COMBINED DIFFERENTIAL GEAR DEVICE

A housing (10) has a planetary gear mechanism (20) composed of an inner gear (21), a planetary gear (22) and a sun gear (23), which mechanism is disposed within the housing (10) on its outer periphery side. The inner gear (21) is connected with a casing (31) arranged on a rotation axis (L). A spherical receiving portion (31a) is formed on the casing (31). This receiving portion (31a) is received in the sun gear (23). A pair of element gears (33, 33) and a pair of side gears (34, 34) of the planetary gear mechanism (30) are received in the receiving portion (31a).