Patents by Inventor Masanori SAWAHATA

Masanori SAWAHATA 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: 20210384779
    Abstract: An object of the present invention is to provide a highly efficient and highly reliable rotary electric machine. A rotary electric machine includes: a stator around which a plurality of coils are wound; and a rotor which is supported to be freely rotatable with a predetermined gap with respect to the stator. The coil has at least one connection portion per turn in a slot of the stator. Conductors to be connected mutually have steps at the connection portion, and are fitted with other conductors so as to mutually fill the steps. The steps have contact surfaces that come into contact with each other in the slot to be electrically conducted. A thermally expandable sheet capable of pressurizing the coil in a radial direction of the stator is arranged in the slot.
    Type: Application
    Filed: January 8, 2020
    Publication date: December 9, 2021
    Inventors: Akeshi TAKAHASHI, Minori NAGATA, Masanori SAWAHATA
  • Patent number: 11075570
    Abstract: There is provided a rotary electric machine that ensures improving a maximum torque and a rated power factor while reducing an increase in a starting current. In view of this, the rotary electric machine includes a shaft, a rotor, and a stator. The rotor is fixed to an outer periphery of the shaft. The stator is located so as to surround an outer periphery of the rotor. The rotor includes a rotor iron core including a plurality of rotor slots located at predetermined intervals in a circumferential direction and rotor bars inserted into the rotor slots. Rotor slits communicate with outer peripheral sides of the rotor slots. The rotor slits have a width ws in a circumferential direction. The width ws is smaller than a height hs in a radial direction of the rotor slit, and when a rated current is denoted as I1, a turn ratio (primary/secondary) is denoted as Tr, and a magnetic permeability in a vacuum is denoted as ?0, a relationship of ws>?0×I1×Tr/0.6 is met.
    Type: Grant
    Filed: July 31, 2017
    Date of Patent: July 27, 2021
    Assignee: Hitachi Industrial Products, Ltd.
    Inventors: Kazuo Nishihama, Masanori Sawahata, Takayuki Koyama, Makoto Imura, Yuuichirou Yoshitake, Kenichi Sugimoto, Kengo Ueda
  • Patent number: 10658905
    Abstract: A rotating electrical machine includes a rotating electrical machine body including a stator, a rotor, a fan configured to circulate a coolant for cooling the stator and the rotor, and a casing containing the stator, the rotor and the fan; and a cooler connected to the rotating electrical machine body. The coolant flows from the machine body into the cooler. The cooler cools the coolant. The coolant flows out of the cooler into the machine body. The cooler has a flow resistance Ra satisfying a relation 0.15<(Ra/Rm)<(P0/P1), wherein Ra is a flow resistance of the coolant in the cooler, Rm is a flow resistance of the coolant in the rotating electrical machine body, P0 is a shutoff pressure of the fan, and P1 is a pressure at an operating point of the fan when the flow resistance Ra of the cooler is assumed to be zero.
    Type: Grant
    Filed: September 7, 2018
    Date of Patent: May 19, 2020
    Assignee: Hitachi Industrial Products, Ltd.
    Inventors: Ryuuichirou Iwano, Masanori Sawahata, Akeshi Takahashi
  • Publication number: 20190140530
    Abstract: There is provided a rotary electric machine that ensures improving a maximum torque and a rated power factor while reducing an increase in a starting current. In view of this, the rotary electric machine includes a shaft, a rotor, and a stator. The rotor is fixed to an outer periphery of the shaft. The stator is located so as to surround an outer periphery of the rotor. The rotor includes a rotor iron core including a plurality of rotor slots located at predetermined intervals in a circumferential direction and rotor bars inserted into the rotor slots. Rotor slits communicate with outer peripheral sides of the rotor slots. The rotor slits have a width ws in a circumferential direction. The width ws is smaller than a height hs in a radial direction of the rotor slit, and when a rated current is denoted as I1, a turn ratio (primary/secondary) is denoted as Tr, and a magnetic permeability in a vacuum is denoted as ?0, a relationship of ws>?0×I1×Tr/0.6 is met.
    Type: Application
    Filed: July 31, 2017
    Publication date: May 9, 2019
    Inventors: Kazuo NISHIHAMA, Masanori SAWAHATA, Takayuki KOYAMA, Makoto IMURA, Yuuichirou YOSHITAKE, Kenichi SUGIMOTO, Kengo UEDA
  • Publication number: 20190109514
    Abstract: A rotating electrical machine includes a rotating electrical machine body including a stator, a rotor, a fan configured to circulate a coolant for cooling the stator and the rotor, and a casing containing the stator, the rotor and the fan; and a cooler connected to the rotating electrical machine body. The coolant flows from the machine body into the cooler. The cooler cools the coolant. The coolant flows out of the cooler into the machine body. The cooler has a flow resistance Ra satisfying a relation 0.15<(Ra/Rm)<(P0/P1), wherein Ra is a flow resistance of the coolant in the cooler, Rm is a flow resistance of the coolant in the rotating electrical machine body, P0 is a shutoff pressure of the fan, and P1 is a pressure at an operating point of the fan when the flow resistance Ra of the cooler is assumed to be zero.
    Type: Application
    Filed: September 7, 2018
    Publication date: April 11, 2019
    Inventors: Ryuuichirou IWANO, Masanori SAWAHATA, Akeshi TAKAHASHI
  • Patent number: 10243430
    Abstract: The invention provides a rotating electrical machine system in which an air volume of a refrigerant is increased near the center of a rotating electrical machine in the axial direction is improved. The rotating electrical machine includes a rotor and a stator, in which the stator core, laminated electromagnetic steel sheets formed by laminating a plurality of electromagnetic steel sheets in the axial direction are divided into a plurality of sets of packet cores, and between one of the packet cores of the plurality of sets and another packet core adjacent to it, there is formed a duct providing a flow channel of the stator, and in a duct situated at the center side from both ends in the axial direction among the duct, there is a portion of two packet cores facing each other across the duct, a diameter direction length of the two packet cores becoming long.
    Type: Grant
    Filed: December 16, 2016
    Date of Patent: March 26, 2019
    Assignee: Hitachi, Ltd.
    Inventors: Daisuke Kori, Ryuichiro Iwano, Masanori Sawahata, Kazuo Nishihama, Motonobu Iizuka, Takayuki Koyama, Kenichi Sugimoto
  • Publication number: 20170187264
    Abstract: The invention provides a rotating electrical machine system in which an air volume of a refrigerant is increased near the center of a rotating electrical machine in the axial direction is improved. The rotating electrical machine includes a rotor and a stator, in which the stator core, laminated electromagnetic steel sheets formed by laminating a plurality of electromagnetic steel sheets in the axial direction are divided into a plurality of sets of packet cores, and between one of the packet cores of the plurality of sets and another packet core adjacent to it, there is formed a duct providing a flow channel of the stator, and in a duct situated at the center side from both ends in the axial direction among the duct, there is a portion of two packet cores facing each other across the duct, a diameter direction length of the two packet cores becoming long.
    Type: Application
    Filed: December 16, 2016
    Publication date: June 29, 2017
    Inventors: Daisuke KORI, Ryuichiro IWANO, Masanori SAWAHATA, Kazuo NISHIHAMA, Motonobu IIZUKA, Takayuki KOYAMA, Kenichi SUGIMOTO
  • Publication number: 20140252910
    Abstract: There is provided an induction machine having a squirrel-cage rotor, the rotor including: a rotor core; a plurality of rotor slots formed on the rotor core and aligned circumferentially at a predetermined interval; a plurality of rotor bars inserted into one of the plurality of rotor slots; and a plurality of rotor slits formed adjacent to the plurality of rotor slots on an outer circumferential side of the rotor core. The each rotor slit is formed as a hollow such that a cross sectional shape thereof is distinguished into three parts of a slit outer circumferential part, a slit intermediate part, and a slit inner circumferential part. A circumferential width of the each rotor slit on an innermost circumferential side is larger than that on an outermost circumferential side. A circumferential width of the slit intermediate part increases from an outer circumferential side toward an inner circumferential side.
    Type: Application
    Filed: March 6, 2014
    Publication date: September 11, 2014
    Applicant: Hitachi, Ltd.
    Inventors: Naoki KUNIHIRO, Kazuo NISHIHAMA, Motonobu IIZUKA, Kenichi SUGIMOTO, Masanori SAWAHATA, Akiyoshi KOMURA
  • Patent number: 8692435
    Abstract: A rotor slot is asymmetrically shaped with respect to a straight line drawn from the central axis of the rotation of the rotor in a radial direction, and has a slot opening, the circumferential width of which is smaller than that of the rotor slot, at the top of the rotor slot, so that a loss generated in the rotor due to a carrier harmonic component can be reduced and the power factor can be improved, enabling a current generated in an armature winding to be suppressed and thereby improving efficiency in a rated operation.
    Type: Grant
    Filed: October 13, 2011
    Date of Patent: April 8, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Masanori Sawahata, Mamoru Kimura, Satoshi Kikuchi, Akiyoshi Komura
  • Patent number: 8546991
    Abstract: A synchronous generator 1 including a rotor having a field winding placed in the slots thereof and a stator having an armature winding placed in the slots thereof, wherein the value of the number of slots per two poles in stator minus the number of slots per two poles in rotor is equal to or greater than +9, or equal to or smaller than ?9.
    Type: Grant
    Filed: July 22, 2009
    Date of Patent: October 1, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Masanori Sawahata, Kazuo Nishihama, Hiroyuki Mikami, Tetsuo Fujigaki, Motonobu Iizuka, Shuji Mizutani
  • Publication number: 20120091850
    Abstract: A rotor slot is asymmetrically shaped with respect to a straight line drawn from the central axis of the rotation of the rotor in a radial direction, and has a slot opening, the circumferential width of which is smaller than that of the rotor slot, at the top of the rotor slot, so that a loss generated in the rotor due to a carrier harmonic component can be reduced and the power factor can be improved, enabling a current generated in an armature winding to be suppressed and thereby improving efficiency in a rated operation.
    Type: Application
    Filed: October 13, 2011
    Publication date: April 19, 2012
    Inventors: Masanori Sawahata, Mamoru Kimura, Satoshi Kikuchi, Akiyoshi Komura
  • Publication number: 20100026008
    Abstract: A synchronous generator 1 including a rotor having a field winding placed in the slots thereof and a stator having an armature winding placed in the slots thereof, wherein the value of the number of slots per two poles in stator minus the number of slots per two poles in rotor is equal to or greater than +9, or equal to or smaller than ?9.
    Type: Application
    Filed: July 22, 2009
    Publication date: February 4, 2010
    Applicant: HITACHI, LTD.
    Inventors: Masanori SAWAHATA, Kazuo NISHIHAMA, Hiroyuki MIKAMI, Tetsuo FUJIGAKI, Motonobu IIZUKA, Shuji MIZUTANI