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: A strain wave gearing has a lubricant sealing structure that prevents a lubricant from leaking to the outside through a gap portion between a hollow input shaft and an end plate. The lubricant sealing structure includes an oil-repellent surface formed on the surface portion facing the gap portion, an oil seal that seals the gap portion, and an oil film forming surface formed at a lip tip surface of the oil seal. The oil-repellent surface has a surface texture in which first fine grooves are formed in a predetermined pattern so that an oil-repellent effect can be obtained with respect to the lubricant. The oil film forming surface has a surface texture in which second fine grooves are formed in a predetermined pattern so that an oil film forming effect of a seal lip grease can be obtained.

Abstract: An outer-ring lubrication groove pattern formed in an outer-race raceway surface and an inner-race lubrication groove pattern formed in an inner-race raceway surface of a wave generator bearing of a strain wave gearing device are patterns in which linear lubrication grooves having very small widths and depths of several micrometers or less are arranged at fine pitches of several micrometers or less. The inner-race lubrication groove pattern includes a second groove pattern formed in long-axis-side inner-race raceway surface portions to hold the lubricant, and a first groove pattern formed in short-axis-side inner-race raceway surface portions to hold the lubricant and guide the lubricant to the second groove pattern. This configuration improves the contact state between balls and the inner-race and outer-race raceway surfaces of the wave generator bearing, thus reducing the coefficient of friction therebetween.

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 strain wave gearing has a lubricant sealing structure that prevents a lubricant from leaking to the outside through a gap portion between a hollow input shaft and an end plate. The lubricant sealing structure includes an oil-repellent surface formed on the surface portion facing the gap portion, an oil seal that seals the gap portion, and an oil film forming surface formed at a lip tip surface of the oil seal. The oil-repellent surface has a surface texture in which first fine grooves are formed in a predetermined pattern so that an oil-repellent effect can be obtained with respect to the lubricant. The oil film forming surface has a surface texture in which second fine grooves are formed in a predetermined pattern so that an oil film forming effect of a seal lip grease can be obtained.

Abstract: In a strain wave gearing device, fine first and second lubricant-holding grooves for holding lubricant are formed at fine pitches in an outer-race external peripheral surface of a wave generator bearing and an outer-race-contacting internal peripheral surface portion of an externally toothed gear in contact therewith. Fine lubricant-guiding grooves for guiding the lubricant to the outer-race-contacting internal peripheral surface portion are formed at fine pitches in a second internal peripheral surface portion, which adjoins the outer-race-contacting internal peripheral surface portion, of an internal peripheral surface of the externally toothed gear. This configuration improves the contact state between the outer-race-contacting internal peripheral surface portion of the externally toothed gear and the outer-race external peripheral surface, thus suppressing fretting wear occurring in these surfaces.

Abstract: In a wave generator for a strain wave gearing, a plug outer peripheral surface of a rigid wave plug has a non-circular profile and is fixed to an inner-race inner peripheral surface of a wave bearing by press-fitting and using an adhesive. The plug outer peripheral surface is a groove formation surface in which microgrooves are formed as adhesive-retaining grooves that can retain the adhesive. When the wave plug is press-fitted into the wave bearing, the amount of adhesive that is scraped out from therebetween is reduced and the bonding strength therebetween can be increased while also preventing unevenness of the bonding strength.

Abstract: An outer-ring lubrication groove pattern formed in an outer-race raceway surface and an inner-race lubrication groove pattern formed in an inner-race raceway surface of a wave generator bearing of a strain wave gearing device are patterns in which linear lubrication grooves having very small widths and depths of several micrometers or less are arranged at fine pitches of several micrometers or less. The inner-race lubrication groove pattern includes a second groove pattern formed in long-axis-side inner-race raceway surface portions to hold the lubricant, and a first groove pattern formed in short-axis-side inner-race raceway surface portions to hold the lubricant and guide the lubricant to the second groove pattern. This configuration improves the contact state between balls and the inner-race and outer-race raceway surfaces of the wave generator bearing, thus reducing the coefficient of friction therebetween.

Abstract: In a strain wave gearing device, fine first and second lubricant-holding grooves for holding lubricant are formed at fine pitches in an outer-race external peripheral surface of a wave generator bearing and an outer-race-contacting internal peripheral surface portion of an externally toothed gear in contact therewith. Fine lubricant-guiding grooves for guiding the lubricant to the outer-race-contacting internal peripheral surface portion are formed at fine pitches in a second internal peripheral surface portion, which adjoins the outer-race-contacting internal peripheral surface portion, of an internal peripheral surface of the externally toothed gear. This configuration improves the contact state between the outer-race-contacting internal peripheral surface portion of the externally toothed gear and the outer-race external peripheral surface, thus suppressing fretting wear occurring in these surfaces.

Abstract: In a wave generator for a strain wave gearing, a plug outer peripheral surface of a rigid wave plug has a non-circular profile and is fixed to an inner-race inner peripheral surface of a wave bearing by press-fitting and using an adhesive. The plug outer peripheral surface is a groove formation surface in which microgrooves are formed as adhesive-retaining grooves that can retain the adhesive. When the wave plug is press-fitted into the wave bearing, the amount of adhesive that is scraped out from therebetween is reduced and the bonding strength therebetween can be increased while also preventing unevenness of the bonding strength.

Abstract: A mounting groove of a seal structure using an O-ring is defined by: a groove bottom surface; an acute-angle-side groove side surface inclined at an acute angle contiguously to the radially inner edge of the groove bottom surface; and an obtuse-angle-side groove side surface inclined at an obtuse angle contiguously to the radially outer edge of the groove bottom surface. The O-ring is mounted in a state of being pushed and expanded to the acute-angle-side groove side surface. The O-ring is constrained, in the mounting groove, between the groove bottom surface and the acute-angle-side groove side surface. The O-ring is prevented from falling off from the mounting groove. A groove width is constant or increases from the groove bottom surface toward a groove opening. Work for mounting the O-ring on the mounting groove is easy, and processing for the mounting groove is also easy.

Abstract: In a magnetic drive linear actuator, a load attachment portion is fixed to the lower side portion of the rectangular tubular coil frame of a mover, and a light-emitting portion of a position detection portion for detecting the movement position of the mover is fixed to the upper side portion of the coil frame. The load attachment portion and the upper side portion of the coil frame are mutually coupled through beam portions bridged there between. This makes it possible to prevent or suppress the behaviors of the load attachment portion and light-emitting portion from being shifted to each other during high-acceleration driving of the mover, thereby improving the responsiveness and positioning accuracy of the linear actuator.

Abstract: The rotary actuator has an outer rotor type motor assembled coaxially in a device hollow part of a strain wave gearing. One end of the device hollow part is closed by an end cover fixed to an output shaft of the strain wave gearing. A detection part is arranged between the motor and the end cover inside the device hollow part. A rotational position of a rotation detection plate mounted on an inside end surface of the end cover is detected by the detection part, to detect the rotational position of the output shaft. A rotary actuator that is small and compact can be realized.

Abstract: The rotary actuator has an outer rotor type motor assembled coaxially in a device hollow part of a strain wave gearing. One end of the device hollow part is closed by an end cover fixed to an output shaft of the strain wave gearing. A detection part is arranged between the motor and the end cover inside the device hollow part. A rotational position of a rotation detection plate mounted on an inside end surface of the end cover is detected by the detection part, to detect the rotational position of the output shaft. A rotary actuator that is small and compact can be realized.

Abstract: In a magnetic drive linear actuator, a load attachment portion is fixed to the lower side portion of the rectangular tubular coil frame of a mover, and a light-emitting portion of a position detection portion for detecting the movement position of the mover is fixed to the upper side portion of the coil frame. The load attachment portion and the upper side portion of the coil frame are mutually coupled through beam portions bridged there between. This makes it possible to prevent or suppress the behaviors of the load attachment portion and light-emitting portion from being shifted to each other during high-acceleration driving of the mover, thereby improving the responsiveness and positioning accuracy of the linear actuator.