Hitachi Industrial Equipment Systems Co., Ltd.

Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Home Appliance Co., Ltd.

Hitachi, Ltd.

Koshin Industries Co., Ltd.

Sun Honest Co., Ltd.

Hideharu Tanaka

Masahiko Takano

Hiroyuki Matsuda

Fusaoki Uchikawa

Mutsuo Sekiya

Hirotaka Kameya

Toshihisa Imai

Yutaka Takahashi

Yoshihiro Noguchi

Akira Iyozumi

Hiroshi Ohta

Toshihide Koda

Koji Ishijima

Norinaga Suzuki

Masakazu Hase

Akihiro Nagasaka

Yasufumi Ohata

Kenji Morita

Takashi Nakajima

Toshiyuki Ajima

Shigeyuki Yorikane

Kunihiko Kaga

Masaru Yamasaki

Masayuki Kasahara

Tetsurou Ogushi

Masaharu Senoo

Ken Morinushi

Kazumasa Kanai

Toshiyuki Toyonaga

Goro Yamanaka

Matsuo Sekiya

Takeshi Tsuchiya

Fumio Takeda

Teruo Miyamoto

Tomohiro Bessho

Shinji Urata

Yoshiyuki Taguchi

Tatsurou Yashiki

Tomofumi Okubo

Tatsuro Hirose

Takehiro Matsuzaka

Yaping Liu

Tsutomu Nozaki

Mitsuhiro Kawaguchi

Toshimitsu Iwai

Hajime Uematsu

Zhijia Ren

Ryusuke Oshiro

Nobuhiro Tottori

Mutuo Sekiya

Kensuke Kuroki

Tatsunori Nishihara

Kouji Wada

Toshimasa Hiraoka

Tsuyoshi Morii

Shingo Goto

Kohtaro Chiba

Yoshihiko Sagawa

Yoriyuki Shinada

Fusoaki Uchikawa

Hayato Adachi

Tomotake Sakaguchi

A technique is provided that can further reduce power at the time of 'unload operation control' in a gas compressor that generates a compressed gas at a set pressure by constant-speed control. The gas compressor includes a compressor main unit, a drive source, an intake throttle valve, a gas release valve, rotation speed converting means, a pressure detecting device that detects a discharge pressure, and a controller that, the relationship between an upper-limit pressure H and a lower-limit pressure L being H&#x3e;L, carries out opening the intake throttle valve and closing the gas release valve and operating the drive source at a full-load rotation speed until the discharge pressure reaches the upper-limit pressure H. The controller carries out at least one of closing the intake throttle valve and opening the gas release valve to reduce the discharge pressure to within a predetermined range when the discharge pressure reaches the upper-limit pressure H. The controller carries out switching to load operation when the discharge pressure drops to the lower-limit pressure L. In the gas compressor, the controller outputs a command of a lower rotation speed than the full-load rotation speed to the rotation speed converting means when the discharge pressure rises and reaches the upper-limit pressure H. The controller outputs a command of the full-load rotation speed to the rotation speed converting means when the discharge pressure drops and reaches the lower-limit pressure L.

Gas compressor

In an oil-cooled screw compressor, a tooth crest arc of a fixed width is provided to the tooth crest of a male tooth profile, and simultaneously a tooth bottom arc is provided to the tooth bottom of a female tooth profile. Due to the actions thereof, the operation chamber immediately before disappearing exists only in a bottom half region from a line that connects the centers of the male and female tooth profiles, and the opening area relative to the volume of the operation chamber can be increased. As a result, the discharge of oil becomes smooth and energy loss is reduced.

Oil-cooled screw compressor

A network simulation device of the present invention: accepts an input of first plane information being positional information on a network projected onto a coordinate plane having any two dimensions out of three dimensions as coordinate axes; creates network model information which defines a coordinate value of the remaining one dimension as unknown based on the accepted first plane information; accepts selection of the element having the coordinate value defined as unknown by a user from the elements which appear in the first plane information; accepts an input of second plane information being positional information on the network projected onto a coordinate plane having any two dimensions including the remaining one dimension as coordinate axes; and determines a numerical value of the coordinate value defined as unknown of the selected element in the created network model information based on the accepted second plane information.

Network simulation device, network simulation method, and network simulation program

Size reduction of a compressor and cooling of an electric motor are effectively achieved. An oilless compressor, having: a compressor main body that has a rotor for compressing air, a rotor shaft for supporting the rotor, and a bearing for rotatably supporting the rotor shaft; an electric motor for producing drive force for driving the compressor main body; at least one gear for transmitting drive force to the rotor shaft; a lubricating oil pipe for conveying lubricating oil to the bearing and/or the gear; and an oil pump for pressure-feeding the lubricating oil; wherein the electric motor has, in the external peripheral direction of an armature, a cooling jacket for channeling the lubricating oil to an internal flow channel to cool the armature of the electric motor, and the lubricating oil circulates through the cooling jacket and the lubricating oil pipe.

Oilless compressor

An oil-cooled gas compressor provided with a compressor body, an oil separator that separates out oil from a compressed gas, a gas pipe for sending the compressed gas, from which oil has been separated out by the oil separator, to a user, and an oil pipe for returning, to the compressor, the oil separated out by the oil separator. An air-cooled heat exchanger for cooling the aforementioned oil, a controllable-speed cooling fan for blowing cooling air at said air-cooled heat exchanger, and a waste-heat-recovery heat exchanger, provided upstream of the air-cooled heat exchanger, for recovering heat from the oil flowing through the abovementioned oil pipe, are also provided. The speed of the cooling fan is controlled so as to bring the temperature of the compressed gas discharged from the compressor body to within a prescribed range. It is possible both to recover waste heat from the oil heated by being used to cool the compressor and to suppress compressor temperature fluctuations, even if the load on the waste-heat-recovery equipment varies.

Oil-cooled gas compressor

In a water-supply line for performing water-supply to the rotors and the mechanical seal of a compressor, or in a condensed-water collection line for collecting condensed water of a dryer into the inlet port of the compressor, a water reservoir is provided at a position higher than the water-supply unit of the compressor. Moreover, there are provided a start-time water-supply line and a solenoid valve set up therein. Here, the start-time water-supply line establishes the connection between the lower portion of the water reservoir, and the inlet port of the compressor and the water-supply unit of the mechanical seal.

Water lubricated screw compressor

Control unit for air compressor with graphical user interface

An air compressor includes a compressor body, an electric motor, a gear mechanism, a gear casing, a partitioning wall, and a screw seal. The screw seal locates in a through hole formed to the partitioning wall, where a rotating shaft of the electric motor passes through, and makes an air flow from the electric motor side to the gear mechanism side in the through hole with rotating of the rotation shaft. The air compressor also includes a bearing that supports that rotating shaft is arranged to the gear mechanism side of the partitioning wall, such that a rotor of the electric motor has overhang structure. The air compressor also includes a communication hole that communicates the electric motor side from the screw seal of the through hole and an outside of the air compressor not through the internal space of the casing of the electric motor.

Vented motor seal for a compressor

Control unit for air compressor

An oil-cooled gas compressor provided with: a compressor body (); an oil separator () that separates out oil from a compressed gas; a gas pipe () for sending the compressed gas, from which oil has been separated out by the oil separator, to a user; and an oil pipe () for returning, to the compressor, the oil separated out by the oil separator. The following are also provided: an air-cooled heat exchanger () for cooling the aforementioned oil; a controllable-speed cooling fan () for blowing cooling air at said air-cooled heat exchanger; and a waste-heat-recovery heat exchanger (), provided upstream of the air-cooled heat exchanger, for recovering heat from the oil flowing through the abovementioned oil pipe. The speed of the cooling fan is controlled so as to bring the temperature of the compressed gas discharged from the compressor body to within a prescribed range. This makes it possible both to recover waste heat from the oil heated by being used to cool the compressor, and to suppress compressor temperature fluctuations even if the load on the waste-heat-recovery equipment varies.

Air compressor

Disclosed is a motor control apparatus for controlling a synchronous motor, which includes a receiver section for receiving the value detected by a temperature sensor installed inside the synchronous motor. The synchronous motor is started up with the current fed into it, whose magnitude is changed in accordance with the temperature received by the receiver section at the time of starting up the synchronous motor. In this way, the stable startup of the synchronous motor can be guaranteed and the useful life of the semiconductor elements can also be prolonged.

Motor controller, air compressor, air conditioner, controller of passenger conveyor and controller of conveyor

An oil-flooded screw compressor drives a pair of rotors at a rotational speed which is low enough not to increase torque for a short amount of time after start-up and accelerates the pair of rotors up to a normal-operation rotational speed after oil discharge. Alternatively, the oil-flooded screw compressor rotates the pair of rotors for a short amount of time after the remaining compressed gas is discharged after a halt, thereby allowing the oil accumulated inside the working chambers to be discharged and ensuring smooth start-up after the halt.

Oil-flooded screw compressor, motor drive system, and motor control

In an oil-cooled air compressor for controlling a temperature of a lubricant by changing a flow rate of a cooling medium supplied to a heat exchanger for the lubricant, for obtaining an energy saving effect by variable control of the flow rate of the cooling medium and preventing securely a condensed water from occurring in a compressor unit even when an exhaust duct is arranged inappropriately, a lubricant flow rate adjustor is arranged to measure a temperature of the lubricant and decreasing a flow rate of the lubricant supplied to the heat exchanger so that the lubricant temperature becomes Tto satisfy T&#x3e;T&#x2267;TD when Tis a control temperature of the lubricant and TD is a condensed water occurrence critical temperature at which a condensed water occurs in the compressor.

Oil-cooled air compressor

Oil-flooded screw compressor, motor drive system, and motor control device

Growing community of inventors

Shizuoka, Japan

Hideharu Tanaka