Patents by Inventor Keiichi Okai

Keiichi Okai 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).

  • Patent number: 7555893
    Abstract: To provide an aircraft propulsion system which can secure the optimum thrust and thrust vector for flight conditions, as well as the optimum sectional area for the engine, and which is highly compatible with the environment. An electrical generator is coupled to a turbofan engine, the electrical generator is driven by output power of the turbofan engine to output electric power, and an electromagnetic driving fan is driven by the electric power. On the other hand, after bringing each of coils in the electromagnetic driving fan to a superconductive state, liquid hydrogen is introduced to a heat exchanger, collects the energy of exhaust as heat, is then vaporized, and thereafter supplied to a combustor and to a fuel cell. Further, the electromagnetic driving fan is changed in its rotational phase by a rotating mechanism portion, is made movable in a width direction of a wing and a wing chord direction by a slide mechanism portion, and can be stored inside or outside the wing by a storage mechanism portion.
    Type: Grant
    Filed: January 23, 2006
    Date of Patent: July 7, 2009
    Assignees: Japan Aerospace Exploration Agency, Nihon University
    Inventors: Keiichi Okai, Takeshi Tagashira, Ryoji Yanagi, Hiroshi Nomura
  • Patent number: 7423405
    Abstract: In order to obtain an electromagnetic rotating machine of lightweight and high energy efficiency, which produces big torque for rotating a large-diameter fan, a coil A and coil B as excitation coils are disposed on an inner peripheral surface of a fan casing so as to face an outer circumference of the fan, and a coil M as an armature coil crosses at a central portion and is disposed on the outer circumference of the fan. The relationships |Iai|=|Iai+1| and Iai=?Iai+1, or |Ibi|=|Ibi+1| and Ibi=?Ibi+1 are obtained respectively for the coil A or coil B by a current control device (not shown). Moreover, the coil A and coil B are subjected to excitation control such that the direction of effective electromagnetic force, which is generated by an interaction between an effective magnetic field formed by the coil A and effective induced current applied to the coil M by the coil B, corresponds to the direction of rotation of the fan.
    Type: Grant
    Filed: January 23, 2006
    Date of Patent: September 9, 2008
    Assignees: Japan Aerospace Exploration Agency, Nihon University
    Inventors: Keiichi Okai, Takeshi Tagashira, Ryoji Yanagi, Hiroshi Nomura
  • Publication number: 20060254255
    Abstract: To provide an aircraft propulsion system which can secure the optimum thrust and thrust vector for flight conditions, as well as the optimum sectional area for the engine, and which is highly compatible with the environment. An electrical generator is coupled to a turbofan engine, the electrical generator is driven by output power of the turbofan engine to output electric power, and an electromagnetic driving fan is driven by the electric power. On the other hand, after bringing each of coils in the electromagnetic driving fan to a superconductive state, liquid hydrogen is introduced to a heat exchanger, collects the energy of exhaust as heat, is then vaporized, and thereafter supplied to a combustor and to a fuel cell. Further, the electromagnetic driving fan is changed in its rotational phase by a rotating mechanism portion, is made movable in a width direction of a wing and a wing chord direction by a slide mechanism portion, and can be stored inside or outside the wing by a storage mechanism portion.
    Type: Application
    Filed: January 23, 2006
    Publication date: November 16, 2006
    Applicants: JAPAN AEROSPACE EXPLORATION AGENCY, NIHON UNIVERSITY
    Inventors: Keiichi Okai, Takeshi Tagashira, Ryoji Yanagi, Hiroshi Nomura
  • Publication number: 20060176009
    Abstract: In order to obtain an electromagnetic rotating machine of lightweight and high energy efficiency, which produces big torque for rotating a large-diameter fan, a coil A and coil B as excitation coils are disposed on an inner peripheral surface of a fan casing so as to face an outer circumference of the fan, and a coil M as an armature coil crosses at a central portion and is disposed on the outer circumference of the fan. The relationships |Iai|=|Iai+1| and Iai=?Iai+1, or |Ibi|=|Ibi+1| and Ibi=?Ibi+1 are obtained respectively for the coil A or coil B by a current control device (not shown). Moreover, the coil A and coil B are subjected to excitation control such that the direction of effective electromagnetic force, which is generated by an interaction between an effective magnetic field formed by the coil A and effective induced current applied to the coil M by the coil B, corresponds to the direction of rotation of the fan.
    Type: Application
    Filed: January 23, 2006
    Publication date: August 10, 2006
    Applicants: JAPAN AEROSPACE EXPLORATION AGENCY, NIHON UNIVERSITY
    Inventors: Keiichi Okai, Takeshi Tagashira, Ryoji Yanagi, Hiroshi Nomura