Patents Assigned to Harmonic Drive Systems, Inc.
  • Two stress-separation strain wave gearing
    Patent number: 10883589
    Abstract: In a strain wave gearing, the addendum tooth profile of an inner gear is defined by a formula and that of an outer gear is by another formula at a principal cross-section located at a tooth-trace-direction center of the outer gear, on the basis of a movement locus (Mc) of ?=1 by the teeth of the outer gear with respect to those of the inner gear. The tooth profiles of the dedenda of each of the inner gear and the outer gear are set to any shape that does not interfere with the tooth profile of the addendum of the other gear. It is possible to avoid superimposed flexion-induced bending stresses and tensile stresses caused by load torque arising at the long-axis locations of the outer gear, and the transmission torque capacity of a strain wave gearing can be improved.
    Type: Grant
    Filed: December 4, 2015
    Date of Patent: January 5, 2021
    Assignee: HARMONIC DRIVE SYSTEMS INC.
    Inventor: Shoichi Ishikawa
  • Strain wave gearing with compound meshing that involves congruity of tooth surfaces
    Patent number: 10871213
    Abstract: The dedendum tooth profiles of the internal teeth and external teeth of a strain wave gearing are prescribed by a first homothetic curve BC and a second homothetic curve AC obtained from a curve segment from a point A, at which the angle formed by the tangent to a movement locus Mc when meshing is approximated by rack meshing and the major axis is ?A, to a low point B. The dedendum tooth profile of the internal teeth is prescribed by a curve formed on the internal teeth in the course of the addendum tooth profile of the external teeth moving from an apex of the movement locus to point A. The dedendum tooth profile of the external teeth is prescribed by a curve formed on the external teeth when the addendum tooth profile of the internal teeth moves from the apex to arrive at point A.
    Type: Grant
    Filed: June 23, 2015
    Date of Patent: December 22, 2020
    Assignee: HARMONIC DRIVE SYSTEMS INC.
    Inventor: Shoichi Ishikawa
  • Rotation detecting device and hollow actuator
    Patent number: 10866123
    Abstract: A hollow type rotation detecting device has a 2-pole magnet ring and a multi-pole gear, the 2-pole magnet being coaxially fixed to the outer circumferential surface of the shaft end part of a hollow motor shaft that extends coaxially inside a cylindrical cover. In an annular gap between the cylindrical cover and the 2-pole magnet ring and multi-pole gear, rigid boards are arranged with an orientation facing in a tangential direction at prescribed intervals along the circumferential direction. The rigid boards are electrically connected to one another by flexible printed wiring boards. It is possible to obtain a rotation detecting device suitable to be incorporated into the narrow annular gap between a motor house and the shaft end part of the hollow motor shaft in a hollow motor having a large hollow diameter.
    Type: Grant
    Filed: June 10, 2016
    Date of Patent: December 15, 2020
    Assignee: HARMONIC DRIVE SYSTEMS INC.
    Inventors: Shintaro Ueno, Ryutaro Yamaguchi, Kiyoto Kobayashi, Keisuke Takewaka
  • Strain wave gearing and actuator
    Patent number: 10865866
    Abstract: A strain wave gearing has a wave generator for generating a wave motion that repeatedly flexes each part in the circumferential direction of an externally toothed gear in the radial direction. The wave generator is provided with a plurality of wave-generating members arranged at positions at a prescribed angular interval along the circumferential direction of the externally toothed gear. Each of the wave-generating members is provided with an outer circumferential cam surface, rotates centered on a rotation center line that is parallel to the device center axis line, and repeatedly flexes each part of the externally toothed gear in the radial direction with a prescribed amplitude. A strain wave gearing, which is suitable for forming a large device hollow part, can be obtained.
    Type: Grant
    Filed: February 2, 2016
    Date of Patent: December 15, 2020
    Assignee: HARMONIC DRIVE SYSTEMS INC.
    Inventor: Naoki Kanayama
  • Strain wave gearing having 3-dimensional meshing tooth profile
    Patent number: 10823259
    Abstract: A strain wave gearing wherein the tooth profile of an external teeth of a cup-shaped or silk-hat-shaped external gear is set as follows. The tooth-tip tooth thickness decreases gradually from an external-teeth outer end toward an external-teeth inner end along an external tooth trace direction. In addition, a pressure angle at a pitch point (P) increases gradually from the external-teeth outer end toward the external-teeth inner end along the external tooth trace direction. Thus, it is possible to realize a cup-type or silk-hat-type strain wave gearing in which external teeth mesh with internal teeth in a wide range along the tooth trace direction, rather than only in one cross-section perpendicular to the axis in the tooth trace direction.
    Type: Grant
    Filed: October 19, 2017
    Date of Patent: November 3, 2020
    Assignee: Harmonic Drive Systems Inc.
    Inventors: Norio Shirokoshi, Yuya Murayama, Yoshitomo Mizoguchi, Satoshi Kishi
  • Silk hat-type strain wave gear device
    Patent number: 10823278
    Abstract: A silk hat-type strain wave gear device has a crossed roller bearing for supporting an internal gear and an external gear so as to allow relative rotation. A first gap part between the inner and outer rings of said bearing is sealed by an oil seal and a second gap part thereof is in communication with a gear-side gap part on the outside of the external gear. A bearing seal separates the second gap part from the gear-side gap part. The bearing seal prevents excessive inflow of lubricant from the gear-side gap part into the second gap part. Excess lubricant that has flowed into the bearing can flow back from the second gap part to the gear-side gap part. Excess lubricant in the bearing is prevented from leaking through the oil seal to the outside.
    Type: Grant
    Filed: April 10, 2017
    Date of Patent: November 3, 2020
    Assignee: Harmonic Drive Systems Inc.
    Inventors: Shunichi Tezuka, Yoshihide Kiyosawa, Toshimi Yamagishi
  • Movable coil type linear motor
    Patent number: 10819206
    Abstract: A linear motor includes a motor movable body which has symmetrical structure with respect to a vertical plane and a horizontal plane that include the motor center axis line. Two linear bearings disposed in a space on the inner side of a rectangular tubular movable coil of the motor movable body are disposed symmetrically to the left and right of the center axis line so that the bearing support center coincides with the motor center axis line. Thrust generation sections of the motor movable body are disposed symmetrically above and below the motor center axis line, so that the thrust center coincides with the motor center axis line. Since the center of gravity of the motor movable body, the thrust center and the bearing support center coincide with the motor center axis line, a high responsive liner motor can be realized with no decrease in the thrust/movable body mass ratio.
    Type: Grant
    Filed: February 2, 2016
    Date of Patent: October 27, 2020
    Assignee: HARMONIC DRIVE SYSTEMS INC.
    Inventor: Toshiki Maruyama
  • Strain wave gearing
    Patent number: 10816073
    Abstract: In a strain wave gearing, a flexible externally toothed gear flexed by a wave generator meshes with a flexible internally toothed gear while in an overlapping meshing state. A floating ring, which supports the internally toothed gear from the outer circumferential side, maintains the overlapping state of the meshing and supports the internally toothed gear in a floating state that allows displacement following a state of radial flexion in the tooth trace direction of the internal teeth of the internally toothed gear. Differences between the meshing states of both gears can be alleviated at each position in the tooth trace direction. Degradation in the transmission characteristics and the strength characteristics of the strain wave gearing caused by manufacturing dimensional accuracy of each component and assembly accuracy can be suppressed.
    Type: Grant
    Filed: November 29, 2017
    Date of Patent: October 27, 2020
    Assignee: HARMONIC DRIVE SYSTEMS INC.
    Inventors: Masaru Kobayashi, Akira Maruyama
  • Flexible external gear and strain wave gearing
    Patent number: 10801585
    Abstract: The flexible external gear of a strain wave gearing is provided with: a cylindrical body part capable of flexing in the radial direction; external teeth formed on the outer circumferential surface thereof with a constant pitch; and grooves formed on the inner circumferential surface of the cylindrical body section along the circumferential direction thereof with the same pitch as the external teeth. The grooves are grooves with a wave-shaped cross-sectional shape having the center line of the tooth crest of the external tooth as the center and extend in the width direction of the external teeth. It is possible to increase the tooth bottom fatigue strength of the flexible external gear by increasing the tooth bottom thickness, while maintaining ease of flexing and a tooth shape that can withstand tangential forces due to meshing.
    Type: Grant
    Filed: November 6, 2015
    Date of Patent: October 13, 2020
    Assignee: Harmonic Drive Systems Inc.
    Inventors: Masaru Kobayashi, Tatsuro Hoshina
  • Strain wave gearing with full separation of two stresses
    Patent number: 10788115
    Abstract: In a strain wave gearing, the addendum tooth profile of an internal gear is defined by the formula a and that of an external gear is by the formula b at a principal cross-section located at a tooth-trace-direction center of the external gear, on the basis of a movement locus (Mc) of ?=1 of the teeth of the external gear with respect to those of the internal gear in the principle cross-section taken at the center of the tooth trace of the external gear obtained when the tooth meshing is approximated by rack meshing. It is possible to avoid superimposition of flexion-induced bending stresses and tensile stresses caused by load torque at the major-axis locations of the external gear, and the transmission torque capacity of a strain wave gearing can be improved.
    Type: Grant
    Filed: January 15, 2016
    Date of Patent: September 29, 2020
    Assignee: Harmonic Drive Systems Inc.
    Inventor: Shoichi Ishikawa
  • Strain wave gearing with full separation of two stresses
    Patent number: 10788114
    Abstract: In a strain wave gearing, the addendum tooth profile of an internal gear is defined by the formula a and that of an external gear is by the formula b at a principal cross-section located at a tooth-trace-direction center of the external gear, on the basis of a movement locus (Mc) of ?=1 by the teeth of the external gear with respect to those of the internal gear. It is possible to avoid superimposition of flexion-induced bending stresses and tensile stresses caused by load torque at the major-axis locations of the external gear, and the transmission torque capacity of a strain wave gearing can be improved.
    Type: Grant
    Filed: June 1, 2018
    Date of Patent: September 29, 2020
    Assignee: Harmonic Drive Systems Inc.
    Inventor: Shoichi Ishikawa
  • UNIT-TYPE STRAIN WAVE GEARING
    Publication number: 20200284333
    Abstract: In a unit-type strain wave gearing, a rotating-side member, which is constituted by a second internally toothed gear and an output shaft is supported, via a first sliding bearing and a second sliding bearing, on a fixed-side member so as to be capable of relative rotation, the fixed-side member being constituted by a unit housing and a first internally toothed gear. Sliding bearing surfaces of the first sliding bearing and sliding bearing surfaces of the second sliding bearing are defined by a conic surface having a central axis line as a center line. It is possible to realize a unit-type strain wave gearing which is advantageous in making smaller and more compact than when a roller bearing is used. It is also easier to adjust the gap between the sliding bearing surfaces because a radial sliding bearing having no function to adjust the radial gap is obviated.
    Type: Application
    Filed: September 20, 2018
    Publication date: September 10, 2020
    Applicant: HARMONIC DRIVE SYSTEMS INC.
    Inventors: Yoshihide KIYOSAWA, Norio SHIROKOSHI
  • WAVE GENERATOR AND STRAIN WAVE GEARING
    Publication number: 20200284332
    Abstract: A wave bearing of a wave generator of a strain wave gearing is provided with steel or stainless steel cylindrical hollow rollers between an inner-race-side raceway surface and an outer-race-side raceway surface, the hollow rollers serving as rolling elements. The ratio Di/Do of the inner diameter Di to the outer diameter Do of the hollow rollers is set to 0.95 or more. The relative radius of curvature of hollow rollers that have been flexed into an ellipsoidal shape increases with respect to the inner-race raceway surface and the outer-race raceway surface with which the hollow rollers are in contact, and the Hertz maximum contact stress is reduced. The hardness of the hollow rollers, the inner-race raceway surface, and the outer-race raceway surface can be reduced.
    Type: Application
    Filed: July 30, 2016
    Publication date: September 10, 2020
    Applicant: HARMONIC DRIVE SYSTEMS INC.
    Inventor: Masaru KOBAYASHI
  • Planetary gear device series
    Patent number: 10760648
    Abstract: In a planetary gear device series composed of eight kinds of planetary gear devices with gear reduction ratios of 3 to 10, the planetary gear device of each gear reduction ratio uses an internal gear with 108 teeth or a slightly different number of teeth, and the module is common among the planetary gear devices of all gear reduction ratios. The combinations of the sun gear teeth number Za and the internal gear teeth number Zc in the planetary gear device of each reduction ratio are given in Table 1 of this application.
    Type: Grant
    Filed: May 29, 2015
    Date of Patent: September 1, 2020
    Assignee: HARMONIC DRIVE SYSTEMS INC.
    Inventors: Norio Shirokoshi, Yasushi Ono
  • Magnetic type rotation transmitting mechanism
    Patent number: 10753450
    Abstract: A magnetic type rotation transmitting mechanism has a rotating plate made of a magnetic material, and a magnet to which the rotational movement of the rotating plate is transmitted through a magnetic coupling between the magnet and the rotating plate. When the rotating plate is rotated, a plurality of oblique edge portions formed on the outer peripheral edge of the rotating plate rotate while sequentially passing through a magnet-facing area. The oblique edge portions move in the direction of the rotation centerline of the rotating plate, the rotation centerline being perpendicular to the center axis line of the magnet. The magnet is rotated about the center axis line by a magnetic force occurring between the magnet and the oblique edge portions passing through the magnet-facing area. It is possible to realize a small and compact mechanism for extracting rotation.
    Type: Grant
    Filed: September 30, 2016
    Date of Patent: August 25, 2020
    Assignee: HARMONIC DRIVE SYSTEMS INC.
    Inventors: Naoki Kanayama, Toru Takeda
  • Rotary actuator provided with strain wave reduction gears
    Patent number: 10753427
    Abstract: A rotary actuator has: one motor, two strain wave reduction gears disposed symmetrically on both sides of the motor, and one output shaft. The output rotation of the motor is reduced in speed at the same reduction ratio by the two strain wave reduction gears and is outputted from the output shaft to a load side. The first and second externally toothed gears of the first and second strain wave reduction gears are flexed into ellipsoidal shapes with 90 degrees shifted in phase, and are meshed with first and second internally toothed gears. The angle transmission errors of the first and second strain wave reduction gears transmitted to the output shaft are reduced by cancelling each other out in the output shaft. Reduced-speed output rotation that has the reduced angle transmission errors is outputted to the load side from the output shaft.
    Type: Grant
    Filed: May 11, 2016
    Date of Patent: August 25, 2020
    Assignee: HARMONIC DRIVE SYSTEMS INC.
    Inventors: Hiroshi Nakagawa, Daisuke Yaguchi
  • STRAIN WAVE GEARING HAVING UNIT STRUCTURE
    Publication number: 20200240500
    Abstract: A cup-type strain wave gearing having a unit structure and having: a stationary-side part including a unit housing and an internally toothed gear; a driving-side part including an output member and an externally toothed gear; and a sliding bearing supporting the stationary-side part and the driving-side part in the radial direction and the thrust direction in a state in which relative rotation is possible. The sliding bearing has a cylindrical bushing accommodated in a radial gap, and annular bushings accommodated respectively in thrust gaps. Thus, it is possible to provide an advantageous strain wave gearing having a unit structure that is more lightweight and compact than when a rolling bearing is used.
    Type: Application
    Filed: October 31, 2017
    Publication date: July 30, 2020
    Applicant: HARMONIC DRIVE SYSTEMS INC.
    Inventors: Yoshihide KIYOSAWA, Norio SHIROKOSHI
  • STRAIN WAVE GEARING PROVIDED WITH LUBRICANT-MIXING-PREVENTION PART
    Publication number: 20200232549
    Abstract: A cup-shaped strain wave gearing has an externally toothed gear formed with a cylindrical extension portion extending from an end of an external tooth forming portion of the externally toothed gear. A space between the external peripheral surface of the cylindrical extension portion and an end face of an internally toothed gear is sealed by an oil seal. A space between an outer-side lubrication portion on the outer side of the externally toothed gear and an inner-side lubrication portion on the inner side of the externally toothed gear is blocked by a lubricant-mixing-prevention part configured from the cylindrical extension portion and the oil seal. The mixing of different types of lubricants supplied to the outer-side and inner-side lubrication portions can be effectively prevented.
    Type: Application
    Filed: August 21, 2017
    Publication date: July 23, 2020
    Applicant: HARMONIC DRIVE SYSTEMS INC.
    Inventor: Norio SHIROKOSHI
  • Wave generator and strain wave gearing
    Patent number: 10718420
    Abstract: A strain wave gearing has a wave generator provided with a plug and a roller bearing. The roller bearing is provided with flange plates fixed to both sides of the plug, and outer circumferential edge portions of the flange plates protrude outwardly from a plug outer circumferential surface so as to locate on both sides, in an axial line direction, of the raceway of rollers. The movements of the rollers in the axial line direction are constrained by the outer circumferential edge portions. The movement of retainer in the axial line direction is constrained by engaging with the rollers. The movement of each component part of the roller bearing in the axial line direction can be constrained without using additional components.
    Type: Grant
    Filed: January 8, 2015
    Date of Patent: July 21, 2020
    Assignee: HARMONIC DRIVE SYSTEMS INC.
    Inventors: Masaru Kobayashi, Tatsuro Hoshina
  • Method for lubricating strain wave gearing
    Patent number: 10718419
    Abstract: A strain wave gearing has contact parts which are the portions to be lubricated other than the teeth of an externally toothed gear and an internally toothed gear, the contact parts being respectively lubricated with an inorganic lubricating powder having a lamellar crystal structure. The lubricating powder, during the operation of the strain wave gearing, is crushed between the contact surfaces of each of the contact parts to move and adhere to the contact surfaces, thereby forming thin surface films thereon. Additionally, the powder is thinly spread by pressure and reduced into finer particles to change into a shape which facilitates intrusion into the space between the contact surfaces. By both the fine particles having changed in shape and the surface films, the lubrication of the contact parts is maintained. Neither the fine particles nor the surface films are viscous.
    Type: Grant
    Filed: November 28, 2014
    Date of Patent: July 21, 2020
    Assignee: HARMONIC DRIVE SYSTEMS INC.
    Inventor: Masaru Kobayashi