Patents by Inventor Kazuki Takahashi

Kazuki Takahashi 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: 6435822
    Abstract: In a fluid machine such as multistage centrifugal compressor, the pressure of a working fluid is raised with the rotation of a impeller. A shaft sealing device is mounted at the end of the rotary shaft in order to prevent the working gas of the raised pressure from leaking out of the fluid machine and then polluting the surroundings. In a case where the fluid machine operates to rotate at high speed, a labyrinth sealing device is employed for the purpose of reducing a frictional loss in the shaft sealing device. The labyrinth sealing device includes a plurality of stages of labyrinth fins which are formed on a casing or the rotary shaft, and a layer of abradable coating to-be-bitten which is formed in the surface part of the rotary shaft or the casing opposing to the labyrinth fins. The clearances between the labyrinth fins and the rotary shaft or the casing are made narrower on the low-pressure side of the labyrinth sealing device than on the high-pressure side thereof.
    Type: Grant
    Filed: May 25, 2001
    Date of Patent: August 20, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Hiromi Kobayashi, Hideo Nishida, Haruo Miura, Takashi Eino, Kazuki Takahashi
  • Publication number: 20020081213
    Abstract: A package-type screw compressor includes a low-pressure stage state compressor and a high-pressure stage compressor. Motive power is transmitted from an electric motor to the two compressors via a speed increaser. The discharge gas, compressed and heated to a high temperature by the low-pressure stage compressor, is cooled by an intercooler. The discharge gas, compressed and heated to a high temperature by the high-pressure stage compressor, is cooled by an aftercooler. A casing of the intercooler and that of the aftercooler are formed integrally with a speed increaser casing, reducing the number of component parts. A cooler portion, formed by the intercooler and the aftercooler, is spaced from the speed increaser casing, thereby preventing heat, produced by the compressed air, from being transmitted to the speed increaser casing.
    Type: Application
    Filed: February 25, 2002
    Publication date: June 27, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Kazuki Takahashi, Seiji Tsuru, Minoru Taniyama, Haruo Miura
  • Publication number: 20020050345
    Abstract: A heat exchanger used in a screw air compressor has a low temperature chamber through which low temperature fluid flows and a high temperature chamber through which high temperature fluid flows. The low temperature chamber and the high temperature chamber are separated by a partition plate. The high temperature chambers and the low temperature chambers are alternately arranged in layers, so that the low temperature chambers are disposed at both ends in a layered direction. Additionally, the flowing direction of the low temperature fluid in the low temperature chambers and the flowing direction of the high temperature fluid in the high temperature chambers are substantially orthogonal to each other.
    Type: Application
    Filed: August 6, 2001
    Publication date: May 2, 2002
    Inventors: Haruo Miura, Kazuki Takahashi, Seiji Tsuru, Minoru Taniyama, Tomohiro Naruse, Toshio Hattori
  • Publication number: 20020001531
    Abstract: A package-type screw compressor includes a low-pressure stage state compressor and a high-pressure stage compressor. Motive power is transmitted from an electric motor to the two compressors via a speed increaser. The discharge gas, compressed and heated to a high temperature by the low-pressure stage compressor, is cooled by an intercooler. The discharge gas, compressed and heated to a high temperature by the high-pressure stage compressor, is cooled by an aftercooler. A casing of the intercooler and that of the aftercooler are formed integrally with a speed increaser casing, reducing the number of component parts. A cooler portion, formed by the intercooler and the aftercooler, is spaced from the speed increaser casing, thereby preventing heat, produced by the compressed air, from being transmitted to the speed increaser casing.
    Type: Application
    Filed: November 30, 2000
    Publication date: January 3, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Kazuki Takahashi, Seiji Tsuru, Minoru Taniyama, Haruo Miura
  • Publication number: 20020001523
    Abstract: An air compressor comprises a compressor main body, and a capacity adjusting apparatus connected to an intake side of the compressor main body for adjusting the intake air flow into the compressor main body. The capacity adjusting apparatus is provided in an intake pipe. The intake pipe is adjacent to a discharge pipe of the compressor. A communicating passage is formed in the adjacent portion so as to introduce the compressed air discharged from the discharge pipe into the intake pipe system. The intake pipe is provided with an opening port for limiting the intake air flow into the compressor main body. The capacity adjusting apparatus opens and closes the communicating passage and the opening by means of an intake port switch valve and a discharge ventilating port switch valve which are provided in an end portion of the capacity adjusting apparatus.
    Type: Application
    Filed: February 9, 2001
    Publication date: January 3, 2002
    Inventors: Seiji Tsuru, Kazuki Takahashi
  • Patent number: 6302645
    Abstract: In a fluid machine such as multistage centrifugal compressor, the pressure of a working fluid is raised with the rotation of a impeller. A shaft sealing device is mounted at the end of the rotary shaft in order to prevent the working gas of the raised pressure from leaking out of the fluid machine and then polluting the surroundings. In a case where the fluid machine operates to rotate at high speed, a labyrinth sealing device is employed for the purpose of reducing a frictional loss in the shaft sealing device. The labyrinth sealing device includes a plurality of stages of labyrinth fins which are formed on a casing or the rotary shaft, and a layer of abradable coating to-be-bitten which is formed in the surface part of the rotary shaft or the casing opposing to the labyrinth fins. The clearances between the labyrinth fins and the rotary shaft or the casing are made narrower on the low-pressure side of the labyrinth sealing device than on the high-pressure side thereof.
    Type: Grant
    Filed: February 16, 2000
    Date of Patent: October 16, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Hiromi Kobayashi, Hideo Nishida, Haruo Miura, Takashi Eino, Kazuki Takahashi
  • Patent number: 6203275
    Abstract: In a multi-stage centrifugal compressor, having a plurality of impellers mounted on a rotation shaft, or a single-stage centrifugal compressor, a vaned diffuser, having a plurality of vanes, is mounted at a downstream side of the impeller, and a vaneless diffuser portion is formed downstream of this vaned diffuser. A meridian plane cross-sectional shape of each of two wall surfaces forming the vaneless diffuser portion provided downstream of the vaned diffuser is such that its channel height is decreased progressively in a downstream direction. Instead of this vaneless diffuser, there can be provided a second vaned diffuser having a small number of vanes. In this case, also, two wall surfaces, forming the second vaned diffuser, are contracted progressively in the downstream direction.
    Type: Grant
    Filed: August 31, 1998
    Date of Patent: March 20, 2001
    Assignee: Hitachi, LTD
    Inventors: Hiromi Kobayashi, Hideo Nishida, Kazuki Takahashi, Takashi Eino
  • Patent number: 6196809
    Abstract: A low pressure-side first-stage compressor impeller and a high pressure-side second-stage compressor impeller are mounted respectively on opposite ends of a rotation shaft. A rotor of an electric motor for driving the two impellers is formed at a central portion of the rotation shaft. A stator of the motor is held by a motor casing. The motor casing, a first-stage compressor casing, which cooperates with the first-stage compressor impeller to form a first-stage compressor, and a second-stage compressor casing, which cooperates with the second-stage compressor impeller to form a second-stage compressor, are cast into an integral construction. This integral casing is further formed integrally with an intermediate cooler, disposed downstream of the first-stage compressor, and a discharge cooler disposed downstream of the second-stage compressor.
    Type: Grant
    Filed: February 13, 1998
    Date of Patent: March 6, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Kazuki Takahashi, Haruo Miura, Hideo Nishida, Naohiko Takahashi, Yasuo Fukushima
  • Patent number: 6111333
    Abstract: In a rotating machine with employment of a sensor-less DC brushless motor, a terminal voltage of a motor is corrected in a phase corrector by using a motor phase current signal. At this time, the terminal voltage is processed in an integrator and a comparator so as to be converted into an ON/OFF signal having a duty ratio of 1:1. Then, a rotation signal is produced based on an induced voltage which is generated by rotating a permanent magnet rotor, so that a rotation sensor is no longer required. On the other hand, an output derived from the phase corrector is entered as a 1-pulse/1-rotation output signal into a PLL circuit. The PLL circuit contains a phase comparator, a low-pass filter, an oscillator, and a counter. The PLL circuit frequency-divides the 1-pulse/1-rotation output signal. The sine wave data are stored into a ROM with respect to each of the frequency-divided signal positions. The unbalance vibrations of the magnetic bearing are controlled every frequency-divided signal.
    Type: Grant
    Filed: March 3, 1999
    Date of Patent: August 29, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Naohiko Takahashi, Tsunehiro Endo, Haruo Miura, Minoru Yoshihara, Yasuo Fukushima, Kazuki Takahashi
  • Patent number: 6047461
    Abstract: A manufacturing method of a rotor for a permanent magnet-excited, high-speed electric rotary machine according to the present invention comprises, covering an outer circumferential surface of at least one permanent magnet by a fiber-reinforced plastic protection cover with prestress compressing in radial direction; inserting a steel sleeve into the at least one permanent magnet to form a permanent magnet assembly; preparing at least one permanent magnet assembly; inserting a rotor shaft into the steel sleeve while applying hydraulic pressure to an inner circumferential surface of the steel sleeve of the prepared at least one permanent magnet assembly to expand the steel sleeve; and then removing the hydraulic pressure to tight fit the at least one permanent magnet assembly onto the rotor shaft.
    Type: Grant
    Filed: September 3, 1998
    Date of Patent: April 11, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Haruo Miura, Kazuki Takahashi, Hideo Nishida, Naohiko Takahashi, Yasuo Fukushima
  • Patent number: 6039535
    Abstract: In a fluid machine such as multistage centrifugal compressor, the pressure of a working fluid is raised with the rotation of a impeller. A shaft sealing device is mounted at the end of the rotary shaft in order to prevent the working gas of the raised pressure from leaking out of the fluid machine and then polluting the surroundings. In a case where the fluid machine operates to rotate at high speed, a labyrinth sealing device is employed for the purpose of reducing a frictional loss in the shaft sealing device. The labyrinth sealing device includes a plurality of stages of labyrinth fins which are formed on a casing or the rotary shaft, and a layer of abradable coating to-be-bitten which is formed in the surface part of the rotary shaft or the casing opposing to the labyrinth fins. The clearances between the labyrinth fins and the rotary shaft or the casing are made narrower on the low-pressure side of the labyrinth sealing device than on the high-pressure side thereof.
    Type: Grant
    Filed: June 23, 1998
    Date of Patent: March 21, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Hiromi Kobayashi, Hideo Nishida, Haruo Miura, Takashi Eino, Kazuki Takahashi
  • Patent number: 5980218
    Abstract: A multi-stage compressor having at least two compressor stages comprises an inter-cooler provided between the stages for cooling a gas being discharged from a compressor in the preceding stage. The compressor stages are driven by a common electric motor, of which a rotating shaft is supported by magnetic bearings. A part of the gas cooled by the inter-cooler and a part of the work gas discharged from a bleed valve provided down-stream of a rear stage of the compressor are selectively introduced into the electric motor or the magnetic bearings. Thus, at the time of load operation the gas discharged from the inter-cooler is introduced into the motor or the magnetic bearings to cool them, and at the time of non-load operation the gas discharged from the bleed valve is introduced into the motor or the magnetic bearings to cool them. It is possible to ensure a flow rate of gas required for cooling the motor during non-load operation with economy during load operation.
    Type: Grant
    Filed: September 2, 1997
    Date of Patent: November 9, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Kazuki Takahashi, Haruo Miura, Hideo Nishida, Naohiko Takahashi
  • Patent number: 5907196
    Abstract: An irradiation direction control apparatus for a vehicular lamp including: a vehicle state detection device for detecting a state of a vehicle; a drive device for directing irradiation light of a lamp toward a desired direction; and a compensation calculation device for performing a compensation calculation to keep the irradiation light of the lamp to a predetermined direction in accordance with a signal from the vehicle state detection device and sending a compensation signal to the drive device, whereby at the time of lighting the lamp or during lighting of the lamp, the compensation calculation device performs the compensation calculation to keep the irradiation light of the lamp to the predetermined direction in accordance with the signal from the vehicle state detection device and sends the compensation signal based on a calculation result to the drive device to drive the lamp or components thereof, whereas at the time of deactivating the lamp or during deactivation of the lamp and with a power source of
    Type: Grant
    Filed: April 24, 1997
    Date of Patent: May 25, 1999
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Toshihisa Hayami, Makoto Izawa, Kazuki Takahashi
  • Patent number: 5528475
    Abstract: A control circuit for automobile headlamps which emit light in variable color. The control circuit prevents left and right headlamps from emitting beams of light in different colors. Each headlamp includes a white light bulb, and a yellow globe is moved from a first position to a second position to cover the bulb when yellow light is selected, and the yellow globe is moved back to the first position when white light is selected. If the movement of the globe stops between the first and second positions, the control circuit generates a fault signal for turning off the headlamp associated with the fault, thus preventing the headlamps from emitting light of different colors. Alternatively, the control circuit can adjust the position of the globe for the headlamp without the fault to be in agreement with the position with the headlamp having the fault, such that both headlamps emit light of the same color.
    Type: Grant
    Filed: December 20, 1994
    Date of Patent: June 18, 1996
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Kazuki Takahashi, Makoto Izawa, Toshihisa Hayami, Hideki Uchida, Takayuki Unno
  • Patent number: 5526242
    Abstract: A vehicle cornering headlamp system which can be applied to any type of vehicle without changing the correspondence to a radiation angle, and which enables the radiation angle to follow the return of driver's eyes when the vehicle exits a curved road. The angular velocity .omega..sub.new is calculated at the time of travelling on a curved road on the basis of the output from an angular velocity sensor and the vehicle speed v is measured on the basis of distance pulses from a distance sensor. The current angular velocity, .omega..sub.new, is divided by the vehicle speed v to calculate the reciprocal number of a revolution radius r, which is multiplied by a constant K, so as to obtain a target value .theta.s of the radiation angle. Then, on the basis of the difference between .omega..sub.old, the angular velocity detected at a previous time, and .omega..sub.new, it is determined that the vehicle is approaching an end of the curved road when the gradient of the angular velocity .omega.
    Type: Grant
    Filed: December 27, 1994
    Date of Patent: June 11, 1996
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Kazuki Takahashi, Takayuki Unno
  • Patent number: 4970906
    Abstract: A method and an apparatus for determining a rotation center of a rotary body comprises a rotary body rotating in clockwise and counterclockwise directions in cooperation with the steering for a vehicle, and original position detecting circuit which detects a predetermined original angular position which the rotary body taken per each rotation, thus judging an original angular position taken when other original angular positions are not detected within a lapse of a predetermined time after the original angular position has been detected as rotation centers in the clockwise and counterclockwise directions of the rotary body.
    Type: Grant
    Filed: April 24, 1990
    Date of Patent: November 20, 1990
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Hiroki Shibata, Atsushi Toda, Kazuki Takahashi, Kiyoshi Wada
  • Patent number: 4963794
    Abstract: A vehicle cornering headlamp system in which the direction of illumination of the headlamps of an automobile are made to follow the actual direction of movement of the vehicle, except that the direction of illumination is returned to the straight-ahead direction more quickly than it is moved away therefrom, thereby more accurately following the usual eye movement of the driver. For this purpose, a control signal is generated which has a pulse width indicative of the steering angle but which has a variation characteristic with respect to steering angle which is larger when the steering wheel is turned back towards the straight-ahead position than when the steering wheel is turned away from the straight-ahead position.
    Type: Grant
    Filed: September 8, 1988
    Date of Patent: October 16, 1990
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Hiromi Shibata, Kazuki Takahashi, Keiichi Tajima, Takashi Kurita, Kiyoshi Wada, Kiyoshi Yamashita
  • Patent number: 4943893
    Abstract: An automotive illumination system with which, when steering the vehicle around a curve or corner, both the path along which the vehicle is to travel and the direction straight ahead of the vehicle are sufficiently illuminated. Four headlamps are provided. Two of the headlamps, preferably the outer two, have directions of illumination fixed in the straight-ahead direction of the vehicle. The other two headlamps have directions of illumination which are controlled in accordance with the steering angle of the vehicle.
    Type: Grant
    Filed: September 16, 1988
    Date of Patent: July 24, 1990
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Hiroki Shibata, Kazuki Takahashi, Keiichi Tajima, Takashi Kurita, Kiyoshi Wada, Kiyoshi Yamashita
  • Patent number: 4908560
    Abstract: In a vehicle cornering lamp system, a control signal having a pulse width corresponding to a steering angle is periodically produced, and the amount of position shift between the actual direction of illumination of the headlamps and the target direction of illumination determined from the steering angle is detected according to the control signal thus produced. An electric motor is driven to change the direction of illumination of the headlamps so that the amount of position shift becomes zero, that is, the direction of illumination of the headlamps is linearly changed with the electric motor while following the steering angle.
    Type: Grant
    Filed: September 8, 1988
    Date of Patent: March 13, 1990
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Hiroki Shibata, Kazuki Takahashi, Keiichi Tajima, Takashi Kurita, Kiyoshi Wada, Kiyoshi Yamashita
  • Patent number: 4860601
    Abstract: An apparatus for determining a rotation center of a rotary body comprises a rotary body rotating in clockwise and counterclockwise directions in cooperation with the steering for a vehicle, and original position detecting circuit which detects a predetermined original angular position which the rotary body taken per each rotation, thus judging an original angular position taken when other original angular positions are not detected within a lapse of a predetermined time after the original angular position has been detected as rotation centers in the clockwise and counterclockwise directions of the rotary body.
    Type: Grant
    Filed: July 5, 1988
    Date of Patent: August 29, 1989
    Assignee: Koito Manufacturing Co., Ltd.
    Inventors: Hiroki Shibata, Atsushi Toda, Kazuki Takahashi, Kiyoshi Wada