Patent ID: 11906027
Assignee: FANUC CORPORATION
Field: Other special machines (Mechanical engineering)
Classification: CPC B  F | IPC B  F

Claim 0:
1. A light-weight gear, comprising:
an annular tooth portion made of metal;
a shaft made of metal extending along a central axis of the annular tooth portion; and
a coupling element configured to couple the shaft to the annular tooth portion, the coupling element made of a resin,
wherein each of a first joining part between the shaft and the coupling element and a second joining part between the annular tooth portion and the coupling element is provided with a plurality of projecting and recessed portions configured to be engaged with one another in a circumferential direction,
wherein a corner of each of the plurality of projecting and recessed portions has a roundness,
wherein torque generated by using the light-weight gear and transmitted to the first joining part and the second joining part is distributed by the plurality of projecting and recessed portions, and stress concentration at the corner is released by the roundness, so that a degree of fatigue in the coupling element is reduced; and
wherein at least one through-hole is provided only in the coupling element, the at least one through-hole configured to enable fastening of a fastening bolt through the through-hole.