Patents by Inventor Kunio Asai

Kunio Asai 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: 20220159791
    Abstract: This high-frequency hardening apparatus is provided with: an induction heating coil which has a U-shaped part that sandwiches a turbine blade, a pair of linear parts, and a connection part connecting the U-shaped part and the linear parts; a temperature detection unit which detects, in a non-contact manner, temperature around the induction heating coil; a moving mechanism which relatively moves the turbine blade and the induction heating coil in the direction of blade height; an electrical current supply unit which supplies a high-frequency electrical current to the induction heating coil; and a control device which has an electrical current control unit that, on the basis of a detection value provided by the temperature detection unit, controls the magnitude of the high-frequency electrical current supplied from the electrical current supply unit such that the detection value will not exceed a predetermined temperature.
    Type: Application
    Filed: June 26, 2020
    Publication date: May 19, 2022
    Inventors: Kunio ASAI, Keiko SHISHIME, Shuichi ISHIZAWA, Takeshi KUDO, Yurika NAGAI, Katsumi TANAKA
  • Patent number: 11060422
    Abstract: A water quality monitoring system is disclosed including a sampling pipe that acquires steam that passes a bleed pipe that bleeds steam from a low pressure turbine to which steam of low pressure is supplied from among steam turbines, a steam inlet tank into which the steam acquired by the sampling pipe flows, a water quality measurement apparatus that measures the water quality of condensed water condensed from the steam flowed in the steam inlet tank, and a water quality diagnosis apparatus that diagnoses the water quality of the condensed water using a result of the measurement of the water quality measurement apparatus. The steam inlet tank is installed at a location higher than that of the water quality measurement apparatus such that the water quality measurement apparatus measures the water quality of the condensed water boosted to the atmospheric pressure utilizing the head difference.
    Type: Grant
    Filed: February 12, 2019
    Date of Patent: July 13, 2021
    Assignee: Mitsubishi Power, Ltd.
    Inventors: Yuichi Sekine, Kunio Asai, Yuichi Iwamoto, Shingo Tamura
  • Publication number: 20210140928
    Abstract: A rubbing detection device for a rotary machine includes an AE sensor configured to acquire an AE signal of a rotary machine, an index calculation unit configured to calculate a rubbing detecting index for determining the presence or absence of rubbing based on information relating to a phase of the AE signal, and a determination unit configured to determine the presence or absence of rubbing based on the rubbing detecting index.
    Type: Application
    Filed: October 28, 2020
    Publication date: May 13, 2021
    Inventors: Satoshi KUMAGAI, Kunio ASAI, Shuichi ISHIZAWA, Ryo KAWABATA
  • Publication number: 20190301308
    Abstract: A water quality monitoring system is disclosed including a sampling pipe that acquires steam that passes a bleed pipe that bleeds steam from a low pressure turbine to which steam of low pressure is supplied from among steam turbines, a steam inlet tank into which the steam acquired by the sampling pipe flows, a water quality measurement apparatus that measures the water quality of condensed water condensed from the steam flowed in the steam inlet tank, and a water quality diagnosis apparatus that diagnoses the water quality of the condensed water using a result of the measurement of the water quality measurement apparatus. The steam inlet tank is installed at a location higher than that of the water quality measurement apparatus such that the water quality measurement apparatus measures the water quality of the condensed water boosted to the atmospheric pressure utilizing the head difference.
    Type: Application
    Filed: February 12, 2019
    Publication date: October 3, 2019
    Inventors: Yuichi SEKINE, Kunio ASAI, Yuichi IWAMOTO, Shingo TAMURA
  • Patent number: 9784110
    Abstract: It is an objective of the invention to provide a steam turbine rotor that is capable of both reducing SCC susceptibility and improving LCF life thereof. There is provided a steam turbine rotor, comprising a rotor disk in a low pressure final stage L-0, and another rotor disk in a plurality of stages including a stage L-1 positioned closer to a high pressure side than the low pressure final stage L-0, the rotor disk in the low pressure final stage L-0 and the rotor disk in a plurality of stages including the stage L-1 being joined by welding, wherein a material of both the rotor disk in the low pressure final stage L-0 and the rotor disk in a plurality of stages including the stage L-1 is a 12Cr steel and has a tensile strength of 900 to 1200 MPa.
    Type: Grant
    Filed: August 7, 2014
    Date of Patent: October 10, 2017
    Assignee: Mitsubishi Hitachi Power Systems, Ltd.
    Inventors: Kunio Asai, Masahiko Arai, Kenichi Murata
  • Patent number: 9341068
    Abstract: A blade avoids fretting damage while reducing stress occurring at the neck portion caused by a stress relief groove. The blade is disposed on an outer periphery of a rotor, and includes a blade portion, a dovetail portion for holding the blade on the rotor, a platform portion that connects the dovetail portion and the blade portion, and a stress relief groove that connects a side surface of the platform portion and a blade load bearing surface of the dovetail portion. The dovetail portion has a width that increases toward its bottom side within a range from a connection point between the side surface of the platform portion and the stress relief groove to a connection point between the dovetail portion and the stress relief groove.
    Type: Grant
    Filed: August 20, 2012
    Date of Patent: May 17, 2016
    Assignee: Mitsubishi Hitachi Power Systems, Ltd.
    Inventors: Kota Nagano, Kunio Asai
  • Patent number: 9028218
    Abstract: A steam turbine having a fork-type joint structure is provided that secures sufficient strength for endurance of stress corrosion cracking, low-cycle fatigue, and high-cycle fatigue, and extends an operating life while making it possible to endure long-term operation. The turbine includes a rotor having a plurality of rotor forks rowed in an axial direction; a turbine blade having blade forks arranged in the axial direction of the rotor, the blade forks engaged with the rotor forks; a plurality of pin holes whose positions are different from each other in the radial direction of the rotor; and a plurality of fork pins inserted into the plurality of pin holes in the axial direction of the rotor. A clearance exists between an inner diameter of the pin hole of the blade fork and a diameter of the fork pin, the clearance varying depending on positions in the axial direction of the turbine.
    Type: Grant
    Filed: May 30, 2012
    Date of Patent: May 12, 2015
    Assignee: Mitsubishi Hitachi Power Systems, Ltd.
    Inventors: Kunio Asai, Keiko Shishime, Yasuyoshi Harashima, Takeshi Kashiwagi, Hideyuki Nomura, Takafumi Wakasa, Masayoshi Ohhira
  • Publication number: 20150044053
    Abstract: It is an objective of the invention to provide a steam turbine rotor that is capable of both reducing SCC susceptibility and improving LCF life thereof. There is provided a steam turbine rotor, comprising a rotor disk in a low pressure final stage L-0, and another rotor disk in a plurality of stages including a stage L-1 positioned closer to a high pressure side than the low pressure final stage L-0, the rotor disk in the low pressure final stage L-0 and the rotor disk in a plurality of stages including the stage L-1 being joined by welding, wherein a material of both the rotor disk in the low pressure final stage L-0 and the rotor disk in a plurality of stages including the stage L-1 is a 12Cr steel and has a tensile strength of 900 to 1200 MPa.
    Type: Application
    Filed: August 7, 2014
    Publication date: February 12, 2015
    Inventors: Kunio ASAI, Masahiko ARAI, Kenichi MURATA
  • Patent number: 8632313
    Abstract: A turbine rotor blade which is enhanced in erosion resistance and reduced in stress corrosion cracking sensitivity is provided. When a blade tip end of the turbine rotor blade is hardened by heat treatment, hardness at an outer circumferential side in a radial direction is made higher than hardness at an inner circumferential side, and thereby, enhancement in erosion resistance and reduction in stress corrosion cracking sensitivity are made compatible with each other all over in a blade length direction.
    Type: Grant
    Filed: June 23, 2010
    Date of Patent: January 21, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Kunio Asai, Takeshi Kudo, Hideo Yoda, Katsumi Tanaka
  • Publication number: 20130084188
    Abstract: Disclosed herein is a blade that avoids fretting damage, while reducing stress occurring at the neck portion as caused by the stress relief groove. The blade disposed on an outer periphery of a rotor is provided. The blade includes: a blade portion; a dovetail portion for holding the blade on the rotor; a platform portion that connects the dovetail portion and the blade portion; and a stress relief groove that connects a side surface of the platform portion and a blade load bearing surface of the dovetail portion, wherein the dovetail portion has a width that increases toward a bottom side thereof within a range from a connection point between the side surface of the platform portion and the stress relief groove to a connection point between the dovetail portion and the stress relief groove.
    Type: Application
    Filed: August 20, 2012
    Publication date: April 4, 2013
    Applicant: Hitachi, Ltd.
    Inventors: Kota NAGANO, Kunio ASAI
  • Patent number: 8333562
    Abstract: A steam turbine rotor blade has a profile and a cover integrally formed on and at an end of the profile, the leading edge of the cover formed on the profile and the trailing edge of a cover formed on an adjacent preceding profile being in contact and connected with each other by the torsional return force produced during rotation. The cover formed on the profile is provided with a radially-formed stepped portion at the trailing edge, the stepped portion having a height large than the thickness of the cover.
    Type: Grant
    Filed: October 4, 2007
    Date of Patent: December 18, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Kunio Asai, Takeshi Kudo, Tateki Nakamura
  • Publication number: 20120308390
    Abstract: A steam turbine having a fork-type joint structure is provided that secures sufficient strength for endurance of stress corrosion cracking, low-cycle fatigue, and high-cycle fatigue, and extends an operating life while making it possible to endure long-term operation. The turbine includes a rotor having a plurality of rotor forks rowed in an axial direction; a turbine blade having blade forks arranged in the axial direction of the rotor, the blade forks engaged with the rotor forks; a plurality of pin holes whose positions are different from each other in the radial direction of the rotor; and a plurality of fork pins inserted into the plurality of pin holes in the axial direction of the rotor. A clearance exists between an inner diameter of the pin hole of the blade fork and a diameter of the fork pin, the clearance varying depending on positions in the axial direction of the turbine.
    Type: Application
    Filed: May 30, 2012
    Publication date: December 6, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Kunio Asai, Keiko Shishime, Yasuyoshi Harashima, Takeshi Kashiwagi, Hideyuki Nomura, Takafumi Wakasa, Masayoshi Ohhira
  • Publication number: 20120183410
    Abstract: It is an objective of the present invention to provide an effective use of the friction stir processing (FSP) technology for Ti-alloy turbine blades with a long radial length, and provide a Ti-alloy turbine blade having both high erosion resistance and high long term reliability. There is provided a turbine blade made of an ?-? titanium alloy having an average Vickers hardness of 320 Hv or less, the turbine blade having a leading edge, in which: the turbine blade includes, at the leading edge thereof, a first hardened surface region having a thickness of from 0.5 to 3.0 mm and having an average Vickers hardness of 340 Hv or more; and the first hardened surface region is formed by friction stir processing a surface region of the leading edge of the turbine blade.
    Type: Application
    Filed: December 27, 2011
    Publication date: July 19, 2012
    Inventors: Shinya IMANO, Hironori Kamoshida, Satoshi Hirano, Kenichi Murata, Seunghwan Park, Kunio Asai, Takehiko Yoshida
  • Publication number: 20100329884
    Abstract: A turbine rotor blade which is enhanced in erosion resistance and reduced in stress corrosion cracking sensitivity is provided. When a blade tip end of the turbine rotor blade is hardened by heat treatment, hardness at an outer circumferential side in a radial direction is made higher than hardness at an inner circumferential side, and thereby, enhancement in erosion resistance and reduction in stress corrosion cracking sensitivity are made compatible with each other all over in a blade length direction.
    Type: Application
    Filed: June 23, 2010
    Publication date: December 30, 2010
    Inventors: Kunio ASAI, Takeshi Kudo, Hideo Yoda, Katsumi Tanaka
  • Patent number: 7841833
    Abstract: A turbine rotor improved in machinability, appropriately balanced in stress, and having rotor hooks and rotor necks constructed to form an attachment structure with respect to an inverted fir tree blade root that has blade hooks and blade necks. The turbine rotor has rotor hooks and rotor necks constructed to form an attachment structure with respect to an inverted fir tree blade root that has blade hooks and blade necks with an ā€œnā€ number of hooks, where n?3. In this structure, a convex portion of the innermost circumferential rotor hook is formed to be concave in a circumferential direction, with respect to a tangential line that connects a convex portion of the (n?1)th hook from the outermost circumferential rotor hook, and a convex portion of the (n?2)th hook.
    Type: Grant
    Filed: April 3, 2007
    Date of Patent: November 30, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Fumiyuki Suzuki, Kunio Asai, Takeshi Kudo, Tateki Nakamura
  • Patent number: 7794208
    Abstract: In a turbine rotor, a rotor radial-direction hook length (Hri) of an i-th rotor hook counting from the outermost circumference of the rotor and a blade radial-direction hook length (Hbi) of an i-th blade hook counting from the outermost circumference of the blade are set to satisfy the relationship of (Hri>Hbi). In the turbine blade, a rotor circumference-direction neck width (Wri) of an i-th rotor neck counting from the outermost circumference of the rotor and a blade circumference-direction neck width (Wbi) of an i-th blade neck counting from the innermost circumference of the blade are set to satisfy the relationship of (Wri>Wbi).
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: September 14, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Fumiyuki Suzuki, Kunio Asai, Takeshi Kudo, Tateki Nakamura
  • Publication number: 20080175712
    Abstract: A subject of the present invention is to prevent the reduction of rigidity caused by the increased length of a steam turbine rotor blade and the degradation of vibration characteristics. A steam turbine rotor blade according to the present invention comprises a profile and a cover integrally formed on and at an end of the profile, the leading edge of the cover formed on the profile and the trailing edge of a cover formed on an adjacent preceding profile being in contact and connected with each other by the torsional return force produced during rotation, and wherein the cover formed on the profile is provided with a radially-formed stepped portion at the trailing edge, the stepped portion having a height large than the thickness of the cover.
    Type: Application
    Filed: October 4, 2007
    Publication date: July 24, 2008
    Inventors: Kunio ASAI, Takeshi KUDO, Tateki NAKAMURA
  • Publication number: 20070237644
    Abstract: The present invention provides a turbine rotor improved in machinability, appropriately balanced in stress, and having rotor hooks and rotor necks constructed to form an attachment structure with respect to an inverted fir tree blade root that has blade hooks and blade necks. The turbine rotor of the present invention has rotor hooks and rotor necks constructed to form an attachment structure with respect to an inverted fir tree blade root that has blade hooks and blade necks with an ā€œnā€ number of hooks, where n?3. In this structure, a convex portion of the innermost circumferential rotor hook is formed to be concave in a circumferential direction, with respect to a tangential line that connects a convex portion of the (n?1)th hook from the outermost circumferential rotor hook, and a convex portion of the (n?2)th neck.
    Type: Application
    Filed: April 3, 2007
    Publication date: October 11, 2007
    Inventors: Fumiyuki Suzuki, Kunio Asai, Takeshi Kudo, Tateki Nakamura
  • Publication number: 20070077146
    Abstract: In a turbine rotor in which a rotor material has lower tensile strength than a blade material and the difference in tensile strength between both the materials is large, a strength margin on the blade side is properly distributed to a strength margin on the rotor side with the aim of reducing shear stress in a rotor hook, increasing stiffness of the rotor hook, and reducing peak stress in a rotor neck, to thereby provide a steam turbine rotor and an inverted fir-tree turbine blade in which stress balance is made more appropriate depending on a material strength ratio of the blade material to the rotor material. In the turbine rotor, a rotor radial-direction hook length (Hri) of an i-th rotor hook counting from the outermost circumference of the rotor and a blade radial-direction hook length (Hbi) of an i-th blade hook counting from the outermost circumference of the blade are set to satisfy the relationship of (Hri>Hbi).
    Type: Application
    Filed: September 29, 2006
    Publication date: April 5, 2007
    Inventors: Fumiyuki Suzuki, Kunio Asai, Takeshi Kudo, Tateki Nakamura
  • Publication number: 20030009347
    Abstract: Minimization of risks to be incurred by a generating plant firm at the time of the firm's non-fulfillment of an agreement for electric power supply which is attributed to an unscheduled shutdown of power generating equipment that supplies electric power to electric power systems. A service center takes an intermediary action for the conclusion of indemnity insurance agreements, in a lump, between a generating plant firm which has power generating equipment and an insurance company, and contracts another indemnity insurance agreement with an electric power company so that a penalty to be incurred at the time of a non-fulfillment of an agreement for electric power supply can be indemnified by the insurance company. Furthermore, the service center subcontracts a maintenance and management service of the power generating equipment, and offers information of operation information and the maintenance status of the power generating equipment to the insurance company for the calculation of insurance premiums.
    Type: Application
    Filed: March 19, 2002
    Publication date: January 9, 2003
    Inventors: Yasushi Iwai, Shigeaki Namba, Kunio Asai, Katsuyuki Yamasaki