Patent ID: 6915770

Claim:
A lubricating oil supplying structure of an engine, comprising: a through hole formed on a lower portion of a crankcase, which is secured to a cylinder of the engine, and which has a first holding room receiving a crankshaft assembly therein; a first gear being arranged in a second holding room of the crankcase, and connected with a shaft part of the crankshaft assembly; a cam shaft assembly being movable by the first gear for controlling a swing arm assembly of the engine; the cam shaft assembly being received in a cam shaft case disposed in the second holding room; a fitting hole formed on the lower portion of the crankcase; a lubricating oil container disposed under, and fixedly connected to the crankcase; the oil container having lubricating oil contained therein; an oil conduit firmly inserted in the fitting hole for the oil container to communicate with the crankcase; a check valve disposed over a lower end of the through hole; the check valve being capable of sealing the through hole lower end when subjected to an upward force; the check valve being movable away from the lower end of the through hole when subjected to a downward force; whereby the lubricating oil is allowed to be drawn into the crankcase via the oil conduit when a piston of the engine is moving away from the crankshaft assembly during a return stroke, and lubricating oil in the crankcase is allowed to be pushed back into the container via the through hole when the piston is moving towards the crankshaft assembly during a forward stroke; wherein a transverse hole is formed on the crankcase for the first holding room to communicate with the second holding room so that lubricating oil can be drawn into the second holding room via the transverse hole during a return stroke of the piston.