| 摘要 |
A belt drive mechanism includes a plurality of pulleys and a belt made from a metal material and wound around the plurality of pulleys. Around the entire circumference of an outer peripheral surface of at least one of the plurality of pulleys, a swelling portion is formed to swell outward in a radial direction of the pulley. The swelling portion includes a first part having a larger swelling amount and a second part having a smaller swelling amount, the first part having a larger linear expansion coefficient than the second part. |
