Abstract: An externally toothed gear of a dual-type strain wave gearing is provided with first and second external teeth having different teeth numbers, and a gap formed between these teeth as a cutter clearance area for tooth cutters. The maximum width L1 of the gap is 0.1 to 0.3 times the width L of the externally toothed gear. The depth from the tooth top land of the first external teeth to the deepest part of the gap is 0.9 to 1.3 times the depth of the first external teeth, and the depth from the tooth top land of the second external teeth to the deepest part of the gap is 0.9 to 1.3 times the depth of the second external teeth. The tooth bottom fatigue strength of the externally toothed gear provided with differing numbers of first and second external teeth is increased.

Abstract: An externally toothed gear of a dual-type strain wave gearing is provided with first and second external teeth having different teeth numbers, and is flexed into an ellipsoidal shape by a wave generator. When the theoretical values of the radial flexing amounts at major-axis positions of the first and second external teeth flexed into the ellipsoidal shape are expressed by d1=m1n1 and d2=m2n2 (m1 and m2 represent the modules of the first and second external teeth, and n1 and n2 represent positive integers), the radial flexing amounts of the first and second external teeth flexed by the wave generator satisfy d1a=?d1 and d2a=?d2, where 1.25???3. Accordingly, a dual-type strain wave gearing can be achieved with which the first and second external teeth having different numbers can be suitably flexed to form excellent mating states with respective internally toothed gears.

Abstract: An externally toothed gear of a dual-type strain wave gearing is provided with first and second external teeth having different tooth numbers, and is flexed into an ellipsoidal shape by a wave generator. When the theoretical values of the radial flexing amounts at major-axis positions of the first and second external teeth flexed into the ellipsoidal shape are expressed by d1=m1n1 and d2=m2n2 (m1 and m2 represent the modules of the first and second external teeth, and n1 and n2 represent positive integers), the radial flexing amount of the first and second external teeth flexed by the wave generator satisfies d=(d1+d2)/?(1.4???2.6). Accordingly, a dual-type strain wave gearing can be achieved with which the first and second external teeth having different numbers can be suitably flexed to form excellent mating states with respective internally toothed gears.

Abstract: An externally toothed gear of a dual-type strain wave gearing is provided with first and second external teeth having different teeth numbers, and is flexed into an ellipsoidal shape by a wave generator. When t(1) represents the tooth bottom rim wall thickness of the first external teeth, and t(2) represents the tooth bottom rim wall thickness of the second external teeth, the ratio of t(1)/t(2) is set to a value satisfying 0.5>t(1)/t(2)<1.5. Accordingly, a dual-type strain wave gearing can be achieved with which the first and second external teeth having different teeth numbers can be suitably flexed to form excellent meshing states with respective internally toothed gears.

Abstract: An externally toothed gear of a dual-type strain wave gearing is provided with first and second external teeth having different teeth numbers. The first and second external teeth are flexed by a wave generator by the same flexing amount, into an ellipsoidal shape. The tooth depth of tooth profiles of the first external teeth having a low teeth number is smaller than the tooth depth of tooth profiles of the second external teeth having a high teeth number. A dual-type strain wave gearing can be achieved with which the first and second external teeth having different teeth numbers can be suitably flexed to form excellent meshing states with respective internally toothed gears.

Abstract: An externally toothed gear of a dual-type strain wave gearing is provided with first and second external teeth having different teeth numbers. The first and second external teeth are flexed by a wave generator by the same flexing amount, into an ellipsoidal shape. The average pressure angle of main-tooth-surface sections of tooth profiles of the first external teeth having a low teeth number is less acute than the average pressure angle of main-tooth-surface sections of tooth profiles of the second external teeth having a high teeth number. Accordingly, a dual-type strain wave gearing can be achieved with which the first and second external teeth having different teeth numbers can be suitably flexed to form excellent meshing states with respective internally toothed gears.

Abstract: A restraint mechanism for limiting the movement of the flexible external gear of a flat strain wave gearing in the axial direction has a first restraining member installed in a floating state in a first recess and a second restraining member installed in a floating state in a second recess. The restraining member is able to limit the movement of the flexible external gear in the axial direction to a range in which there are no difficulties during actual use. Moreover, compared with when movement of the flexible external gear is limited using members that are disposed at fixed positions, it is possible to reduce the sliding abrasion that occurs between the flexible external gear and the first and second restraining members.

Abstract: A foreign-matter intrusion preventing mechanism of a strain wave gearing is provided with a filter attachment plate attached to a wave generator plug and a filter attached to the ellipsoidal outer peripheral surface of the filter mounting plate. Lubricant flows, via the filter, between a wave generator bearing and a meshing portion between an external gear and an internal gear. Foreign matters included in the lubricant are captured by the filter. Because the filter is in contact with the inner peripheral surface of an external-tooth forming portion of the external gear, foreign matters can be assuredly prevented from intruding into a sliding friction portion between an outer-ring outer peripheral surface of the wave generator bearing and the inner peripheral surface of the external-tooth forming portion of the external gear.

Abstract: A wave generator for a strain wave gearing makes a flexible externally toothed gear to flex into an elliptical shape and mesh with rigid internally toothed gears, and makes meshing positions of the flexible externally toothed gear with the both gears to move in a circumferential direction. On the inner side of a rigid plug of the wave generator, a plug support ring is secured and integrated. The rigid plug is formed from an iron-based material, and the plug support ring is formed from a high-rigidity material that is more rigid than the iron-based material. Since deformation of the rigid plug is suppressed, the wave generator provided with a large hollow part can be obtained.

Abstract: Disclosed is a variable compression ration mechanism in which a control shaft is rotated and driven by an electric motor through a wave gear reducer. The wave gear reducer includes: a first internal gear member; an external gear member arranged concentrically inside the internal gear member; a wave generator arranged inside the external gear member; and a second internal gear member, wherein a ratio of the number of teeth of a fixed gear portion of the first internal gear member to the number of teeth of a first gear portion of the external gear member is set lower than a ratio of the number of teeth of an output-side gear portion of the second internal gear member to the number of teeth of a second gear portion of the external gear member.

Abstract: A wave generator of a flat-type strain wave gearing has an insertion member disposed between two wave bearings. The insertion member is pressed into an elliptical outer peripheral surface of a plug and is fixed thereto by an adhesive. An inner ring contact part of the insertion member is in contact with inner rings of the wave bearings from the direction of a center axis. When the flat-type strain wave gearing is in an operating state, the wave bearings can be prevented from moving relative to the plug in the direction of the center axis by means of thrust force acting on the wave bearings.

Abstract: In a rotation transmission mechanism that transmits the rotational driving force of a motor to a load-side member via a speed reducer, a strain wave gearing is used as the speed reducer, and the allowable load torque of members in the powertrain other than the strain wave gearing is greater than a predetermined upper-limit load torque. The allowable load torque of the strain wave gearing is dictated by the ratcheting torque, which is set so as not to exceed the upper-limit load torque. In an overload state, ratcheting is generated in the strain wave gearing, so that the strain wave gearing functions as a mechanical fuse. Other power transmission members can be protected from an overload state without adding a separate member such as a torque limiter.

Abstract: Disclosed is a variable compression ration mechanism in which a control shaft is rotated and driven by an electric motor through a wave gear reducer. The wave gear reducer includes: a first internal gear member; an external gear member arranged concentrically inside the internal gear member; a wave generator having an oval outer shape and arranged inside the external gear member; and a second internal gear member, wherein a ratio of the number of teeth of a fixed gear portion of the first internal gear member to the number of teeth of a first gear portion of the external gear member is set greater than a ratio of the number of teeth of an output-side gear portion of the second internal gear member to the number of teeth of a second gear portion of the external gear member.

Abstract: A reduction drive-side mounting end face on a strain wave gearing reduction drive unit has a circular center hole, and a motor-side mounting end face on a motor has a circular projection. The strain wave gearing reduction drive unit and motor are coaxially mounted by the circular projection being fit into the circular center hole with a regulating ring therebetween. The regulating ring, which regulates the motion of a flexible external gear, can be easily mounted to the strain wave gearing reduction drive unit by using the motor. The strain wave gearing reduction drive unit can be mounted to a motor comprising a circular projection with a different outer diameter by using a regulating ring with a different inner diameter.

Abstract: A relieving portion is formed between a first external tooth portion and a second external tooth portion in the external teeth of a flexible externally toothed gear of a flat strain wave gearing. The length L1 of the relieving portion in the tooth trace direction is within the range of 0.1 to 0.5 of the tooth width L of the external teeth. The maximum relieving amount t from the tooth top land of an external tooth in the relieving portion is 3.3×10?4<t/PCD<6.3×10?4 where the PCT is defined as the pitch circle diameter of the external teeth. The tooth face load distribution of the external tooth in the tooth trace direction can be equalized, and a flat strain wave gearing having a high transmitted-load capacity can be achieved.

Abstract: An externally toothed gear of a dual-type strain wave gearing is provided with first and second external teeth having different teeth numbers. The first and second external teeth are flexed by a wave generator by the same flexing amount, into an ellipsoidal shape. The tooth depth of tooth profiles of the first external teeth having a low teeth number is smaller than the tooth depth of tooth profiles of the second external teeth having a high teeth number. A dual-type strain wave gearing can be achieved with which the first and second external teeth having different teeth numbers can be suitably flexed to form excellent meshing states with respective internally toothed gears.

Abstract: An externally toothed gear of a dual-type strain wave gearing is provided with first and second external teeth having different teeth numbers, and is flexed into an ellipsoidal shape by a wave generator. When the theoretical values of the radial flexing amounts at major-axis positions of the first and second external teeth flexed into the ellipsoidal shape are expressed by d1=m1n1 and d2=m2n2 (m1 and m2 represent the modules of the first and second external teeth, and n1 and n2 represent positive integers), the radial flexing amounts of the first and second external teeth flexed by the wave generator satisfy d1a=?d1 and d2a=?d2, where 1.25???3. Accordingly, a dual-type strain wave gearing can be achieved with which the first and second external teeth having different numbers can be suitably flexed to form excellent mating states with respective internally toothed gears.

Abstract: An externally toothed gear of a dual-type strain wave gearing is provided with first and second external teeth having different tooth numbers, and is flexed into an ellipsoidal shape by a wave generator. When the theoretical values of the radial flexing amounts at major-axis positions of the first and second external teeth flexed into the ellipsoidal shape are expressed by d1=m1n1 and d2=m2n2 (m1 and m2 represent the modules of the first and second external teeth, and n1 and n2 represent positive integers), the radial flexing amount of the first and second external teeth flexed by the wave generator satisfies d=(d1+d2)/? (1.4???2.6). Accordingly, a dual-type strain wave gearing can be achieved with which the first and second external teeth having different numbers can be suitably flexed to form excellent mating states with respective internally toothed gears.

Abstract: An externally toothed gear of a dual-type strain wave gearing is provided with first and second external teeth having different teeth numbers. The first and second external teeth are flexed by a wave generator by the same flexing amount, into an ellipsoidal shape. The average pressure angle of main-tooth-surface sections of tooth profiles of the first external teeth having a low teeth number is less acute than the average pressure angle of main-tooth-surface sections of tooth profiles of the second external teeth having a high teeth number. Accordingly, a dual-type strain wave gearing can be achieved with which the first and second external teeth having different teeth numbers can be suitably flexed to form excellent meshing states with respective internally toothed gears.

Abstract: An externally toothed gear of a dual-type strain wave gearing is provided with first and second external teeth having different teeth numbers, and is flexed into an ellipsoidal shape by a wave generator. When t(1) represents the tooth bottom rim wall thickness of the first external teeth, and t(2) represents the tooth bottom rim wall thickness of the second external teeth, the ratio of t(1)/t(2) is set to a value satisfying 0.5>t(1)/t(2)<1.5. Accordingly, a dual-type strain wave gearing can be achieved with which the first and second external teeth having different teeth numbers can be suitably flexed to form excellent meshing states with respective internally toothed gears.