Abstract: A strain wave gearing has a detection mechanism that detects thrust force generated between a wave generator and an externally toothed gear. The detection mechanism is provided with a strain gauge or piezoelectric load meter, and a transmission mechanism that transmits thrust force from the wave generator to the load meter. Only rotational force is transmitted to the wave generator from a from a motor shaft side, and axial force is not transmitted. The load meter and the transmission mechanism provide a small and compact detection mechanism that can be incorporated inside the externally toothed gear. In the strain wave gearing into which the detection mechanism is incorporated, operation control according to detected thrust force becomes possible using thrust force information during operation.

Abstract: In the interior of a device housing of a strain wave gearing, a detection mechanism is incorporated at a site on the outer peripheral side of a hub of a wave generator. The hub of the wave generator is linked to a motor shaft so that axial force does not act thereon. The detection mechanism detects minute displacements in the axial direction that occur in the hub of the wave generator due to thrust acting on the wave generator. Thrust acting on the wave generator is obtained on the basis of the detected minute displacements. With this strain wave gearing in which the detection mechanism is incorporated, operation control that is responsive to sensed thrust is possible through the use of thrust information during operation.

Abstract: A strain wave gearing includes an internally toothed gear integrated with an inner ring. A bolt hole is formed in the internally toothed gear. The bolt hole includes a bolt passage hole part, and a screw hole part extending in the direction of an axial line, continuously from the bolt passage hole part. The screw hole part, to which a bolt-fastening force is applied, is formed at a location away in the direction of the axial line from a location adjacent to a radially outer side of an internally toothed gear. Deformation, occurring during fastening of a bolt, at a portion in which the internally toothed gear is formed can be reduced, and adverse effects caused by the deformation such as a decrease in the accuracy of engagement or meshing of the internally toothed gear and an externally toothed gear can be inhibited.

Abstract: In a strain wave gearing, a thrust force applied on an externally toothed gear during an increased-speed operation causes the externally toothed gear to move along an axis in a first direction, and the output-side end surface thereof is pressed, by a prescribed force, against a friction surface of a friction plate integrated with a rotating shaft part of a strain wave generator. Torque transmission efficiency can be reduced only during increased-speed operation, by means of a friction loss occurring between the externally toothed gear and the friction plate. When large load torque is applied from an output shaft which is an output-side member during reduced-speed operation, retention torque of the strain wave generator which is an input-side member during speed-reduction operation can be reduced.

Abstract: In a strain wave gearing, both of a pulley for transmitting rotation in a direction orthogonal to a rotation central axis and an output shaft are arranged on an axial-direction first side relative to a cup-shaped externally toothed gear. The input shaft, which transmits input rotation from the pulley to the wave generator, functions as a support shaft for both the pulley and the wave generator and is supported at both ends by the first and second bearings. A mechanism for transmitting rotation from the pulley to the wave generator, and a mechanism for supporting the rotation-transmitting mechanism, can be made compact, and support strength can also be ensured.

Abstract: According to a tooth profile designing method for a strain wave gear device, a first curve from a point A (?=0) to a point B (?=?/2) in a moving locus of external teeth with respect to internal teeth is extracted. A similarity curve is obtained by multiplying the first curve by (1??) using the point B as a center of similarity, and a second curve is obtained by rotating the similarity curve by 180° about a midpoint C between the point A and the point B as a center of similarity. A third curve is obtained by multiplying only the x-coordinate of the second curve by ? (?<1), or a fourth curve is obtained by multiplying only the y-coordinate of the second curve by ? (?>1). An addendum tooth profile of the external teeth is defined using the third curve or the fourth curve.

Abstract: A rotary encoder is incorporated in an annular space formed between a hollow rotating shaft and an encoder case. The rotary encoder has an annular printed wiring substrate, a plurality of mounting substrates that are outward from the printed wiring substrate in the radial direction and are arranged in the circumferential direction, and inter-substrate wiring cables bridged between the printed wiring substrate and each of the mounting substrates in the radial direction. Power supply to the mounting substrates and signal transmission and reception between the mounting substrates can be accomplished without routing around the wiring cables. It is possible to achieve a rotary encoder that is suitable for being incorporated in a narrow annular space.

Abstract: In a strain wave gearing, a thrust force applied on an externally toothed gear during an increased-speed operation causes the externally toothed gear to move along an axis in a first direction, and the output-side end surface thereof is pressed, by a prescribed force, against a friction surface of a friction plate integrated with a rotating shaft part of a strain wave generator. Torque transmission efficiency can be reduced only during increased-speed operation, by means of a friction loss occurring between the externally toothed gear and the friction plate. When large load torque is applied from an output shaft which is an output-side member during reduced-speed operation, retention torque of the strain wave generator which is an input-side member during speed-reduction operation can be reduced.

Abstract: In the interior of a device housing of a strain wave gearing, a detection mechanism is incorporated at a site on the outer peripheral side of a hub of a wave generator. The hub of the wave generator is linked to a motor shaft so that axial force does not act thereon. The detection mechanism detects minute displacements in the axial direction that occur in the hub of the wave generator due to thrust acting on the wave generator. Thrust acting on the wave generator is obtained on the basis of the detected minute displacements. With this strain wave gearing in which the detection mechanism is incorporated, operation control that is responsive to sensed thrust is possible through the use of thrust information during operation.

Abstract: A strain wave gearing is provided with a lubricant sealing structure that prevents a lubricant from leaking to the outside through a gap between a hollow input shaft and an end plate. The lubricant sealing structure is provided with a labyrinth seal that seals the gap. The labyrinth seal is configured by a plurality of gap portions defined by an oil-repellent surface in which fine grooves are formed in a prescribed groove array pattern. The oil-repellent surface is also formed at an outer peripheral surface portion on an upstream side of the labyrinth seal. Leakage of a lubricant oil to outside of the device can be reliably prevented through the oil-repellent effect of the oil-repellent surface at the upstream side, the sealing effect of the labyrinth seal, and the oil-repellent effect from the oil-repellent surface of the labyrinth seal.

Abstract: A powder supply mechanism, which is provided with a press-molded article obtained by consolidating a solid lubricant powder in advance, is incorporated into an inner-side space of an externally toothed gear of a strain wave gearing. While the strain wave gearing is operating, the press-molded article is worn down by the friction plate, whereby the powder supply mechanism can incrementally supply very small amounts of a solid lubricant abrasion powder from the press-molded article over an extended period. It is possible to suppress any reduction in efficiency caused by loss torque produced due to a large amount of the solid lubricant powder infiltrating gaps in, inter alia, a contact section of a wave generator rotating at high speed. Thus, it is possible to extend the service life of the powder-lubricated strain wave gearing while keeping the efficiency consistently high.

Abstract: A rotary actuator includes a PWB motor and a wave gear drive. The PWB motor is an axial gap motor. A motor rotor in the PWB motor includes a rotor disk coaxially affixed to a hollow motor shaft and a rotor magnet affixed to the rotor disk. A motor stator is composed of a printed wiring board, and includes an insulating substrate and a motor coil defined by printed wiring formed on the insulating substrate. Compared with a conventional rotary actuator using an SPM motor or the like, the shaft length can be shortened and the hollow diameter thereof can be increased.

Abstract: A strain wave gearing is provided with: a rigid internally toothed gear; a flexible externally toothed gear that is arranged coaxially on the inside of the internally toothed gear; and a wave generator that is arranged coaxially on the inside of the externally toothed gear, and, on the inside of the externally toothed gear, in addition to the wave generator, a brake mechanism that constrains or prevents the rotation of the wave generator is installed. Since the empty space on the inside of the external gear is used as a space for installing the brake mechanism, the strain wave gearing with a brake can be realized without increasing the axial length thereof. Accordingly, by using the strain wave gearing, an axially short, flat actuator with a brake can be realized.

Abstract: A strain wave gearing is lubricated by a non-hydrophobized powder enclosed in an internal space until the strain wave gearing is fully broken in, and the non-hydrophobized powder is transferred to contact surfaces of contact parts to form a lubricating film. During operation under load, the strain wave gearing is lubricated by a hydrophobized powder enclosed in the internal space instead of the non-hydrophobized powder. Each of the powders used is a powder of an ionic crystalline compound (MoS2, WS2, etc.) having a layered crystal structure. By lubricating the strain wave gearing with the hydrophobized powder during operation under load, any temporary decrease in efficiency at the start of operation is minimized and stable operation of the strain wave gearing can be maintained.

Abstract: In a laser welding method for welding a first metal member and a second metal member, a first wobbling process is carried out in which a first laser beam is directed in a first scanning pattern along a butt-joining line and a first welded part is formed. A second wobbling process is subsequently performed in which a second laser beam is directed in a second scanning pattern along the surface of the first welded part formed through the first wobbling process and a second welded part that is wider and shallower than the first welded part is formed overlapping the first welded part. A welded part in which delayed cracking can be prevented or suppressed is thus formed.

Abstract: In a strain wave gearing, in order to regulate axial-direction movement of an externally toothed gear thereof, first balls are directly interposed between a first annular end surface and a device housing, whereby the first annular end surface and the device housing are in rolling contact with one another. Similarly, second balls, are directly interposed between a second annular end surface and an output shaft, whereby the second annular end surface and the output shaft are in rolling contact with one another. No contact occurs other than rolling contact of contact portions. Additionally, pressure is applied in the axial direction to the portions that make rolling contact, and axial-direction rattling is eliminated, whereby axial-direction movement of the externally toothed gear is reliably suppressed, and generation of high thrust force is prevented.

Abstract: A lubrication mechanism of a strain wave gearing is disposed in an interior space of an externally toothed gear and comprises a powder-accommodating bag that stores solid lubricant powder. A diaphragm of the externally toothed gear is repeatedly deflected during the driving of the strain wave gearing. Vibration or deflection is repeatedly imparted to the powder-accommodating bag and the solid lubricant powder is discharged from a powder discharge hole formed in the powder-accommodating bag into the interior space. A site to be lubricated is lubricated with the solid lubricant powder discharged into the interior space. Harmful effects due to a large amount of the solid lubricant powder being supplied to the site to be lubricated at one time can be resolved, and a necessary amount of the solid lubricant powder can be continuously supplied to the site to be lubricated.

Abstract: A wave bearing of a space strain wave gearing device comprises an inner ring formed from a bearing steel, an outer ring formed from a martensitic stainless steel, and balls formed from ceramics. On the inner ring formed from a bearing steel, a ceramic coating formed by an AD method is formed as a rust-preventive coating. In the space strain wave gearing device that adopts solid lubrication (powder lubrication), it is possible to reliably prevent rust from developing on the inner ring formed from a bearing steel of the wave bearing. In a space environment where the temperature greatly changes, appropriate setting of the linear expansion coefficients of the inner ring, the outer ring, and the balls enables a change in the radial gap of the wave bearing to be suppressed to a range that does not interfere with practical use.

Abstract: In a strain wave gearing, in order to regulate axial-direction movement of an externally toothed gear thereof, first balls are directly interposed between a first annular end surface and a device housing, whereby the first annular end surface and the device housing are in rolling contact with one another. Similarly, second balls, are directly interposed between a second annular end surface and an output shaft, whereby the second annular end surface and the output shaft are in rolling contact with one another. No contact occurs other than rolling contact of contact portions. Additionally, pressure is applied in the axial direction to the portions that make rolling contact, and axial-direction rattling is eliminated, whereby axial-direction movement of the externally toothed gear is reliably suppressed, and generation of high thrust force is prevented.

Abstract: A powder supply mechanism, which is provided with a press-molded article obtained by consolidating a solid lubricant powder in advance, is incorporated into an inner-side space of an externally toothed gear of a strain wave gearing. While the strain wave gearing is operating, the press-molded article is worn down by the friction plate, whereby the powder supply mechanism can incrementally supply very small amounts of a solid lubricant abrasion powder from the press-molded article over an extended period. It is possible to suppress any reduction in efficiency caused by loss torque produced due to a large amount of the solid lubricant powder infiltrating gaps in, inter alia, a contact section of a wave generator rotating at high speed. Thus, it is possible to extend the service life of the powder-lubricated strain wave gearing while keeping the efficiency consistently high.