Patents by Inventor Kooji Aizawa

Kooji Aizawa 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: 5839880
    Abstract: Disclosed is a bearing unit which can be used in a drainage pump operated without supply of clean water or a hydraulic pump, which exhibits excellent wear resistance against water containing earth and sand and satisfactory assembling facility, and a method of manufacturing the bearing unit.The contact surface of a bearing made of stainless steel and/or that of a sleeve is applied with a sprayed coating, the main component of which is WC, and which contains one or more elements selected from a group consisting of nickel, chromium and cobalt as a binder material thereof, or a sprayed coating, the main component of which is Cr.sub.3 C.sub.2, and which contains NiCr as a binder material, after the sprayed coating has been formed, heating at from 300.degree. C. to 550.degree. C. is performed for one hour or longer so that hardness and wear resistance equivalent to those of a WC-12% sintered article is attained.
    Type: Grant
    Filed: July 18, 1995
    Date of Patent: November 24, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Ryoji Okada, Kooji Aizawa, Masayuki Yamada, Kenji Otani, Kunio Takada, Mitsuaki Haneda, Toshihiro Yamada
  • Patent number: 5458460
    Abstract: Disclosed is a bearing unit which can be used in a drainage pump operated without supply of clean water or a hydraulic pump, which exhibits excellent wear resistance against water containing earth and sand and satisfactory assembling facility, and a method of manufacturing the bearing unit.The contact surface of a bearing made of stainless steel and/or that of a sleeve is applied with a sprayed coating, the main component of which is WC, and which contains one or more elements selected from a group consisting of nickel, chromium and cobalt as a binder material thereof, or a sprayed coating, the main component of which is Cr.sub.3 C.sub.2, and which contains NiCr as a binder material, after the sprayed coating has been formed, heating at from 300.degree. C. to 550.degree. C. is performed for one hour or longer so that hardness and wear resistance equivalent to those of a WC-12% sintered article is attained.
    Type: Grant
    Filed: February 16, 1994
    Date of Patent: October 17, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Ryoji Okada, Kooji Aizawa, Masayuki Yamada, Kenji Otani, Kunio Takada, Mitsuaki Haneda, Toshihiro Yamada
  • Patent number: 5297927
    Abstract: A vertical shaft type pump including a bearing device in which water in the pump is utilized as lubricating water without supplying water to the bearing from the outside of the pump, thereby repeatedly conducting no-load operation in the air (in such a state that water is not pumped) stably for a long period of time. In the pump, a water storage tank upwardly opened is fixed to a rotary shaft, and the lubricating water (the water in the pump) is retained within the water storage tank so that the bearing is operated while being always soaked in the lubricating water. Also, foreign substances in the water storage tank are mixed with the water without deposition, and the water containing the foreign substances is replaced by the newly pumped water.
    Type: Grant
    Filed: January 28, 1993
    Date of Patent: March 29, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Kooji Aizawa, Katsutoshi Nii, Ryoji Okada, Masayuki Yamada, Kunio Takada
  • Patent number: 5035519
    Abstract: A thrust bearing including a ring-like form plate body, and a plurality of rib members provided on the ring-like form plate body of the thrust bearing. Such a plurality of rib members may be provided on a thrust runner. The rib members cause a difference in load deformation amount in a circumferential direction according to thrust load and generate a wedge-shaped form clearance between a sliding face of the thrust bearing and a sliding face of the thrust runner. Since the wedge-shaped form clearance is formed by utilizing the load deformation, even when the thrust load becomes large, the wedge-shaped form clearance does not become narrow. The occurrence of dynamic pressure by the wedge effect and the formation of a water film can be assured, and the temperature increase between the sliding face of the thrust runner and the sliding face of the thrust bearing can be restrained.
    Type: Grant
    Filed: March 5, 1990
    Date of Patent: July 30, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Kooji Aizawa, Katsutoshi Nii, Kazuhiko Kawaike, Kengo Hasegawa, Akira Saruta, Ryoichi Nakashima