Abstract: A wave gear drive (1) includes an annular rigid internal gear (2), an annular flexible external gear (3) arranged inside of the annular rigid internal gear (2), and a wave generator (4) fitted inside of the annular flexible external gear. The wave generator (4) includes a rigid cam plate (41) having a predetermined outline, and a hub (43) inserted into a fitting hole (42) formed in the center of the rigid cam plate (41). A transfer-torque control mechanism for limiting the torque transferred through the wave generator (4) to the flexible external gear (3) is defined by a nut (46) that fastens the rigid cam plate (41) and the hub (42). When the torque equal to or greater than a predetermined value is transferred, a slip is generated in a rotational direction between the rigid cam plate (41) and the hub (42), thus limiting the transfer torque to a predetermined limit value. As a result, the torque limiter is not required.

Abstract: A method of manufacturing a lightweight bearing in which raceway surface parts are formed of iron-based material and body members are formed of a lightweight material that is lighter than the iron-based material. Bearing rings are manufactured by producing first and second split body members whose shapes are identical to those obtained by dividing the body members transversely along a plane perpendicular to the center axis, producing split raceway surface members whose shapes are identical to those obtained by similarly dividing the raceway surface formation members, and bonding together split raceway surface members and split body members.

Abstract: A wave gear drive unit 1 has a unit case 2, a wave reduction gear mechanism 3 disposed inside the unit case 2, an input shaft 4 and an output shaft 5. The output shaft 5 is integrally formed on a boss 323 of a cup-shaped flexible external gear 32 of the mechanism 3 and extends through a second end plate 5 to project outside. The boss 323 is screwed into the second end plate 22. A cross roller bearing 6 is constituted by the outer circumferential surface of the boss 323 and the inner circumferential surface of the unit case, by measn of which the second end plate 22 is rotatably supported on the unit case 2. The wave gear drive unit 1 has a simple structure with a small number of assembled parts, and can be assembled easily.

Abstract: A wave gear drive unit 1 has an annular housing 2 and a wave reduction gear mechanism 3 placed inside the housing 2. The wave reduction gear mechanism 3 has a cup-shaped flexible external gear 6 which serves as an output element of the unit and is rotatably supported on the housing 2 via a cross roller bearing 4. An outer race 11 of the bearing 4 is screwed to the housing 2. Whereby, it is possible to suppress deformation of the outer ring and uneven axial-force distribution thereof which may occur when a number of fastening bolts are used to fasten the outer race to the housing. Assembling and processing operations can also be simplified, thereby reducing the manufacturing cost. The unit can also be made small and compact since the space for mounting the fastening bolts is eliminated.

Abstract: A phase regulating speed reducer(20) in a phase regulating apparatus (100) has first and second cup-shaped wave gear gear drives (30,40). A first wave generator (33) for the first wave gear drive (30) is connected to a phase regulating motor. A first flexible external gear (32) and a second flexible external gear (42) of the second wave gear drive (40) are fixed together by a plurality of fastening bolts (60) so that these external gear are rotated together in a back-to-back state. A second wave generator (43) for the second wave gear drive (40) is made non-rotatable. During a normal power transmission time, the phase regulating motor is not operated. Therefore, the reduction ratio of the two drives is set equal, an input rotation of the first wave gear drive (30) into a first rigid internal gear (31) is outputted at the same rotational frequency from a second rigid internal gear (41).

Abstract: A rigid internal gear of a wave gear drive is comprise by a tooth-formed member having inner teeth and a circular gear body member, these two members being integrally connected with each other. The tooth-formed member is made of ferrous or copper material having a high strength and wear resistance, while the gear body member is made of lightweight material such as aluminum alloy and the like. These members are connected integrally with each other in a manner that one of these members is formed with baffle means and the other member is made by enveloped casting, or that the member having baffle means is pressed into the other member. These members are therefore surely connected with each other, so that a high torque can be transferred between these members. Also, the lightweight of the rigid internal gear can be achieved without deteriorating strength, wear resistance or the like thereof.

Abstract: A sealed-type wave gear device 1 has a sealed space 13 formed by a device housing 2, first and second end plates 3 and 4 placed in openings at both the ends thereof, a hollow Input shaft 5, and first to fourth seals (8, 9, 11, 12) for sealing these members. A flat wave gear mechanism 20 is accommodated in the sealed space 13, which comprises a rigid internal gear 210, a silk-hat-shaped flexible external gear 220 inside the rigid internal gear 210, and a wave generator 230 fixed inside the flexible external gear 220. A lubricant in the wave gear mechanism 20 is completely prevented from leaking outside. Only the device housing 2, the first and second end plates 3 and 4, and both the ends of the input shaft 5 which are exposed outside need to be protected from rusting. The wave gear device 1 is suitable for being used as a speed reduction unit of a driving mechanism employed in a clean room.

Abstract: In a power assist device 5, a hollow type electric motor 6 and a hollow-type wave drive gear 7 are concentrically arranged, and a steering shaft 2 is inserted into the center of these component parts. The rotational output of the hollow output shaft 61 of the electric motor 6 is input to a wave generator 74, and a rotational output of reduced speed is derived from a cup-shaped flexible external gear 73. This rotational output is transferred as a force assisting the steering shaft 2 in steering operation. The power assist device 5 employs a small, compact wave gear drive and has the motor 6 and the wave drive gear 7 each of hollow type adaptable to be concentrically mounted on the outer periphery of the steering shaft 2. Therefore a small, compact power assist device can be configured, substantially reducing the installation space.

Abstract: A wave gear drive (1) has a silk-hat shaped flexible external gear (12) comprising a cylindrical body (13), a circular diaphragm (14), a circular boss (15) formed integrally on the diaphragm (14), and external teeth (16) formed on the body (13) at a side of an open end (13a) thereof. The boss (13) of the flexible external gear, a cross roller bearing (7) and the rigid internal gear (11) are arranged between first and second end plates (2, 3) so as to define a substantially sealed inside space of the wave gear drive (1). A resilient seal ring member (8) is mounted on the open end (13a) of the flexible external gear to divide the inside space into an inside portion (9) where a first lubricant having a high viscosity is supplied and an outside portion (10) where a second lubricant having a low viscosity is supplied.

Abstract: A flexible meshing type gear device 1 has an internal gear 2 having internal teeth 21, a flexible external gear 3 having external teeth 31, and a wave generator 4. Only the internal teeth 21 of the internal gear 2 are formed thereon with a metal plated coating 21a. Further, a tooth profile 211 of the internal teeth 21 of the rigid internal gear 2 before metal plating is modified from a desired tooth profile of the internal teeth so that a tooth profile 212 defined by a surface of the internal teeth 21 after metal plating corresponds substantially to the desired tooth profile of the internal teeth for assuring a proper meshing between the internal and external gears. Accordingly, a flexible meshing type gear device having a high wear resistance can be realized while maintaining a high fatigue strength of the external gear and a proper meshing between gears.

Abstract: A rotational power transmission device 1 has a rotational input shaft 3, rotational input to which is transferred, via a sun gear 4 (the number of teeth is Za) and first planetary gears 5 (Zb), to second planetary gears 6 (Zc). The first and second planetary gears 5, 6 are mounted on a common planetary carrier 7. Planetary shafts 6a of the second planetary gears 6 also support third planetary gears 8 (Zd), and rotation of the second planetary gear 6 is transferred directly to the third planetary gears 8. The rotation of the third planetary gears 8 is transferred via an external gear 9 (Ze) to a rotational output shaft 11. The common planetary carrier 7 can be connected and disconnected to the input shaft 3 by means of a clutch means 12 and a clutch brake 13. The relationship of the numbers of teeth of the respective gears are Za/Zc=Ze/Zd, the normal and reverse rotations at an equal speed can be obtained from the output shaft 11.

Abstract: In a flexing contact type gear drive (1), the respective tooth profiles of the internal gear (2) and external gear (3) are constructed such that the tooth face portion is formed of a straight line AM disposed in the vicinity of a datum point, a first convex circular arc (AB) smoothly connected thereto and a second convex circular arc (BC) smoothly connected to the first convex circular arc and having a radius of curvature larger than the first convex circular arc, while, the dedendum portion excluding the root is created by a standard rack consisting of a tooth profile formed by a curve point-symmetrical with respect to the datum point to the tooth profile at the tooth face or a curve obtained by correcting the above curve.

Abstract: The present invention relates to a positioning device capable of positioning a member in any direction with a high degree of resolution by using a hollow type harmonic drive mechanism, and to a drilling-direction control device for a drilling system utilizing the positioning device. The device of the present invention is mainly constituted by a double eccentric mechanism section (10). A first annular member (12) is rotatably supported by a circular inner circumferential surface (11a) of the cylindrical member (11) of this mechanism section, and a second annular member (13) is rotatably supported by a circular inner circumferential surface (11b) of the first annular member.

Abstract: An attitude control device has a plurality of harmonic drive mechanisms of the hollow type, preferably first and second harmonic drive mechanisms. First and second rotational members are connected to the outputs of the first and second harmonic drive mechanisms. These rotational members have eccentric hollow portions which rotate eccentrically around the rotational axes of the harmonic drive mechanisms. A member to be driven is placed to extend through the eccentric hollow portions such that it is supportedly contacted with the inner surfaces of the eccentric hollow portions. In operation, the eccentric hollow portions are rotated relative to each other, whereby the member to be driven is controllably oriented to a desired direction.The attitude control device can be employed as a drillingdirection control device wherein a rotational drill shaft is supported by inner surfaces of eccentric hollow portions of first and second rotational members.

Abstract: An attitude control device has a plurality of harmonic drive mechanisms of the hollow type, preferably first and second harmonic drive mechanisms. First and second rotational members are connected to the outputs of the first and second harmonic drive mechanisms. These rotational members have eccentric hollow portions which rotate eccentrically around the rotational axes of the harmonic drive mechanisms. A member to be driven is placed to extend through the eccentric hollow portions such that it is supportedly contacted with the inner surfaces of the eccentric hollow portions. In operation, the eccentric hollow portions are rotated relative to each other, whereby the member to be driven is controllably oriented to a desired direction.The attitude control device can be employed as a drilling-direction control device wherein a rotational drill shaft is supported by inner surfaces of eccentric hollow portions of first and second rotational members.

Abstract: A cup-type harmonic gear drive comprises a rigid circular spline, a cup-shaped flexspline disposed inside the circular spline and a wave generator means fitted inside the flexspline for flexing the flexspline into elliptic to engage it with the circular spline and for rotating the engagement portions to thereby produce relative rotation between the splines. The flexspline has a tube, a disc-shaped diaphragm connected integrally to the end of said tube to define the cup bottom, and a thick boss formed on the center of the diaphragm. The diaphragm has a root portion from the boss, a thickness of which is set at least about three times the minimum thickness of the diaphragm. The outer profile of the diaphragm is defined, when viewed along a plane including the axis of the flexspline, by a plurality of curves having a different curvature. These curves are arranged from one having a larger curvature from the root protion to the tube portion of the diaphragm.

Abstract: A strain wave gearing comprising a circular spline, flexspline inside the circular spline, a wave generator for deforming the flexspline into, for example, an ellipsoid and a motor for rotating the wave generator to produce a relative rotation between the flexspline and the circular spline. The strain wave gearing is sometimes termed a harmonic drive transmission, and there is a type of gearing called flat-shaped strain wave gearing which is composed of two circular splines juxtaposed with each other, a flexspline in the circular splines having the same number of teeth as the first circular spline, a wave generator for deforming the flexspline into an ellipsoid and a motor for rotating the wave generator. In the flat-shaped gearing, each tooth of the flexspline is provided with a convex tooth face and a concave tooth flank.