A scroll compressor includes an oil circulation pipe having one end inserted through a casing to be connected to an oil storage space inside the casing and another end connected to a suction passage for supplying refrigerant from outside of the casing to a compression chamber, an oil circulation valve disposed between the both ends of the oil circulation pipe to selectively open or close the oil circulation pipe, and a controller to control an opening or closing operation of the oil circulation pipe to reduce or eliminate frictional loss due to a shortage of oil by adjusting an oil level of the oil storage space at an initial operation.

The present invention provides a compressor for refrigeration and air conditioning and a refrigeration and air conditioning device capable of achieving both favorable environmental performance and favorable refrigeration cycle efficiency. In the compressor for refrigeration and air conditioning, a refrigerator oil containing a polyol ester and a refrigerant containing difluoromethane are enclosed. The polyol ester has two or more repetitions of poly[2,2-di(alkanoyloxymethyl)oxytrimethylene] as a structural unit. Further, the polyol ester is composed of only one or both of a cyclic polyol ester, which is obtained by cyclically polymerizing a molecular chain having the structural unit, and a crosslinked polyol ester, which is obtained by crosslinking molecular chains having the structural unit with each other through a crosslinkable structural unit polymerized with the structural unit.

A downhole-type device includes an electric machine. The electric machine includes an electrical rotor configured to couple with a device to drive or be driven by the electric machine. An electrical stator surrounds the electric rotor. The electric stator includes a seal configured to isolate stator windings from an outside, downhole environment. An inner surface of the seal and an outer surface of the electric rotor define an annulus exposed to the outside environment. A bearing couples the electric rotor to the electric stator. A lubrication system is fluidically coupled to the downhole-type device. The lubrication system includes a topside pressure pump and a downhole-type distribution manifold configured to be used within a wellbore. The distribution manifold is fluidically connected to the topside pressure pump and the bearing to receive a flow of lubricant from the topside pressure pump.

A gas-side stop valve on the gas refrigerant side and a liquid-side stop valve on the liquid refrigerant side are provided in a package of an outdoor unit. A gas-side filter on the gas refrigerant side is mounted on the indoor unit side relative to the gas-side stop valve and inside the package of the outdoor unit. A liquid-side filter 9 on the liquid refrigerant side is mounted on the indoor unit side relative to the liquid-side stop valve and inside the package of the outdoor unit. As a result, it is not necessary to ensure a place for mounting the gas-side filter and the liquid-side filter at the time of installation on site and the workability can be improved.

A subcooler is made up of a plate type heat exchanger. The accumulator is located between a compressor and the subcooler in a width direction of an outdoor unit in a planar view. The subcooler overlaps with the accumulator in the width direction in the planar view. As a result, a compact heat pump can be provided when the subcooler is a plate type heat exchanger.

An outdoor unit of the heat pump includes a compressor, an oil separator provided in a discharge path of the compressor, an outdoor-unit connecting pipe connecting an intake path of the compressor and an outdoor unit of an another heat pump for supplying a refrigerant to the outdoor unit of the another heat pump, an oil supply pipe extending from a predetermined position of the oil separator and connecting to the outdoor-unit connecting pipe, an on-off valve provided on the oil supply pipe, an expansion valve provided in a portion of the outdoor-unit connecting pipe between a connecting part connected to the intake path and a connecting part connected to the oil supply pipe, and a refrigerant filling port provided in a portion of the outdoor-unit connecting pipe between the connecting part and the expansion valve.

A compressor may include a shell, a compression mechanism, first and second temperature sensors, and a control module. The shell may define a lubricant sump. The compression mechanism may be disposed within the shell and may be operable to compress a working fluid. The first temperature sensor may be at least partially disposed within the shell at a first position. The second temperature sensor may be at least partially disposed within the shell at a second position that is vertically higher than the first position. The control module may be in communication with the first and second temperature sensors and the pressure sensor and may determine whether a liquid level in the lubricant sump is below a predetermined level based on data received from the first and second temperature sensors.

A vacuum generation system, in particular for applications to hybrid-drive motor vehicles, comprises a vacuum pump (10) arranged to be independently driven by either an internal combustion engine (1 1) or an electric motor (12) depending on the vacuum conditions in utilizing devices (15) and the operating conditions of the internal combustion engine. A pump for use in such a system and a method of vacuum generation by using the system are also provided.

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 network device that is used in a mobile communication system that supports cellular communication in which a data path passes through a core network, and D2D communication that is direct device-to-device communication in which a data path does not pass through the core network, comprises: a control unit that sets a D2D radio resource that is ensured for the D2D communication from radio resources be available to the mobile communication system. The control unit changes an amount of the D2D radio resource such that the D2D radio resource reaches an appropriate amount.