Patents by Inventor Takuma HAYAKAWA
Takuma HAYAKAWA 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).
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Patent number: 11469016Abstract: An R-T-B based sintered magnet containing a first heavy rare earth element, in which R includes Nd, T includes Co and Fe, the first heavy rare earth element includes Tb or Dy, the R-T-B based sintered magnet has a region in which a concentration of the first heavy rare earth element decreases from the surface toward the inside, a first grain boundary phase which contains the first heavy rare earth element and Nd but does not contain Co is present in one cross section including the region, and an area occupied by the first grain boundary phase in one cross section including the region is 1.8% or less.Type: GrantFiled: June 23, 2020Date of Patent: October 11, 2022Assignee: TDK CorporationInventors: Ayato Kakoki, Makoto Iwasaki, Tetsuya Hidaka, Takuma Hayakawa
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Publication number: 20210305852Abstract: A rare earth permanent magnet has a first surface and satisfies A1<B1, A1?C1, and A1?D1 where A1 is a coercive force of a portion a1 including a center of gravity of the first surface, B1 is a coercive force of a portion b1, C1 is a coercive force of a portion c1, and D1 is a coercive force of a portion d1, and a heavy rare earth element is present on a top layer of the first surface.Type: ApplicationFiled: March 22, 2021Publication date: September 30, 2021Applicant: TDK CorporationInventor: Takuma HAYAKAWA
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Patent number: 10964463Abstract: Provided is an alloy for R-T-B based rare earth magnet. “R” is one or more of a rare earth element, ‘T’ is one or more of a transition metal element essentially including Fe or Fe and Co, and “B” is boron. The alloy includes a single or a plural number of main phase (A), having a minimum length of 10 ?m or more and a maximum length of 30 ?m or more and 300 ?m or less, in a cross section cut along a thickness direction of the alloy. The main phase (A) includes an R2T14B phase, and an area ratio of the main phase (A) to an entire cross section is 2% or more and 60% or less.Type: GrantFiled: March 27, 2018Date of Patent: March 30, 2021Assignee: TDK CORPORATIONInventors: Takuma Hayakawa, Makoto Iwasaki, Tetsuya Hidaka, Eiji Kato, Hidetake Kitaoka
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Patent number: 10848023Abstract: Provided is a motor including a permanent magnet, in which the permanent magnet includes a high temperature side permanent magnet part exposed to a high temperature inside the motor, and a low temperature side permanent magnet part exposed to a temperature lower than the high temperature inside the motor, and a coercive force of the high temperature side permanent magnet part is higher than the coercive force of the low temperature side permanent magnet part.Type: GrantFiled: March 27, 2018Date of Patent: November 24, 2020Assignee: TDK CORPORATIONInventors: Hidetake Kitaoka, Makoto Iwasaki, Tetsuya Hidaka, Eiji Kato, Takuma Hayakawa
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Patent number: 10825589Abstract: Provided is an R-T-B based rare earth magnet. R is one or more rare earth elements, T is one or more transition metal elements essentially including Fe or Fe and Co, and B is boron. B content with respect to a total R-T-B based rare earth magnet is 0.80 mass % or more and 0.98 mass % or less. The R-T-B based rare earth magnet includes an R1T4B4 phase.Type: GrantFiled: March 22, 2018Date of Patent: November 3, 2020Assignee: TDK CORPORATIONInventors: Makoto Iwasaki, Tetsuya Hidaka, Eiji Kato, Takuma Hayakawa, Hidetake Kitaoka
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Publication number: 20200321151Abstract: An R-T-B based sintered magnet containing a first heavy rare earth element, in which R includes Nd, T includes Co and Fe, the first heavy rare earth element includes Tb or Dy, the R-T-B based sintered magnet has a region in which a concentration of the first heavy rare earth element decreases from the surface toward the inside, a first grain boundary phase which contains the first heavy rare earth element and Nd but does not contain Co is present in one cross section including the region, and an area occupied by the first grain boundary phase in one cross section including the region is 1.8% or less.Type: ApplicationFiled: June 23, 2020Publication date: October 8, 2020Applicant: TDK CorporationInventors: Ayato Kakoki, Makoto Iwasaki, Tetsuya Hidaka, Takuma Hayakawa
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Patent number: 10755840Abstract: An R-T-B based sintered magnet includes “R”, “T”, and “B”. “R” represents a rare earth element. “T” represents a metal element other than rare earth elements including at least Fe, Cu, Mn, Al, Co, Ga, and Zr. “B” represents boron or boron and carbon. With respect to 100 mass % of a total mass of the R-T-B based sintered magnet, a content of “R” is 28.0 to 31.5 mass %, a content of Cu is 0.04 to 0.50 mass %, a content of Mn is 0.02 to 0.10 mass %, a content of Al is 0.15 to 0.30 mass %, a content of Co is 0.50 to 3.0 mass %, a content of Ga is 0.08 to 0.30 mass %, a content of Zr is 0.10 to 0.25 mass %, and a content of “B” is 0.85 to 1.0 mass %.Type: GrantFiled: May 1, 2018Date of Patent: August 25, 2020Assignee: TDK CORPORATIONInventors: Tetsuya Hidaka, Takuma Hayakawa, Makoto Iwasaki, Ayato Kakoki
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Patent number: 10748683Abstract: An R-T-B based sintered magnet includes “R”, “T”, and “B”. “R” represents a rare earth element including at least Tb. “T” represents a metal element except rare earth elements including at least Fe, Cu, Mn, Al, and Co. “B” represents boron or boron and carbon. With respect to 100 mass % of a total mass of the R-T-B based sintered magnet, a content of “R” is 28.0 to 32.0 mass %, a content of Cu is 0.04 to 0.50 mass %, a content of Mn is 0.02 to 0.10 mass %, a content of Al is 0.15 to 0.30 mass %, a content of Co is 0.50 to 3.0 mass %, and a content of “B” is 0.85 to 1.0 mass %. Tb2/Tb1 is 0.40 to less than 1.0, where Tb1 and Tb2 (mass %) denote a content of Tb at a surface portion and at a core portion, respectively.Type: GrantFiled: October 4, 2016Date of Patent: August 18, 2020Assignee: TDK CORPORATIONInventors: Tetsuya Hidaka, Takuma Hayakawa, Makoto Iwasaki, Ayato Kakoki, Naoto Tsukamoto, Fumitaka Baba
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Patent number: 10242777Abstract: Provided is a sintered magnet that is an R-T-B based sintered magnet having a region having a concentration of at least one heavy rare earth element decreasing from the surface toward the inside, in which the at least one heavy rare earth element includes at least either of Tb or Dy, R includes Nd, T includes Fe, Co, and Cu, there is a grain boundary phase containing at least either of Tb or Dy and Nd between two main phase particles, and a value obtained by subtracting a half value width of a concentration distribution curve of Cu from a half value width of a concentration distribution curve of Tb or Dy in a part including the grain boundary phase is from 10 to 20 nm.Type: GrantFiled: January 31, 2017Date of Patent: March 26, 2019Assignee: TDK CorporationInventors: Makoto Iwasaki, Tetsuya Hidaka, Takuma Hayakawa, Ayato Kakoki, Yoshinori Fujikawa, Syota Goto, Haruna Nakajima, Takeshi Masuda, Chikara Ishizaka
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Publication number: 20190074114Abstract: Provided is a sintered magnet that is an R-T-B based sintered magnet having a region having a concentration of at least one heavy rare earth element decreasing from the surface toward the inside, in which the at least one heavy rare earth element includes at least either of Tb or Dy, R includes Nd, T includes Fe, Co, and Cu, there is a grain boundary phase containing at least either of Tb or Dy and Nd between two main phase particles, and a value obtained by subtracting a half value width of a concentration distribution curve of Cu from a half value width of a concentration distribution curve of Tb or Dy in a part including the grain boundary phase is from 10 to 20 nm.Type: ApplicationFiled: November 6, 2018Publication date: March 7, 2019Applicant: TDK CorporationInventors: Makoto IWASAKI, Tetsuya HIDAKA, Takuma HAYAKAWA, Ayato KAKOKI, Yoshinori FUJIKAWA, Syota GOTO, Haruna NAKAJIMA, Takeshi MASUDA, Chikara ISHIZAKA
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Publication number: 20180294082Abstract: An R-T-B based sintered magnet includes “R”, “T”, and “B”. “R” represents a rare earth element. “T” represents a metal element other than rare earth elements including at least Fe, Cu, Mn, Al, Co, Ga, and Zr. “B” represents boron or boron and carbon. With respect to 100 mass % of a total mass of the R-T-B based sintered magnet, a content of “R” is 28.0 to 31.5 mass %, a content of Cu is 0.04 to 0.50 mass %, a content of Mn is 0.02 to 0.10 mass %, a content of Al is 0.15 to 0.30 mass %, a content of Co is 0.50 to 3.0 mass %, a content of Ga is 0.08 to 0.30 mass %, a content of Zr is 0.10 to 0.25 mass %, and a content of “B” is 0.85 to 1.0 mass %.Type: ApplicationFiled: May 1, 2018Publication date: October 11, 2018Applicant: TDK CORPORATIONInventors: Tetsuya HIDAKA, Takuma HAYAKAWA, Makoto IWASAKI, Ayato KAKOKI
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Publication number: 20180287441Abstract: Provided is a motor including a permanent magnet, in which the permanent magnet includes a high temperature side permanent magnet part exposed to a high temperature inside the motor, and a low temperature side permanent magnet part exposed to a temperature lower than the high temperature inside the motor, and a coercive force of the high temperature side permanent magnet part is higher than the coercive force of the low temperature side permanent magnet part.Type: ApplicationFiled: March 27, 2018Publication date: October 4, 2018Applicant: TDK CORPORATIONInventors: Hidetake KITAOKA, Makoto IWASAKI, Tetsuya HIDAKA, Eiji KATO, Takuma HAYAKAWA
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Publication number: 20180286544Abstract: Provided is an alloy for R-T-B based rare earth magnet. “R” is one or more of a rare earth element, ‘T’ is one or more of a transition metal element essentially including Fe or Fe and Co, and “B” is boron. The alloy includes a single or a plural number of main phase (A), having a minimum length of 10 ?m or more and a maximum length of 30 ?m or more and 300 ?m or less, in a cross section cut along a thickness direction of the alloy. The main phase (A) includes an R2T14B phase, and an area ratio of the main phase (A) to an entire cross section is 2% or more and 60% or less.Type: ApplicationFiled: March 27, 2018Publication date: October 4, 2018Applicant: TDK CORPORATIONInventors: Takuma HAYAKAWA, Makoto IWASAKI, Tetsuya HIDAKA, Eiji KATO, Hidetake KITAOKA
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Publication number: 20180277288Abstract: Provided is an R-T-B based rare earth magnet. R is one or more rare earth elements, T is one or more transition metal elements essentially including Fe or Fe and Co, and B is boron. B content with respect to a total R-T-B based rare earth magnet is 0.80 mass % or more and 0.98 mass % or less. The R-T-B based rare earth magnet includes an R1T4B4 phase.Type: ApplicationFiled: March 22, 2018Publication date: September 27, 2018Applicant: TDK CORPORATIONInventors: Makoto IWASAKI, Tetsuya HIDAKA, Eiji KATO, Takuma HAYAKAWA, Hidetake KITAOKA
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Patent number: 10026532Abstract: An R-T-B based sintered magnet includes “R”, “T”, and “B”. “R” represents a rare earth element. “T” represents a metal element other than rare earth elements including at least Fe, Cu, Mn, Al, Co, Ga, and Zr. “B” represents boron or boron and carbon. With respect to 100 mass % of a total mass of the R-T-B based sintered magnet, a content of “R” is 28.0 to 31.5 mass %, a content of Cu is 0.04 to 0.50 mass %, a content of Mn is 0.02 to 0.10 mass %, a content of Al is 0.15 to 0.30 mass %, a content of Co is 0.50 to 3.0 mass %, a content of Ga is 0.08 to 0.30 mass %, a content of Zr is 0.10 to 0.25 mass %, and a content of “B” is 0.85 to 1.0 mass %.Type: GrantFiled: October 4, 2016Date of Patent: July 17, 2018Assignee: TDK CORPORATIONInventors: Tetsuya Hidaka, Takuma Hayakawa, Makoto Iwasaki, Ayato Kakoki
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Patent number: 9991035Abstract: An R-T-B based sintered magnet includes “R”, “T”, and “B”. “R” represents a rare earth element. “T” represents a metal element other than rare earth elements including at least Fe, Cu, Mn, Al, Co, Ga, and Zr. “B” represents boron or boron and carbon. With respect to 100 mass % of a total mass of the R-T-B based sintered magnet, a content of “R” is 28.0 to 31.5 mass %, a content of Cu is 0.04 to 0.50 mass %, a content of Mn is 0.02 to 0.10 mass %, a content of Al is 0.15 to 0.30 mass %, a content of Co is 0.50 to 3.0 mass %, a content of Ga is 0.08 to 0.30 mass %, a content of Zr is 0.10 to 0.25 mass %, and a content of “B” is 0.85 to 1.0 mass %.Type: GrantFiled: October 4, 2016Date of Patent: June 5, 2018Assignee: TDK CORPORATIONInventors: Tetsuya Hidaka, Takuma Hayakawa, Makoto Iwasaki, Ayato Kakoki
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Publication number: 20180025820Abstract: An R-T-B based sintered magnet containing a first heavy rare earth element, in which R includes Nd, T includes Co and Fe, the first heavy rare earth element includes Tb or Dy, the R-T-B based sintered magnet has a region in which a concentration of the first heavy rare earth element decreases from the surface toward the inside, a first grain boundary phase which contains the first heavy rare earth element and Nd but does not contain Co is present in one cross section including the region, and an area occupied by the first grain boundary phase in one cross section including the region is 1.8% or less.Type: ApplicationFiled: July 21, 2017Publication date: January 25, 2018Applicant: TDK CorporationInventors: Ayato KAKOKI, Makoto IWASAKI, Tetsuya HIDAKA, Takuma HAYAKAWA
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Publication number: 20170221616Abstract: Provided is a sintered magnet that is an R-T-B based sintered magnet having a region having a concentration of at least one heavy rare earth element decreasing from the surface toward the inside, in which the at least one heavy rare earth element includes at least either of Tb or Dy, R includes Nd, T includes Fe, Co, and Cu, there is a grain boundary phase containing at least either of Tb or Dy and Nd between two main phase particles, and a value obtained by subtracting a half value width of a concentration distribution curve of Cu from a half value width of a concentration distribution curve of Tb or Dy in a part including the grain boundary phase is from 10 to 20 nm.Type: ApplicationFiled: January 31, 2017Publication date: August 3, 2017Applicant: TDK CorporationInventors: Makoto IWASAKI, Tetsuya HIDAKA, Takuma HAYAKAWA, Ayato KAKOKI, Yoshinori FUJIKAWA, Syota GOTO, Haruna NAKAJIMA, Takeshi MASUDA, Chikara ISHIZAKA
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Publication number: 20170103835Abstract: An R-T-B based sintered magnet includes “R”, “T”, and “B”. “R” represents a rare earth element including at least Tb. “T” represents a metal element except rare earth elements including at least Fe, Cu, Mn, Al, and Co. “B” represents boron or boron and carbon. With respect to 100 mass % of a total mass of the R-T-B based sintered magnet, a content of “R” is 28.0 to 32.0 mass %, a content of Cu is 0.04 to 0.50 mass %, a content of Mn is 0.02 to 0.10 mass %, a content of Al is 0.15 to 0.30 mass %, a content of Co is 0.50 to 3.0 mass %, and a content of “B” is 0.85 to 1.0 mass %. Tb2/Tb1 is 0.40 to less than 1.0, where Tb1 and Tb2 (mass %) denote a content of Tb at a surface portion and at a core portion, respectively.Type: ApplicationFiled: October 4, 2016Publication date: April 13, 2017Applicant: TDK CORPORATIONInventors: Tetsuya HIDAKA, Takuma HAYAKAWA, Makoto IWASAKI, Ayato KAKOKI, Naoto TSUKAMOTO, Fumitaka BABA
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Publication number: 20170103836Abstract: An R-T-B based sintered magnet includes “R”, “T”, and “B”. “R” represents a rare earth element. “T” represents a metal element other than rare earth elements including at least Fe, Cu, Mn, Al, Co, Ga, and Zr. “B” represents boron or boron and carbon. With respect to 100 mass % of a total mass of the R-T-B based sintered magnet, a content of “R” is 28.0 to 31.5 mass %, a content of Cu is 0.04 to 0.50 mass %, a content of Mn is 0.02 to 0.10 mass %, a content of Al is 0.15 to 0.30 mass %, a content of Co is 0.50 to 3.0 mass %, a content of Ga is 0.08 to 0.30 mass %, a content of Zr is 0.10 to 0.25 mass %, and a content of “B” is 0.85 to 1.0 mass %.Type: ApplicationFiled: October 4, 2016Publication date: April 13, 2017Applicant: TDK CORPORATIONInventors: Tetsuya HIDAKA, Takuma HAYAKAWA, Makoto IWASAKI, Ayato KAKOKI