Abstract: A belt drive has a drive gear, an output gear, a tensioning gear, and at least two belts. Each belt partly loops the drive gear and the output gear, and a strand of each belt partly loops the tensioning gear. A strand of a first belt loops the tensioning gear in one circumferential direction. This strand extends from the drive gear to the output gear. A strand of a second belt loops the tensioning gear in the other circumferential direction. This strand extends from the drive gear to the output gear. This belt drive achieves a large looping angle for the drive gear and the output gear, and correspondingly, a large transmission power. Additionally, the effect of the other belt enables a belt self-tensioning function which is independent of the rotational direction. Guiding the belts in this manner enables omission of an additional mounting of the tensioning gear.