Abstract: A wave generator (5) for a flat-type strain wave gearing (1) has a first elliptical outer circumferential surface (6S) of a first wave generator portion (5S) defined by a first elliptical curve (C1), and a second elliptical outer circumferential surface (6D) of a second wave generator section (5D) defined by a second elliptical curve (C2). Compared to using a wave generator for which the contour is defined by a single elliptical curve, differences between the ball load distribution of the first wave generator portion (5S) and the ball load distribution of the second wave generator portion (5D) can be suppressed, both ball load distributions can be equalized, and the equivalent ball load can be reduced; therefore, an increase in the lifespan of the wave generator bearing can be achieved.

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 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: In a self-propelled wheel apparatus of an aircraft, a drive mechanism composed of a wave gear drive and a motor is coaxially linked to an axle of a wheel via a one-way clutch, and rotational force in the reverse direction of the aircraft is transmitted to the wheel axle via the one-way clutch. When the aircraft moves forward, the link between the wheel axle and an output shaft of the wave gear drive is cut off by the one-way clutch, and motor rotational force is transmitted to the wheel axle, causing the wheel to rotate, only when the aircraft moves backward.

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 wave reduction gear (5) is disposed inside a device case (2) of a rotating table device (1). Lubrication oil is sprayed from an oil supply channel (22), which is formed in the device case (2), toward an oil supply hole (22) formed in a cup-shaped flexible externally toothed gear (12). A wave bearing (19) disposed in the interior is lubricated via the oil supply hole (21). Lubricating oil that has entered into the flexible externally toothed gear (12) is forcibly suctioned to the exterior via an oil recovery channel (23) that is formed in the device case (2). Accordingly, it will be possible to prevent oil from being suctioned due to the negative pressure state in the interior of the flexible externally toothed gear accompanying the high-speed rotation, and regions of the wave bearing (19) can be reliably lubricated.

Abstract: In an automatic torque-switching apparatus (1), a fixed member (12) of a reduction device (8) is attached to an apparatus housing (2) via a one-way clutch (9) so as to not rotate in the direction of torque acting on the fixed member from the load side. A rotational input member (13) of the reduction device (8) and the fixed member (12) of the reduction device are linked via a torque limiter (10) so as to rotate integrally only when the torque acting on the fixed member (12) is less than or equal to a prescribed value. The speed reducing operation is not performed while the torque is less than or equal to the prescribed value, and the rotation of a motor (3) is output directly. When the torque exceeds the prescribed value, the reducing operation is performed, and a switch is automatically made to a rotational output having reduced speed and a large torque.

Abstract: The drill bit shaft structure for an excavation apparatus has a thin-walled shaft portion formed on a hollow drill bit shaft. The thin-walled shaft portion has a thinner wall than that of shaft portions of the hollow drill bit shaft adjacent to both ends of the thin-walled shaft portion. A cylindrical body provided with an adjustable joining structure is disposed so as to envelop the thin-walled shaft portion. Both ends of the cylindrical body are connected to the shaft portions of the hollow drill bit shaft adjacent to the both ends of the thin-walled shaft portion. The direction of excavation is controlled by bending the thin-walled shaft portion and the cylindrical body.

Abstract: In a self-propelled wheel apparatus of an aircraft, a drive mechanism composed of a wave gear drive and a motor is coaxially linked to an axle of a wheel via a one-way clutch, and rotational force in the reverse direction of the aircraft is transmitted to the wheel axle via the one-way clutch. When the aircraft moves forward, the link between the wheel axle and an output shaft of the wave gear drive is cut off by the one-way clutch, and motor rotational force is transmitted to the wheel axle, causing the wheel to rotate, only when the aircraft moves backward.

Abstract: A composite roll bearing (1), comprising an outer ring (2) and an annular inner ring (3) of groove shape in cross section having first, second, and third receiving surfaces (3a, 3b, 3c) facing the both end face inner peripheral portions (2a, 2b) and the circular inner peripheral surface (2c) of the outer ring (2) at specified intervals. A plurality of rollers (4) for thrust bearing are installed between one end face portion (2a) of the outer ring (2) and the first receiving surface (3a) of the inner ring (3) and between the other end face (2b) of the outer ring (2) and the second receiving surface (3b) of the inner ring (3). A plurality of rollers (5) for radial bearing are installed between the circular inner peripheral surface (2c) of the outer ring (2) and the third receiving surface (3c) of the inner ring (3). The rollers (5) are restricted to move in a thrust direction by retainer portions (8a, 8a) formed at the inner ends of retainers (6, 7) for the rollers (4) for thrust bearing.

Abstract: A wave gear device, wherein, when a wave generator is in a low speed rotating state, a rolling bearing state is formed by a wave bearing and the wave generator and a flexible external gear are held in a relatively rotatable state and when the wave generator is in a high speed rotating state, partition pieces and split side plate pieces forming the retainer of the web bearing are displaced to the outside to stop the rotation of balls in their axes and the revolution thereof. Accordingly, a sliding bearing state is formed by lubricating oil film formed between the wave generator and the flexible external gear and the wave generator and the flexible external gear are held in a relatively rotatable state.

Abstract: A composite roll bearing (1), comprising an outer ring (2) and an annular inner ring (3) of groove shape in cross section having first, second, and third receiving surfaces (3a, 3b, 3c) facing the both end face inner peripheral portions (2a, 2b) and the circular inner peripheral surface (2c) of the outer ring (2) at specified intervals. A plurality of rollers (4) for thrust bearing are installed between one end face portion (2a) of the outer ring (2) and the first receiving surface (3a) of the inner ring (3) and between the other end face (2b) of the outer ring (2) and the second receiving surface (3b) of the inner ring (3). A plurality of rollers (5) for radial bearing are installed between the circular inner peripheral surface (2c) of the outer ring (2) and the third receiving surface (3c) of the inner ring (3). The rollers (5) are restricted to move in a thrust direction by retainer portions (8a, 8a) formed at the inner ends of retainers (6, 7) for the rollers (4) for thrust bearing.

Abstract: A wave reduction gear (5) is disposed inside a device case (2) of a rotating table device (1). Lubrication oil is sprayed from an oil supply channel (22), which is formed in the device case (2), toward an oil supply hole (22) formed in a cup-shaped flexible externally toothed gear (12). A wave bearing (19) disposed in the interior is lubricated via the oil supply hole (21). Lubricating oil that has entered into the flexible externally toothed gear (12) is forcibly suctioned to the exterior via an oil recovery channel (23) that is formed in the device case (2). Accordingly, it will be possible to prevent oil from being suctioned due to the negative pressure state in the interior of the flexible externally toothed gear accompanying the high-speed rotation, and regions of the wave bearing (19) can be reliably lubricated.

Abstract: In an automatic torque-switching apparatus (1), a fixed member (12) of a reduction device (8) is attached to an apparatus housing (2) via a one-way clutch (9) so as to not rotate in the direction of torque acting on the fixed member from the load side. A rotational input member (13) of the reduction device (8) and the fixed member (12) of the reduction device are linked via a torque limiter (10) so as to rotate integrally only when the torque acting on the fixed member (12) is less than or equal to a prescribed value. The speed reducing operation is not performed while the torque is less than or equal to the prescribed value, and the rotation of a motor (3) is output directly. When the torque exceeds the prescribed value, the reducing operation is performed, and a switch is automatically made to a rotational output having reduced speed and a large torque.

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 diaphragm of a cup-shaped flexible external gear of a cup-shaped wave gear device having a high reduction ratio of 100 or higher is given a thickness t in a position of a radius r of the diaphragm whereby the thickness t is a value that satisfies the expression A/r2 when A is a constant. The constant A is preferably a value that satisfies the expression 0.0014 D3<A<0.0026 D3, where D is a pitch diameter of the flexible external gear, and the range of the radius r whereby the thickness t is defined as described above in the diaphragm is preferably set to satisfy the expression 0.6 d<r<0.4 D, where d is a diameter of a discoid rigid boss made continuous with an internal peripheral end of the diaphragm. Stress concentration can be alleviated, and it is possible for the allowable transmission torque to be increased compared to the prior art.

Abstract: A wave gear device (1), wherein when a wave generator (4) is in a low speed rotating state, a rolling bearing state is formed by a wave bearing (43) and the wave generator (4) and a flexible external gear (3) are held in a relatively rotatable state and when the wave generator (4) is in a high speed rotating state, partition pieces (7) and split side plate pieces (8) forming the retainer (47) of the web bearing (43) are displaced to the outside to stop the rotation of balls (46) in their axes and the revolution thereof. Accordingly, a sliding bearing state is formed by lubricating oil film (9) formed between the wave generator (4) and the flexible external gear (3) and the wave generator and the flexible external gear are held in a relatively rotatable state. When the wave generator (4) returns to the low speed state, the constraint of the wave bearing (43) is released by the elastic return force of the elastic ring (5) of the retainer (47) and the wave bearing (43) returns to the rolling bearing state.

Abstract: A diaphragm of a cup-shaped flexible external gear of a cup-shaped wave gear device having a high reduction ratio of 100 or higher is given a thickness t in a position of a radius r of the diaphragm whereby the thickness t is a value that satisfies the expression A/r2 when A is a constant. The constant A is preferably a value that satisfies the expression 0.0014D3<A<0.0026D3, where D is a pitch diameter of the flexible external gear, and the range of the radius r whereby the thickness t is defined as described above in the diaphragm is preferably set to satisfy the expression 0.6d<r<0.4D, where d is a diameter of a discoid rigid boss made continuous with an internal peripheral end of the diaphragm. Stress concentration can be alleviated, and it is possible for the allowable transmission torque to be increased compared to the prior art.

Abstract: A wave gear device has a rigid internal gear, a flexible external gear, and a wave generator. The tooth profiles of both gears are initially defined by a basic rack tooth profile shape. The lower parts of the dedendum portions of these tooth profiles are modified by curves C2 and C3 having pressure angles ?2 and ?3 that are less than the standard pressure angle ?1 of the basic rack tooth profile shape C1. An increase in thickness of the tooth bottom side can be minimized even if the tooth depth is increased and the tooth thickness/tooth space ratio changed to increase the tooth thickness. Hence, the ratcheting torque of a wave gear device having a high reduction gear ratio can be increased without reducing the service life and strength of a pinion cutter for the rigid internal gear, or the fatigue strength of the flexible external gear.

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.