Patent ID: 7647906

Claim:
A vertical internal combustion engine comprising: a hollow crankcase having a crank chamber formed therein; a transmission case attached to an upper portion of the crankcase and having a belt chamber formed therein; a crankshaft enclosed in the crank chamber and oriented with its center axis substantially vertically extended; a driven mechanism including a driven shaft rotatively driven by the crankshaft; a belt-drive transmission mechanism held in the belt chamber and including a belt made of rubber for transmitting power of the crankshaft to the driven shaft; and a lubrication delivery structure for supplying a regulated amount of oil to the belt; wherein the engine is provided with a substantially horizontally-oriented partition wall disposed between the crank chamber and the belt chamber, wherein the partition wall is configured and arranged for substantially isolating the belt chamber from the crank chamber such that an oil-containing gas, flowing from the crank chamber into the belt chamber, flows in a direction other than a direction toward the belt.