US 12,259,032 B2
Strain wave gear device
Yutaka Imagawa, Niigata (JP)
Assigned to SKG INC., Niigata (JP)
Appl. No. 18/688,484
Filed by SKG INC., Niigata (JP)
PCT Filed Sep. 16, 2021, PCT No. PCT/JP2021/034077
§ 371(c)(1), (2) Date Mar. 1, 2024,
PCT Pub. No. WO2023/042331, PCT Pub. Date Mar. 23, 2023.
Prior Publication US 2024/0384784 A1, Nov. 21, 2024
Int. Cl. F16H 49/00 (2006.01)
CPC F16H 49/001 (2013.01) [F16H 2049/003 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A strain wave gear device, comprising:
an internal gear including an inner gear formed along an inner peripheral surface of the internal gear;
a wave generator including a cam that rotates around an axis in accordance with a rotation input;
a flex gear including an outer gear having a ring shape, formed along an outer peripheral surface of the flex gear, and having a smaller number of teeth than that of the inner gear, an inner peripheral side of the flex gear being fitted around the wave generator; and
an outputter that rotates relative to the internal gear in conjunction with the flex gear, wherein
the cam has N poles, N being an integer of 2 or greater, positioned at equal intervals in a circumferential direction centered on the axis and causes the outer gear to engage with the inner gear at N positions,
the flex gear includes a first annular portion that is formed of the same material as the outer gear and integrally formed with the outer gear, the first annular portion being positioned closer to the outputter in a direction along the axis than the outer gear is,
the outputter includes a second annular portion that faces against the first annular portion in a radial direction centered on the axis,
one of the first annular portion and the second annular portion is provided with a transmission tooth that protrudes in the radial direction while the other of the first annular portion and the second annular portion is provided with a recess to receive the transmission tooth,
the recess has a width along the circumferential direction that is wider than that of the transmission tooth and tolerates relative displacement in the circumferential direction of the flex gear with respect to the outputter, and
a plurality of transmission pairs, the transmission pair including the transmission tooth and the recess, is arranged in the circumferential direction.