摘要 |
A concentrically aligned planetary gear assembly and a power transmission device are provided. The planetary gear assembly includes a ring gear, having a bottom cover and a top cover; a graded transmission module; a power input module, having a power shaft and a power input gear; and a power output module, having a planet wheel set and an output shaft. The graded transmission module includes a planetary arm and plural planetary gears. The planetary arm has a transmission tray and a coaxial sun gear, in which the transmission tray has plural planetary pivoting structures, and an outer diameter of the transmission tray is coaxial with an addendum circle of the internal gear, so as to be slidingly fitted to each other. The plurality of planetary gears is engaged with the internal gear, pivoted on the planetary pivoting structures, and freely rotates with respect to the planetary pivoting structures.
|