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).

  • Publication number: 20040055328
    Abstract: 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: Application
    Filed: September 25, 2003
    Publication date: March 25, 2004
    Inventors: Shunsuke Yasunori, Kenji Tojo, Mutsunori Matsunaga
  • Patent number: 6708520
    Abstract: 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: Grant
    Filed: September 10, 2002
    Date of Patent: March 23, 2004
    Assignee: Hitachi Ltd. trustee for the benefit of Hitachi Air Conditioning Systems Co. Ltd.
    Inventors: Shunsuke Yasunori, Kenji Tojo, Mutsunori Matsunaga
  • Publication number: 20040040323
    Abstract: 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: Application
    Filed: July 8, 2003
    Publication date: March 4, 2004
    Inventors: Atsuhiko Yokozeki, Susumu Nakayama, Kenji Tojo, Akira Saruta, Mutsunori Matsunaga, Satoshi Kikuchi
  • Publication number: 20030046952
    Abstract: 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: Application
    Filed: September 10, 2002
    Publication date: March 13, 2003
    Inventors: Shunsuke Yasunori, Kenji Tojo, Mutsunori Matsunaga
  • Publication number: 20030033165
    Abstract: An environmental service business-entity designs at least one of a unit for heating a space or target space higher than an outside-air temperature and a unit for cooling the target space lower than an outside-air temperature, the target space having been defined between the business-entity and a client. The business-entity guarantees that the quality of environment including the temperature of the target space will be maintained in a range determined in consultation with the client. This condition substantially guarantees the total cost that results from assessing both an initial cost and a running cost. Accordingly, the user finds it easier to introduce an environmental facility without risk.
    Type: Application
    Filed: August 6, 2002
    Publication date: February 13, 2003
    Inventors: Kazuhiko Inoue, Kenji Tojo
  • Patent number: 6406279
    Abstract: A displacement type fluid machine has a sliding contact portion between a cylinder 4 and a displacer 5 made into a predetermined section, and the cylinder and the displacer so contoured that when they are made concentric, the normal distance in the sliding contact section between the cylinder contour and the displacer contour may be smaller than that of the remaining section, thereby to decrease the radial gap to lower the internal leakage of the working fluid and to improve the performance and the reliability.
    Type: Grant
    Filed: March 16, 2001
    Date of Patent: June 18, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Hirokatsu Kohsokabe, Masahiro Takebayashi, Shunichi Mitsuya, Hiroaki Hata, Yasuhiro Ohshima, Kenji Tojo
  • Patent number: 6352418
    Abstract: A displacement type fluid machine which is easier to machine and assemble than a scroll type fluid machine and has high performance and low cost. A displacer is revolved in a cylinder having an inside wall formed by a curve such that a planar shape is continuous, whereby a working fluid is discharged through a plurality of discharge ports, there is provided a driving unit in which the orbiting radius of the displacer is variable along the shape of a movement line contact portion of the cylinder and the displacer.
    Type: Grant
    Filed: March 8, 2000
    Date of Patent: March 5, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Hirokatsu Kohsokabe, Kunihiko Takao, Masahiro Takebayashi, Isao Hayase, Hiroaki Hata, Shigetaroo Tagawa, Kenji Tojo, Takeshi Kouno
  • Patent number: 6332764
    Abstract: A displacement type fluid machine for reducing a fluid loss of a discharge process as much as that of a scroll fluid machine has a displacer which is provided with at least one through hole for working the outer wall surface of said displacer during manufacture of said displacer, said at least one through hole extending in an axial direction of a rotating shaft.
    Type: Grant
    Filed: June 13, 2000
    Date of Patent: December 25, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Hirokatsu Kohsokabe, Masahiro Takebayashi, Hiroaki Hata, Koichi Inaba, Isao Hayase, Kenji Tojo
  • Patent number: 6332763
    Abstract: In order to provide a displacement type fluid machine for reducing a fluid loss of a discharge process as much as that of a scroll fluid machine, easily prepared than the scroll fluid machine, in the displacement type fluid machine wherein a shaft is gyrated in a hollow cylinder whose section shape comprises a series of curves so that a working fluid is discharged from a plurality of discharge ports, a shaft angle &thgr;c of a compression process of each working chamber is given by the following algorithm: (((N−1)/N·360°)<&thgr;c≦360° (where, N is the number of threads).
    Type: Grant
    Filed: June 13, 2000
    Date of Patent: December 25, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Hirokatsu Kohsokabe, Masahiro Takebayashi, Hiroaki Hata, Koichi Inaba, Isao Hayase, Kenji Tojo
  • Patent number: 6286334
    Abstract: The refrigerating apparatus of the invention has a scroll compressor having a compressing section sucking and compressing a hydrofluorocarbon-based refrigerant, a condenser and the like, in which a plain bearing slidably supporting a driving shaft driving the compressing section of the scroll compressor is made of a material containing lead, and an ether oil miscible with the refrigerant used in a refrigerant circuit is used as a lubricant for lubricating the plain bearing.
    Type: Grant
    Filed: April 18, 2000
    Date of Patent: September 11, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Tojo, Hideyuki Ueda, Yoshikatsu Tomita, Takao Mizuno
  • Publication number: 20010010800
    Abstract: A displacement type fluid machine has a sliding contact portion between a cylinder 4 and a displacer 5 made into a predetermined section, and the cylinder and the displacer so contoured that when they are made concentric, the normal distance in the sliding contact section between the cylinder contour and the displacer contour may be smaller than that of the remaining section, thereby to decrease the radial gap to lower the internal leakage of the working fluid and to improve the performance and the reliability.
    Type: Application
    Filed: March 16, 2001
    Publication date: August 2, 2001
    Inventors: Hirokatsu Kohsokabe, Masahiro Takebayashi, Shunichi Mitsuya, Hiroaki Hata, Yasuhiro Ohshima, Kenji Tojo
  • Patent number: 6213743
    Abstract: A conventional displacement type fluid machine is featured by a low sliding rate and in low vibrations and pulsations, but has a problem, that the radial gap in a displacer sliding portion is enlarged by the clearance of a shaft drive system and a rotating moment acting on a displacer so that the internal leakage of a working fluid is increased to lower the performance and the reliability. To eliminate this problem, the sliding contact portion between a cylinder 4 and a displacer 5 is made into a predetermined section, and the cylinder and the displacer are so contoured that when they are made concentric, the normal distance in the sliding contact section between the cylinder contour and the displacer contour may be smaller than that of the remaining section, thereby to decrease the radial gap to lower the internal leakage of the working fluid and to improve the performance and the reliability.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: April 10, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Hirokatsu Kohsokabe, Masahiro Takebayashi, Shunichi Mitsuya, Hiroaki Hata, Yasuhiro Ohshima, Kenji Tojo
  • Patent number: 6179593
    Abstract: Side wall surface of an orbiting piston and inner wall surface of a cylinder define therebetween a plurality of working chambers, a space for compressing (discharging) a working fluid is defined between spaces for sucking thereinto the working fluid among the working chambers in any operating condition, and one of end plates, between which the orbiting piston is axially interposed, is formed with suction ports or discharge ports while the other of end plates, opposing the end plate formed with the suction or discharge ports, is formed with holes, whereby it is possible to provide a highly efficient and reliable displacement fluid machine which can stabilize pressure balance in the working chambers, and which can greatly reduce fluid loss during discharge stroke.
    Type: Grant
    Filed: March 19, 1998
    Date of Patent: January 30, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Shunichi Mitsuya, Hirokatsu Kohsokabe, Masahiro Takebayashi, Koichi Inaba, Hiroaki Hata, Kenji Tojo
  • Patent number: 6164941
    Abstract: In order to provide a displacement type fluid machine for reducing a fluid loss of a discharge process as much as that of a scroll fluid machine, easily prepared than the scroll fluid machine, in the displacement type fluid machine wherein a shaft is gyrated in a hollow cylinder whose section shape comprises a series of curves so that a working fluid is discharged from a plurality of discharge ports, a shaft angle .theta.c of a compression process of each working chamber is given by the following algorithm:(((N-1)/N.multidot.360.degree.)<.theta.c.ltoreq.360.degree.(where, N is the number of threads).
    Type: Grant
    Filed: March 12, 1999
    Date of Patent: December 26, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Hirokatsu Kohsokabe, Masahiro Takebayashi, Hiroaki Hata, Koichi Inaba, Isao Hayase, Kenji Tojo
  • Patent number: 6152714
    Abstract: A conventional displacement type fluid machine involves a problem that a mechanical friction loss and leakage in sliding portions are large, so that its reliability and performance are poor, and therefore it has not yet been put into practical use. In a displacement type fluid machine, a displacer makes an orbital motion within a cylinder to draw and discharge a working fluid. An compression element includes the displacer of a specified configuration, and the cylinder engaged with this displacer, and a connecting member (rotation prevention member), which abuts against the displacer and the cylinder, is provided inwardly of compression working chambers. With this construction, a rotating moment acting on the displacer can be completely avoided, thereby achieving the high efficiency and the high reliability.
    Type: Grant
    Filed: September 18, 1997
    Date of Patent: November 28, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Shunichi Mitsuya, Hirokatsu Kohsokabe, Masahiro Takebayashi, Koichi Inaba, Hiroaki Hata, Kenji Tojo
  • Patent number: 6055827
    Abstract: The refrigerating apparatus of the invention has a scroll compressor having a compressing section sucking and compressing a hydrofluorocarbon-based refrigerant, a condenser and the like, in which a plain bearing slidably supporting a driving shaft driving the compressing section of the scroll compressor is made of a material containing lead, and an ether oil miscible with the refrigerant used in a refrigerant circuit is used as a lubricant for lubricating the plain bearing.
    Type: Grant
    Filed: August 13, 1999
    Date of Patent: May 2, 2000
    Assignee: Hitachi, Ltd
    Inventors: Kenji Tojo, Hideyuki Ueda, Yoshikatsu Tomita, Takao Mizuno
  • Patent number: 6006542
    Abstract: The refrigerating apparatus of the invention has a scroll compressor having a compressing section sucking and compressing a hydrofluorocarbon-based refrigerant, a condenser and the like, in which a plain bearing slidably supporting a driving shaft driving the compressing section of the scroll compressor is made of a material containing lead, and an ether oil miscible with the refrigerant used in a refrigerant circuit is used as a lubricant for lubricating the plain bearing.
    Type: Grant
    Filed: September 11, 1998
    Date of Patent: December 28, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Tojo, Hideyuki Ueda, Yoshikatsu Tomita, Takao Mizuno
  • Patent number: 5775893
    Abstract: Fixed scrolls 4, 5 are supported so to be movable axially relative to an orbiting scroll 6, so that a proper space is kept between wraps 4a, 5a and 6a to avoid an excessive load in the contacting area. Further, an end portion of an outer curve of the wrap 6a of the orbiting scroll 6 is formed to come close to or coincide to an outer edge of a panel 6f of the orbiting scroll 6 and an Oldham's coupling is accommodated in a concave groove 6e formed on an outer circumference surface of the panel 6f, so that the size of the scroll compressor is reduced.
    Type: Grant
    Filed: June 19, 1996
    Date of Patent: July 7, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Kunihiko Takao, Masahiro Takebayashi, Yoshishige Endo, Yuji Yoshitomi, Shigeru Machida, Kenji Tojo, Kazuo Sekigami
  • Patent number: 5660539
    Abstract: A lubricating construction of a scroll compressor includes a seal member provided between an orbiting scroll and a main frame to isolate a back pressure chamber from bearing portions to thereby keep the bearing portions substantially under a discharge pressure, a first oil feed passage extending from a lubricating oil portion under the discharge pressure to a space, disposed adjacent to an end of a crank portion of the crankshaft, through the crankshaft, a second oil feed passage extending from the above space to be opened to sliding portions of end plates of the orbiting and stationary scrolls through the end plate of the orbiting scroll, and communicating with the back pressure chamber, and a third oil feed passage extending from midway the first oil feed passage to be opened to an outer peripheral surface of the crankshaft, and serving to supply a lubricating oil to a main bearing portion by the use of a centrifugal pumping action produced by rotation of the crankshaft.
    Type: Grant
    Filed: October 24, 1995
    Date of Patent: August 26, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Mutsunori Matsunaga, Takao Mizuno, Kenji Tojo, Hideyuki Ueda, Takeshi Hida
  • Patent number: 5622488
    Abstract: A scroll type compressor having high efficiency and high reliability is obtained by preventing leakage of a compression chamber, increasing air tightness thereof and securing a smooth motion of an orbiting scroll member. A second frame member supported by a first frame member and slightly movable in the axial direction is disposed in the rear of an orbiting scroll member. Force is applied to the rear of the second frame member, and a slight axial movement of the orbiting scroll member is regulated by a fixed scroll member and the second frame member. As a result, both the scroll members are in tight contact or close to each other with a small space, and a smooth movement thereof can be secured, which makes it possible to obtain a scroll type compressor having high efficiency and high reliability.
    Type: Grant
    Filed: August 15, 1995
    Date of Patent: April 22, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Tojo, Hideyuki Ueda, Takao Mizuno, Takeshi Hida