Patents by Inventor Takashi Imanishi

Takashi Imanishi 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: 6328669
    Abstract: A toroidal type continuously variable transmission, includes: at least one pair of disks concentrically disposed on each other and rotatably supported independent from each other; a trunnion swingable about a pivot shaft; a displacement shaft including a support shaft portion and a pivot shaft portion that are parallel and eccentric to each other, the support shaft portion rotatably supported to the circular hole of the trunnion through a radial bearing, the pivot shaft portion being protruded from an inner surface of the middle portion of said trunnion; a power roller nipped between the concave surfaces of the pair of disks while being rotatably supported on an outer circumferential surface of the pivot shaft portion; and a thrust bearings located between the power roller and the inner surface of the middle portion of the trunnions. An eccentric quantity of the displacement shaft being a distance between the support shaft portion and the pivot shaft portion is within a range from 5 mm to 15 mm.
    Type: Grant
    Filed: June 25, 1999
    Date of Patent: December 11, 2001
    Assignee: NSK Ltd.
    Inventors: Takashi Imanishi, Nobuo Goto, Makoto Fujinami, Hiroshi Kato, Nobuaki Mitamura, Hiroyuki Itoh, Seiji Higuchi, Hiroshi Fukushima
  • Publication number: 20010046921
    Abstract: A toroidal type continuously variable transmission, includes: at least one pair of disks concentrically disposed on each other and rotatably supported independent from each other; a trunnion swingable about a pivot shaft; a displacement shaft including a support shaft portion and a pivot shaft portion that are parallel and eccentric to each other, the support shaft portion rotatably supported to the circular hole of the trunnion through a radial bearing, the pivot shaft portion being protruded from an inner surface of the middle portion of said trunnion; a power roller nipped between the concave surfaces of the pair of disks while being rotatably supported on an outer circumferential surface of the pivot shaft portion; and a thrust bearings located between the power roller and the inner surface of the middle portion of the trunnions. An eccentric quantity of the displacement shaft being a distance between the support shaft portion and the pivot shaft portion is within a range from 5 mm to 15 mm.
    Type: Application
    Filed: June 22, 2001
    Publication date: November 29, 2001
    Applicant: NSK LTD.
    Inventors: Takashi Imanishi, Nobuo Goto, Makoto Fujinami, Hiroshi Kato, Nobuaki Mitamura, Hiroyuki Itoh, Seiji Higuchi, Hiroshi Fukushima
  • Patent number: 6261200
    Abstract: In a continuously variable transmission comprising: an input shaft which is rotated by a drive source; an output shaft which takes out a driving force attributing the rotation of the input shaft; and a variator and a planet gear mechanism which are arranged between the input shaft and the output shaft, the variator having a clutch which provides a first mode in which a driving force circulation is carried out, and a second mode in which the driving force circulation is not carried out, the speed of a first driving force transmitting system which is inputted to the planet gear mechanism through the variator and the speed of a second driving force transmitting system which is inputted to the planet gear mechanism directly, not through the variator are detected with first and second speed detecting sensors, and, upon detection of the substantial coincidence in the ratio of speed of the first and second driving force transmitting shafts, the mode switching operation is carried out with the clutches.
    Type: Grant
    Filed: March 16, 2000
    Date of Patent: July 17, 2001
    Assignee: NSK Ltd.
    Inventors: Shinji Miyata, Takashi Imanishi
  • Patent number: 6251041
    Abstract: The toroidal type continuously variable transmission includes: first and second disks concentrically disposed on each other and supported such that they can be rotated freely; a pair of trunnions; a pair of displacement shafts respectively including support shaft portions and pivot shaft portions; a plurality of power rollers interposed between and held by the first and second disks; a plurality of thrust ball bearings respectively for supporting their associated power rollers; and, a plurality of thrust needle bearings respectively interposed between the outer surfaces of outer rings respectively forming the thrust ball bearings and the inner surfaces of the trunnions. A retainer for retaining the thrust needle roller in a freely rollable manner is formed of a single plate, and is carbonitrided, while the surface hardness Hv of the retainer is set higher than or equal to 550.
    Type: Grant
    Filed: June 10, 1999
    Date of Patent: June 26, 2001
    Assignee: NSK Ltd.
    Inventors: Kouji Ishikawa, Seiji Higuchi, Nobuo Goto, Takashi Imanishi
  • Patent number: 6251038
    Abstract: A continuously variable transmission unit, which combines a toroidal-type continuously variable transmission of the double-cavity type and an epicyclic train, comprises a low-speed clutch and a high-speed clutch. In a low-speed drive mode, the low-speed clutch is connected to allow all torque to be transmitted to an output shaft through the toroidal-type continuously variable transmission. In a high-speed drive mode, the high-speed clutch is connected to allow most of torque to be transmitted to the output shaft through an epicyclic train and some of the torque to be applied to output discs of the toroidal-type transmission. The combination of the transmission and the epicyclic train serve to improve the transfer efficiency and durability of the continuously variable transmission unit.
    Type: Grant
    Filed: October 18, 1999
    Date of Patent: June 26, 2001
    Assignee: NSK Ltd.
    Inventors: Kouji Ishikawa, Takashi Imanishi
  • Patent number: 6238318
    Abstract: In order to facilitate an assembling operation of a structure which is correctly operated with a proper positional relation, in a power roller unit for a toroidal type continuously variable transmission according to the present invention, a displacement shaft, a power roller, a radial needle bearing, a thrust ball bearing and a thrust needle bearing are pre-assembled to a trunnion. After dimensional relations and operation conditions of the constructural parts of the assembly or unit are ascertained, the assembly is assembled within a housing together with other unit, thereby completing the toroidal type continuously variable transmission.
    Type: Grant
    Filed: March 29, 1999
    Date of Patent: May 29, 2001
    Assignee: NSK Ltd.
    Inventors: Hiroyuki Itoh, Hisashi Machida, Nobuo Goto, Makoto Fujinami, Hiroshi Kato, Takashi Imanishi
  • Patent number: 6203466
    Abstract: This invention realizes a compact and light-weight structure having excellent durability and transmission efficiency. A toroidal type continuously variable transmission is provided around an input shaft concentric with a driving shaft, and a planetary gear mechanism is provided around an output shaft. This output shaft is disposed obliquely above the input shaft. By such disposition, the effective utilization of space is achieved, and compactness and lighter weight are realized.
    Type: Grant
    Filed: July 27, 1999
    Date of Patent: March 20, 2001
    Assignee: NSK Ltd.
    Inventors: Kouji Ishikawa, Takashi Imanishi, Hisashi Machida, Shinji Miyata, Hiroyuki Itoh
  • Patent number: 6196946
    Abstract: A power roller of a power roller bearing in a half-toroidal type continuously variable transmission is manufactured as follows. In step S1, a work used as material is heated up to a temperature suitable for forging. In step S2, the work is pressed by using a first die set, with its end face being held. In step S3, the work is forged by using a second die set. The work is formed into a work having a curved face corresponding to a traction surface, a hole corresponding to a center hole, and a recess corresponding to a raceway groove. In step S4, the work is punched by using a third die set. In step S5, the work is subjected to a cutting process and a heating process, thereby obtaining the power roller.
    Type: Grant
    Filed: January 21, 1999
    Date of Patent: March 6, 2001
    Assignee: NSK Ltd.
    Inventors: Hiroyuki Sawai, Takafumi Kuwano, Nobuo Gotou, Takashi Imanishi, Nobuaki Mitamura
  • Patent number: 6176806
    Abstract: A cam disk for use in a loading cam mechanism of a toroidal type continuously variable transmission comprises a first projecting portion, a second projecting portion, a flange portion, a cam surface, a bearing raceway and a corner section. The cam disk has metal flows along the cam surface, metal flows along a surface of the raceway, and metal flows along a surface of the corner section. To produce the cam disk, material is shaped into a predetermined form through a first forging step using a first die unit, a second forging step using a second die unit, a third forging step using a third die unit, a finishing step, etc. The metal flows are also formed in these steps.
    Type: Grant
    Filed: July 7, 1999
    Date of Patent: January 23, 2001
    Assignee: NSK Ltd.
    Inventors: Kiyoshi Okubo, Hiroyuki Itoh, Nobuaki Mitamura, Nobuo Goto, Makoto Fujinami, Hiroshi Kato, Takashi Imanishi
  • Patent number: 6174258
    Abstract: There is provided a trunnion for a toroidal continuously variable transmission in which the material is strengthened against the wear and plastic deformation of a trunnion. The trunnion includes a base portion having a body portion, which connects and supports a base end portion of a displacement shaft at a surface intermediate portion, and a pair of plate portions, in which an edge apart from the body portion is a tip end edge, and a pair of axis (shaft) portions protruding from the outside surfaces of the plate portions in opposite directions to each other. The toroidal continuously variable transmission is characterized in that at least the rolling surface of a radial needle bearing for supporting the tilted rotation of the trunnion has a hardness not lower than HRC55, and a core portion has a hardness not lower than HRC20 and not higher than HRC45.
    Type: Grant
    Filed: October 29, 1998
    Date of Patent: January 16, 2001
    Assignee: NSK Ltd.
    Inventors: Takashi Imanishi, Nobuo Goto, Hiroshi Kato, Nobuaki Mitamura
  • Patent number: 6174257
    Abstract: An outer race of a thrust ball bearing supporting a thrust load applied to a power roller is rotatably supported around a displacement shaft. A portion in which the contact pressure between an outer race track and the rolling surface of a rolling member is high changes so that the fatigue of the outer race track does not progress locally. Also, the power roller and the outer race are subjected to predetermined treatment and working. Irrespective of a great thrust load applied during operation, stress is alleviated and the lubricating property of the portion of contact is made good to thereby prevent cracks or early wear from occurring.
    Type: Grant
    Filed: July 1, 1998
    Date of Patent: January 16, 2001
    Assignee: NSK Ltd.
    Inventors: Takashi Imanishi, Nobuaki Mitamura, Nobuo Goto, Makoto Fujinami, Hiroshi Kato
  • Patent number: 6171210
    Abstract: A toroidal type continuous variable transmission system to be used as a transmission of an automobile comprises: an input shaft rotatably actuated by means of a drive source; an output shaft for acquiring power stemming from rotation of the input shaft; a variator which is interposed between the input and output shafts and includes a pair of input disks which rotate on the basis of rotation of the input shaft, a pair of output disks which are provided in a coaxial relationship with the input disks and rotate in synchronous with each other, and power rollers which are provided between the input and output disks while remaining in contact with the disks and which rotate at an angle; a planetary gear mechanism which is interposed between the input and output shafts and includes a sun gear, a ring gear provided around the sun gear, a plurality of planetary gears which are provided between the sun gear and the ring gear so as to be rotatable, and carriers supporting the planet gears; a pressing mechanism which pre
    Type: Grant
    Filed: August 12, 1998
    Date of Patent: January 9, 2001
    Assignee: NSK Ltd.
    Inventors: Shinji Miyata, Takashi Imanishi
  • Patent number: 6132331
    Abstract: A continuously variable transmission of the toroidal type comprises an input disc, an output disc, and a pair of rockable trunnions. A synchronous cable is passed around and between the trunnions, crossing in the shape of the figure "8". The synchronous cable includes a wire rope and a pair of retainers fixed thereto. Each retainer is formed of an arcuate metallic tube attached to its corresponding trunnion. The intermediate portion of the tube other than the opposite end portions thereof in the lengthwise direction is fixed to the wire rope by caulking. The opposite ends of the wire rope are connected by means of one of the retainers under a torsional stress such that the synchronous cable can maintain the 8-shaped form in a free state without the influence of any external force.
    Type: Grant
    Filed: February 9, 1999
    Date of Patent: October 17, 2000
    Assignee: NSK, Ltd.
    Inventors: Takashi Imanishi, Hiroyuki Itoh
  • Patent number: 6117043
    Abstract: In a continuously variable transmission yokes for supporting pivot shafts provided on the end portions of trunnions are supported for displacement only in the axial direction of the pivot shafts and oscillation in a predetermined direction, relative to a support post fixed to the inner surface of a casing. By this construction, the contact pressure between the peripheral surfaces of a pair of power rollers supported on a pair of trunnions supported by the yokes and the inner sides of input side and output side discs is made uniform.
    Type: Grant
    Filed: November 4, 1998
    Date of Patent: September 12, 2000
    Assignee: NSK Ltd.
    Inventors: Takashi Imanishi, Shinji Miyata, Hiroyuki Itoh
  • Patent number: 6113514
    Abstract: The disk has a traction surface having a concave-arc-shaped cross section which is interposed between a small diameter end portion and a large diameter end portion. In the central portion of the end face of the disk on the small diameter end portion side, there is formed a through hole which extends through the disk up to the large diameter end portion side end face of the disk, while the inner peripheral surface of the through hole is used as an inside diameter surface of the disk. Here, when, among metal flows existing in the disk, a metal flow, which has such a positional relationship with respect to the surface of the disk that an angle .theta. formed between a metal flow on the traction surface side and the tangent of the traction surface is smaller than or equal to 30 degrees, is defined as a "metal flow along the disk surface", the disk is structured such that the "metal flow along the disk surface" exists at least in the traction surface.
    Type: Grant
    Filed: December 28, 1998
    Date of Patent: September 5, 2000
    Assignee: NSK Ltd.
    Inventors: Kiyoshi Okubo, Akira Tsubouchi, Takashi Imanishi, Nobuo Gotou
  • Patent number: 6083137
    Abstract: A power roller for a toroidal type continuous variable transmission system comprises a trunnion having a central shaft, a bearing outer race connected to the trunnion, one face of which is provided with a first track groove concentric with the central shaft, a power roller rotatably mounted on one end portion of the central shaft, the power roller having a face opposing to the one face of the bearing outer race, the face being provided with a second track groove concentric with the central shaft, a plurality of rolling elements retained between the bearing outer race and the power roller and capable of rotating within a track formed by the first track groove and the second track groove, and a disk-like cage coaxially disposed between the bearing outer race and the power roller and rotatable about the central shaft, the cage including a plurality of through pockets for accommodating the rolling elements therein so as to retain the rolling elements within the track, the pockets being arranged at regular interva
    Type: Grant
    Filed: September 22, 1998
    Date of Patent: July 4, 2000
    Assignee: NSK Ltd.
    Inventors: Hiroshi Kato, Hirotoshi Aramaki, Nobuo Goto, Takashi Imanishi, Tutomu Abe
  • Patent number: 6074320
    Abstract: In a continuously variable transmission comprising: an input shaft which is rotated by a drive source; an output shaft which takes out a driving force attributing the rotation of the input shaft; and a variator and a planet gear mechanism which are arranged between the input shaft and the output shaft, the variator having a clutch which provides a first mode in which a driving force circulation is carried out, and a second mode in which the driving force circulation is not carried out, the speed of a first driving force transmitting system which is inputted to the planet gear mechanism through the variator and the speed of a second driving force transmitting system which is inputted to the planet gear mechanism directly, not through the variator are detected with first and second speed detecting sensors, and, upon detection of the substantial coincidence in the ratio of speed of the first and second driving force transmitting shafts, the mode switching operation is carried out with the clutches.
    Type: Grant
    Filed: October 2, 1998
    Date of Patent: June 13, 2000
    Assignee: NSK Ltd.
    Inventors: Shinji Miyata, Takashi Imanishi
  • Patent number: 6074324
    Abstract: Improved input and output discs for toroidal type continuously variable transmissions are obtained by select processing techniques to form hardened layers. Processing techniques include, e.g., carburizing, carbonitriding, and high-frequency induction hardening. Shot peening may be used to impart compressive residual surface stress to predetermined disc portions to enhance resistance to cracking.
    Type: Grant
    Filed: November 10, 1998
    Date of Patent: June 13, 2000
    Assignee: NSK Ltd.
    Inventors: Kouji Ishikawa, Nobuo Goto, Hisashi Machida, Takashi Imanishi, Makoto Fujinami, Hiroshi Kato
  • Patent number: 6071210
    Abstract: The ball spline for use in a troidal-type continuously variable transmission comprises a plurality of spline grooves and a plurality of balls which are arranged in series within spline gaps each constituted by a set of mutually opposing spline grooves, in which, while allowing the movement of the input disc in the direction of an input shaft by means of contact between the spline gaps and balls, the input shaft and input disc can be drivingly connected to each other. In the ball spline, the number of spline gaps is set different from integral multiples of the number of power rollers which are held by and between the input and output discs in contact with the two discs in order to transmit a rotation torque between the input and output discs.
    Type: Grant
    Filed: November 12, 1998
    Date of Patent: June 6, 2000
    Assignee: NSK Ltd.
    Inventors: Hiroshi Kato, Hisashi Machida, Takashi Imanishi, Nobuo Goto, Makoto Fujinami
  • Patent number: 6041807
    Abstract: A flow control device, responsive to the rotational speed of a pump and to load pressure, has a simple structure. And a housing of the flow control device for saving energy can make use of a general pump housing not for saving energy as a common housing.The flow control device of a power steering apparatus, arranged in a housing of a pump, includes a flow control valve and a load pressure responsive valve. The flow control valve includes a bypass spool with a control rod penetrating a metering orifice. The load pressure responsive valve is incorporated in a union for response to the load pressure. The control rod is located on the bypass spool for response to the rotational speed of the pump.
    Type: Grant
    Filed: April 9, 1998
    Date of Patent: March 28, 2000
    Assignee: Toyoda Koki Kabushiki Kaisha
    Inventors: Susumu Honaga, Hidetoshi Fujiwara, Yoshiharu Inaguma, Hideya Kato, Kazuhiro Watanabe, Takashi Imanishi