Transmission device

A transmission device comprising a transmission unit,

• the transmission unit comprising a gear reducer and a differential device whose differential case receives an output of the gear reducer, and being housed in a transmission case,
• the gear reducer comprising:
• a sun gear;
• a ring gear arranged concentrically to the sun gear and fixed to the transmission case;
• and
• two or more planetary gears integrally including large-diameter gear parts meshing with the sun gear and small-diameter gear parts meshing with the ring gear,
• the differential case being configured to be divided into first and second cases defining therebetween a mechanism chamber housing a differential mechanism therein and capable of storing an oil at a bottom part of the mechanism chamber,
• the two or more planetary gears being pivotally supported by a carrier of the gear reducer in the vicinity of the large-diameter gear parts and pivotally supported by the differential case in the vicinity of the small-diameter gear parts,
• the second case being held between the first case and the carrier coupled to the first case, whereby the second case is fixed to the first case,
• wherein the differential mechanism comprises:
• paired side gears rotatably supported by the differential case;
• two or more pinion gears meshing with the paired side gears;
• and
• a pinion shaft rotatably supporting the pinion gears on the differential case,
• wherein the first case is provided with a pinion shaft supporting part supporting the pinion shaft, and
• wherein the planetary gears are pivotally supported by the first case in the vicinity of the small-diameter gear parts thereof.