US 11,746,874 B2
Bending meshing type gear device and method of manufacturing bending meshing type gear device
Masayuki Ishizuka, Kanagawa (JP); Hideo Fukumura, Kanagawa (JP); and Takashi Maruyama, Kanagawa (JP)
Assigned to SUMITOMO HEAVY INDUSTRIES, LTD., Tokyo (JP)
Filed by SUMITOMO HEAVY INDUSTRIES, LTD., Tokyo (JP)
Filed on Jul. 30, 2021, as Appl. No. 17/390,004.
Claims priority of application No. 2020-136089 (JP), filed on Aug. 12, 2020.
Prior Publication US 2022/0049761 A1, Feb. 17, 2022
Int. Cl. F16H 49/00 (2006.01)
CPC F16H 49/001 (2013.01) 16 Claims
OG exemplary drawing
 
1. A bending meshing gear device comprising:
a wave generator;
an external gear that is bent and deformed by the wave generator;
an internal gear that meshes with the external gear; and
a wave generator bearing disposed between the wave generator and the external gear, wherein
an inner ring rolling surface on which a rolling element of the wave generator bearing rolls includes a hardened layer,
the hardened layer has a characteristic that a surface hardness after operating for a predetermined time is increased compared to a surface hardness before operation or has a characteristic that a surface hardness of a rolling portion of the inner ring rolling surface with which the rolling element is in contact is increased compared to a surface hardness of a non-rolling portion of the inner ring rolling surface with which the rolling element is not in contact after operating for a predetermined time,
the internal gear includes a first internal gear and a second internal gear,
a contact surface pressure of the inner ring rolling surface with the rolling element is higher in a first portion located inside the first internal gear in a radial direction than in a second portion located inside the second internal gear in the radial direction, and
a surface hardness after operating for the predetermined time is higher in the first portion than in the second portion.