Daikin Industries, Ltd.

Satoshi Ishikawa

Takahiro Yamaguchi

Eiji Kumakura

Kazuhiro Furusho

Takeshi Hikawa

Masanori Masuda

Masahiro Yamada

Toshiyuki Maeda

Katsumi Sakitani

Masahide Higuchi

Kazutaka Hori

Yasuto Yanagida

Sumikazu Matsuno

Toshiaki Yoshii

A compressor () is provided with compression mechanisms () to have four compression chambers () in total. In the compressor (), the first compression chamber () and the second compression chamber () differ in the phase of capacity changing cycle from each other by 180&#xb0; and the third compression chamber () and the fourth compression chamber () also differ in the phase of capacity changing cycle from each other by 180&#xb0;. In a cylinder nonoperating mode, refrigerant is compressed in a single stage in each of the first compression chamber () and the second compression chamber () while the refrigerant compression operation is halted in the third compression chamber () and the fourth compression chamber (). In a two-stage compression mode, refrigerant compressed in a single stage in each of the first compression chamber () and the second compression chamber () is further compressed in the third compression chamber () and the fourth compression chamber ().

Refrigeration system

To reduce a leakage current when a motor for driving a compressor is energized, with the compressor unoperated. Setting the carrier frequency of an inverter at a value lower than that used during normal operation to cause phase interruption electrification of the motor.

Method of preheating inverter-driven compressor and device therefor

A hermetic compressor is disposed with an annular motor stator, a motor rotor, a casing and plural spot joining portions. The motor rotor is disposed such that it may freely rotate in a space inside the motor stator. The casing includes a cylindrical portion. The cylindrical portion houses the motor stator and the motor rotor. The plural spot joining portions fix the motor stator to the cylindrical portion by spot joining in a state where a clearance is secured between the motor stator and the cylindrical portion.

Hermetic compressor with spot joining portions fixing a motor stator to a cylindrical portion of a casing where a clearance is secured therebetween

Resistance of the coil of a DC motor is calculated by using the motor current and the motor voltage, and the coil temperature is estimated by using the resistance-temperature characteristics of the coil.

Method for estimating DC motor coil temperature, DC motor control method and their devices

Growing community of inventors

Osaka, Japan

Satoshi Ishikawa