Air-cooled internal combustion engine with soundproofing enclosure

Claim 1

An air-cooled, soundproof internal combustion engine comprising a cooling-air blower driven by a crankshaft, with cooling surfaces on the cylinders and cylinder heads of the engine, a valve chamber housing to be cooled and defining the upper end of the engine and a crankcase with outer surfaces to be cooled, an engine-soundproofing encasing encompassing the outer surfaces of the engine and providing a cavity therewith, a first sound-absorbing coated housing built into the encasing of the engine and including an inlet for the cooling air, a second sound-absorbing coated housing built into the encasing of the engine and including an outlet for the cooling air, a distributing chamber, the entire cooling air supplied by the said blower being directed through the said cooling-air inlet into the said distributing chamber and from there in separate part currents over the said cylinder and cylinder head cooling surfaces and further elements of the engine requiring cooling, said valve chamber housing being located above the cylinder head of the engine, said cooling-air blower being laterally offset at the front end of the engine between said sound-absorbing coated housing including the cooling-air inlet and said distributing chamber, the latter extending alongside the sidewall of the crankcase closest to said cooling-air blower, separate coolingair ducts branching off said distributing chamber, one of said cooling-air ducts leading from the distributing chamber to said cylinder and cylinder head cooling surfaces, a second cooling-air duct connecting the distributing chamber with said valve chamber housing, and at least one-third cooling-air duct leading from the distributing chamber to a sidewall of the crankcase opposite said distributing chamber.