Patent ID: 7717100

Claim:
A breather structure of an engine having a crank case and a cylinder block, comprising: a breather chamber configured to separate air including oil mist within the crank case into an oil component and a gas component, to return the oil component to an oil reservoir of the engine, and to discharge the gas component out of the crank case, wherein an upper part of the crank case is integrally formed with a transmission case portion and the cylinder block, and extends from the cylinder block to a rear of the engine in a direction orthogonal to an axial direction of a crankshaft of the engine, wherein the upper part of the crank case and the cylinder block are arranged approximately in an L-shape as viewed in the axial direction of the crankshaft of the engine, and wherein the breather chamber, includes a wall as a reinforcing rib, the wall extending from a rear surface of the cylinder block toward the rear of the engine in the direction orthogonal to the axial direction of the crankshaft, the wall being integrally formed with the cylinder block and an upper external surface of the upper part of the crank case further comprising a rotating member accommodating chamber arranged at a side of the breather chamber in the axial direction of the crank shaft of the engine, wherein the breather chamber and the rotating member accommodating chamber share the wall as a common wall arranged between the breather chamber and the rotating member accommodating chamber, wherein upper surfaces of the breather chamber and the rotating member accommodating chamber include openings, respectively, the openings of the breather chamber and the rotating member accommodating chamber being arranged to be closed by a lid common to both chambers.