Patent ID: 6968934

Claim:
A friction engaging device, comprising: a rotating drum which is a cylindrical rotating body, around a perimeter of which there is provided a friction member, and which is engaged with/disengaged from a predetermined coupling member via the friction member; and a ring gear which is spline-coupled to an inner surface of the rotating drum and which contacts an inward flange that is integrally provided with the rotating drum, wherein a centrifugal oil passage which is formed between the ring gear and the inward flange, and which introduces lubricating oil inside the rotating drum to a spline-coupled portion of the ring gear and the rotating drum by centrifugal force, and a plurality of through holes which are formed in the rotating drum and through which the lubricating oil, that has flowed into the spline-coupled portion, flows to an outside of the rotating drum where the friction member is provided.