Patents by Inventor Kazuharu Hirokawa

Kazuharu Hirokawa 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: 20200165709
    Abstract: A gas turbine disk material according to the present invention contains: C: from 0.05 to 0.15%; Ni: from 0.25 to 1.50%; Cr: from 9.0 to 12.0%; Mo: from 0.50 to 0.90%; W: from 1.0 to 2.0%; V: from 0.10 to 0.30%; Nb: from 0.01 to 0.10%; Co: from 0.01 to 4.0%; B: from 0.0005 to 0.010%; N: from 0.01 to 0.05%; Mn: 0.40% or less; Si: 0.10% or less; and Al: 0.020% or less. A balance is of Fe and unavoidable impurities. Additionally, as a heat treatment method, a quenching temperature of a forged material having the component composition is set within a range from 1050 to 1150° C.
    Type: Application
    Filed: September 19, 2018
    Publication date: May 28, 2020
    Inventors: Hiroki TANAKA, Yuichi HIRAKAWA, Yoshikuni KADOYA, Tomoyuki HIRATA, Takayoshi IIJIMA, Kazuharu HIROKAWA
  • Patent number: 9284851
    Abstract: In a variable vane drive device of an axial-flow fluid machine, a ring support unit supporting a movable ring includes: a first roller; a first support part supporting the first rollers so as to be relatively immovable with respect to a vane holding ring in a radial direction and in an axial direction; a second roller; a second support part supporting the second roller so as to be relatively movable with respect to the vane holding ring in the radial direction and pressing the second roller in the radial direction; a third roller allowing relative movement of the movable ring in the radial direction and restricting relative movement of the movable ring in the axial direction; and a third support part supporting the third roller so as to be relatively immovable with respect to the vane holding ring in the axial direction and in the radial direction.
    Type: Grant
    Filed: September 11, 2012
    Date of Patent: March 15, 2016
    Assignee: MITSUBISHI HEAVY INDUSTRIES, LTD.
    Inventors: Yoshimasa Takaoka, Kazuharu Hirokawa, Hiroki Nishiyama
  • Patent number: 9206705
    Abstract: In a sealing device which seals between an outside space between an outer side in the radial direction of an external diffuser which has a tubular shape and forms an exhaust channel through which combustion gas rotating a rotor of a gas turbine passes in the inner side in the radial direction and an outside member which is disposed outside the external diffuser with an interval between them in the radial direction, and the exhaust channel by an end of the external diffuser, a first seal plate group and a second seal plate group in which a plurality of seal plates, which extend to the outer side in the radial direction from the end of the tubular external diffuser and reach the outside member, are laminated in contact with each other, and a spacer which maintains the first seal plate group and the second seal plate group with an interval in an axial direction in which a rotational axis of the rotor extends are provided.
    Type: Grant
    Filed: November 6, 2012
    Date of Patent: December 8, 2015
    Assignee: MITSUBISHI HITACHI POWER SYSTEMS, LTD.
    Inventors: Shinya Hashimoto, Norikazu Tezuka, Kazuharu Hirokawa
  • Patent number: 8899934
    Abstract: The rotor structure is provided with a rotation shaft body in which a blade groove is formed at an outer circumference part, and extends in a circumferential direction of the axis line, and a plurality of blade bodies which are arrayed in the circumferential direction at the outer circumference part of the rotation shaft body, wherein a blade fixing piece is installed so as to be a positioned between at least one set of adjacent two blade bodies in the circumferential direction inside the blade groove, a projected part is formed at where either an opening wall part or the groove opening side of the blade groove and the blade fixing piece, and a recessed part which is fitted into the projected part is formed at where the other one of them.
    Type: Grant
    Filed: January 31, 2012
    Date of Patent: December 2, 2014
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Tomoyuki Hirata, Kazuharu Hirokawa, Yoshimasa Takaoka
  • Patent number: 8834103
    Abstract: A structure that mounts to a rotation shaft a lever that causes this rotation shaft to rotate, including a plurality of engaging members that are provided in the lever so as to be offset from the center axis of the rotation shaft, and that are capable of advancing toward and retracting from the outer periphery of the rotation shaft, and a plurality of abutted faces that are provided on the outer periphery of the rotation shaft so that the distal end faces of the plurality of engaging members respectively make contact, in which, when at least one of the engaging members and the abutted face that corresponds to that engaging member are in contact, relative rotation of the rotation shaft about the axis thereof in one direction with respect to the lever is restricted, and when another engaging member and another abutted face corresponding to the engaging member are in contact, relative rotation of the rotation shaft about the axis thereof in the other direction with respect to the lever is restricted.
    Type: Grant
    Filed: September 3, 2009
    Date of Patent: September 16, 2014
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Kazuharu Hirokawa, Eiichi Tsutsumi, Masaru Nishikatsu
  • Patent number: 8607604
    Abstract: A bolt has a male screw with a surface hardening portion that has an increased surface hardness and that is applied with a compressive residual stress. The male screw is formed by cutting the bolt, and performing a process to provide at least on the surface of the male screw of the bolt the surface hardening portion that has increased hardness and that is applied with a compressive residual stress. As a result, the fatigue resistance of the male screw is improved and the bolt is effective for use in a portion where the male screw is subject to a repetitive stress.
    Type: Grant
    Filed: July 8, 2011
    Date of Patent: December 17, 2013
    Assignee: Mitsubishi Heavy Industries
    Inventors: Norikazu Tezuka, Kazuharu Hirokawa, Keisuke Ihara, Kei Osawa, Hiroshi Ishikawa, Taiji Torigoe, Ryuichi Yamamoto, Yukihiro Hashimoto, Nobuyuki Izutsu, Koji Takahashi
  • Publication number: 20130236305
    Abstract: In a sealing device which seals between an outside space between an outer side in the radial direction of an external diffuser which has a tubular shape and forms an exhaust channel through which combustion gas rotating a rotor of a gas turbine passes in the inner side in the radial direction and an outside member which is disposed outside the external diffuser with an interval between them in the radial direction, and the exhaust channel by an end of the external diffuser, a first seal plate group and a second seal plate group in which a plurality of seal plates, which extend to the outer side in the radial direction from the end of the tubular external diffuser and reach the outside member, are laminated in contact with each other, and a spacer which maintains the first seal plate group and the second seal plate group with an interval in an axial direction in which a rotational axis of the rotor extends are provided.
    Type: Application
    Filed: November 6, 2012
    Publication date: September 12, 2013
    Applicant: MITSUBISHI HEAVY INDUSTRIES, LTD.
    Inventors: Shinya Hashimoto, Norikazu Tezuka, Kazuharu Hirokawa
  • Publication number: 20130216360
    Abstract: In a variable vane drive device of an axial-flow fluid machine, a ring support unit supporting a movable ring includes: a first roller; a first support part supporting the first rollers so as to be relatively immovable with respect to a vane holding ring in a radial direction and in an axial direction; a second roller; a second support part supporting the second roller so as to be relatively movable with respect to the vane holding ring in the radial direction and pressing the second roller in the radial direction; a third roller allowing relative movement of the movable ring in the radial direction and restricting relative movement of the movable ring in the axial direction; and a third support part supporting the third roller so as to be relatively immovable with respect to the vane holding ring in the axial direction and in the radial direction.
    Type: Application
    Filed: September 11, 2012
    Publication date: August 22, 2013
    Applicant: MITSUBISHI HEAVY INDUSTRIES, LTD.
    Inventors: Yoshimasa Takaoka, Kazuharu Hirokawa, Hiroki Nishiyama
  • Publication number: 20120251329
    Abstract: The rotor structure is provided with a rotation shaft body in which a blade groove is formed at an outer circumference part, and extends in a circumferential direction of the axis line, and a plurality of blade bodies which are arrayed in the circumferential direction at the outer circumference part of the rotation shaft body, wherein a blade fixing piece is installed so as to be a positioned between at least one set of adjacent two blade bodies in the circumferential direction inside the blade groove, a projected part is formed at where either an opening wall part or the groove opening side of the blade groove and the blade fixing piece, and a recessed part which is fitted into the projected part is formed at where the other one of them.
    Type: Application
    Filed: January 31, 2012
    Publication date: October 4, 2012
    Applicant: MITSUBISHI HEAVY INDUSTRIES, LTD.
    Inventors: Tomoyuki Hirata, Kazuharu Hirokawa, Yoshimasa Takaoka
  • Patent number: 8123409
    Abstract: A journal bearing has a plurality of pad stops which include a first pad stop located at a most forward position in the rotation direction of the rotation shaft, and the pad stops other than the first pad stop function as oiling nozzles for releasing lubricating oil between the outer circumferential surface of the rotation shaft and the inner circumferential surfaces of the pads.
    Type: Grant
    Filed: November 23, 2009
    Date of Patent: February 28, 2012
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Yuichiro Waki, Takashi Nakano, Shingo Yamasue, Shingo Tanaka, Takaaki Kaikogi, Kazuharu Hirokawa
  • Publication number: 20110268533
    Abstract: A bolt has a male screw with a surface hardening portion that has an increased surface hardness and that is applied with a compressive residual stress. The male screw is formed by cutting the bolt, and performing a process to provide at least on the surface of the male screw of the bolt the surface hardening portion that has increased hardness and that is applied with a compressive residual stress. As a result, the fatigue resistance of the male screw is improved and the bolt is effective for use in a portion where the male screw is subject to a repetitive stress.
    Type: Application
    Filed: July 8, 2011
    Publication date: November 3, 2011
    Inventors: Norikazu TEZUKA, Kazuharu Hirokawa, Keisuke Ihara, Kei Osawa, Hiroshi Ishikawa, Taiji Torigoe, Ryuichi Yamamoto, Yukihiro Hashimoto, Nobuyuki Izutsu, Koji Takahashi
  • Publication number: 20110211941
    Abstract: A structure that mounts to a rotation shaft a lever that causes this rotation shaft to rotate, including a plurality of engaging members that are provided in the lever so as to be offset from the center axis of the rotation shaft, and that are capable of advancing toward and retracting from the outer periphery of the rotation shaft, and a plurality of abutted faces that are provided on the outer periphery of the rotation shaft so that the distal end faces of the plurality of engaging members respectively make contact, in which, when at least one of the engaging members and the abutted face that corresponds to that engaging member are in contact, relative rotation of the rotation shaft about the axis thereof in one direction with respect to the lever is restricted, and when another engaging member and another abutted face corresponding to the engaging member are in contact, relative rotation of the rotation shaft about the axis thereof in the other direction with respect to the lever is restricted.
    Type: Application
    Filed: September 3, 2009
    Publication date: September 1, 2011
    Applicant: MITSUBISHI HEAVY INDUSTRIES, LTD.
    Inventors: Kazuharu Hirokawa, Eiichi Tsutsumi, Masaru Nishikatsu
  • Publication number: 20100220944
    Abstract: To reduce the amount of lubricating oil released (supplied) between the outer circumferential surface of a rotation shaft and the inner circumferential surfaces of pads, so as to reduce the churning loss, and to reduce the bearing loss. The journal bearing comprises: a plurality of pads arranged radially inside a lower half-carrier ring at intervals, for receiving load from the rotation shaft; and a plurality of pad stops respectively arranged at the circumferentially opposite ends of the respective pads, for restraining circumferential movements of the respective pads, wherein, among these pad stops, the pad stops other than the pad stop located in the most forward position in the axial rotation direction of the rotation shaft have functions as oiling nozzles for releasing lubricating oil between the outer circumferential surface of the rotation shaft and the inner circumferential surfaces of the pads.
    Type: Application
    Filed: November 23, 2009
    Publication date: September 2, 2010
    Inventors: Yuichiro Waki, Takashi Nakano, Shingo Yamasue, Shingo Tanaka, Takaaki Kaikogi, Kazuharu Hirokawa
  • Publication number: 20090003968
    Abstract: The present invention provides a surface hardening portion 11 that has increased surface hardness and that is applied with a compressive residual stress, at least on the surface of a male screw 10 of a bolt 1. The present invention includes the steps of cutting to form the male screw 10 of the bolt 1, and processing to provide at least on the surface of the male screw 10 of the bolt 1 the surface hardening portion 11 that has increased hardness and that is applied with a compressive residual stress. As a result, the present invention can improve the fatigue resistance of the male screw 10 and the bolt is effective as a bolt to be used in a portion where the male screw 10 is subject to a repetitive stress.
    Type: Application
    Filed: January 25, 2007
    Publication date: January 1, 2009
    Inventors: Norikazu Tezuka, Kazuharu Hirokawa, Keisuke Ihara, Kei Osawa, Hiroshi Ishikawa, Taiji Torigoe, Ryuichi Yamamoto, Yukihiro Hashimoto, Nobuyuki Izutsu, Koji Takahashi
  • Publication number: 20070234703
    Abstract: A first stage rotor disk (50a) and a connecting member (30) on the compressor side are fixed by a spindle bolt (20). The spindle bolt (20) is covered with a tubular member (100), between the first stage rotor disk (50a) and the connecting member (30) on the compressor side.
    Type: Application
    Filed: September 21, 2005
    Publication date: October 11, 2007
    Applicant: MITSUBISHI HEAVY INDUSTRIES LTD.
    Inventors: Kazuo Uematsu, Kazuharu Hirokawa
  • Patent number: 7114915
    Abstract: A refrigerant supplied from a refrigerant supply pipe flows into a first space, being a passage of the refrigerant, from a space between first stage and second stage rotor disks. The refrigerant supplied to the first space is guided to second, third and forth spaces through a gap between a spindle bolt and a bolt hole, during which the rotor disks are warmed up or cooled. In the second stage rotor disk, a refrigerant through hole axially penetrating this rotor disk is provided near the center thereof. The refrigerant flowing into the first space passes through the refrigerant through hole to flow into the second space, to thereby promote the convection in the first, second, third and fourth spaces and equalization of temperatures in the rotor disks.
    Type: Grant
    Filed: January 10, 2003
    Date of Patent: October 3, 2006
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Kazuo Uematsu, Kazuharu Hirokawa
  • Patent number: 6991429
    Abstract: A first stage rotor disk (50a) and a connecting member (30) on the compressor side are fixed by a spindle bolt (20). The spindle bolt (20) is covered with a tubular member (100), between the first stage rotor disk (50a) and the connecting member (30) on the compressor side.
    Type: Grant
    Filed: October 10, 2002
    Date of Patent: January 31, 2006
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Kazuo Uematsu, Kazuharu Hirokawa
  • Patent number: 6807870
    Abstract: A rotary shaft axial elongation measuring method and device enable accurate measuring of rotary shaft axial elongation regardless of the amount of the elongation. Grooves (10, 12), arranged opposite to each other in a turned V shape along the axial direction, are provided in a rotational surface of the rotary shaft (1) whose axial elongation is to be measured. A sensor (14) is arranged opposite the rotational surface of the rotary shaft (1). The sensor (14) generates pulses upon passing of the groves (10, 12) following rotation of the rotary shaft (1). As a circumferential interval between the grooves (10, 12) differs according to the axial directional position of the rotary shaft (1), if the positions of the grooves (10, 12) at the position of the sensor (14) change due to the axial elongation, the interval of the pulses generated by the sensor (14) changes. Thus, by the change in the pulse generation interval, the axial elongation is measured.
    Type: Grant
    Filed: August 14, 2001
    Date of Patent: October 26, 2004
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Mitsuru Kondo, Kazuharu Hirokawa
  • Patent number: 6688847
    Abstract: A shaft structure of a rotor tail end of a gas turbine in which a steam passage for supplying and recovering a steam for cooling rotor blades of the gas turbine extends along a center axis of the rotor assembly of the gas turbine is provided, wherein a center hole of the rotor tail end coaxial to the center axis of the steam passage is formed in the rotor tail end. Provision is also made of a thermal sleeve between the steam passage and the inner surface of the center hole of the rotor tail end, so that a thermal insulation gas layer is formed between the inner surface of the center hole of the rotor tail end and the thermal sleeve. The thermal insulation gas layer is isolated gas-tightly and liquid-tightly from the outside.
    Type: Grant
    Filed: August 31, 2001
    Date of Patent: February 10, 2004
    Assignee: Mitsubishi Heavy Industries, Ltd.
    Inventors: Takeaki Oya, Kazuharu Hirokawa, Tadateru Tanioka, Tanehiro Shinohara, Katsunori Tanaka, Kazuo Uematsu
  • Publication number: 20040007830
    Abstract: A first stage rotor disk (50a) and a connecting member (30) on the compressor side are fixed by a spindle bolt (20). The spindle bolt (20) is covered with a tubular member (100), between the first stage rotor disk (50a) and the connecting member (30) on the compressor side.
    Type: Application
    Filed: April 25, 2003
    Publication date: January 15, 2004
    Inventors: Kazuo Uematsu, Kazuharu Hirokawa