| 摘要 |
A gear transmission device is provided with an internally toothed gear, an externally toothed gear, and a crankshaft. The externally toothed gear eccentrically rotates relative to the internally toothed gear while meshing therewith. The crankshaft has an eccentric body engaging with a through-hole formed in the externally toothed gear. The crankshaft eccentrically rotates the externally toothed gear. A ball bearing is disposed between the inner peripheral surface of the through-hole and the outer peripheral surface of the eccentric body. A first groove serving as the outer race of the ball bearing is formed in the inner peripheral surface of the through-hole, and a second groove serving as the inner race of the ball bearing is formed in the outer peripheral surface of the eccentric body. |
