| 摘要 |
The present invention relates to a gearbox (1), particularly for cycles or the like, characterized in that it comprises a gear train (2) comprising: a first sun gear (3) that is rotatable about an axis O; at least one second sun gear (4, 5) that is coaxial to the first sun gear (3); a plurality of planetary gears (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24) of different sizes for enabling a plurality of basic common ratios for the gear train (2) of the gearbox to be achieved; a planet carrier (9) coaxial to the sun gears (3, 4, 5) and rotatable about the axis O, the planetary gears (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24) being mounted onto the planet carrier (9); and a device (25) for selecting and shifting gears, making it possible to select the planetary gears (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24) corresponding to the desired gear ratio. |
