Abstract: To enable a reliable differential lock without setting an actuator to be large-sized, a differential apparatus has a differential casing rotated by driving force of an engine, output side helical side gears supported within this differential casing, helical pinion gears connecting the gears, storage holes for storing the gears slidably and rotatably, a locked member connected to the gear, a lock member integrally rotated with the differential casing, a clutch mechanism formed between the members and locking a differential rotation, an actuator for coupling and operating the clutch mechanism, and a cam mechanism for increasing coupling force of the clutch mechanism by receiving differential torque when the clutch mechanism is coupled.

Abstract: A differential apparatus comprises a differential casing, a pair of helical side gears, and at least one pair of long and short helical pinion gears. The long helical pinion gear includes first and second gear portions and the short helical pinion gear includes first and second gear portions. The apparatus may include gear coupling portions for coupling the first and second gear portions of the long and short helical pinion gears via a long gear shaft or a short gear shaft, respectively. Since the first and second gear portions of the long or short helical pinion gear can be coupled to the long or short gear shaft by use of the common coupling portions, it is possible to obtain a larger or smaller differential limiting force by exchanging the helix angle relationship (thrust directions) of the two helical pinion gears.