Input shaft structure easy to quickly assemble for automobile speed reducer

The utility model belongs to the technical field of automobile accessories, in particular to an input shaft structure for an automobile speed reducer, which is easy to quickly assemble and comprises an input shaft body, a belt pulley, an auxiliary stabilizing guide wheel and a detachable limiting disc, the input shaft body is fixedly sleeved with a fixed limiting disc. An elastic balance assembly is installed on the side face, facing the auxiliary stabilizing guide wheel, of the detachable limiting disc. According to the input shaft for the automobile speed reducer, the belt pulley is connected to the input shaft body in a sleeved mode, the fixed limiting disc is used for positioning, the limiting short shaft is used for guaranteeing the follow-up performance of the input shaft and the belt pulley, the stable guide wheel is assisted to limit the belt pulley from the other side, and the detachable limiting disc is used for keeping stability; and through the structural form of the auxiliary stabilizing guide wh