A power system includes: a rotating body; a housing accommodating the rotating body; and a storage portion provided at a bottom of the housing. A part of the rotating body is located in the storage portion. The housing includes: a supply target portion; and a direction changing portion. The direction changing portion includes: a collecting portion that is gradually inclined toward a downstream side in a rotation direction of the rotating body so as to be separated from an outer periphery of the rotating body and that receives the liquid medium scattered by the rotating body; and a guiding portion that is provided so as to cross a lower end of the collecting portion and that is gradually inclined downward toward the supply target portion.