The present invention relates to a crankshaft support structure in a two-stroke engine.
In the conventional two-stroke engine (as disclosed in Japanese Patent Examined Publication No. 56-53123 and Utility Model Unexamined Publication No. 58-112799 and so on), lubrication in a ball bearing for supporting a crankshaft is performed with a lubricant contained within a fuel. Therefore, the conventional fuel should contain a lubricant, thereby producing exhaust gas containing a lot of white smoke, which pollutes the air.
Further, an oil passage must be provided within a cylinder block, for guiding the lubricant contained in the mixed gas (fuel) toward the position of the ball bearing for supporting the crankshaft, which makes the structure disadvantageously complex.
USPTO Backgrounds
USPTO Backgrounds