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 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 cup-shaped flexible externally toothed gear of a wave gear device, wherein a diaphragm plate slopes from a diaphragm internal peripheral edge portion contiguous to a boss part toward a diaphragm external peripheral edge portion contiguous to a cylindrical body portion in a direction in which the diaphragm external peripheral edge portion is at greater distance from an open end of the cylindrical body portion with respect to an orthogonal plane orthogonal to a central axis line of the device. The length dimension of the diaphragm plate and the length dimension of the cylindrical body portion in the axial direction can be increased. Therefore, the fatigue strength of the diaphragm plate and the load capacity of the wave gear device in which the flexible externally toothed gear has been incorporated can be increased.

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: A concentric double axis actuator has a two-stage cross roller bearing, and a preceding-stage actuator and a subsequent-stage actuator which are linked in tandem. The front end of a subsequent stage rotary output shaft of the subsequent actuator, said subsequent stage rotary output shaft passing through a hollow section of the preceding-stage actuator and projecting forward, is linked and fixed to an inner ring of the two-stage cross roller bearing, and the inner ring functions as a subsequent-stage rotary output member. The output rotary side of the preceding-stage actuator is linked to an middle ring of the two-stage cross roller bearing, which functions as a preceding-stage rotary output member. The rotary output element of each stage is supported by the two-stage cross roller bearing, and surface oscillations of the rotary output member of each stage can be minimized, and the moment stiffness of the members can be increased.

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: 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 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: According to a method for performing adaptive friction compensation of an actuator including a wave gear drive, there is used as a friction compensation current applied to a motor drive current a static friction compensation current is when a motor shaft stops with a deviation, and a Coulomb friction compensation current ic in other circumstances. The static friction compensation current is is obtained by adding a compensation amount isr of a monotonically increasing ramp function to a compensation amount iss of a step function, and a step-function compensation amount ics is used as the Coulomb friction compensation current ic. Since the amount of friction compensation can be changed adaptively based on the data during positioning-control response, a motor shaft can be stabilized at a target angle without prominent accompanying vibration, even if the ambient temperature changes and the friction characteristics of the wave gear drive fluctuate.

Abstract: A method for controlling positioning of an actuator having a wave gear device uses an exact linearization technique to compensate effects relative to positioning control of a load shaft caused by the non-linear spring characteristics of the wave gear device. A plant model is constructed from the actuator, and linearized using the exact linearization technique; measurements are taken of non-linear elastic deformation of the wave gear device relative to load torque; the non-linear spring model ?g(?tw) is defined using a cubic polynomial with the constant defined as zero to allow the measurement results to be recreated; and the current input into the model and motor position of the model when a load acceleration command is a command value are entered into a processor arranged as a semi-closed loop control system for controlling positioning of the load shaft, as a feed-forward current command and a feed-forward motor position command.

Abstract: The flexible bearing of the wave generator for a wave gear device is a deep-groove ball bearing in which an outer race and an inner race form an annular flexible bearing ring capable of bending in a radial direction. A ball diameter Da is set to be 5 to 15% greater than that of each model of the currently available product. Dimensions of orbital plane radii ro, ri of the inner and outer races are set so that the ratio ro/Da of the orbital plane radius ro of the inner race and the ball diameter Da, as well as the ratio ri/Da of the orbital plane radius ri of the outer race and the ball diameter Da, are both in the range of 0.51 to 0.52. With this configuration, the service life of the flexible bearing can be extended.

Abstract: In a galvano scanner system (1), a light position detection unit (30) is mounted so as to match the scanning center of the workpiece surface (7), the light position detection unit being provided with a two-dimensional light position sensor (32) disposed in the center and four one-dimensional light position sensors (33(1)) to (33(4)) concyclically disposed at equal angles about the center of the two-dimensional light position sensor. An origin position command is given to galvano scanners (3, 4), laser light is irradiated at low output, and the offset adjustment value is calculated based on the detection output of the two-dimensional light position sensor (32).

Abstract: A method for manufacturing a rigid internal gear of a wave gear device in which an internally toothed portion formed with internal teeth and a gear main body portion are joined integrally, the method including preforming an internal teeth-forming ring or disc for forming the internally toothed portion by using a first aluminum alloy powder; manufacturing a forging in which the internal teeth-forming ring or disc is placed in a forging die and is integrally formed on its outer side with the gear main body portion using a second aluminum alloy powder, the first aluminum alloy powder being harder and having higher abrasion resistance than the second aluminum alloy powder; and applying post-processing including cutting teeth to the forging.

Abstract: According to a method for performing adaptive friction compensation of an actuator including a wave gear drive, there is used as a friction compensation current applied to a motor drive current a static friction compensation current is when a motor shaft stops with a deviation, and a Coulomb friction compensation current ic in other circumstances. The static friction compensation current is is obtained by adding a compensation amount isr of a monotonically increasing ramp function to a compensation amount iss of a step function, and a step-function compensation amount ics is used as the Coulomb friction compensation current ic. Since the amount of friction compensation can be changed adaptively based on the data during positioning-control response, a motor shaft can be stabilized at a target angle without prominent accompanying vibration, even if the ambient temperature changes and the friction characteristics of the wave gear drive fluctuate.

Abstract: A method for controlling positioning of an actuator having a wave gear device uses a strict linearization technique to compensate for the effects relative to positioning control of a load shaft in the, as caused by the non-linear spring characteristics of the wave gear device. In the method, a plant model is constructed from the actuator to be controlled, the model being linearized using a strict linearization technique; measurements are taken of the non-linear elastic deformation of the wave gear device relative to load torque; the non-linear spring model ?g(?tw) is defined using a cubic polynomial with the constant defined as zero to allow the measurement results to be recreated; and the current input into the plant model and the motor position of the plant model when a load acceleration command is a command value are entered into a semi-closed loop control system for controlling the positioning of the load shaft, as a feed-forward current command and a feed-forward motor position command.

Abstract: A ball screw/nut type linear actuator (1) where a ball nut (32) moves in forward-backward directions by rotation of a ball screw shaft (31) connected to a motor (22), wherein the ball screw shaft (31) is connected and fixed, in a small diameter hollow section (22c) of the motor shaft (22), to the motor shaft so that a part of the locus of the movement of the ball nut (32) also enters into a large diameter hollow section (22a) of the motor shaft (22). The construction eliminates the need of a coupling for connecting the motor shaft (22) and the ball screw shaft (31) and enables the ball screw shaft (31) to be supported together with the motor shaft (22) by bearings (27, 28) of the motor. As a result, a support bearing for supporting the ball screw shaft can be eliminated. Thus, a short and light linear actuator is realized.

Abstract: In a flat wave gear device, there is determined a rack-approximated movement locus Lc1 of a flexible externally toothed gear with respect to an S-side rigid internally toothed gear accompanying rotation of a wave generator. (?OPT is a minimum value of the radius of curvature of the movement locus Lc1, and is determined from an evolute e of the movement locus Lc1. A convex arc having a radius ? (???OPT) is used in a main part of a tooth profile of the flexible externally toothed gear. A parallel curve c that is set apart from a movement locus Lc2 by the arc radius p is used on a main part of a tooth profile to be generated on the S-side rigid internally toothed gear. The movement locus Lc2 accounts for the actual number of teeth, and is obtained from a center A of a convex arc of the flexible externally toothed gear being drawn with respect to the rigid internally toothed gear.

Abstract: In a wave linear motion mechanism (4) of a holding mechanism (1), those portions of a flexible screw (14) where first and second male screws (32, 33) are formed are elliptically deformed by first and second wave generators (12, 13) installed on an input shaft (11), and the first and second male screws (32, 33) are respectively partially engaged with first and second female screws (42, 44) of first and second circular nuts (15, 16). First and second holding members (5, 6) are mounted on the first and second circular nuts (15, 16), respectively. When the input shaft (11) is rotated by a motor (3), the first and second holding members (5, 6) are opened or closed depending on the rotation direction to release or hold an object (W).