Variable-speed transmission mechanism and mode adaptation device of tilting rotorcraft thereof

The variable-speed transmission mechanism comprises a first sun gear and a second sun gear which are coaxially arranged, the first sun gear is meshed with a plurality of first planetary gears, and the first planetary gears and the second sun gear are jointly meshed with second planetary gears; the second planetary gear is meshed with a gear ring; the first planet gear and the second planet gear are rotationally connected to the planet carrier; the first sun gear is connected with an input end; the gear ring is connected with an output end; when the planet carrier is locked, the second planet gear only rotates; and when the second sun gear is locked, the second planetary gear revolves around the second sun gear while rotating. When the planet carrier and the second sun gear are locked, the rotating state of the second planet gear can be changed, then the rotating state of the gear ring is changed, output of two different transmission ratios is achieved, and the tilting rotorcraft is suitable for the requiremen