Patents by Inventor Kazutoyo Murakami

Kazutoyo Murakami 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: 9694567
    Abstract: A fluid dynamic bearing apparatus with an increased adhesive strength between a component having an adhesion fixing face and a bracket is provided by appropriately controlling the adhesion gap. Materials for a bracket and a housing are selected so that the value obtained by dividing the linear expansion coefficient of the housing fixed to the inner periphery of the bracket by the linear expansion coefficient of the bracket having a portion for mounting a stator coil of a motor is not lower than 0.5 but not higher than 2.0. An adhesion fixing face formed on the outer periphery of the housing is adhesively fixed to the inner circumferential surface of the bracket with an anaerobic adhesive or an epoxy-based adhesive.
    Type: Grant
    Filed: September 24, 2014
    Date of Patent: July 4, 2017
    Assignee: NTN CORPORATION
    Inventors: Kazutoyo Murakami, Masaki Egami
  • Patent number: 9062380
    Abstract: The present invention provides a pore-sealing agent and a member of coating a spray deposit. The pore-sealing agent is excellent in permeability into pores (gaps) of a spray deposit and can be favorably filled thereinto and is capable of sealing pores until gaps in a spray deposit material are substantially entirely filled. The pore-sealing agent contains an epoxy group-containing component and a hardener and does not contain a polymerizable vinyl group-containing solvent. The epoxy group-containing component is a mixture containing a polyglycidyl ether compound in which the number of epoxy groups contained in one molecule is not less than three as and, an alkylenediglycidyl ether compound or a cyclic aliphatic diepoxy compound, both of which contain two epoxy groups in one molecule thereof. Excluding the hardener, the mixing ratio of the polyglycidyl ether compound to the epoxy group-containing component of the mixture is 10 to 95 wt %.
    Type: Grant
    Filed: April 12, 2007
    Date of Patent: June 23, 2015
    Assignee: NTN CORPORATION
    Inventor: Kazutoyo Murakami
  • Publication number: 20150007937
    Abstract: A fluid dynamic bearing apparatus with an increased adhesive strength between a component having an adhesion fixing face and a bracket is provided by appropriately controlling the adhesion gap. Materials for a bracket and a housing are selected so that the value obtained by dividing the linear expansion coefficient of the housing fixed to the inner periphery of the bracket by the linear expansion coefficient of the bracket having a portion for mounting a stator coil of a motor is not lower than 0.5 but not higher than 2.0. An adhesion fixing face formed on the outer periphery of the housing is adhesively fixed to the inner circumferential surface of the bracket with an anaerobic adhesive or an epoxy-based adhesive.
    Type: Application
    Filed: September 24, 2014
    Publication date: January 8, 2015
    Applicant: NTN CORPORATION
    Inventors: Kazutoyo Murakami, Masaki Egami
  • Patent number: 8821024
    Abstract: The present invention provides a member for a rolling bearing (1) which is capable of decreasing the amount of carbon dioxide generated from a polymeric member in discarding the rolling bearing, contributing to restraint or prevention of an increase in the concentration of the carbon dioxide in the atmosphere or a decrease of the concentration thereof in the atmosphere, and allows a continuous use temperature to be high and an endurance time to be long and a rolling bearing using the member. The member for the rolling bearing (1) is composed of a molding of a polymeric elastic body or a synthetic resin composition. The member is at least one member selected from among an inner ring (2), an outer ring (3), rolling elements (4), a retainer (5), and a sealing member (6). A raw material derived from a biomass is at least partially used for a producing raw material of a polymeric matrix composing the polymeric elastic body or the synthetic resin composition.
    Type: Grant
    Filed: February 20, 2009
    Date of Patent: September 2, 2014
    Assignee: NTN Corporation
    Inventors: Eiichirou Shimazu, Masaki Egami, Yoshihide Himeno, Kazutoyo Murakami
  • Patent number: 8778242
    Abstract: Provided is a housing for a resin fluid dynamic bearing device in which deterioration with time of a fixing force for another member is mitigated and which can maintain a high bearing performance for a long period of time. The housing formed of a resin composition exhibiting a compression creep amount of 8% or less when a compressive pressure of 80 MPa is applied for 168 hours at an atmosphere temperature of 80° C., provides a sufficient fixing force for the another member fixed with a press-fitting force, for example, a bearing sleeve press-fitted into an inner periphery of the housing even after a long term use. Thus, there is no fear of fixing positions of the another member with respect to the housing being deviated and a high bearing performance is maintained for a long period of time.
    Type: Grant
    Filed: January 30, 2012
    Date of Patent: July 15, 2014
    Assignee: NTN Corporation
    Inventors: Kazutoyo Murakami, Masaki Egami, Kenji Ito, Isao Komori
  • Patent number: 8388226
    Abstract: A dynamic bearing device allows production of a smaller housing at low cost and suppresses ion elution from the resin portion to thereby maintain cleanliness in the dynamic bearing device and exert a desired bearing performance. A dynamic bearing device 1 is equipped with a bearing sleeve 8 fixed to the inner periphery of the housing 7, and a rotary member rotatable relative to the bearing sleeve 8 and the housing 7, in which the rotary member is supported in the radial direction and the thrust direction in a non-contact manner by a dynamic pressure action of a lubricant fluid generated in a bearing clearance. The housing 7 is formed by injection molding of a resin composition containing polyphenylene sulfide (PPS) as the base resin and PAN type carbon fibers as a filler.
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: March 5, 2013
    Assignee: NTN Corporation
    Inventors: Kazutoyo Murakami, Masaki Egami, Eiichiro Shimizu, Kenji Ito, Fuminori Satoji
  • Patent number: 8267587
    Abstract: A housing for a fluid lubrication bearing apparatus is formed of a resin composition containing polyphenylene sulfide (PPS) as a base resin. The ratio of the base resin to the resin composition is not lower than 40 vol % but not higher than 70 vol %. Moreover, in the composition, an epoxy compound having two or more epoxy groups per molecule of the compound and epoxy value of 0.5 meq/g or more to the resin composition may be added so that the amount of epoxy groups in the resin composition is 8 meq/100 g or more. A carbon fiber may also be added to the resin composition in an amount of not less than 10 vol % but not more than 35 vol %. An inorganic compound may be further added to the resin composition to be the remainder of the resin composition.
    Type: Grant
    Filed: April 11, 2006
    Date of Patent: September 18, 2012
    Assignee: NTN Corporation
    Inventors: Kazutoyo Murakami, Masaki Egami
  • Publication number: 20120175984
    Abstract: Disclosed is a dynamic bearing device which allows production of a smaller housing at low cost and which suppresses ion elution from the resin portion to thereby maintain cleanliness in the dynamic bearing device and exert a desired bearing performance. A dynamic bearing device 1 is equipped with a bearing sleeve 8 fixed to the inner periphery of the housing 7, and a rotary member rotatable relative to the bearing sleeve 8 and the housing 7, in which the rotary member is supported in the radial direction and the thrust direction in a non-contact manner by a dynamic pressure action of a lubricant fluid generated in a bearing clearance. The housing 7 is formed by injection molding of a resin composition containing polyphenylene sulfide (PPS) as the base resin and PAN type carbon fibers as a filler.
    Type: Application
    Filed: March 20, 2012
    Publication date: July 12, 2012
    Applicant: NTN CORPORATION
    Inventors: Kazutoyo Murakami, Masaki Egami, Eiichiro Shimazu, Kenji Ito, Fuminori Satoji
  • Publication number: 20120126443
    Abstract: Provided is a housing for a resin fluid dynamic bearing device in which deterioration with time of a fixing force for another member is mitigated and which can maintain a high bearing performance for a long period of time. The housing formed of a resin composition exhibiting a compression creep amount of 8% or less when a compressive pressure of 80 MPa is applied for 168 hours at an atmosphere temperature of 80° C., provides a sufficient fixing force for the another member fixed with a press-fitting force, for example, a bearing sleeve press-fitted into an inner periphery of the housing even after a long term use. Thus, there is no fear of fixing positions of the another member with respect to the housing being deviated and a high bearing performance is maintained for a long period of time.
    Type: Application
    Filed: January 30, 2012
    Publication date: May 24, 2012
    Applicant: NTN CORPORATION
    Inventors: Kazutoyo MURAKAMI, Masaki EGAMI, Kenji ITO, Isao KOMORI
  • Publication number: 20110142387
    Abstract: Impregnation of a resin into a sintered body (15) enables reduction in an amount of oil to be impregnated into inner pores. Further, by forming pores into which the resin is unimpregnated in a bearing surface (inner peripheral surface (15a)), it is possible to supply oil retained in the pores into bearing gaps and to cause the pores to function as filters for catching contaminants such as abrasion powder in a bearing.
    Type: Application
    Filed: August 31, 2009
    Publication date: June 16, 2011
    Applicant: NTN CORPORATION
    Inventors: Norihide Sato, Akihiro Omori, Katsutoshi Muramatsu, Kazutoyo Murakami
  • Publication number: 20100316315
    Abstract: The present invention provides a member for a rolling bearing (1) which is capable of decreasing the amount of carbon dioxide generated from a polymeric member in discarding the rolling bearing, contributing to restraint or prevention of an increase in the concentration of the carbon dioxide in the atmosphere or a decrease of the concentration thereof in the atmosphere, and allows a continuous use temperature to be high and an endurance time to be long and a rolling bearing using the member. The member for the rolling bearing (1) is composed of a molding of a polymeric elastic body or a synthetic resin composition. The member is at least one member selected from among an inner ring (2), an outer ring (3), rolling elements (4), a retainer (5), and a sealing member (6). A raw material derived from a biomass is at least partially used for a producing raw material of a polymeric matrix composing the polymeric elastic body or the synthetic resin composition.
    Type: Application
    Filed: February 20, 2009
    Publication date: December 16, 2010
    Applicant: NTN CORPORATION
    Inventors: Eiichirou Shimazu, Masaki Egami, Yoshihide Himeno, Kazutoyo Murakami
  • Publication number: 20100061669
    Abstract: A housing for fluid lubrication bearing apparatuses having improved adhesiveness with other components is provided at low costs. A housing 7 constituting a fluid lubrication bearing apparatus 1 was formed of a resin composition comprising polyphenylene sulfide (PPS) as a base resin, and the ratio of the base resin added to the resin composition was set to not lower than 40 vol % but not higher than 70 vol %. Moreover, a composition prepared by adding an epoxy compound having two or more epoxy groups per molecule of the compound and epoxy value of 0.5 meq/g or more to the resin composition so that the amount of epoxy groups in the resin composition is 8 meq/100 g or more was used. A carbon fiber was added to the resin composition comprising the base resin in an amount of not less than 10 vol % but not more than 35 vol %.
    Type: Application
    Filed: April 11, 2006
    Publication date: March 11, 2010
    Applicant: NTN CORPORATION
    Inventors: Kazutoyo MURAKAMI, Masaki EGAMI
  • Publication number: 20090302697
    Abstract: Provided is a housing for a resin fluid dynamic bearing device in which deterioration with time of a fixing force for another member is mitigated and which can maintain a high bearing performance for a long period of time. The housing formed of a resin composition exhibiting a compression creep amount of 8% or less when a compressive pressure of 80 MPa is applied for 168 hours at an atmosphere temperature of 80° C., provides a sufficient fixing force for the another member fixed with a press-fitting force, for example, a bearing sleeve press-fitted into an inner periphery of the housing even after a long term use. Thus, there is no fear of fixing positions of the another member with respect to the housing being deviated and a high bearing performance is maintained for a long period of time.
    Type: Application
    Filed: April 11, 2006
    Publication date: December 10, 2009
    Applicant: NTN CORPORATION
    Inventors: Kazutoyo Murakami, Masaki Egami, Kenji Ito, Isao Komori
  • Publication number: 20090297076
    Abstract: A hub portion of a fluid dynamic bearing device is formed from a resin composition in which polyphenylene sulfide (PPS) is employed as a base resin and with which carbon fibers are mixed. In this manner, the wear resistance and the conductivity can be improved. Alternatively, both portions of a stationary body and a rotating body of the fluid dynamic bearing device which portions face to each other through a bearing gap are formed from a resin composition in which polyphenylene sulfide (PPS) is employed as the base resin. In this manner, excellent wear resistance can be obtained.
    Type: Application
    Filed: August 10, 2006
    Publication date: December 3, 2009
    Applicant: NTN CORPORATION
    Inventors: Kazutoyo Murakami, Masaki Egami, Kenji Ito, Isao Komori, Mitsuo Sasabe
  • Publication number: 20090245709
    Abstract: The present invention provides a pore-sealing agent and a member of coating a spray deposit. The pore-sealing agent is excellent in permeability into pores (gaps) of a spray deposit and can be favorably filled thereinto and is capable of sealing pores until a state in which gaps in a spray deposit material are substantially entirely filled is obtained. The pore-sealing agent contains an epoxy group-containing component and a hardener and does not contain a polymerizable vinyl group-containing solvent. The epoxy group-containing component is a mixture containing a polyglycidyl ether compound in which the number of epoxy groups contained in one molecule is not less than three as an essential component thereof and in addition, an alkylenediglycidyl ether compound or a cyclic aliphatic diepoxy compound, both of which contain two epoxy groups in one molecule thereof. Excluding the hardener, the mixing ratio of the polyglycidyl ether compound to the epoxy group-containing component of the mixture is 10 to 95 wt %.
    Type: Application
    Filed: April 12, 2007
    Publication date: October 1, 2009
    Applicant: NTN CORPORATION
    Inventor: Kazutoyo Murakami
  • Patent number: 7592799
    Abstract: A magnetic encoder includes a multipolar magnet, having magnetic poles formed therein so as to alternate with each other in a direction circumferentially thereof, and a core metal supporting the multipolar magnet. The multipolar magnet is prepared from a sintered element formed by sintering a powdery mixture of a magnetic powder and a non-magnetic metallic powder. This multipolar magnet is fixed to the core metal to form a unitary component made up of the sintered element and the core metal. The unitary component is subjected to a surface treatment for anticorrosion.
    Type: Grant
    Filed: September 10, 2004
    Date of Patent: September 22, 2009
    Assignee: NTN Corporation
    Inventors: Tatsuo Nakajima, Kouya Oohira, Arito Matsui, Kazutoyo Murakami
  • Publication number: 20090206708
    Abstract: A fluid dynamic bearing apparatus with an increased adhesive strength between a component having an adhesion fixing face and a bracket is provided by appropriately controlling the adhesion gap. Materials for a bracket 6 and a housing 7 are selected so that the value obtained by dividing the linear expansion coefficient of the housing 7 fixed to the inner periphery of the bracket 6 by the linear expansion coefficient of the bracket 6 having a portion 6b for mounting a stator coil 4 of a motor is not lower than 0.5 but not higher than 2.0. An adhesion fixing face 7e formed on the outer periphery of the housing 7 is adhesively fixed to the inner circumferential surface 6a of the bracket 6 with an anaerobic adhesive or an epoxy-based adhesive.
    Type: Application
    Filed: April 11, 2006
    Publication date: August 20, 2009
    Applicant: NTN CORPORATION
    Inventors: Kazutoyo Murakami, Masaki Egami
  • Patent number: 7534045
    Abstract: To provide an IC-tagged bearing device, in which the IC tag can easily and assuredly fitted to the bearing device and can easily be protected from an environment of elevated temperature. A sealing member 5 for sealing a bearing space delimited between inner and outer races 1 and 2 has the IC tag 9 attached thereto. The sealing member 5 includes a core metal 6 provided with an elastic element 7, which is made of rubber or resin, and the IC tag 9 is held embedded in this elastic element 7. The IC tag 9 may be fixedly either bonded by vulcanization or engaged in a groove defined in the elastic element 7.
    Type: Grant
    Filed: November 22, 2004
    Date of Patent: May 19, 2009
    Assignee: NTN Corporation
    Inventors: Tatsuo Nakajima, Kazutoyo Murakami
  • Publication number: 20080309183
    Abstract: Disclosed is a dynamic bearing device which allows production of a smaller housing at low cost and which suppresses ion elution from the resin portion to thereby maintain cleanliness in the dynamic bearing device and exert a desired bearing performance. A dynamic bearing device 1 is equipped with a bearing sleeve 8 fixed to the inner periphery of the housing 7, and a rotary member rotatable relative to the bearing sleeve 8 and the housing 7, in which the rotary member is supported in the radial direction and the thrust direction in a non-contact manner by a dynamic pressure action of a lubricant fluid generated in a bearing clearance. The housing 7 is formed by injection molding of a resin composition containing polyphenylene sulfide (PPS) as the base resin and PAN type carbon fibers as a filler.
    Type: Application
    Filed: August 1, 2005
    Publication date: December 18, 2008
    Applicant: NTN CORPORATION
    Inventors: Kazutoyo Murakami, Masaki Egami, Eiichiro Shimazu, Kenji Ito, Fuminori Satoji
  • Publication number: 20080226211
    Abstract: A magnetic encoder which can be assembled having a thin-walled structure while securing an excellent detection sensitivity and which can provide an excellent moldability by suitably selecting materials. The magnetic encoder includes a multi-pole magnet having a plurality of opposite magnetic poles alternating in a direction circumferentially thereof, and a core metal for supporting the multi-pole magnet. The multi-pole magnet contains a powdery magnetic material mixed in an amount within the range of 20 to 90 vol. % relative to the total volume of the multi-pole magnet. The multi-pole magnet may be a sintered magnet.
    Type: Application
    Filed: April 11, 2008
    Publication date: September 18, 2008
    Applicant: NTN Corporation
    Inventors: Tatsuo Nakajima, Kouya Oohira, Arito Matsui, Kazutoyo Murakami