Hitachi, Ltd.

Hitachi Metals, Ltd.

Akihiko Ishiyama

Hiroaki Hata

Tadashi Iizuka

Hideki Nakamura

Hirokatsu Kohsokabe

Shoichi Nakashima

Hideki Yazawa

Isao Hayase

Shigeru Machida

Yozo Nakamura

Akira Arai

Kazushi Fukuda

Kenichi Oshima

Tunehiro Endo

Ken'ichi Kawashima

Naoyuki Tanaka

Masahiko Gommori

Kazuo Sekigami

Takeshi Kouno

Kazuo Ikeda

Koichi Sato

Yoshihisa Uneyama

Toshiki Yoshida

Fujio Yamane

Keiji Yamasaki

Takahiro Kaneko

Katsutoshi Shinohara

Takeoshi Katoh

A compressor includes a compression chamber for compressing working fluid within an inside thereof, a discharge port, through which the working fluid flows out from the compression chamber, and a discharge valve for opening or closing the discharge port. The discharge valve includes a valve seat portion provided in the discharge port and having a tapered surface, so that a cross-section area of the discharge port comes to be large from a side of the compression chamber. The valve has a projection portion having a tapered surface in contact with the tapered surface of the valve seat portion. A spring is provided on a member formed in one body with the valve seat portion, for positioning the valve to the valve seat portion, wherein clearance volume of the discharge port is reduced, so as to improve the performances thereof.

Compressor including tapered discharged valve and valve seat

A compressor comprising a roller made of a cast iron which has a hardness of HRC 50 or more after heat treatment, and contains not less than 5 area % of graphite, and not less than 2 area % of crystallized eutectic structure including iron phosphide, and either a vane made of a material which has a hardness of HRC 70 or more after heat treatment and contains not less than 25 area % of undissolved carbides and nitride particles in total, the undissolved carbides including not less than 10 area % of MC type carbides, the nitride particles including at least one of TiN and NbN of not less than 5 area %, the undissolved carbides and the nitride particles having a mean grain size of not more than 5 .mu.m, or a vane made of a material including at least one of TiN and NbN particles of not less than 5 area %, the TiN and NbN particles having a mean grain size of not more than 5 .mu.m, the material essentially consisting of, by weight, 2.0 to 4.0 % of C, not more than 2.0 % of Si, not more than 1.5 % of Mn, 2.5 to 8.0 % of Cr, 20 to 40 % of W+2Mo, 3.0 to 15 % of V, not more than 15 % of Co, and the balance of Fe, the material having a hardness of HRC 65 or more after heat treatment.

Rotary type compressor

A refrigerator comprises a compressor for compressing and discharging a coolant, a first heat exchanger which performs heat exchange between the compressed coolant from the compressor and the atmosphere to cool the compressed coolant, an adiabatic expansion orifice where the compressed and cooled coolant after passing the first heat exchanger is adiabatically expanded, and a second heat exchanger which performs heat exchange between the adiabatically expanded coolant and the air in refrigerating chambers so as to cool the air in the refrigerating chambers by the coolant and to heat the coolant by the air in the refrigerating chambers. The refrigerator further includes a third heat exchanger which performs heat exchange between water produced when frost attached on the refrigerating chambers is melted and the compressed coolant discharged from the compressor so as to heat and evaporate the water, and a fourth heat exchanger which performs heat exchange between the compressed coolant and the atmosphere so as to cool the compressed coolant. The third heat exchanger and the fourth heat exchanger are connected in series so that the compressed coolant discharged from the compressor is supplied to the first heat exchanger after it passes and is cooled by both the third and fourth heat exchangers.

Refrigerator

A rotary compressor has a compression chamber defined by a rolling piston which is eccentrically rotated in a cylinder by a rotary shaft including an eccentric crank portion, and by a blade which slides in a groove formed in the cylinder and of which the tip contacts an outer-peripheral surface of the rolling piston. In such a rotary compressor, abnormal wear in the contact portion between the rolling piston and the blade can be prevented as follows: Assuming that the rotation angle of the rolling piston when the blade is located at a start position of reciprocating motion is zero degrees, the contact surface of the blade which is in contact with the rolling piston is formed to have a curvature of substantially zero and as a flat surface when the rotation angle of the rolling piston is about 90 degrees and about 270 degrees and the pressing force of the blade with respect to the rolling piston reaches the maximum value; and also, a material which has an elastic modulus lower than that of the material of the rolling piston which is highly self-lubricative is used for the blade.

Rotary compressor and blade tip structure

A roller of a rotary type compressor is made of an iron base alloy essentially consisting of 2.0 to 3.9% carbon, 2.0 to 3.0% Si, 0.3 to 1.0% Mn, up to 0.10% S, more than zero and not more than 0.50% V, 0.3 to 1.0% P, 0.01 to 0.5% Sb, and balance of Fe and incidental impurities. Preferably, the iron base alloy further includes 0.001 to 0.5% B. This roller is suitable when hydrofluorocarbon is used as a refrigerant.

Iron-base alloy for rotary type compressors

A motor-driven compressor used as a compressor or high-pressure gas generator for a refrigerating cycle, in which the output torque of the electric motor for driving the compressor is controlled so as to make the output torque agree with the load torque required for performing compression in any revolutional angular position of the driving main shaft to thereby reduce revolutional torsional vibrations caused by disagreement between the load torque and the output torque.

Motor-driven compressor provided with torque control device

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Tochigi, Japan

Akihiko Ishiyama