Patent ID: 6769391
Filing Date: 2004-08-03
Classification: F01M,F02B,F16N

Abstract:
A four-stroke internal combustion engine comprising:an engine body having a block having a top, a bottom, a cylinder and a piston reciprocally mounted in the cylinder; a head formed at the top of the block; a crankcase formed at the bottom of the block and having a bottom, an inner chamber, a crankshaft rotatably mounted in the inner chamber of the crankcase and a connecting rod connecting the piston to the crankshaft for rotating the crankshaft with the reciprocal movement of the piston relative to the cylinder; and an oil pan attached to the bottom of the crankcase and having an inner chamber to hold lubricating oil; an oil spray generating assembly attached to the bottom of the crankcase in the inner chamber of the oil pan to produce oil spray for lubrication and the oil spray generating assembly comprising a closed sidewall formed at the bottom of the crankcase to define a mist chamber; a valve mounted in the bottom of the crankcase in the mist chamber and comprising a valve port defined through the bottom of the crankcase and communicating with the inner chamber of the crankcase and the mist chamber; a resilient valve flap attached to the bottom of the crankcase corresponding to the valve port to selectively cover the valve port; and a curved limiting stop attached to the bottom of the crankcase corresponding to the valve flap to limit maximum deformation of the valve flap; a bottom cap attached to the closed wall to enclose the mist chamber and having a top; a bottom; a transverse channel defined in the bottom cap between the top and the bottom; and a vertical channel defined through the top of the bottom cap and communicating with the transverse channel; an upper nozzle mounted in the top of the bottom cap out of the mist chamber and communicating with the transverse channel; lower nozzle mounted in the bottom of the bottom cap out of the mist chamber and communicating with the transverse channel; and a connecting tube mounted in the mist chamber and having a top end and a bottom end, the top end of the connecting tube passing through the bottom of the crankcase and the bottom end of the connecting tube connected to the vertical channel at the top of the bottom cap to communicate with the inner chamber of the crankcase and the transverse channel in the bottom cap; and an oil recycling assembly attached to the block of the engine body to recycle the oil spray exhausted out of the cylinder.