Air-cooled single-cylinder internal combustion engine

Claim 1

An air-cooled single-cylinder internal combustion engine comprising, a crankcase having a crankshaft, a cylinder head mounted on the crankcase, a flywheel attached to one extremity of the crankshaft, a cooling-air blower located at a front end of the flywheel facing the engine and rigidly connected with the latter, a cooling-air spiral surrounding the blower, a mounting plate extending in transverse relation to the crankshaft axis between the engine and the blower and attached to the engine, said mounting plate having a first perforation through which the crankshaft extends and which defines a cooling-air gap in combination with the crankshaft, and a second perforation located in the area of the cylinder and the cylinder head of the engine, a sheet-metal shell attached to the side of the mounting plate facing the engine and encompassing the engine, a partition arranged within said sheet-metal sheel and subdividing the free space between the engine and the sheet-metal shell into a lower and an upper portion, the lower portion defining a first coolingair duct leading alongside the crankcase via the first perforation of the mounting plate to the suction end of the blower, the upper portion defining a second cooling-air duct leading from the second perforation of the mounting plate via the cylinder and cylinder head of the engine to the outside, a cowl attached to the side of the mounting plate facing the blower and covering the flywheel with the blower and cooling-air spiral, the space covered by the cowl intErconnecting the two cooling-air ducts.