Four-stroke internal combustion engine has pairs of coaxially superposed cylinders both ends of air-cooled crankcase and four pushrods and shuttle valve forming air-precompression chamber.

摘要

The flat-build engine has stacked cylinder pairs (3) and an externally ventilated crankcase (26) pressuretightly and coaxially sealed to superposed cylinders each end. The smoothwalled pistons (4) work via four commonly mounted (28) pushrods (5) and connecting rod (29) on the crankshaft (2). Four pushrod guides (6) pressuretightly fitted to the crankcase together with the inside sector of the cylinders and the hollow piston (4) form respective chambers for pre-compressing the combustion air assisted by respective intake channels and shuttle valve in the cylinder foot per chamber (21). The pre-compressed air is discharged via outlet (8) and with the air of the valve (10) fed into the charging line (9). Each piston has a lubricating groove and oil scraper ring (18) straddled by two piston-rings (19) above and one piston ring below.