Power dividing type stepless speed variator

The utility model discloses a power bypass type stepless speed changer. The speed changer comprises a group of two-free-degree planetary wheel system, a group of belt type stepless speed changing device which belt wheel radius can be changed, and parts connecting the gears and gear shifting actuating mechanism, the belt type stepless speed changing device is comprised of a driving belt wheel and a driven belt wheel, each belt wheel is comprised of a movable disc with one side to be axially moved and a fixed disc on the other side, the movable disc is pushed by the controlling actuating mechanism to perform axial movement, to continuously change the working radius to enable the transmission ratio of the belt type stepless speed changing device to be continuously changed. After the power of the engine of the utility model in output, a part of power is transmitted to the gear ring of the planetary wheel system, one part of power is transmitted to the sun wheel of the planetary wheel system through the stepless speed changing unit, and output after being merged by the planetary frame of the planetary wheel system. In order to improve the stepless speed changing scope, when the system outputs, a two state gear transmission is added and a reverse gear mechanism is arranged.