公开(公告)号：US10883589B2

公开(公告)日：2021-01-05

申请号：US15112467

申请日：2015-12-04

Applicant: HARMONIC DRIVE SYSTEMS INC.

Inventor： Shoichi Ishikawa

IPC: F16H49/00 ,  F16H55/08 ,  F16H1/32 ,  F16H3/70

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 κ=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.

公开(公告)号：US10823278B2

公开(公告)日：2020-11-03

申请号：US16493111

申请日：2017-04-10

Applicant: HARMONIC DRIVE SYSTEMS INC.

Inventor： Shunichi Tezuka ,  Yoshihide Kiyosawa ,  Toshimi Yamagishi

IPC: F16H57/04 ,  F16H1/32 ,  F16H49/00 ,  F01D25/16 ,  F01D25/18 ,  F16C33/10 ,  F16C33/58

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.

公开(公告)号：US10760648B2

公开(公告)日：2020-09-01

申请号：US15572664

申请日：2015-05-29

Applicant: Harmonic Drive Systems Inc.

Inventor： Norio Shirokoshi ,  Yasushi Ono

IPC: F16H57/033 ,  F16H1/28 ,  F16H1/32

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.

公开(公告)号：US20200232549A1

公开(公告)日：2020-07-23

申请号：US16633391

申请日：2017-08-21

Applicant: HARMONIC DRIVE SYSTEMS INC.

Inventor： Norio SHIROKOSHI

IPC: F16H49/00 ,  F16H1/32

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.

公开(公告)号：US10508726B2

公开(公告)日：2019-12-17

申请号：US15532857

申请日：2014-12-05

Applicant: Harmonic Drive Systems Inc.

Inventor： Tatsuro Hoshina ,  Masaru Kobayashi ,  Akira Nagai

IPC: F16H49/00 ,  F16H57/00

Abstract: A boss-side fastening surface formed in a boss of a flexible externally toothed gear of a strain wave gearing and a shaft-side fastening surface of an output shaft are coaxially fastened with bolts. The boss-side fastening surface is a convex-side fastening surface defined by two symmetrical inclined surfaces that are intersected at a prescribed angle to form a ridge line on a diameter line of the surface. The shaft-side fastening surface is a concave-side fastening surface defined by two symmetrical inclined surfaces that are intersected at a prescribed angle to form a trough line on a diameter line of the surface. The inclination angle of the inclined surfaces is set in the range of 2° to 16°. Transmission torques equal to or larger than those for combined bolt and pin fastening can be secured with bolt-only fastening.

公开(公告)号：US20190368576A1

公开(公告)日：2019-12-05

申请号：US16476587

申请日：2017-10-19

Applicant: HARMONIC DRIVE SYSTEMS INC.

Inventor： Norio SHIROKOSHI ,  Yuya MURAYAMA ,  Yoshitomo MIZOGUCHI ,  Satoshi KISHI

IPC: F16H1/32 ,  F16H57/08 ,  F16H55/17

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.

公开(公告)号：US20190353236A1

公开(公告)日：2019-11-21

申请号：US16477227

申请日：2017-12-08

Applicant: HARMONIC DRIVE SYSTEMS INC.

Inventor： Norio SHIROKOSHI

IPC: F16H49/00

Abstract: A strain wave gearing has a rigid internally toothed gear, a flexible externally toothed gear, and a wave generator. Before being flexed by the wave generator, the externally toothed gear has a cylindrical body part, an inside diameter of which is such that the inside diameter D is smallest at a rear end thereof and increases gradually from the rear end to an opening end thereof. After being flexed by the wave generator, D1≤D is satisfied where D1 is the minor diameter of an elliptical inner circumferential surface of the opening end of the cylindrical body part. The externally toothed gear, which is provided with such a tapered cylindrical body part, is suitable for manufacturing by die molding such as casting, and can also alleviate excessive uneven contact thereof with a wave bearing.

公开(公告)号：US20190113106A1

公开(公告)日：2019-04-18

申请号：US16091203

申请日：2016-05-11

Applicant: HARMONIC DRIVE SYSTEMS INC.

Inventor： Hiroshi Nakagawa ,  Daisuke Yaguchi

IPC: F16H1/32 ,  H02K7/116 ,  F16H49/00

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.

公开(公告)号：US20190085962A1

公开(公告)日：2019-03-21

申请号：US15760671

申请日：2015-09-29

Applicant: HARMONIC DRIVE SYSTEMS INC.

Inventor： Masaru KOBAYASHI

IPC: F16H49/00

Abstract: The wave generator of a strain wave gearing is provided with an ellipsoidally contoured wave generator plug and a wave generator bearing. The wave generator bearing is provided with an annular body fitted between inner and outer races in a sliding contact state. The annular body is composed of an endless coil spring and has a rigidity that is able to maintain a constant gap between the inner and outer races. The annular body also has a specified overall flexibility in the radial direction so that the annular body can be flexed into an ellipsoidal shape by the wave generator plug. Since sliding occurs between the annular body and the inner race when the wave generator plug rotates, it is possible to generate a wave motion in an externally toothed gear with a small rotational torque.

公开(公告)号：US10174825B2

公开(公告)日：2019-01-08

申请号：US15102409

申请日：2014-12-09

Applicant: Harmonic Drive Systems Inc.

Inventor： Shoichi Ishikawa

IPC: F16H49/00

Abstract: A strain wave gearing is a negative deflection strain wave gearing. The tooth profile shape for the internally toothed gear is defined by using a convex, basic tooth profile curve, which is a curve portion from an inflection point (A) to a bottom-part point (B) of a moving locus (Mc) of an externally toothed gear with regard to an internally toothed gear obtained by a rack meshing approximation. The tooth profile shape for the externally toothed gear at a principal cross section is defined by a concave, basic tooth profile curve, which is generated in the externally toothed gear by the convex, basic tooth profile curve of the internally toothed gear moving from an apex (C) to an inflection point (A) of the moving locus (Mc). Passing-type meshing that is effective in lubrication is established, and bending stress in the tooth-bottom rim of the externally toothed gear can be reduced.