Patent ID: 7316629

Claim:
A double pinion planetary gear unit comprising: a first sun gear; a second sun gear; a plurality of short pinions that mesh with the first sun gear; a plurality of long pinions that mesh with the second sun gear and with the short pinions; a ring gear that meshes with the long pinions; and a carrier that rotatably supports the short pinions and the long pinions, the carrier comprising: a first flange portion that supports an end side of the short pinions and an end side of the long pinions, a cylindrical portion that is connected to the first flange portion and that forms a cover for an outer peripheral side where the short pinions and the long pinions mesh with each other, a second flange portion that supports another end side of the long pinions, and a plurality of bridge portions that extend from the second flange portion toward the short pinions and that support another end side of the short pinions, wherein: the cylindrical portion and the plurality of bridge portions are joined via an annular protruded portion, and a window is formed in the first flange portion adjacent the plurality of bridge portions.