Hitachi, Ltd.

Masatoshi Muramatsu

Kensaku Oguni

Kazumoto Urata

Takao Senshu

Susumu Nakayama

Hiromu Yasuda

Hirokiyo Terada

Kenji Tokusa

Rumi Minakata

Kazutaka Suefuji

Takeshi Endo

Akira Murayama

Tetsuya Arata

Katsumi Matsubara

Riichi Uchida

Kotaro Naya

Jyoji Okamoto

Naoto Katsumata

Fumihiko Kitani

Michiko Endo

Tsuneharu Takagi

A refrigerating system having a refrigerating cycle constructed by connecting an accumulator, a refrigerant compressor, a four-way valve, an outdoor unit heat exchanger, an outdoor unit expander, a receiver, an indoor unit expander and an indoor unit heat exchanger sequentially by pipes. Normally, excessive refrigerant is stored in the receiver and when it becomes necessary to raise a ratio of lower boiling point refrigerants, a flow amount of the refrigerant is decreased by restricting the outdoor unit expander during the cooling operation or by restricting the indoor unit expander during the heating operation to move the excessive refrigerant within the receiver to the accumulator. Thereby, the composition of the refrigerant circulating within the refrigerating system using non-azeotrophic refrigerant mixtures may be changed without using a complicated system structure or control method thereof and the capacity of the refrigerating cycle may be changed.

Refrigerating system and operating method thereof

A heat-pump device indicates a weight of inappropriate amount of refrigerant in a heat-pump cycle by comparing an actual amount of refrigerant in the heat-pump cycle with an appropriate amount thereof, operates in accordance with a refrigerant amount judging operational mode when the actual amount of refrigerant is measured, and includes a judging device for judging the amount of refrigerant in the heat-pump cycle on the basis of a temperature of refrigerant at a condensor side and at least one information showing an operational condition of the heat-pump cycle.

Refrigerator and method for indicating refrigerant amount

An air-conditioner system having a compressor, a plurality of heat exchangers for heating or cooling the air in a room, a radiator for transferring heat energy of refrigerant outside of the room, a plurality of orifices, a manifold with a main port and a plurality of sub-ports, flow direction control multi-port valves directing the flow of the refrigerant from the compressor to the main port and not from the main port to the compressor when at least one of the heat-exchangers is heating the room. The refrigerant does not flow from the compressor to the radiator when at least one of the heat exchangers is heating and none of the heat exchangers is cooling. Also, it does not flow from the compressor to the main port but flows instead from the compressor to the radiator and from the main port to the compressor when none of the heat exchangers is heating and at least one of the heat exchangers is cooling. The system also employs a plurality of valve pairs each of which having a first valve and second valve such that the first valve opens (closes) when the second valve closes (opens). The first valves are arranged for providing flow of refrigerant to the inlet of the compressor from the heat exchangers and the second valves provide flow of refrigerant from the outlet port of the compressor to the respective heat exchanger first ports via the sub-ports of the manifold.

Air-conditioner system

A scroll-type fluid machine comprises a stationary scroll member, an orbiting scroll member, a rotation-prevention mechanism for the orbiting scroll member, and a casting accommodating therein both members and the mechanism. The involute angle of a terminal end of a wrap of the orbiting scroll member is selected to be less than that of the wrap of the stationary scroll member by an angle which ranges between 60.degree. and 120.degree., preferably, about 90.degree., thereby reducing a level of force applied to the rotation-prevention mechanism which prevents the orbiting scroll member from rotating about its own axis.

Scroll-type fluid machine with different terminal end wrap angles

A screw vacuum pump including a plurality of casings and a pair of rotors defining a plurality of working chambers. The working chambers are constituted by working chambers whose volumes undergo a change as the rotors rotate, and working chambers whose volumes undergo substantially no change as the rotors rotate. The screw vacuum pump is capable of achieving pressure of 10.sup.-1 to 10.sup.-4 Torr or a low or medium vacuum by means of a single pump operating in a single stage.

Screw type vacuum pump

Growing community of inventors

Shimizu, Japan

Masatoshi Muramatsu