Abstract: An externally toothed gear of a cup-type strain wave gearing has external teeth, the tooth profile of which gradually changes in the tooth-trace direction. The external teeth are formed with an external teeth portion capable of meshing with internal teeth of an internally toothed gear, a first external teeth extension portion and a second external teeth extension portion, in which the first and second external teeth extension portions do not mesh with the internal teeth. The second external teeth extension portion has a narrowing tapered tooth profile so that the second external teeth extension portion serves as a guide when the external teeth is inserted into the internal teeth. The work of assembling the externally toothed gear in the internally toothed gear is made easier.

Abstract: The addendum tooth profile of the inner teeth and outer teeth of a strain wave gearing is stipulated by a first and second similar curve obtained from the curve segment from an inflection point to a low point in a movement trajectory when the meshing of both teeth is approximated by rack meshing. The addendum tooth profile of the inner teeth is stipulated by a curve generated at the inner teeth in the process of the addendum profile of the outer teeth moving from the inflection point to the apex of the movement trajectory. The addendum tooth profile of the outer teeth is stipulated by a curve generated at the outer teeth when the addendum profile of the inner teeth moves from the inflection point to the apex. The addendum profile of the outer teeth makes double contact with the addendum profile and dedendum profile of the inner teeth.

Abstract: In a roll rotation mechanism (1) for continuously causing a film-rolling roll to rotate at a constant rate, an Oldham coupling (4) is interposed in a transmission path between a wave gear reduction mechanism (3) and a roll (10). The Oldham coupling (4) forms a connection between a gear rotation output shaft (34) and a roll rotation shaft (11) in a state in which latitude of movement ? is present about a central axis line (4a). When a roll (10) is continuously rotated at a constant rate, the Oldham coupling (4) is held in a state in which no latitude of movement is present in a rotation direction R and latitude of movement ? is present in a direction opposite the rotation direction; and rotation torque is transmitted.

Abstract: A robot hand converts the longitudinal extending and retracting motion of an actuating rod of a linear actuator into opening and closing motion of left and right first links via a link mechanism. The link mechanism includes left and right middle links composed of coil springs. When the left and right first links come in contact with an object to be gripped, the middle links elastically deform and expand, and the force gripping the object gradually increases due to the elastic deformation of the middle links. It is possible to prevent a large gripping force from acting suddenly on the object and to prevent the object from being deformed, damaged, or otherwise suffering harmful effects.