| 摘要 |
<p>A gear transmission device (1) is provided with: a crankshaft (10) having a fitting section (10c); gear members (14, 16) having tooth sections (14a, 16a); a first tube section (2) having a tooth section (3) meshing with the tooth sections (14a, 16a) of the gear members (14, 16); a second tube section (4) capable being rotated relative to the first tube section (2) by the pivoting of the gear members (14, 16) caused by the rotation of the crankshaft (10); and a transmission gear (20) having a fitting hole (20b) in which the fitting section (10c) of the crankshaft (10) is fitted. The shape of a cross-section of the fitting hole (20b) of the transmission gear (20), the cross-section being obtained by cutting the transmission gear (20) by a plane perpendicular to the axial direction of the crankshaft (10), is a polygon, and the shape of a cross-section of the fitting section (10c) of the crankshaft (10), the cross-section being obtained by cutting the fitting section (10c) by a plane perpendicular to the axial direction of the crankshaft (10), is a polygon having a shape matching the cross-sectional shape of the fitting hole (20b).</p> |
