US 12,222,028 B2
Strain wave gearing
Masaru Kobayashi, Azumino (JP)
Assigned to HARMONIC DRIVE SYSTEMS INC., Tokyo (JP)
Appl. No. 18/573,062
Filed by HARMONIC DRIVE SYSTEMS INC., Tokyo (JP)
PCT Filed Aug. 24, 2021, PCT No. PCT/JP2021/031054
§ 371(c)(1), (2) Date Dec. 21, 2023,
PCT Pub. No. WO2023/026377, PCT Pub. Date Mar. 2, 2023.
Prior Publication US 2024/0376972 A1, Nov. 14, 2024
Int. Cl. F16H 49/00 (2006.01)
CPC F16H 49/001 (2013.01) 4 Claims
OG exemplary drawing
 
1. A strain wave gearing comprising:
a first internally toothed gear and a second internally toothed gear that have differing numbers of teeth;
a flexible externally toothed gear that is capable of meshing with the first and second internally toothed gears and has the same number of teeth as the second internally toothed gear; and
a wave generator that causes the externally toothed gear to flex into a non-circular shape and partially mesh with each of the first and second internally toothed gears,
wherein
the strain wave gearing has a friction member provided with a friction surface that is disposed at a position with which the externally toothed gear can come into contact when moving in a first direction, where the first direction is a direction extending from a side of the first internally toothed gear toward a side of the second internally toothed gear along an axis; and
the friction member is attached to a rotating shaft part of the wave generator or is formed integrally with the rotating shaft part so as to rotate integrally with the rotating shaft part and so as not to move relative to the rotating shaft part in the direction of the axis, and
wherein
the strain wave gearing has a restricting member provided with a contact surface that is disposed at a position with which the externally toothed gear can come into contact when moving in a second direction,
where the second direction is a direction extending from the side of the second internally toothed gear toward the side of the first internally toothed gear along the axis,
the contact surface is a surface having a frictional resistance that is lower than that of the friction surface.