The spur-gear planetary differential produces an unequal torque distribution on the drive shafts. A spur-gear toothed planetary set is used along with hollow and sun wheels of different size. As illustrated in the figure above, the input is transferred over the planetary support. Hollow and sun wheel, each form an output. The ratio of the output torques is determined by the ratio i0 of the pitch circle radii of hollow and sun wheel.
The spur-gear planetary differential is used as a center differential in multi-axle drives with asymmetrical torque distribution.