Multi-cylinder engine of crankcase scavenging type for watercraft
AssigneeYamaha Hatsudoki Kabushiki Kaisha
InventorsJune Taue, Kenji Mori
Life of this patent
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Abstract
A multi-cylinder engine of a crankcase scavenging type suitable for use in watercraft. The engine has a very compact arrangement so that it can be used in either an outboard motor or as the prime mover for a watercraft such as a personal watercraft, to embodiments of which are illustrated.
Claims21
A four cycle, internal combustion engine comprised of a cylinder block having a plurality of cylinder bores with crankcase chambers formed at one end thereof, a cylinder head closing the other end of said cylinder bores, a plurality of pistons each reciprocating in a respective one of said cylinder bores and forming with said cylinder bores and said cylinder head a plurality of combustion chambers, a crankshaft rotatably journalled in said crankcase chamber, a plurality of connecting rods each coupled to a respective one of said pistons and said crankshaft for transmitting motion therebetween, means for providing a seal between one end of each of said connecting rods and the respective one of said pistons and between the sides of said connecting rods and the side surfaces of said crankcase chamber, said connecting rods each 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 plurality of pairs of variable volume chambers formed solely by said pistons, said cylinder bores, said connecting rods, said crankshaft and said crankcase chamber for acting as a positive displacement pump, intake means for admitting an air charge to said crankcase chambers at one side of said engine, delivery means for discharging a compressed air charge from said crankcase chamber at the other side of said engine, a compressor chamber fixed contiguous to said crankcase chambers at said other side of said engine for receiving the compressed charge therefrom, said cylinder head having a plurality of intake ports on said other side of said engine for serving said combustion chambers, means for supplying a compressed charge from said compressor chamber to said intake ports entirely located on said other side of said engine comprising a plurality of intake pipes each extending from spaced inlet ends formed within said compressor chamber and externally therefrom to said intake ports along said cylinder block in spaced relation thereto, a plurality of exhaust passages formed in said cylinder head on said one side of said engine for discharging exhaust products from said combustion chambers, and an exhaust manifold on said one side of said engine for collecting the exhaust gasses from said exhaust passages.
A four cycle, internal combustion engine comprised of a cylinder block having a plurality of cylinder bores with crankcase chambers formed at one end thereof, a cylinder head closing the other end of said cylinder bores, a plurality of pistons each reciprocating in a respective one of said cylinder bores and forming with said cylinder bores and said cylinder head a plurality of combustion chambers a crankshaft rotatable journalled in said crankcase chamber, a plurality of connecting rods each coupled to a respective one of said pistons and said crankshaft for transmitting motion therebetween, means for providing a seal between one end of each of said connecting rods and the respective one of said pistons and between the sides of said connecting rods and the side surfaces of said crankcase chamber, said connecting rods each 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 plurality of pairs of variable volume chambers formed solely by said pistons, said cylinder bores, said connecting rods, said crankshaft and said crankcase chamber for acting as a positive displacement pump, intake means for admitting an air charge to said crankcase chambers at one side of said engine, an induction system at least in part on said one side of said engine for delivering said air charge to said crankcase chamber, and including an air inlet device positioned adjacent said crankcase chamber on the side opposite said cylinder bores delivery means for discharging a compressed air charge from said crankcase chamber at the other side of said engine, a compressor chamber located at said other side of said engine for receiving the compressed charge therefrom, said cylinder head having a plurality of intake ports on said other side of said engine for serving said combustion chambers, means for supplying a compressed charge from said compressor chamber to said intake ports entirely located on said other side of said engine, a plurality of exhaust passages formed in said cylinder head on said one side of said engine for discharging exhaust products from said combustion chambers, and an exhaust manifold on said one side of said engine for collecting the exhaust gasses from said exhaust passages.
Dependencies are inferred from the claim text.