Helical gear differential with geared lube pump

摘要

A differential casing is provided which is rotatable about an axis. The differential casing is generally cylindrically shaped and defines a first end surface and a second end surface. A pair of side gears is disposed within the differential casing and is individually rotatable about the axis. At least one pair of pinion bores are also formed in the differential casing and extend substantially through the second end surface of the differential casing. Pinion gears are slidably and rotatably disposed in the pinion bores for transmitting power from the engine to the pair of side gears. The pinion gears have rotational axes that are fixed in relation to the differential casing and are engaged with the pair of side gears. Each pair of pinion gears further include a mutually meshing portion, which extends beyond the second end surface of the differential casing. Such arrangement enables a gear pumping effect, caused by rotation of the meshing pinion gears, to pump lubricant from outside the differential casing into the casing for improved wear protection and reduced heat and friction.