Patent ID: 7131928

Claim:
A differential transmission apparatus, comprising: a base; a fixed gear fixed on the base; a rotating member adjacent to the fixed gear, wherein the fixed gear is between the base and the rotating member; an output shaft rotatably fitting in the rotating member, fixed gear, and base; a reduction gear slidably disposed on the output shaft; an acceleration gear slidably disposed on the output shaft and connected to the reduction gear, wherein the acceleration gear is between the reduction gear and the rotating member; a shifting device disposed on the base and output shaft to adjust position of the reduction and acceleration gears on the output shaft, adjusting rotational speed of the output shaft; at least one transmission shaft rotatably fitting in the rotating member; at least one first gear fixed on the transmission shaft and adjacent to the rotating member, wherein the first gear engages the fixed gear; at least one second gear fixed on the transmission shaft, wherein the reduction gear selectively engages the second gear by means of the shifting device; and at least one third gear fixed on the transmission shaft and between the second gear and the rotating member, wherein the acceleration gear selectively engages the third gear by means of the shifting device.