Hitachi, Ltd.

Hatachi Ltd

Shintaro Sado

Yasushi Izunaga

Norihide Saho

Akira Murayama

Susumu Harada

Takeo Nemoto

Hiroaki Kuno

Toshiaki Koyama

Sigeaki Kuroda

Sachihiro Yoshimatsu

Fumio Yoshinaga

Tadashi Takada

Toshio Hirai

Tadao Ochiai

Tadashi Fukuishi

Shouji Kikuchi

A scroll type compressor having a pair of scroll type compression units which are encased in the same casing so as to make a common use of a lubricating oil reservoir provided in the casing, wherein the compression units have compression elements, drive shafts, driving motors and other components which are of the same constructions and specifications, and wherein each of the compression units are adapted to be driven selectively by commercial electrical power or through a frequency-variable inverter so as to operate at different speeds. Since both compression units can be made up from the same components such as the compression elements, loads in the production, service and administration, are greatly reduced contributing to a reduction in the labor and cost, while eliminating any mounting error. Various operation patterns are obtainable by selecting the combination of the direct commercial power and the power supplied through the inverters, so as to provide delicate control of refrigeration capacity over a wide range in accordance with the level of the load demand. Common use of the lubricating oil reservoir by both compression units eliminates necessity for specific measure for preserving oil levels equally for both compression units.

Scroll type compressor and refrigeration cycle using the same

A compressor unit in which the oil separated by a plurality of oil separators to a gas suction side pipe of the previous stage oil separator which contains gas whose oil concentration is higher than that of the gas from which oil has been separated, with the separated oil being returned to a compressor. The plurality of separators enables a simplification of the arrangement of the oil returning pipe, a prevention in a reduction in the discharge flow rate of the compressor, and reduction in space required for the separators.

Compressor unit and separator therefor

In a scroll compressor, an open end of an oil extraction pipe which is placed in oil stored in a bottom portion of a hermetic casing is positioned at a location higher than an open end of an oil suction pipe that opens in the same stored oil, and a thermostat is provided for sensing a temperature rise of a compressed gas to cause the compressor to be stopped. Accordingly, even when an amount of oil injected into the compressed gas decreases, an amount of oil necessary for lubrication of a bearing portion is assured. The provision of the thermostat enables the compressor to be stopped before an amount of supply of the lubrication oil to the bearing portion has decreased. It is, accordingly, possible to positively prevent burning of the bearing portion of a crankshaft.

Mechanism for prevention of burning of bearing portions in a hermetic

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Shimizu, Japan

Shintaro Sado