frame received in the airtight case; a compression mechanism disposed in the frame and to compress a refrigerant; a motor mechanism including a stator fixed to the frame and a rotor to rotate inside the stator; a rotation shaft coupled to the rotor and provided with a cavity at a lower portion of the rotation shaft, wherein the rotation shaft rotates together with the rotor and operates the compression mechanism; a stationary shaft inserted into the cavity of the rotation shaft, fixed to the airtight case, and provided with a helical groove formed on an outer circumferential surface; and an oil raising member fixed to the cavity of the rotation shaft and configured to surround the stationary shaft. The oil raising member raises the oil stored in the airtight case.

A closed compressor is provided with a flexible oil fence, of which a fixed portion as one end is fixed onto an upper surface of a cylinder between a shaft and a cylinder head and a free end as the other end extends toward an upper inner surface of a closed container. According to this configuration, a collision sound can be prevented from being generated even when the oil fence collides with the upper inner surface of the closed container and hot oil can be prevented from flowing along a surface of suction muffler.

The present invention refers to a crankshaft (1) for an alternative compressor comprising a main shaft (21) connected to an eccentric pin (2) by means of a peripheral flange (3) containing a lubricating hole (24) extending through said eccentric pin (2) and through at least part of the body of main shaft (21), one of the edges of said hole (24) being on the cylindrical surface (2a) of said eccentric pin (2). With this type of hole, the present invention allows for the use of shafts having extremely low diameters (and, as result, with low viscous loss), even with high eccentricities, whereby an excellent capacity of oil pumping and mechanical strength is maintained.

A reciprocating compressor is provided. The reciprocating compressor includes a case containing an oil reservoir, a motor including a stator disposed inside the case and a rotor that rotates with respect to the stator, a drive shaft that rotates integrally with the rotor and including a cavity formed at a lower portion thereof, a primary oil pump inserted into the cavity of the drive shaft and disposed in the case, a secondary oil pump into which a lower end portion of the drive shaft is inserted and coupled to the primary oil pump, a primary oil passage formed between an inner circumferential surface of the cavity of the drive shaft and the primary oil pump, and a secondary oil passage formed around the primary oil pump between an outer circumferential surface of the lower end portion of the drive shaft and the secondary oil pump, wherein, when the drive shaft rotates, oil contained in the oil reservoir moves to an upper portion of the cavity of the drive shaft along the primary oil passage and the secondary oil passage.