Continuously variable transmission and variable-diameter wheel structure and application thereof

The invention discloses a continuously variable transmission and a variable-diameter wheel structure and application thereof. The continuously variable transmission comprises a mounting shaft, a first sun gear is coupled to the mounting shaft, a first planet wheel is meshed with the periphery of the first sun gear, the first planet wheel is coupled to a first planet carrier, and the first planet carrier is connected with the mounting shaft; the first planet wheel is connected with a belt piece through a connecting rod to form a variable-diameter structure, the first sun gear is connected with a second sun gear, the periphery of the second sun gear is meshed with a second planet wheel, the second planet wheel is coupled with a second planet carrier, and a regulation and control structure is formed on the periphery of the second planet carrier; and a third sun gear is fixed on the mounting shaft, and the third sun gear is externally meshed with a third planet wheel. By means of the continuously variable transmi