TRANSMISSION

Provided is a transmission enabling space saving. The transmission includes at least a first shaft, a second shaft, a third shaft, and a fourth shaft. These shafts are parallel to each other. The first shaft includes a first gear and a second gear. The first gear couples to the first shaft. The second gear couples to or idles around the first shaft when a first clutch is switched. The second shaft includes a third gear and a fourth gear. The third gear meshes with the first gear and couples to the second shaft. The fourth gear couples to or idles around the second shaft when a second clutch is switched. The third shaft includes a sixth gear and a seventh gear. The sixth gear meshes with the first gear and couples to the third shaft. The seventh gear couples to or idles around the third shaft when a fourth clutch is switched. The fourth shaft includes a ninth gear. The ninth gear meshes with the second gear, the fourth gear, and the seventh gear, and couples to the fourth shaft.