Hitachi, Ltd.

Sigeaki Kuroda

Kensaku Oguni

Takao Senshu

Hiromu Yasuda

Masamichi Hanada

Akira Murayama

Susumu Nakayama

Masakatsu Hayashi

Katsuaki Kikuchi

Shinjiro Ueda

Akira Arai

Masato Itagaki

Hirokiyo Terada

Toshiaki Koyama

Yasushi Izunaga

Makoto Nagai

Fumio Yoshinaga

Rumi Minakata

Yasuro Ohishi

Mineo Takahashi

Shintaro Sado

Eiji Maeda

Hironori Etou

Toshio Hirai

Tadao Ochiai

Tadashi Fukuishi

Shouji Kikuchi

Isamu Horiuchi

Yutaka Mori

Kimito Kasukabe

Yuji Tsujita

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

An air conditioner comprising a compressor, a four-way directional control valve, an outdoor heat exchanger, and a plurality of indoor heat exchangers, which are arranged to enable the cooling/heating combined operation. The air conditioner further comprises a first connecting pipe bypassed from a piping line, which is adapted to feed a compressed coolant from the compressor toward the outdoor heat exchanger, for line communication with at least one indoor unit, and a second connecting pipe bypassed from a piping line, which is adapted to feed the compressed refrigerant from the compressor toward at least one indoor heat exchanger, for line communication with the outdoor heat exchanger.

Air conditioner and operating method thereof

An air conditioner includes a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger which are connected via pipings to form a heat pump type refrigerant circuit, the four-way valve being switched over to select a heating or cooling mode of operation. This air conditioner is further provided with a first and second branch pipes which extend from an outlet conduit of the compressor, the first branch pipe forming a first bypass pipe connected to an inlet conduit of the compressor. The first and second branch pipes have first and second valves, respectively. The air conditioner is also provided with a microcomputer for selectively opening and closing the second valve in response to the degree of superheating of discharged gaseous refrigerant after the first valve has been opened so that the discharged gaseous refrigerant is supplied to the outdoor heat exchanger to effect a defrosting operation while a heating operation is continued. When the degree of superheating of discharged gaseous refrigerant is low, a part of discharged gas is supplied to the inlet conduit so as to regulate the degree of superheating.

Defrosting of refrigerator system out-door heat exchanger

An impeller of a centrifugal blower includes a hub, a hub plate, a plurality of blades and a shroud. The hub plate has an outer diameter which is smaller than an inner diameter of the shroud and a portion of the blades existing in the difference between the diameters is provided with a parting plane of molds, whereby the impeller can be integrally molded by the injection molding.

Impeller of centrifugal blower

A centrifugal blower including a casing formed with a discharge port and a suction port, and an impeller mounted in the casing and having a plurality of backwardly curved vanes arranged circumferentially of the impeller. The suction port has a semicircular suction member located in spaced juxtaposed relation to a semicircular curled portion formed at the forward end of a shroud of the impeller. An annular guide plate may be attached to the inner side of the suction member and formed at its open end with a wall portion disposed along the shroud which is formed at its forward end with an annular wall extending into a space defined between the suction member and the guide plate. Hair may be provided on one of opposed wall surfaces of the suction member and the annular wall of the shroud.

Blower

A heat pump type refrigeration system for air conditioners. The system has a heat pump type refrigeration circuit including a compressor the suction side and discharge side of which are switchably connected to an indoor heat exchanger and an outdoor heat exchanger through a four-way valve. The other sides of the heat exchangers are connected to each other through a first pressure reducer, gas-liquid separator and a second pressure reducer. A refrigerant tank is disposed in a pipe interconnecting the four-way valve and the indoor heat exchanger, in a heat exchanging relation to the pipe. The gas-liquid separator is connected at its upper portion to the refrigerant tank. The heat pump type refrigerant circuit confines a bi-component refrigerant consisting of two refrigerants of different boiling temperatures.

Heat pump type refrigeration system

Growing community of inventors

Shimizu, Japan

Sigeaki Kuroda