摘要 |
PROBLEM TO BE SOLVED: To ensure reliable working of a push rod and also reduce a friction loss of a rotary member by which oil in a working chamber is scattered, by forming an oil sump, which is opened to the edge of the working chamber side of a bottom wall of a cam chain chamber, in an engine body, and communicating it to the inside of the working chamber through a restriction hole. SOLUTION: A ring gear 121 is rotated in a working chamber 106, and oil in the working chamber 106 is stirred and scattered by the ring gear 121. An oil sump 137 for gathering scattered oil, which is opened to the edge of the working chamber 106 side of a bottom wall 124a of a cam chain chamber 124 where a cam chain 127, wrapped on a driving sprocket 125 and a driven sprocket, is run, is formed in an engine body 34. Besides, the oil sump 137 is communicated to the inside of the working chamber 106 through a restriction hole 149, therefore, during the operation of the engine, the level of oil in the working chamber 106 is reduced, because a part of the oil is gathered in the oil sump 137. Consequently, a friction loss caused by the rotation of the ring gear 121 can be reduced. |