Daikin Industries, Ltd.

Dalkin Industries, Ltd.

Tetsuo Nakata

Yasuto Yanagida

Sumikazu Matsuno

Yoshiyuki Ochi

Kazuhiro Furusho

Takahiro Yokoyama

Atsushi Suhara

Takashi Hirouchi

Takayuki Miyajima

Takayuki Takahashi

Toshihiro Susa

Fumiaki Yakushiji

Yasutoshi Mizutani

Keisuke Kudou

Yukio Nishihama

Junpei Yamamoto

Yuzo Sawada

Junichi Miyagi

A motor drive apparatus includes a motor, a power converter, and a controller that controls the voltage supplied to the motor by the power converter. The power converter converts a voltage of a 400 V-class AC power supply to a voltage with an effective value lower than an effective value of the 400 V-class AC power supply. The power converter converts the voltage by a switching operation of a plurality of switching elements. The motor is configured so that a value of &#x3c6;&#xd7;Vx/Ld is greater than Pmax when an effective value voltage Vx=200 V. A d-axis inductance of the motor is Ld. A flux linkage of the motor is &#x3c6;. A maximum output of the motor in a device where the motor is mounted is Pmax. The controller has a control mode in which an effective value voltage higher than Vx is applied to the motor.

Motor drive apparatus and cooling apparatus

An oil-hydraulic unit includes a power module generating heat when energized. The power module is provided on the bottom surface of a recess facing hydraulic oil in a tank. Thus, the power module is cooled by the hydraulic oil in the tank. This reduces the difference in temperature between the power module and the hydraulic oil in the tank. In the oil-hydraulic unit, the temperature sensor detects the temperature of the power module. The oil temperature in the tank is estimated based on the temperature detected by the temperature sensor.

Hydraulic unit

A current detector and a voltage detector respectively detect a current value and a voltage value outputted from an engine generator. An operating block determines a weight constant on the basis of the current value and the voltage value, weights the operating time of an engine by using the weight constant, and integrates the weighted operating time to calculate an integral time. A judging block compares the integral time and a reference time, and gives a notification to an indicator when it judges that the integral time exceeds the reference time. Receiving the notification, the indicator makes an external indication. The current detector and the voltage detector can be made of electric circuitry, so that the life of the engine can be predicted at low costs and with high reliability.

Engine life predicting apparatus and refrigerating apparatus

In a positioning apparatus (), a fixed scroll () is positioned with respect to an assembly body () in which a compressor motor () has been incorporated. In positioning the fixed scroll (), electric power is supplied to the compressor motor () from an inverter () to rotate a crank shaft () by the compressor motor (), thereby shifting a movable scroll (). In the positioning apparatus (), the shift of the movable scroll () leads to calculation of an appropriate position of the fixed scroll (). A striking unit () applies impact force to the fixed scroll () to stir the fixed scroll () to the appropriate position.

Fixed scroll positioning apparatus and fixed scroll positioning method

A trailer refrigeration system comprising: an electricity generator (); an electricity-generator engine () for driving the electricity generator (); a converter () for converting ac electric power generated by the electricity generator () into dc electric power; an inverter () including inverters (), (), () each for converting dc electric power from the converter () into ac electric power; a refrigerant circuit () having an electric compressor () and a fan () including fans (), (), the electric compressor (), the fan (), and the fan () being driven respectively by ac electric power from inverters (), (), (); and a control means () for individually controlling the speed of rotation of the electric compressor (), the fan (), and the fan ().

Trailer refrigeration system

Capacitors act as bootstrap capacitors of a high side control circuits. The capacitors are charged in a period in which all of high arm switching devices are non-conductive, so-called in a precharge period. When any of U-phase current, V-phase current and W-phase current is smaller than a negative predetermined value (when an absolute value is larger), it is judged which is the largest value. The low arm switching device is turned on only for a phase corresponding to the current of the largest value and the low arm switching devices of other phases are turned off.

Polyphase inverter, control method thereof, air sending device and polyphase current output system

A pump driving apparatus has a characteristic changing section which receives a set pressure, a set flowing amount, a set horse power, and a DC voltage of the converter section as input, outputs modified values of pressure, flowing amount, and horse power, and supplies the modified values to the horse power command generation section. Therefore, the motor can be driven to suit the change in power voltage so that the motor capacity can be utilized sufficiently.

Pump driving method and device therefor

An apparatus for warm up control of an autonomous inverter-driven hydraulic unit has a warm up control section and a switch section. The warm up control section performs a predetermined process using a current speed and current pressure as input information and outputs a first switch command. The switch section is controlled by the first switch command so as to control on/off of power supplied to a fan motor. The apparatus causes an oil temperature to quickly rise to a level where a hydraulic unit driven by a hydraulic pump can work in an optimum condition.

Method and apparatus for warm up control of autonomous inverter-driven hydraulic unit

In an oil conditioner comprising: a coolant oil circulation circuit ( ) through which a coolant oil of a machine tool ( ) is circulated by an oil pump ( ); a refrigeration circuit ( ) formed by interconnecting, in the order given, a compressor ( ), a condenser ( ), a pressure reducing mechanism ( ), and an evaporator ( ) for cooling the coolant oil in the coolant oil circulation circuit ( ) by heat exchange with refrigerant; and an inverter ( ) for controlling the operating frequency of a motor ( ) of the compressor ( ), the output from the inverter ( ) is switched to a motor ( ) of the oil pump ( ) during the time the compressor ( ) is out of operation so that the amount of coolant oil that the oil pump ( ) circulates is made variable, and the amount of coolant oil that the oil pump ( ) circulates is reduced when the amount of heat produced in the operation of the machine tool ( ) decreases because, for example, the machine tool ( ) is stopped, for reducing wasteful consumption of energy by the oil pump ( ). Energy savings are achieved through the oil pump ( ).

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Kusatsu, Japan

Tetsuo Nakata