Abstract: In a strain wave gearing, external teeth of a flexible externally toothed gear are elastically deformable in a direction in which the tooth thickness of the external teeth decreases. Engagement between internal teeth of a first and a second rigid internally toothed gears and the external teeth is set in an overlapping state in which the external teeth elastically deform and engage in a state in which no gap is present. The tooth profile of the internal teeth is a corrected tooth profile so that no interference occurs between a tooth top portion of the internal teeth and a dedendum portion of the external teeth when the teeth are engaged in the overlapping state. A strain wave gearing capable of minimizing or eliminating tooth engagement backlash is realized.

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.

Abstract: A press plate is tacked to a boss of a cup-shaped flexible externally toothed gear of a wave gear device unit. A second arm as a driven member is attached by a fastening bolt to an end surface on an outer side of an output flange of the wave gear device unit. The fastening bolt is screwed into and secured in a tap hole of the press plate from each bolt insertion hole of the second arm, via a flange-side bolt insertion hole and a boss-side bolt insertion hole. A fastening structure can be achieved in which a driven member is fastened to a wave gear device unit in which holes are easily machined into the output flange, and only a few fastening bolts are needed to fasten the boss, the output flange, and the driven member.

Abstract: A hollow-type strain wave gearing unit has a cup-shaped flexible externally-toothed gear, in which one shaft end portion of a hollow rotation shaft of a wave generator is located. The shaft end portion is supported by a bearing mounted on a bearing holder fixed to a boss of the flexible externally-toothed gear. The bearing holder has a retainer holding portion to prevent a retainer of a wave generator bearing from coming off in the axis line direction. There is no need to dispose a retainer holding plate of the wave generator bearing inside the flexible externally-toothed gear, whereby the axial length of the hollow-type strain wave gearing unit can be reduced.

Abstract: In this hollow strain wave gearing unit, a shaft end part of a hollow rotary shaft of a wave generator is located inside a cup-shaped flexible external gear. The shaft end part is supported by a bearing attached to a bearing holder that is fixed to a boss of the flexible external gear. In the bearing holder, an elastic leaf spring part that is displaceable in the axial direction constitutes a part that supports a holder body part that holds the bearing. A preload is applied by the leaf spring part to the bearing in the axial direction. Thus, there is no need to separately arrange a preload application member inside the flexible external gear, and the axial length of the hollow strain wave gearing unit can be shortened.

Abstract: A wave generator of a strain wave gearing has a rigid plug and a needle roller bearing mounted on the plug external peripheral surface. The plug external peripheral surface has a retainer engaging part for engaging with a retainer that would move in an axis line direction and for restricting the movement thereof along the axis line direction. The retainer has an outer ring engaging part for engaging with an outer ring that would move in the axis line direction and for restricting the movement thereof along the axis line direction. The movements of the retainer and the outer ring can be restricted without providing a separate member. A wave generator of a strain way gearing can be realized, which is provided with a roller bearing capable of restricting the movement of the outer ring with a simple structure.

Abstract: A slotted rigid coupling is configured in such a manner that an inner peripheral surface portion of a shaft hole, the inner peripheral surface portion being located within the slit-equipped fastening section of the coupling body, has an inner diameter d. The inner diameter d of an inner peripheral surface portion of the shaft hole, the inner peripheral surface portion being adjacent to the inner peripheral surface portion, is slightly larger than the inner diameter d. The inner peripheral surface portion is a relief surface recessed outward in the radial direction relative to the inner peripheral surface portion. A shaft is inserted in the shaft hole, and the fastening section is fastened. The region where the inner peripheral surface portion adjacent to the inner peripheral surface portion is provided does not come into contact with the shaft. The shaft can be fastened and affixed to the shaft hole without tilt.

Abstract: A strain wave gearing unit is provided with an internal gear, which surrounds the periphery of a cup-shaped external gear, and a bearing. An annular gap is formed between the inner ring of the bearing and the internal gear. The gap communicates with the sliding portions of the bearing and the section where the two gears mesh. An annular filter member made of non-woven fabric is fitted in the gap. Foreign matter such as abrasion powder, which is contained in lubricant that flows in the gap, is trapped by the filter member. The present invention can prevent penetration of abrasion powder generated in the sliding portions into the meshing section via the gap.

Abstract: In a positioning apparatus for an actuator, a sliding mode controller for compensating for nonlinear characteristics of a wave gear device of the actuator generates a control input u to a controlled object, based on a position command ?l* and a state variable x for expressing the controlled object. The controlled object is defined in the following formula. {dot over (x)}=Ax+Bu+E?l* y=Cx The switching surfaces of the sliding mode control system are defined by a variable S expressed in the following formula. S=BTP The control input u is the sum of the linear-state feedback control term ul and the nonlinear control input unl u = u l + u nl = - ( SB ) - 1 ? ( SAx + SE ? ? ? l * ) - k ? ( SB ) - 1 ? ? ? ? ? ? = Sx , where ? is the switching function, and k is the switching gain.

Abstract: A cup-shaped flexible externally toothed gear of a wave gear device comprises a cylindrical body part, and an external-teeth area thereof includes a pushed portion pushed radially outward by a wave generator and a groove formed in a position adjacent to the pushed portion toward a diaphragm. The reaction force of the wave generator can be reduced because the groove is formed to partially reduce thickness in a portion that does not affect the root strength of the external teeth. The increase in root stress can be suppressed when the roots of the external teeth are thickened, and root strength can be effectively increased. The load torque of the wave gear device can thereby be increased.

Abstract: In a wave gear device, an annular rigid externally toothed gear is disposed on the inner side of a cup-shaped flexible internally toothed gear. An internal-tooth-formation portion of the flexible internally toothed gear and a pushed portion pushed by a wave generator and flexed ellipsoidally are formed in different positions along the center axis line. The wave generator is disposed on the inner side of the flexible internally toothed gear, the pushed cylindrical portion is pushed from the inner side to the outside along the radial direction thereof by the wave generator, whereby the pushed cylindrical portion is flexed ellipsodially. As the outside diameter dimension of the wave gear device is determined by that of the flexible internally toothed gear, a wave gear device having a small outside diameter dimension can be obtained.

Abstract: Provided with a sealed rotational output unit (3) which includes a tubular shaft (12) having an outer circumferential surface sealed with a ferrofluidic seal (13); a rotating output shaft (14) disposed inside the tubular shaft (12); and an O-ring (17, 18) that seals between the tubular shaft (12) and the rotating output shaft (14). When the rotating output shaft (14) is directly coupled to a hollow motor shaft (9), shaking thereof is absorbed by the O-ring (17, 18), causing no excessive stress to be produced on the bearing side of the hollow motor shaft (9) or on a bearing (15, 16) side of the ferrofluidic seal (13). Since the tubular shaft (12) rotates in conjunction with the rotating output shaft (14), the O-ring (17, 18) that seals therebetween does not degrade in sealing capability due to wear by sliding. The sealed rotational output unit can be used with high rotational accuracy by directly coupling to a hollow motor (2) without any joint.

Abstract: A wave gear unit has an input shaft positioned along a center axis by first and second input bearings. A first unit end plate at the first-input-bearing side is a composite member in which a bearing housing member of an iron-based material is integrated with an end plate main body member of a lightweight material. A second unit end plate at the second-input-bearing side is integrated with a rigid internally toothed gear, and is a composite member in which a second member of a lightweight material is integrated with a first member of a lightweight material. The first member has an end plate main body portion of the second unit end plate and a gear main body portion of the rigid internally toothed gear, while the second member has a bearing housing portion of the second unit end plate and a teeth formation portion of the rigid internally toothed gear.

Abstract: In an elliptical rim neutral line of each axially perpendicular cross section in a tooth trace direction of a flexible externally toothed gear of a wave gear device, external teeth are applied with addendum modification along the external teeth tooth trace direction so that the bending stress generated at the root rim surface of the external teeth that is caused by flexing of the flexible externally toothed gear is averaged out, the maximum value thereof can be reduced, and the transferred torque of the wave gear device can be increased.

Abstract: A gap measurement device 1 comprises a light source 5 for projecting light on a gap 3 to be measured, a lens optical system 6 for focusing on an imaging surface 7 a gap image 3A from light transmitted through the gap 3, and a light-receiving element 9 for receiving light of the gap image 3A formed on the imaging surface 7 of the lens optical system 6. A holed mask 8 provided with a light-transmitting hole 8a having a prescribed aperture size is arranged on the imaging surface 7, and the light-receiving element 9 receives the light of the gap image 3A via the hole 8a. A gap size at a point to be measured in an extended gap 3 can be measured by forming an image of the gap with the lens optical system 6 and placing the hole 8a of the holed mask 8 on the point to be measured on the imaging surface 7 of the lens optical system 6.

Abstract: A unit type wave gear device (1) has a unit housing (2), one end of which is defined by a two-stage cross roller bearing (7). The two-stage cross roller bearing (7) has: an inner cross roller bearing formed by an inner ring (13), an intermediate ring (12), and inner rollers (17) inserted into an inner track (16); and has an outer cross roller bearing formed by an outer ring (11), the intermediate ring (12), and outer rollers (15) inserted into an outer track (14). A flexible externally-toothed gear (22) affixed to the intermediate ring (12) is rotatably supported by the unit housing (2) via the outer cross roller bearing. An input shaft (4) affixed to the inner ring (13) and a wave generator (23) affixed to the input shaft (4) are rotatably supported by the intermediate ring (12) via the inner cross roller bearing. A unit type wave gear device can be realized in which the number of components are reduced and a large moment load is applied.

Abstract: When a first output shaft (5) of a planetary differential reduction device (1) is driven to rotate, a first internal gear (24) of a first planetary reduction part (20) and a second internal gear (34) of a second planetary reduction part (30) are rotated in the same direction at the same speed, and a planetary carrier (63) of a third planetary reduction part (40) is also rotated in the same direction at the same speed, whereby a second output shaft (6) connected to the planetary carrier (63) is rotated synchronously with the first output shaft (5). When differential rotation is inputted to the second sun gear (31), a reduced rotational output is output to the planetary carrier (63) of the third planetary reduction part (40). The second output shaft (6) is added with the reduced rotational output for differential rotation, whereby the second output shaft (6) is shifted to a differential rotating state.

Abstract: A retainer for a roller bearing holds needle rollers within slit-shaped pockets which are formed separately by means of partitions arranged with a fixed pitch in the circumferential direction. Each partition is equipped with two side faces, which face the sides of the adjacent partitions, and an outer-circumferential-side end face, which faces the outer circumferential side of the retainer, and retaining protrusions are formed at the corner parts where the outer-circumferential-side end faces and each side face intersect. Each retaining protrusion protrudes farther to the outer circumferential side from the outer-circumferential-side end face, and protrudes obliquely in the direction in which the aperture width of the pockets is narrowed. For each pocket the positions where the retaining protrusions are formed in the longitudinal direction of the partitions are set so as not to overlap the adjacent pockets.

Abstract: A magnetic absolute encoder includes: a board-holding assembly mounted to a motor case assembly side; and a flexible printed wiring board which is held, by the board-holding assembly, in the shape of a loop surrounding multipolar and bipolar ring magnets. On the flexible printed wiring board, multipolar-side hall elements and bipolar-side hall elements are mounted and a wiring pattern relating to the hall elements are printed. The assembling work and wiring work of the magnetic absolute encoder provided with a multipolar magnetic encoder and a bipolar magnetic encoder can be performed simply in a short time.

Abstract: In a wave gear device, the inner race and the boss are fixed together by a laser welded part formed along the entire periphery thereof. The laser welded part also functions as an oil seal for sealing the inner race and the boss. The boss and the inner race are fixed together in a manner that a required axial length is short, and that machining and assembling steps are reduced. Oil seal members are not required to seal the boss and the inner race.