Patents by Inventor Ryoichi Otaki

Ryoichi Otaki 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: 7347115
    Abstract: A rotary shaft and a rotation driven member are connected as to transmit motive power when the rotary shaft rotates relatively to the rotation driven member. A roller gets displaced to a first position where a frictional force with an outer race and the rotation driven member decreases, thereby permitting transmission of a rotational force from the rotary shaft to the rotation driven member. When the rotation driven member rotates relatively to the rotary shaft, the roller gets displaced to a second position where the frictional force with the outer race and the rotation driven member increases, thereby rotationally fixing the rotation driven member with respect to the outer race. The power transmission from a brake apparatus to an electric motor can be hindered while permitting the power transmission to the brake apparatus from the electric motor by using either a worm exhibiting a relatively low transmission efficiency or a worm wheel.
    Type: Grant
    Filed: February 17, 2003
    Date of Patent: March 25, 2008
    Assignee: NSK Ltd.
    Inventors: Ryoichi Otaki, Tomofumi Yamashita
  • Patent number: 7205688
    Abstract: An actuator has an electric motor, a screw shaft connected to a rotational shaft of the electric motor in such a manner as to be capable of transmitting power, a nut member disposed on peripherally of the screw shaft and connected to the rotational shaft of the electric motor in such a manner as to be capable of transmitting the power and a ball rolling within a spiral groove formed between the screw shaft and the nut member, characterized in that the rotational speed of the screw shaft and the rotational speed of the nut member are different.
    Type: Grant
    Filed: January 20, 2004
    Date of Patent: April 17, 2007
    Assignee: NSK Ltd.
    Inventors: Ryoichi Otaki, Koji Hashimoto
  • Publication number: 20060081076
    Abstract: An actuator has an electric motor, a screw shaft connected to a rotational shaft of the electric motor in such a manner as to be capable of transmitting power, a nut member disposed on peripherally of the screw shaft and connected to the rotational shaft of the electric motor in such a manner as to be capable of transmitting the power and a ball rolling within a spiral groove formed between the screw shaft and the nut member, characterized in that the rotational speed of the screw shaft and the rotational speed of the nut member are different.
    Type: Application
    Filed: January 20, 2004
    Publication date: April 20, 2006
    Inventors: Ryoichi Otaki, Koji Hashimoto
  • Publication number: 20050155444
    Abstract: A rotary shaft (3) and a rotation driven member (4) are so connected as to be capable of transmitting motive power when the rotary shaft (3) rotates relatively to the rotation driven member (4). A roller (6) gets displaced to a first position where a frictional force with an outer race (5) and the rotation driven member (4) decreases, thereby permitting transmission of a rotational force from the rotary shaft (3) to the rotation driven member (4). When the rotation driven member (4) rotates relatively to the rotary shaft (3), the roller (6) gets displaced to a second position where the frictional force with the outer race (5) and the rotation driven member (4) increases, thereby rotationally fixing the rotation driven member (4) with respect to the outer race (5). The power transmission from a brake apparatus (e.g.
    Type: Application
    Filed: February 17, 2003
    Publication date: July 21, 2005
    Applicant: NSK Ltd.
    Inventors: Ryoichi Otaki, Tomofumi Yamashita
  • Patent number: 6908405
    Abstract: A ball screw mechanism that can drive a movable pulley disk in an axial direction includes a screw cylinder and a nut member. A stopper pin is inserted through the screw cylinder from one end surface of the circumferential wall of the screw cylinder to the other end surface. As an end portion of the stopper pin is engaged with a notch portion of a transmission case, the rotation of the screw cylinder is inhibited. A stopper projection is provided on the nut member. As the other end portion of the stopper pin abuts against the stopper projection, the rotation range of the nut member is regulated. The stopper projection and the stopper pin function as excessive fastening preventing means for preventing the excessive fastening of the ball screw mechanism.
    Type: Grant
    Filed: April 28, 2004
    Date of Patent: June 21, 2005
    Assignee: NSK Ltd.
    Inventors: Ryoichi Otaki, Hideki Hashitani
  • Publication number: 20050128035
    Abstract: A portion of an outer face 41a installed with a second electric motor 18b is recessed more than a portion of projecting a switch shaft 2a. By the constitution, an outer diameter D18 of the shifting electric motor 18b is increased while ensuring a rigidity of a switch shaft 2a by restraining an amount of projecting the switch shaft 2a. Further, swift and firm gear change operation is made to be able to carry out by increasing an output of the shifting electric motor 18b.
    Type: Application
    Filed: January 8, 2003
    Publication date: June 16, 2005
    Applicant: NSK LTD.
    Inventors: Ryoichi Otaki, Daisaku Kawada, Hiroshi Suzuki, Hideki Hashitani
  • Patent number: 6860827
    Abstract: In an actuator device which comprises a screw shaft, a nut member, and balls, the nut member moves relatively to the screw shaft in a first axial direction and a second axial direction opposite thereto in a manner such that it is continually subjected to a load in the first axial direction. A ball screw groove of the screw shaft is formed having a loaded surface which is pressed against the balls, on the side of a groove base in the first axial direction. A ball screw groove of the nut member is having a loaded surface which is pressed against the balls, on the side of its groove base in the second axial direction. These loaded surfaces are finished so that their surface roughness is lower than that of the unloaded surfaces.
    Type: Grant
    Filed: May 4, 2004
    Date of Patent: March 1, 2005
    Assignee: NSK Ltd.
    Inventors: Ryoichi Otaki, Hideki Hashitani
  • Publication number: 20040247437
    Abstract: A transmission 3 is provided between a propeller that catches wind to rotate and a generator 5 which is a friction roller transmission of the wedge type functioning as a speed increaser whereby a structure with good generating efficiency is realized with low noise for use in a normal home etc.
    Type: Application
    Filed: August 4, 2004
    Publication date: December 9, 2004
    Inventors: Ryoichi Otaki, Hiroyuki Itoh, Oshima Atsushi, Hideo Okano
  • Publication number: 20040235596
    Abstract: A ball screw mechanism that can drive a movable pulley disk in an axial direction includes a screw cylinder and a nut member. A stopper pin is inserted through the screw cylinder from one end surface of the circumferential wall of the screw cylinder to the other end surface. As an end portion of the stopper pin is engaged with a notch portion of a transmission case, the rotation of the screw cylinder is inhibited. A stopper projection is provided on the nut member. As the other end portion of the stopper pin abuts against the stopper projection, the rotation range of the nut member is regulated. The stopper projection and the stopper pin function as excessive fastening preventing means for preventing the excessive fastening of the ball screw mechanism.
    Type: Application
    Filed: April 28, 2004
    Publication date: November 25, 2004
    Inventors: Ryoichi Otaki, Hideki Hashitani
  • Publication number: 20040204271
    Abstract: In an actuator device which comprises a screw shaft, a nut member, and balls, the nut member moves relatively to the screw shaft in a first axial direction and a second axial direction opposite thereto in a manner such that it is continually subjected to a load in the first axial direction. A ball screw groove of the screw shaft is formed having a loaded surface which is pressed against the balls, on the side of a groove base in the first axial direction. A ball screw groove of the nut member is having a loaded surface which is pressed against the balls, on the side of its groove base in the second axial direction. These loaded surfaces are finished so that their surface roughness is lower than that of the unloaded surfaces.
    Type: Application
    Filed: May 4, 2004
    Publication date: October 14, 2004
    Applicant: NSK Ltd.
    Inventors: Ryoichi Otaki, Hideki Hashitani
  • Publication number: 20040129097
    Abstract: In a traction roller type reduction gear (3a) disposed in the middle of a passage for transmitting power from a starter motor to the rotating shaft of an engine, a relation Pmean>{(Umax)1/2}/9 or Pmean>0.3[GPa] is satisfied, assuming the maximum circumferential speed of a drive side cylindrical surface (42) under use state is Umax [m/sec], and the average contact pressure at the radially outer side contact area (50b) of a movable roller (25) based on the preload of a compression coil spring (45) is Pmean [Gpa]. According to the arrangement, transmission efficiency is ensured by preventing slip at both radially inner and outer side contact areas (49a, 49b, 50a, 50b) even during light load operation and damage such as seizure can be prevented.
    Type: Application
    Filed: October 16, 2003
    Publication date: July 8, 2004
    Inventor: Ryoichi Otaki
  • Patent number: 6691551
    Abstract: The present invention provides a traction coefficient measurement device having a driving roller rotated around a driving shaft, a driven shaft is rotated together with a driven shaft, corresponding to the rotation of the driving roller, based on the engagement with the driving roller, and a load device for applying a resistance to the driven shaft against the rotation, wherein the driving shaft is fixed in position and the driven shaft is supported so as to move to and from the driving shaft, and a press apparatus is used to force the driven shaft to the driving shaft for measurement operation, and the driven shaft is positioned lower than the driving shaft in height, and the traction force acting on the engagement portion between the driving roller and the driven roller is directed in a direction to push the driven shaft downward.
    Type: Grant
    Filed: July 23, 2002
    Date of Patent: February 17, 2004
    Assignee: NSK, Ltd.
    Inventors: Ryoichi Otaki, Hiroya Achiha, Shinichi Natsumeda
  • Patent number: 6644094
    Abstract: The present invention provides a traction coefficient measurement device having a driving roller rotated around a driving shaft, a driven shaft is rotated together with a driven shaft, corresponding to the rotation of the driving roller, based on the engagement with the driving roller, and a load device for applying a resistance to the driven shaft against the rotation, wherein the driving shaft is fixed in position and the driven shaft is supported so as to move to and from the driving shaft, and a press apparatus is used to force the driven shaft to the driving shaft for measurement operation, and the driven shaft is positioned lower than the driving shaft in height, and the traction force acting on the engagement portion between the driving roller and the driven roller is directed in a direction to push the driven shaft downward.
    Type: Grant
    Filed: April 12, 2000
    Date of Patent: November 11, 2003
    Assignee: NSK Ltd.
    Inventors: Ryoichi Otaki, Hiroya Achiha, Shinichi Natsumeda
  • Patent number: 6554730
    Abstract: An auxiliary equipment of driving force for bicycle is provided wherein a reduction gear of the traction roller type is adopted, and the contact pressure between the outer peripheral surfaces of the traction rollers and the outer peripheral surface of the rotatable shaft and the inner peripheral surface of the outer ring is controlled corresponding to the torque to be transmitted, so that the battery is less exhausted and that the traveling distance of the electrically power augmented bicycle is prolonged.
    Type: Grant
    Filed: January 28, 1998
    Date of Patent: April 29, 2003
    Assignee: NSK Ltd.
    Inventors: Koichi Sakai, Ryoichi Otaki, Hisashi Machida, Atsushi Ozawa
  • Publication number: 20020189320
    Abstract: The present invention provides a traction coefficient measurement device comprises a driving roller rotated around a driving shaft, a driven shaft is rotated together with a driven shaft, corresponding to the rotation of the driving roller, based on the engagement with the driving roller, and a load device for applying a resistance to the driven shaft against the rotation, wherein the driving shaft is fixed in position and the driven shaft is supported so as to move to and from the driving shaft, and a press apparatus is used to force the driven shaft to the driving shaft for measurement operation, and the driven shaft is positioned lower than the driving shaft in height, and the traction force acting on the engagement portion between the driving roller and the driven roller is directed in a direction to push the driven shaft downward.
    Type: Application
    Filed: July 23, 2002
    Publication date: December 19, 2002
    Applicant: NSK Ltd.
    Inventors: Ryoichi Otaki, Hiroya Achiha, Shinichi Natsumeda
  • Patent number: 6260654
    Abstract: A frictional transmission comprises first and second rotary shafts arranged in directions in which the central axes thereof crossed each other, a roller supported coaxially with the first rotary shaft for rotating with the first rotary shaft, a first frictional surface provided on the roller coaxially with the first rotary shaft, a disc supported coaxially with the second rotary shaft for rotating with the second rotary shaft, and a second frictional surface provided on this disc coaxially with the second rotary shaft. The second frictional surface and the first frictional surface are brought into frictional engagement with each other. A loading cam device is arranged so as to press the second frictional surface toward the first frictional surface at the time of driving. A further disc coaxial with the aforementioned disc is disposed in the environs of the second rotary shaft, and the roller is sandwiched by and between the two discs.
    Type: Grant
    Filed: February 4, 1999
    Date of Patent: July 17, 2001
    Assignee: NSK Ltd.
    Inventors: Hiroyuki Ito, Hisashi Machida, Ryoichi Otaki, Toshihiro Fukuda, Hiroshi Eda, Kazuo Chikaraishi
  • Patent number: 5931759
    Abstract: A friction-roller speed changer has three intermediate rollers (12a, 12b, 12c). Two rollers (12a, 12b) of which act as a wedge roller and can be moved into the narrower area of an annular space (10) by the transmission of power, wherein during power transmission from the input side in the normal state to the output side. The other intermediate roller (12a or 12b), which does not act as the wedge roller, moves into the wider area of the annular space (10) against the elastic force of the spring (14) whereby transmission efficiency for bidirectional rotation is maintained while preventing backflow of power.
    Type: Grant
    Filed: May 7, 1998
    Date of Patent: August 3, 1999
    Assignee: NSK Ltd.
    Inventors: Ryoichi Otaki, Koichi Sakai, Hisashi Machida