Patents by Inventor Kenji Tojo
Kenji Tojo has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20090010776Abstract: In order to make a displacement type compressor be able to reliably start without increasing an outside diameter dimension of the compressor while using a self-start synchronous motor having high energy efficiency, the displacement type compressor according to the invention includes the self-start synchronous motor which starts as an induction-motor and performs synchronous operation by performing synchronization pull-in almost at a synchronous rotational frequency, a compression part having a compression chamber which compresses a working fluid, and a hermetic container which houses the self-start synchronous motor and the compression part. The displacement type compressor is provided with a start load reducing means which reduces a load of the compression part at startup and is placed at the compression part in the hermetic container.Type: ApplicationFiled: September 10, 2008Publication date: January 8, 2009Applicant: Hitachi Appliances, Inc.Inventors: Takeshi Tsuchiya, Yuuichi Yanagase, Kzuyuki Fujimura, Mutsunori Matsunaga, Shigekazu Nozawa, Kenji Tojo, Haruo Koharagi, Satoshi Kikuchi, Hirokatsu Kohsokabe
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Publication number: 20080304994Abstract: A scroll fluid machine is configured by engaging a fixed scroll and an orbiting scroll having spiral bodies formed on base plates. A seal member is provided between a rear surface of the orbiting scroll and a frame member arranged opposite thereto to divide a rear side chamber into an inner space and an outer space. The inner space inside the seal member is subjected to a pressure substantially corresponding to a discharge pressure, and the outer space is subjected to a pressure lower than that of an inner back pressure chamber to press the orbiting scroll against the fixed scroll. The scroll members are formed such that the width of a groove and the thickness of a tooth of the spiral body formed inside the seal member are larger than those of the spiral body formed outside the seal member.Type: ApplicationFiled: June 11, 2008Publication date: December 11, 2008Inventors: Masaru OHTAHARA, Masashi Miyake, Kenji Tojo, Kazuo Sakurai
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Patent number: 7442017Abstract: In order to make a displacement type compressor be able to reliably start without increasing an outside diameter dimension of the compressor while using a self-start synchronous motor having high energy efficiency, the displacement type compressor according to the invention includes the self-start synchronous motor which starts as an induction-motor and performs synchronous operation by performing synchronization pull-in almost at a synchronous rotational frequency, a compression part having a compression chamber which compresses a working fluid, and a hermetic container which houses the self-start synchronous motor and the compression part. The displacement type compressor is provided with a start load reducing means which reduces a load of the compression part at startup and is-placed at the compression part in the hermetic container.Type: GrantFiled: December 27, 2005Date of Patent: October 28, 2008Assignee: Hitachi Appliances, Inc.Inventors: Takeshi Tsuchiya, Yuuichi Yanagase, Kazuyuki Fujimura, Mutsunori Matsunaga, Shigekazu Nozawa, Kenji Tojo, Haruo Koharagi, Satoshi Kikuchi, Hirokatsu Kohsokabe
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Patent number: 7437882Abstract: An apparatus for driving a compressor comprises a compressor having a compression mechanism part for sucking a fluid to compress the same, and an electric motor for driving the compression mechanism part, and an inverter device for driving the electric motor at variable speeds. The electric motor comprises a self-starting type electric motor having a rotor, which comprises a cage conductor and a polarized permanent magnet, and the inverter device comprises a plurality of semiconductor switches for controlling drive frequencies of the electric motor.Type: GrantFiled: May 13, 2005Date of Patent: October 21, 2008Assignee: Hitachi Air Conditioning Systems Co., Ltd.Inventors: Mutsunori Matsunaga, Kenji Tojo, Yoshikatsu Tomita, Susumu Nakayama, Syunsuke Yasunori
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Patent number: 7438539Abstract: A hermetic type scroll compressor according to the invention includes a scroll compressor element in which an end plate of a orbiting scroll and an end plate of a fixed scroll are assembled such that they slide against each other, an electric motor element which drives the scroll compressor element, a hermetic casing housing the scroll compressor element and the electric motor element and holding lubricating oil collected at a bottom thereof, and an oil separator disposed on a discharge side of the scroll compressor element. An interior of the hermetic casing is kept at an intermediate pressure between a suction pressure and a discharge pressure. An oil return mechanism is provided, which intermittently returns lubricating oil from the oil separator to sliding parts of the orbiting scroll end plate and the fixed scroll end plate. The hermetic type scroll compressor 31 can be improved in performance and reliability while promoting cost reduction.Type: GrantFiled: March 24, 2006Date of Patent: October 21, 2008Assignees: Hitachi Air Conditioning Systems Co., Ltd, The Tokyo Electric Power Company, IncorporatedInventors: Hirokatsu Kohsokabe, Kazuto Higa, Kenji Tojo, Daisuke Kuboi
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Publication number: 20080038127Abstract: A screw compressor is for use of a screw chiller, and comprises a pair of screw rotors and a casing housing the screw rotors, a capacity control valve for varying a ratio of volume, a motor for driving the screw rotors and an inverter for varying the rotational speed of the motor. The screw compressor is controlled using rotational speed control means by the inverter and mechanical capacity control means by the capacity control valve independently or combined together according to loads. The maximum efficient point in a capacity control performed solely by the inverter is set to a rotational speed side lower than the rated operation point. In a region where the rotational speed is higher than the maximum efficient point, the inverter solely takes control from a rated rotational speed to a high rotational speed side.Type: ApplicationFiled: August 9, 2007Publication date: February 14, 2008Inventors: Ryuichiro Yonemoto, Yasuaki Iizuka, Kenji Tojo
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Publication number: 20080008614Abstract: In a horizontal type scroll compressor discharging compressed gas from a discharge pipe provided in a sealed container in which a compressor mechanism portion and an electric motor portion are stored, for preventing a refrigerator oil from flowing out of a compressor, for supplying an oil in an oil holding portion chamber to a bearing sliding portion, and for reducing an oil ascent, the horizontal type scroll compressor is provided with a support plate separating an inside of the sealed container into a first space in which the compressor mechanism portion and the electric motor portion are stored, and a second space in which the discharge pipe is provided, and a communication path communicating a bottom portion of the first space and a space above the drive shaft within the second space in a lower side of the support plate, and regulates an oil level by the communication path in the case that the oil level difference becomes large at a time of a high-speed operation.Type: ApplicationFiled: July 9, 2007Publication date: January 10, 2008Inventors: Takao Mizuno, Mutsumi Otsuka, Katsuya Ohashi, Yasushi Izunaga, Mutsunori Matsunaga, Masashi Miyake, Kenji Tojo
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Publication number: 20070231172Abstract: A scroll fluid machine comprises compression chambers defined with an orbiting scroll orbiting relative to a fixed scroll, and a back pressure chamber provided on the face opposite from a wrap of the orbiting scroll. A back pressure port is provided, which is formed in an end-plate of the orbiting scroll and connects from a compression chamber side opening opened to a compression chamber side and to a back pressure chamber side opening opened to a back pressure chamber side. The compression chamber side opening is opened and closed by an end-plate of the fixed scroll according as the orbiting motion of the orbiting scroll to perform connection and blockage of the back pressure port. The flow resistance of fluid flowing in and out between the back pressure chamber and the compression chamber is reduced and the compression efficiency and reliability are improved.Type: ApplicationFiled: January 29, 2007Publication date: October 4, 2007Inventors: Kazuyuki Fujimura, Takeshi Tsuchiya, Yuichi Yanagase, Makoto Aoki, Masashi Miyake, Mutsunori Matsunaga, Satoshi Nakamura, Masaru Ohtahara, Syuuji Hasegawa, Hiroyuki Imamura, Yoshinobu Yosuke, Kenji Tojo
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Publication number: 20060277931Abstract: A scroll back pressure chamber in a scroll compressor is composed of a space 111 filled with suction pressure (or intermediate pressure) and a space filled with discharge pressure, and the summation of the suction pressure (or the intermediate pressure) and the discharge pressure presses one of scrolls against the other of the scrolls. An injection hole, through which refrigerant in gas state or refrigerant in liquid state is injected into a compression chamber of the scroll compressor, is provided on a fixed scroll, and the gas refrigerant injection or the liquid refrigerant injection is selected and carried out according to an operating pressure ratio.Type: ApplicationFiled: June 7, 2006Publication date: December 14, 2006Inventors: Satoshi Nakamura, Mutsunori Matsunaga, Shuji Hasegawa, Kenji Tojo
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Publication number: 20060216182Abstract: A hermetic type scroll compressor according to the invention includes a scroll compressor element in which an end plate of a orbiting scroll and an end plate of a fixed scroll are assembled such that they slide against each other, an electric motor element which drives the scroll compressor element, a hermetic casing housing the scroll compressor element and the electric motor element and holding lubricating oil collected at a bottom thereof, and an oil separator disposed on a discharge side of the scroll compressor element. An interior of the hermetic casing is kept at an intermediate pressure between a suction pressure and a discharge pressure. An oil return mechanism is provided, which intermittently returns lubricating oil from the oil separator to sliding parts of the orbiting scroll end plate and the fixed scroll end plate. The hermetic type scroll compressor 31 can be improved in performance and reliability while promoting cost reduction.Type: ApplicationFiled: March 24, 2006Publication date: September 28, 2006Inventors: Hirokatsu Kohsokabe, Kazuto Higa, Kenji Tojo, Daisuke Kuboi
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Patent number: 7082786Abstract: The scroll compressor includes a scroll compression mechanism portion in combination of an orbiting scroll and a fixed scroll, a frame for supporting the compression portion, a rotary shaft fitted in the orbiting scroll, a motor portion coupled to the rotary shaft, and a hermetic chamber incorporating the above-mentioned components. Windings of a stator of a motor in the motor portion are formed of aluminum wires which are coated with fluororesin compound, that is, the aluminum wires are coated with fluororesin and is molded with a resin material. Ammonia group refrigerant is used in the scroll compressor. Further, a refrigerating system using the above-mentioned scroll compressor, is incorporated therein with a circuit for injecting ammonia group refrigerant into a compression room in the compression mechanism portion.Type: GrantFiled: September 25, 2003Date of Patent: August 1, 2006Assignee: Hitachi, Ltd.,Inventors: Shunsuke Yasunori, Kenji Tojo, Mutsunori Matsunaga
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Publication number: 20060140792Abstract: In order to make a displacement type compressor be able to reliably start without increasing an outside diameter dimension of the compressor while using a self-start synchronous motor having high energy efficiency, the displacement type compressor according to the invention includes the self-start synchronous motor which starts as an induction-motor and performs synchronous operation by performing synchronization pull-in almost at a synchronous rotational frequency, a compression part having a compression chamber which compresses a working fluid, and a hermetic container which houses the self-start synchronous motor and the compression part. The displacement type compressor is provided with a start load reducing means which reduces a load of the compression part at startup and is-placed at the compression part in the hermetic container.Type: ApplicationFiled: December 27, 2005Publication date: June 29, 2006Applicant: Hitachi Air Conditioning Systems Co., Ltd.Inventors: Takeshi Tsuchiya, Yuuichi Yanagase, Kazuyuki Fujimura, Mutsunori Matsunaga, Shigekazu Nozawa, Kenji Tojo, Haruo Koharagi, Satoshi Kikuchi, Hirokatsu Kohsokabe
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Publication number: 20050268631Abstract: An apparatus for driving a compressor comprises a compressor having a compression mechanism part for sucking a fluid to compress the same, and an electric motor for driving the compression mechanism part, and an inverter device for driving the electric motor at variable speeds. The electric motor comprises a self-starting type electric motor having a rotor, which comprises a cage conductor and a polarized permanent magnet, and the inverter device comprises a plurality of semiconductor switches for controlling drive frequencies of the electric motor.Type: ApplicationFiled: May 13, 2005Publication date: December 8, 2005Inventors: Mutsunori Matsunaga, Kenji Tojo, Yoshikatsu Tomita, Susumu Nakayama, Syunsuke Yasunori
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Patent number: 6966194Abstract: A refrigerating machine having a compressor driven by a motor. The motor incorporates an armature with an iron core having a cage type conductor and a permanent magnet which is magnetized so as to enable the motor to operate as a synchronous motor. A bypass passage is provided between a discharge side of the compressor and a suction side of the compressor, a shut-off valve is provided for opening and closing the bypass passage, a pressure detecting device is provided for detecting a discharge pressure from the compressor and a current detector is provided for detecting a value of drive current for the compressor. The shut-off valve is opened and closed in accordance with the discharge pressure and the value of the drive current.Type: GrantFiled: December 13, 2004Date of Patent: November 22, 2005Assignee: Hitachi, Ltd.Inventors: Atsuhiko Yokozeki, Susumu Nakayama, Kenji Tojo, Akira Saruta, Mutsunori Matsunaga, Satoshi Kikuchi
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Patent number: 6925824Abstract: An apparatus for driving a compressor comprises a compressor having a compression mechanism part for sucking a fluid to compress the same, and an electric motor for driving the compression mechanism part, and an inverter device for driving the electric motor at variable speeds. The electric motor comprises a self-starting type electric motor having a rotor, which comprises a cage conductor and a polarized permanent magnet, and the inverter device comprises a plurality of semiconductor switches for controlling drive frequencies of the electric motor.Type: GrantFiled: September 8, 2003Date of Patent: August 9, 2005Inventors: Mutsunori Matsunaga, Kenji Tojo, Yoshikatsu Tomita, Susumu Nakayama, Syunsuke Yasunori
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Patent number: 6923016Abstract: In a refrigerant cycle apparatus, an energy-saving operation is performed by using a refrigerant which is used in a supercritical state. A refrigeration cycle apparatus is constituted by a main compressor, an expander, a sub compressor independently placed in an upstream side of the main compressor, a use side heat exchanger, a heat source side heat exchanger and the like. A refrigerant such as a carbon dioxide or the like which is used in a supercritical state is employed as the refrigerant. The sub compressor is driven by utilizing a recovered energy by the expanding device. Further, a refrigerant tank is provided, and properly controls an amount of the refrigerant circulating in the refrigerant cycle.Type: GrantFiled: April 7, 2004Date of Patent: August 2, 2005Inventors: Sunao Funakoshi, Hirokatsu Kohsokabe, Kazuhiro Endoh, Kenji Tojo, Hiroaki Matsushima
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Publication number: 20050086960Abstract: A refrigerating machine having a compressor driven by a motor. The motor incorporates an armature with an iron core having a cage type conductor and a permanent magnet which is magnetized so as to enable the motor to operate as a synchronous motor. A bypass passage is provided between a discharge side of the compressor and a suction side of the compressor, a shut-off valve is provided for opening and closing the bypass passage, a pressure detecting device is provided for detecting a discharge pressure from the compressor and a current detector is provided for detecting a value of drive current for the compressor. The shut-off valve is opened and closed in accordance with the discharge pressure and the value of the drive current.Type: ApplicationFiled: December 13, 2004Publication date: April 28, 2005Inventors: Atsuhiko Yokozeki, Susumu Nakayama, Kenji Tojo, Akira Saruta, Mutsunori Matsunaga, Satoshi Kikuchi
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Patent number: 6832488Abstract: A refrigerating machine includes a plurality of compressors driven by motors each having an armature core incorporating a squirrel cage conductor and a permanent magnet which is magnetized so as to allow the motor to serve as a synchronous motor, and a compressor drive circuit for selectively driving the motor at a power source frequency by a commercial power source or at a variable frequency by an inverter. Thus, the overall efficiency of the refrigerating machine can be enhanced.Type: GrantFiled: July 8, 2003Date of Patent: December 21, 2004Assignee: Hitachi, Ltd.Inventors: Atsuhiko Yokozeki, Susumu Nakayama, Kenji Tojo, Akira Saruta, Mutsunori Matsunaga, Satoshi Kikuchi
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Publication number: 20040200233Abstract: In a refrigerant cycle apparatus, an energy-saving operation is performed by using a refrigerant which is used in a supercritical state. A refrigeration cycle apparatus is constituted by a main compressor, an expander, a sub compressor independently placed in an upstream side of the main compressor, a use side heat exchanger, a heat source side heat exchanger and the like. A refrigerant such as a carbon dioxide or the like which is used in a supercritical state is employed as the refrigerant. The sub compressor is driven by utilizing a recovered energy by the expanding device. Further, a refrigerant tank is provided, and properly controls an amount of the refrigerant circulating in the refrigerant cycle.Type: ApplicationFiled: April 7, 2004Publication date: October 14, 2004Inventors: Sunao Funakoshi, Hirokatsu Kohsokabe, Kazuhiro Endoh, Kenji Tojo, Hiroaki Matsushima
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Publication number: 20040159115Abstract: An apparatus for driving a compressor comprises a compressor having a compression mechanism part for sucking a fluid to compress the same, and an electric motor for driving the compression mechanism part, and an inverter device for driving the electric motor at variable speeds. The electric motor comprises a self-starting type electric motor having a rotor, which comprises a cage conductor and a polarized permanent magnet, and the inverter device comprises a plurality of semiconductor switches for controlling drive frequencies of the electric motor.Type: ApplicationFiled: September 8, 2003Publication date: August 19, 2004Inventors: Mutsunori Matsunaga, Kenji Tojo, Yoshikatsu Tomita, Susumu Nakayama, Syunsuke Yasunori