Lubricating oil has a kinematic viscosity in a range of 1 mm.sup.2/S to 7 mm.sup.2/S at 40° C., has a mass average molecular weight in a range of 150 to 400, and contains 0.5% by mass or more of a high molecular weight component. The high molecular weight component has a mass molecular weight of greater than or equal to 500. A crankshaft serving as a shaft part of a compression element includes a main shaft that includes a sliding surface. In a case where the sliding surface is a single sliding surface, a length of the single sliding surface in an axial direction is a single sliding length L, whereas in a case where the sliding surface is divided into a plurality of sliding surfaces, a length of one of the sliding surfaces in the axial direction, the one sliding surface having a least length in the axial direction among the plurality of sliding surfaces, is the single sliding length L, and a ratio L/D of the single sliding length L to an external diameter D of the main shaft is less than or equal to 2.0.

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 system includes a dynamic compressor and a controller having a processor and a memory. The compressor includes a first compressor stage having a first variable inlet guide vane (VIGV) and a second compressor stage having a second VIGV. The memory stores instructions that program the processor to operate the compressor at a current speed, a first position of the first VIGV, and a second position of the second VIGV to compress the working fluid, and to determine if a condition is satisfied. If the condition is not satisfied, the processor is programmed to continue to operate the compressor at the current speed, the first position of the first VIGV, and the second position of the second VIGV. If the condition is satisfied, the processor is programmed to change the second position of the second VIGV to a third position and maintain the first position of the first VIGV.

According to one embodiment, a refrigeration cycle apparatus includes a motor which including a plurality of phase windings in a mutually unconnected state, a first inverter which controls application of electric power to one ends of the phase windings, a second inverter which controls application of electric power to the other ends of the phase windings, switches connected between the other ends of the phase windings, and a motor controller which selectively sets one of an open-windings mode and a star-connection mode. The motor controller sets, at the time of startup of the motor, the open-windings mode.

A rotary compressor of an embodiment has a rotating shaft, an electric motor, a compression mechanism, a balancer, and a balancer cover. The compression mechanism has a cylinder, a main bearing, and a sub-bearing. The balancer is provided on the rotating shaft on a second side of the sub-bearing in an axial direction thereof. The balancer cover covers the balancer. A lubricating oil supply path that opens on a second side end face in the axial direction is provided in the rotating shaft. A supply hole that allows the supply path to communicate with the outside of the balancer cover is formed in the balancer cover at a position facing the supply path in the axial direction. A seal mechanism that seals between the balancer cover and the rotating shaft is provided between the balancer cover and the rotating shaft while allowing relative movement between the balancer cover and the rotating shaft in the axial direction.

This disclosure relates to a compressor having a shaft, wherein the shaft is hollow to define a fluid passage extending along the shaft and a motor arranged along the shaft. A motor cooling line is configured to convey a cooling fluid to the motor, wherein the motor cooling line is fluidly connected to the fluid passage. The compressor may be a refrigerant compressor used in a heating, ventilation, and air conditioning (HVAC) chiller system.

A compressor including a housing, and a motor including a stator to be interference fitted into and fixed to an inner circumferential surface of the housing and a rotor rotatable inside the stator. The stator includes an annular back yoke disposed inside the housing, a plurality of teeth extending radially inward from the back yoke, and a coil wound on the plurality of teeth. The back yoke includes a deformation portion compressed and deformed by the housing while the stator is interference fitted into the inner circumferential surface of the housing, a contact portion which protrudes radially outward from the deformation portion and being in contact with the housing, and a cavity formed on a radial inner side of the deformation portion into which the deformation portion is deformed.

Thermal management systems include an open-circuit refrigeration system featuring a receiver configurable to store a refrigerant fluid, an evaporator configurable to extract heat from a heat load when the heat load contacts the evaporator, and an exhaust line, where the receiver, the evaporator, and the exhaust line are connected to form a refrigerant fluid flow path, and a first control device configurable to control a vapor quality of the refrigerant fluid at an outlet of the evaporator along the refrigerant fluid flow path.

Thermal management systems include an open-circuit refrigeration system featuring a receiver configurable to store a refrigerant fluid, an evaporator configurable to extract heat from a heat load when the heat load contacts the evaporator, and an exhaust line, where the receiver, the evaporator, and the exhaust line are connected to form a refrigerant fluid flow path, and a first control device configurable to control a vapor quality of the refrigerant fluid at an outlet of the evaporator along the refrigerant fluid flow path.

A single-stage enthalpy enhancing rotary compressor and an air conditioner having same. The single-stage enthalpy enhancing rotary compressor includes: at least one single-stage cylinder, a rotator, an upper flange, and a lower flange. The rotator is arranged inside the cylinder and is rotatable, a compression chamber is formed between the rotator and an inner peripheral wall of the cylinder, a vapor injection opening is defined in at least one of the upper flange the lower flange, and the vapor injection opening is configured to supply gas outside the compressor to the compression chamber directly. According to the present disclosure, two-stage compression is realized without adding an extra cylinder, thereby effectively enhancing a circulation of refrigerant, improving cooling performance of the air conditioner under high environmental temperatures.