In a hermetic refrigerant compressor, a thrust bearing (e.g., thrust ball bearing (210)) is provided on a thrust surface (136) of a main bearing (134). One end of a sliding surface of the main bearing (134), the one end being closer to a compression chamber (133) than an opposite end of the sliding surface, is a first end, and the opposite end of the sliding surface is a second end. A distance between a center axis of the compression chamber (133) and the second end of the sliding surface (sliding surface lower end (139)) of the main bearing (134) is a distance L, and a distance between the center axis of the compression chamber (133) and the first end of the sliding surface (sliding surface upper end (138)) of the main bearing (134) is a distance La. When the distance L is in a range of 38 mm to 51 mm, the distance La is less than or equal to 16 mm.

A compressor includes: a shell forming an outer portion thereof and having lower part in which an oil pan is formed to store oil; a motor provided in the shell; a compression unit provided in the shell to compress a working gas when being driven by the motor; a frame fixed to the shell and supporting the compression unit; a shaft supported by the frame, connecting the motor and the compression unit, provided to transmit a turning force of the motor to the compression unit, and including an oil passage; and an oil pump provided at lower part of the shaft to draw oil from the pan and supply the oil into the oil passage. The pump includes a bypass valve that is opened, when a pressure of oil flowing in the oil passage is higher than a threshold pressure, to return part of the oil to the pan.

According to a hermetic electric compressor of the present invention, a discharge port 66a is placed downstream of eddying flow from the joint portion 66b, a bent portion 66c is formed between the joint portion 66b and the discharge port 66a, an imaginary plumb line 66aY of an opening surface formed on the discharge port 66a is oriented to a circumferential direction of a hermetic container 10, and fluid having a small lubrication oil content is taken out from the discharge port 66a utilizing eddying flow of mixture fluid of refrigerant and lubrication oil in a gap space between a compressing mechanism 20 and a motor section 30, thereby reducing a discharge amount from the hermetic container 10.

The present invention relates to a lubricating oil transport system in a compressor, in which:

the rotating shaft (3) has at least one concavity (35) that extends over part of the rotating surface (33) in contact with the internal surface (11) of the rotor (1) and at least one restrictor hole (34) that communicates with the internal region of the rotating shaft (3) and with the concavity (35);

the rotor (1) comprises a circumferential channel (12) and at least one radial channel (13) extending through the inner wall (11) of the rotor (1);

the radial channel (13) is arranged around the circumferential channel (12);

said circumferential channel (12) and the radial channel (13) communicating with the concavity (35);

the circumferential channel (12), the radial channel (13) and the concavity (35) transport oil for cooling the upper part of the rotor (1) and the stator (2).

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 rotor has at its two axis end portions an upper large-diameter inner circumferential portion and a lower large-diameter inner circumferential portion that have inner diameters larger than the inner diameter of the axially middle portion of the rotor and are offset in the radial direction. A crankshaft has a passageway, which is formed in the crankshaft and allows refrigerant to flow therethrough, and a gas venting hole, which provides communication between the passageway and at least one discharge opening formed in the outer circumferential surface of the crankshaft. The at least one discharge opening is formed at a position facing the inner circumferential surface of the lower large-diameter inner circumferential portion 5b on the compression unit side.

A compressor includes a compression mechanism that compresses refrigerant; a main shaft that transmits a rotational driving force to the compression mechanism; a balance weight provided below the compression mechanism and integrated with the main shaft, the balance weight having a cylindrical outer peripheral surface centered at the main shaft; and an oil sump portion provided below the balance weight and stores lubricating oil to be supplied to the compression mechanism. The balance weight has an annular oil-receiving recessed portion in an upper surface, the oil-receiving recessed portion being centered at the main shaft and integrated with the balance weight. The balance weight has a hollow portion in a lower surface, the hollow portion extending in part of the lower surface in a peripheral direction around the main shaft and being integrated with the balance weight. The oil-receiving recessed portion communicates with at least part of the hollow portion.

A hermetic compressor accommodates in hermetic container (101) electric motor element (102) and compression element (103) driven by electric motor element (102). Compression element (103) includes crankshaft (110) including main shaft (115), eccentric shaft (114), and flange (116), cylinder block (111) having cylinder bore (123) passing through cylinder block (111) in a cylindrical shape, and piston (112) configured to reciprocate in cylinder bore (123). Compression element (103) also includes connecting rod (113) connecting piston (112) and eccentric shaft (114) and bearing (124) formed on cylinder block (111) for pivotally supporting a radial load that acts on main shaft (115) of crankshaft (110). Crankshaft (110) further includes communicating oil supply passage (118) provided in flange (116), main shaft oil supply passage (119) configured for communication between communicating oil supply passage (118) and cylindrical surface (115a) of main shaft (115), and eccentric shaft oil supply passage (120) configured for communication between communicating oil supply passage (118) and cylindrical surface (114a) of eccentric shaft (114).

The present invention provides a shaft-cylinder assembly for high-temperature operation comprising a pair of first and second dynamic sealing members having a helical coiled seal ring structure configured to be in contact with the shaft for providing dynamic sealing function in the cylinder; and a cylindrical cooling jacket configured to circumferentially surround the dynamic sealing members such that a cavity is defined between the dynamic sealing members inside the cooling jacket; wherein the cooling jacket comprises one or more inflow cooling channels and one or more outflow cooling channels configured to communicating with the cavity and circulating a cooling fluid through the cavity for moving heat away from the dynamic sealing members.

In the two-cylinder hermetic compressor, a first compression mechanism unit includes a first cylinder and a first piston, and a second compression mechanism unit includes a second cylinder and a second piston. A main bearing is disposed on one surface of the first cylinder, and an intermediate plate is disposed on another surface of the first cylinder. The intermediate plate is disposed on one surface of the second cylinder, and an auxiliary bearing is disposed on another surface of the second cylinder. A shaft is constituted by a main shaft portion which has a rotor attached thereto and is supported by the main bearing, a first eccentric portion having a first piston attached thereto, a second eccentric portion having a second piston attached thereto, and an auxiliary shaft portion supported by the auxiliary bearing. The diameter of the auxiliary shaft portion is set larger than the diameter of the main shaft portion.