Engine lubrication method

摘要

A four-cycle engine with an enclosed oil reservoir for mounting on a power tool is provided. An oil pump driven by a camshaft, which mates by a cam gear with crank gear that is driven by a crank shaft, inhales the oil from the oil reservoir to lubricate the engine parts. A circular arc wall surrounds around web of the crankshaft with a slight distance from the web. A scroll-shaped wall has gradually increased distance from the circular arc wall to the direction of rotation of the web and has partial overlap with the circular arc wall. In case of stock of engine oriented power take off side up or down, oil is prevented to flow from oil reservoir to combustion chamber by a weir which is provided between the circular arc wall and the scrolled wall. The check valve splashes breathing mist oil from the crankshaft to the breather room and causes the oil to supply lubricant to lubricate the engine parts.