Patents by Inventor Yoshitomo Yabuuchi

Yoshitomo Yabuuchi 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: 11396872
    Abstract: A nitriding layer (13) is formed on the front surface side of a base material of a cylinder block (7) including an opening side end surface (7B) and each cylinder hole (12). Then, a piston sliding surface (12A) of each cylinder hole (12) is formed as a compound layer-removed hole (17) by removing a compound layer (16) that is located on the front surface side of the nitriding layer (13) by using polishing means such as, for example, honing and so forth. Further, a compound layer-removed surface (18) is formed on a part (A) where a compound layer-removed hole (17) and a cylinder inlet side tapered surface (12B) of each cylinder hole (12) intersect by using the polishing means such as, for example, the honing and so forth. This compound layer-removed surface (18) is formed as a tapered-state inclined surface of an angle ?.
    Type: Grant
    Filed: November 3, 2017
    Date of Patent: July 26, 2022
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Tsuyoshi Yamada, Yoshitomo Yabuuchi, Naoyuki Okuno
  • Publication number: 20210277891
    Abstract: A nitriding layer (13) is formed on the front surface side of a base material of a cylinder block (7) including an opening side end surface (7B) and each cylinder hole (12). Then, a piston sliding surface (12A) of each cylinder hole (12) is formed as a compound layer-removed hole (17) by removing a compound layer (16) that is located on the front surface side of the nitriding layer (13) by using polishing means such as, for example, honing and so forth. Further, a compound layer-removed surface (18) is formed on a part (A) where a compound layer-removed hole (17) and a cylinder inlet side tapered surface (12B) of each cylinder hole (12) intersect by using the polishing means such as, for example, the honing and so forth. This compound layer-removed surface (18) is formed as a tapered-state inclined surface of an angle ?.
    Type: Application
    Filed: November 3, 2017
    Publication date: September 9, 2021
    Inventors: Tsuyoshi YAMADA, Yoshitomo YABUUCHI, Naoyuki OKUNO
  • Publication number: 20130180809
    Abstract: A plurality of rotating side brake disks and a plurality of non-rotating side brake disks are arranged outside in the radial direction from a motor shaft in a brake case while alternately overlapping with each other. A frictional material is provided only on the non-rotating side brake disk in these rotating side brake disk and the non-rotating side brake disk. As a result, the weight of the rotating side brake disk can be reduced, and drag resistance of the rotating side brake disk rotating also in brake release can be reduced.
    Type: Application
    Filed: September 29, 2011
    Publication date: July 18, 2013
    Applicant: HITACHI CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Yoshitomo Yabuuchi, Takashi Niidome, Yutaka Komaru
  • Publication number: 20090090103
    Abstract: A hydraulic drive system is provided with a front casing 50 and a rear ceasing 51. The front casing 50 is formed of a single member, and accommodates therein rotary members, which include a cylinder block 30A and the like, and a part of an output shaft 36 of a hydraulic motor 30 and rotary members, which include a cylinder block 31A and the like, and a part of an output shaft 32 of a hydraulic motor 31. The rear casing 51 is joined to the front casing 50, and has a ports plate 30C and a ports plate 31C arranged therein. The rear casing 51 has an oilway 52 communicating to a first port 30C1 of the ports plate 30C, an oilway 53 communicating to the oilway 52 and also communicating to a first port 31C1 of the ports plate 31C, an oilway 54 communicating to a second port 30C2 of the ports plate 30C, and an oilway 55 communicating to the oilway 54 and also communicating to a second port 31C2 of the ports plate 31C.
    Type: Application
    Filed: May 25, 2006
    Publication date: April 9, 2009
    Applicant: Hitachi Construction Machinery Co., Ltd.
    Inventors: Yoshitomo Yabuuchi, Genroku Sugiyama, Takeshi Kobayashi, Takashi Niidome, Takeshi Kurihara
  • Publication number: 20070180986
    Abstract: A pair of leg portions are provided on a swash plate. A main hydrostatic bearing is provided on one leg portion, in communication with one supply/discharge passage through an oil guide passage, and an auxiliary hydrostatic bearing is provided on the other leg portion, in communication with the oil guide passage. Another main hydrostatic bearing is provided on the other leg portion, in communication with the other supply/discharge passage through an oil guide passage, and another auxiliary hydrostatic bearing is provided on one leg portion, in communication with the oil guide passage. By the main hydrostatic bearings and auxiliary hydrostatic bearings, dissociative forces are generated between the leg portions of the swash plate and a swash plate support member in balance with hydraulic reaction forces which are exerted on the swash plate by pistons.
    Type: Application
    Filed: May 18, 2005
    Publication date: August 9, 2007
    Inventors: Takashi Niidome, Yoshitomo Yabuuchi, Takeshi Kobayashi
  • Patent number: 7243492
    Abstract: A motion converting section (31) and a translation bar (33) of a feedback mechanism (30) are provided between a lateral side of a swash plate (21) and a control sleeve (26) of a regulator (24). When the swash plate (21) is in a neutral position, the motion converting section (31) is located in an initial position (F—F) at one end of axial direction along an axis line (O—O) passing through a tilting center (C) of tilting motions, and, when the swash plate (21) is driven to tilt in a forward or reverse direction, displaced to the other end of axial direction along the axis line (O—O) to convert a tilting motion of the swash plate (21) into an axial displacement. Through the translation bar (33), the axial displacement is transmitted to the control sleeve (26) of the regulator (24) as an axial displacement.
    Type: Grant
    Filed: November 19, 2004
    Date of Patent: July 17, 2007
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Takashi Niidome, Yoshitomo Yabuuchi, Takeshi Kobayashi
  • Publication number: 20070017219
    Abstract: A motion converting section (31) and a translation bar (33) of a feedback mechanism (30) are provided between a lateral side of a swash plate (21) and a control sleeve (26) of a regulator (24). When the swash plate (21) is in a neutral position, the motion converting section (31) is located in an initial position (F-F) at one end of axial direction along an axis line (O-O) passing through a tilting center (C) of tilting motions, and, when the swash plate (21) is driven to tilt in a forward or reverse direction, displaced to the other end of axial direction along the axis line (O-O) to convert a tilting motion of the swash plate (21) into an axial displacement. Through the translation bar (33), the axial displacement is transmitted to the control sleeve (26) of the regulator (24) as an axial displacement.
    Type: Application
    Filed: November 19, 2004
    Publication date: January 25, 2007
    Inventors: Takashi Niidome, Yoshitomo Yabuuchi, Takeshi Kobayashi