| 摘要 |
A speed reducer that is formed by combining speed reducer units to achieve high output torque without an increase in the diameter of a second speed reducer unit and that even has a through-hole. A first speed reducer unit (34) has a first input shaft (24) rotating following rotation of an output shaft (29) of a motor (28), a first externally toothed gear revolving about the axis of the first input shaft (24), and a first internally toothed gear (36) having teeth provided in a number different from the number of teeth of the first externally toothed gear. The second speed reducer unit (2) has a crankshaft (2) rotating following rotation of a first output shaft (20), second externally toothed gears (162X, 162Y) having through-holes formed in their centers, a tube body (16) passing through the through-holes of the second externally toothed gears (162X, 162Y), a second internally toothed gear (4) having teeth provided in a number different from the number of teeth of each second externally toothed gear (162X, 162Y), and a second output shaft rotating about the axis of the second internally toothed gear (4). The first speed reducer unit (34) is placed between an outer peripheral surface (18) of the second speed reducer unit (2) and an inner surface (14) of the tube body (16). |
