Patents by Inventor Kikuo Maeda

Kikuo Maeda 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: 9404531
    Abstract: A bearing apparatus for wheel with ensured high durability by including a part with improved fatigue strength in a non-hardened portion includes an outer member, an inner member, and a roller. The inner member includes a hub ring made of steel and having a wheel attachment flange formed. The hub ring has a hardened portion hardened to attain at least 50 HRC as a result of quench hardening and a non-hardened portion which is a portion other than the hardened portion. Compressive stress in a range from at least 50 MPa to at most 500 MPa remains in the surface of the non-hardened portion.
    Type: Grant
    Filed: July 26, 2007
    Date of Patent: August 2, 2016
    Assignee: NTN CORPORATION
    Inventors: Kikuo Maeda, Hisashi Ohtsuki
  • Patent number: 9346097
    Abstract: A process for manufacturing a rolling contact member comprises preparing a steel member consisting of a steel containing 0.7 mass % or more of carbon; performing hot forging of the steel member prepared in the steel member preparation step to thereby obtain a blank ring as the first forged member; performing turning of the blank ring obtained in the hot forging step to thereby remove part of the blank ring; and performing cold forging of the blank ring wrought in the first turning step to thereby obtain a stepped ring. In the steps subsequent to the cold forging step, on the stepped ring, the area wrought in the first turning step is not subjected to cutting.
    Type: Grant
    Filed: December 2, 2011
    Date of Patent: May 24, 2016
    Assignee: NTN Corporation
    Inventors: Kikuo Maeda, Yuji Okamoto
  • Patent number: 8535457
    Abstract: The invention provides a deep groove ball bearing which exhibits a long life even in a high-temperature environment or an environment involving the penetration of water in spite of its low alloying element content. The outer race, inner race and ball constituting the bearing are made of a steel which contains 0.3 to 0.4% of carbon, 0.3 to 0.7% of silicon, 0.3 to 0.8% of manganese, 0.5 to 1.2% of nickel, 1.6 to 2.5% of chromium, 0.1 to 0.7% of molybdenum and 0.2 to 0.4 of vanadium with the balance consisting of iron and impurities and in a total content of silicon and manganese of 1.0% or below, a total content of nickel and chromium of 2.3% or above and a total content of chromium, molybdenum and vanadium of 3.0% or below.
    Type: Grant
    Filed: May 9, 2008
    Date of Patent: September 17, 2013
    Assignee: NTN Corporation
    Inventor: Kikuo Maeda
  • Publication number: 20120137523
    Abstract: A process for manufacturing a rolling contact member comprises preparing a steel member consisting of a steel containing 0.7 mass % or more of carbon; performing hot forging of the steel member prepared in the steel member preparation step to thereby obtain a blank ring as the first forged member; performing turning of the blank ring obtained in the hot forging step to thereby remove part of the blank ring; and performing cold forging of the blank ring wrought in the first turning step to thereby obtain a stepped ring. In the steps subsequent to the cold forging step, on the stepped ring, the area wrought in the first turning step is not subjected to cutting.
    Type: Application
    Filed: December 2, 2011
    Publication date: June 7, 2012
    Applicant: NTN Corporation
    Inventors: Kikuo Maeda, Yuji Okamoto
  • Patent number: 8192088
    Abstract: There is provided a wheel support bearing assembly in which at least one of the outer member (5) and inner member, which includes a wheel mounting flange (10), is, after having been forged, air cooled or thermally refined. The respective rolling surfaces of the outer member (5) and the inner member are hardened to have a predetermined surface hardness. The root radial dimension of the section of a groove bottom arc in the serrations (9) of the hub unit (1) is regulated to a value within the range of 0.2 mm to 0.8 mm.
    Type: Grant
    Filed: February 19, 2008
    Date of Patent: June 5, 2012
    Assignee: NTN Corporation
    Inventors: Hisashi Ohtsuki, Kikuo Maeda
  • Publication number: 20110081106
    Abstract: A manufacturing method of a thin component is characterized by heating a thin component, and thereafter, while sizing with molds and using molds as cooling media, performing one of quenching and isothermal transformation processes on thin component. Thus, a manufacturing method of a thin component without warping or deformation in heat treatment with even and high hardness, a bearing ring, a thrust needle roller bearing, a manufacturing method of a rolling bearing ring, a rolling bearing ring, and a rolling bearing can be obtained.
    Type: Application
    Filed: December 13, 2010
    Publication date: April 7, 2011
    Applicant: NTN CORPORATION
    Inventors: Kikuo MAEDA, Yuuki Kataoka, Mitsuo Sasabe
  • Patent number: 7909517
    Abstract: A wheel support bearing assembly with a hub axle of enhanced strength and a durability under a rotational bending condition as well as weight reduction, and without changing a shape and a dimension of a wheel mounting flange nor deteriorating a surface runout, and a manufacturing method thereof. A surface hardness is set to 20 HRC or more and than 35 HRC or less by applying an air cooling or a thermal refinement after hot forging a raw material of the hub axle, and a shot peening treatment is applied to an inner diameter portion of the hub axle.
    Type: Grant
    Filed: February 12, 2008
    Date of Patent: March 22, 2011
    Assignee: NTN Corporation
    Inventors: Hisashi Ohtsuki, Kikuo Maeda
  • Patent number: 7867345
    Abstract: A manufacturing method of a thin component is characterized by heating a thin component, and thereafter, while sizing with molds and using molds as cooling media, performing one of quenching and isothermal transformation processes on thin component. Thus, a manufacturing method of a thin component without warping or deformation in heat treatment with even and high hardness, a bearing ring, a thrust needle roller bearing, a manufacturing method of a rolling bearing ring, a rolling bearing ring, and a rolling bearing can be obtained.
    Type: Grant
    Filed: October 1, 2004
    Date of Patent: January 11, 2011
    Assignee: NTN Corporation
    Inventors: Kikuo Maeda, Yuuki Kataoka, Mitsuo Sasabe
  • Publication number: 20100150489
    Abstract: The invention provides a deep groove ball bearing which exhibits a long life even in a high-temperature environment or an environment involving the penetration of water in spite of its low alloying element content. The outer race, inner race and ball constituting the bearing are made of a steel which contains 0.3 to 0.4% of carbon, 0.3 to 0.7% of silicon, 0.3 to 0.8% of manganese, 0.5 to 1.2% of nickel, 1.6 to 2.5% of chromium, 0.1 to 0.7% of molybdenum and 0.2 to 0.4 of vanadium with the balance consisting of iron and impurities and in a total content of silicon and manganese of 1.0% or below, a total content of nickel and chromium of 2.3% or above and a total content of chromium, molybdenum and vanadium of 3.0% or below.
    Type: Application
    Filed: May 9, 2008
    Publication date: June 17, 2010
    Inventor: Kikuo Maeda
  • Patent number: 7707723
    Abstract: A method is provided for producing a roller thrust bearing having a plurality of rows of rollers, the bearing featuring reduced differential slip, reduced friction and wear, and increased longevity without flaking. The method includes forming a cage to accommodate the rollers, crowning the rollers, and arranging the rollers in pockets such that the rollers held by a pocket have respective end surfaces in direct contact with each other.
    Type: Grant
    Filed: August 17, 2005
    Date of Patent: May 4, 2010
    Assignee: NTN Corporation
    Inventors: Kenji Tamada, Kikuo Maeda, Tomoaki Kawamura, Hirokazu Nakashima, Takumi Fujita, Mitsuo Sasabe
  • Patent number: 7690847
    Abstract: A rolling bearing (10) having an outer ring (1), an inner ring (2), and a plurality of rolling elements, wherein at least one of the members, the outer ring (1), inner ring (2) and rolling elements (3), has a nitrogen rich layer and the grain size number of austenite crystal grains is in the range exceeding the number 10.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: April 6, 2010
    Assignee: NTN Corporation
    Inventors: Chikara Ohki, Kikuo Maeda
  • Patent number: 7666346
    Abstract: A steel-member manufacturing facility that can suppress distortion occurring in a quenching process while preventing increase in manufacturing cost includes: a die-cutting apparatus to form a washer; a high-frequency induction heating apparatus for quenching purpose as well as a mold-constraining cooling apparatus that heat the washer as formed and thereafter cool the washer so as to quench-harden the washer; and a high-frequency induction heating apparatus for tempering purpose that heats the quench-hardened washer so as to temper the washer. The high-frequency induction heating apparatus for quenching purpose can heat the washer by induction heating to the temperature of at least Ac1 point. The mold-constraining cooling apparatus uses a mold to constrain the heated washer while using the mold as a cooling member, thereby cooling the washer to the temperature of at most Ms point.
    Type: Grant
    Filed: April 4, 2006
    Date of Patent: February 23, 2010
    Assignee: NTN Corporation
    Inventor: Kikuo Maeda
  • Patent number: 7647887
    Abstract: A thin film forming apparatus includes: a first electrode having a first discharge surface and a second electrode having a second discharge surface, the first discharge surface facing opposite to the second discharge surface to form a discharge space; a gas supply unit for supplying a gas including a thin film formation gas to the discharge space; a power source for discharging and activating the gas by applying a high frequency electric field across the discharge space; and a film transporting mechanism for transporting a protecting film for preventing at least one of the first electrode and the second electrode from being exposed to the activated gas, wherein a thin film is formed by exposing a substrate to the activated gas and, the protecting film is transported in contact with at least one of the first discharge surface and the second discharge surface and with at least a part of a surface other than the discharge surface which continues to the discharge surface.
    Type: Grant
    Filed: March 23, 2004
    Date of Patent: January 19, 2010
    Assignee: Konica Minolta Holdings, Inc.
    Inventors: Kikuo Maeda, Yoshiro Toda, Koji Fukazawa
  • Publication number: 20100002972
    Abstract: There is provided a wheel support bearing assembly in which at least one of the outer member (5) and inner member, which includes a wheel mounting flange (10), is, after having been forged, air cooled or thermally refined. The respective rolling surfaces of the outer member (5) and the inner member are hardened to have a predetermined surface hardness. The root radial dimension of the section of a groove bottom arc in the serrations (9) of the hub unit (1) is regulated to a value within the range of 0.2 mm to 0.8 mm.
    Type: Application
    Filed: February 19, 2008
    Publication date: January 7, 2010
    Inventors: Hisashi Ohtsuki, Kikuo Maeda
  • Publication number: 20090276992
    Abstract: A method for manufacturing a raceway member, in which a hardness of a region to be plastically deformed is controllable in a stable manner and a sufficient rolling contact fatigue life is ensured by making a hardness of a region including a raceway surface sufficiently high, while suppressing increase in the manufacturing cost, includes a steel member preparation step, a heat treatment step, and a finishing step. The heat treatment step includes: a carbonitriding step, in which the steel member is heated to a carbonitriding temperature, which is a temperature not lower than A1 point, and carbonitrided; a temperature holding step, in which the steel member is cooled from the carbonitriding temperature to a temperature range between not lower than a temperature 100° C.
    Type: Application
    Filed: June 11, 2007
    Publication date: November 12, 2009
    Inventors: Kikuo Maeda, Hirokazu Nakashima
  • Publication number: 20090257701
    Abstract: A process for manufacturing a rolling contact member that while simultaneously avoiding the problem attributed to generation of decarburized layer and the problem attributed to scale generation, attains reduction of manufacturing cost. The process comprises the steel member preparation step of preparing a steel member consisting of a steel containing 0.7 mass % or more of carbon; the hot forging step of performing hot forging of the steel member prepared in the steel member preparation step to thereby obtain a blank ring as the first forged member; the first turning step of performing turning of the blank ring obtained in the hot forging step to thereby remove part of the blank ring; and the cold forging step of performing cold forging of the blank ring wrought in the first turning step to thereby obtain a stepped ring. In the steps subsequent to the cold forging step, on the stepped ring, the area wrought in the first turning step is not subjected to cutting operation.
    Type: Application
    Filed: May 21, 2007
    Publication date: October 15, 2009
    Inventors: Kikuo Maeda, Yuji Okamoto
  • Patent number: 7490583
    Abstract: A full-type rolling bearing that can be used under the conditions of high-speed, heavy-load and lowered viscosity of lubricating oil is provided. The full-type rolling bearing is formed of an outer ring, an inner ring and rollers made of steel, at least one of the outer ring, inner ring and rollers has a carbonitrided layer in its surface layer, and the austenite crystal grain size number of the surface layer is larger than 10.
    Type: Grant
    Filed: October 17, 2003
    Date of Patent: February 17, 2009
    Assignee: NTN Corporation
    Inventors: Tadatoshi Suzuki, Kenichi Ichikawa, Kikuo Maeda, Yukio Fujii
  • Publication number: 20090016662
    Abstract: A wheel support bearing assembly with a hub axle (1) of enhanced strength and a durability under a rotational bending condition as well as weight reduction, and without changing a shape and a dimension of a wheel mounting flange (10) nor deteriorating a surface runout, and a manufacturing method thereof. A surface hardness is set to 20 HRC or more and than 35 HRC or less by applying an air cooling or a thermal refinement after hot forging a raw material of the hub axle (1), and a shot peening treatment is applied to an inner diameter portion of the hub axle (1).
    Type: Application
    Filed: February 12, 2008
    Publication date: January 15, 2009
    Applicant: NTN CORPORATION
    Inventors: Hisashi Ohtsuki, Kikuo Maeda
  • Publication number: 20080276458
    Abstract: An inexpensive rolling bearing is proposed which can be used stably for a long time where the lubricating conditions are severe or bending stresses act. Inner and outer rings of rolling bearings mounted in a rocker arm of an automobile are made of high-carbon chrome bearing steel. They are subjected to heat treatment in which after carbonitriding, high-temperature tempering is carried out. Then they are induction hardened to impart resistance to material quality change and a compressive stress of not less than 200 MPa to the surface layer, thereby markedly improving the rolling contact fatigue life and the tension-compression fatigue strength while keeping the material cost as before. Thus, this bearing can be used stably for a long time even though it is a full complement type bearing, lubricating conditions tend to worsen and the outer ring is repeatedly subjected to bending stress from the cam.
    Type: Application
    Filed: July 9, 2008
    Publication date: November 13, 2008
    Inventors: Kikuo Maeda, Yukio Matsubara
  • Publication number: 20080205810
    Abstract: A bearing apparatus for wheel with ensured high durability by including a part with improved fatigue strength in a non-hardened portion includes an outer member, an inner member, and a roller. The inner member includes a hub ring made of steel and having a wheel attachment flange formed. The hub ring has a hardened portion hardened to attain at least 50 HRC as a result of quench hardening and a non-hardened portion which is a portion other than the hardened portion. Compressive stress in a range from at least 50 MPa to at most 500 MPa remains in the surface of the non-hardened portion.
    Type: Application
    Filed: July 26, 2007
    Publication date: August 28, 2008
    Inventors: Kikuo Maeda, Hisashi Ohtsuki