Patent ID: 6079378
Filing Date: 2000-06-27
Classification: F02B,F02D,F02M,Y02T

Abstract:
A crankcase supercharged engine comprised of a cylinder having a cylinder bore with a crankcase chamber formed at one end thereof, a piston reciprocating in said cylinder bore, a crankshaft rotatably journalled in said crankcase chamber, a connecting rod coupled to said piston and said crankshaft for transmitting motion therebetween, means for providing a seal between one end of said connecting rod and said piston and between the sides of said connecting rod and the side surfaces of said crankcase chamber, said connecting rod having a portion thereof in sealing engagement with said crankcase during at least a portion of a single rotation of said crankshaft for dividing said crankcase chamber into a pair of variable volume chambers formed by said piston, said cylinder bore, said connecting rod, said crankshaft and said crankcase chamber for acting as a positive displacement supercharger mechanism having two pumping cycles per each revolution of said crankshaft, intake means for admitting an air charge to said crankcase chamber, and a suction passage for discharging a compressed air charge from said crankcase chamber through an intake valve to a combustion chamber formed at least in part by said piston and said cylinder bore, wherein the volumetric capacity of said suction passage is V and displacement of said combustion chamber is V0, the ratio V/V0 being within the range of from 1 to 20, and said intake valve being closed within the range of from 70 to 100 degrees after a bottom dead center position of said piston.