Patent ID: 7137922

Claim:
A differential device comprising: a flywheel with a center hole; a main shaft penetrating said center hole and having inner and outer ends stretched on both sides the flywheel; a main central gear integrated in an inside of said main shaft; a main train of planet gears, being comprised of several gears, each gear being positioned around and connected to said flywheel at a same axis direction at intervals by a jack post, wherein an off-center side of each gear is geared up with the main central gear transmitting drive; a secondary train of planet gears, being comprised of several gears, each gear being positioned around and connected to said flywheel at a same axis direction at intervals by a jack post, each gear of the secondary train of planet gears being geared up with a corresponding gear of the main train of planet gears, wherein the gears of the secondary train of planet gears are underlaid with a space block staggered with the main central gear; a secondary shaft with a central sheath at an inner end thereof, fittable into an inner end of the main shaft; a secondary central gear fixed at said inner end of the secondary shaft and positioned to be geared with the secondary train of the planet gears; and a fixing plate having a penetration hole at center thereof, fittable into the secondary shaft, an off-center of said fixing plate being planted with fixing holes to fit the jack posts of the main and secondary train of planet gears.