Patent ID: 6840884

Claim:
A fluctuating gear ratio limited-slip differential assembly comprising: a differential case driven by an input shaft and adapted to allow differential rotational speed between a pair of side gears situated within said differential case; a pinion shaft fixed within said differential case; and plural pinions supported by said pinion shaft engaged with said side gears, wherein the gear ratio between said pinions and said side gears fluctuates during the engagement process, said gear ratio fluctuates with a period of at least two pitches, and the number of said pitches involved in each said period is corresponding to the common factor in the number of teeth in said pinion and said side gears, whereby each said period of gear ratio involves a group of teeth, and the number of teeth involved in each group are corresponding to the number of said pitches involved in each said period of gear ratio, the combined working range of the teeth involved in each said group covers the whole working range involved in a said period of gear ratio, and for each group of the same gear the corresponding teeth have the same structure, said pinion has an odd group number, so that during the engagement process, when the gear ratio between said pinions and one said side gear reaches the maximum, the gear ratio between said pinions and other said side gear reaches the minimum, and the group number in said side gears is a multiple of the number of said pinions, so that each said pinion works at the same phase angle.