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Automobile Patents: Moment-cancelling Four Stroke Engine
In the world of super cars and super bikes, we often sideline the numerous components which go into making these ‘mean machines’. One such component is the internal combustion engine (ICE). An ICE is a heat engine where the combustion of fuel occurs with an oxidizer, in a combustion chamber, that is essential to the working fluid flow circuit. Internal combustion Engines are in general subjected to torsional vibrations due to the moment produced by the reciprocating pistons connected to a single crankshaft via a connecting rod. The torsional vibration developed in the crankshaft tends to transmit the torsional vibrations to the rest of the engine components, thereby causing fatigue resulting in mechanical failure in the long term. Another problem that the internal combustion engines faces is the lack of efficient combustion which has adverse effects on the engine power output, fuel economy and emissions. The aforementioned problems are particularly experienced in two wheeler vehicles.
American auto racing legend, Dan Gurney solved the aforementioned problems by inventing a compact engine, for which he was recently granted US Patent no. 9103277. The invention titled “Moment- cancelling four stroke engine” has come as a major breakthrough in the automotive field as it achieves both optimum combustion and user friendly operation.
The invention basically features two innovations that set it apart from the other types of ICEs. Firstly, the moment cancelling four stroke engine is a two cylinder engine that has two reciprocating pistons connected to two different crankshafts. The two crankshafts rotate in opposite directions with respect to each other and balance the moments produced by both the reciprocating pistons, thereby achieving reduced torsional vibrations.
Another unique feature of the moment-cancelling four stroke engine is the intake system. The inlet port is configured to have a tapered cross-section which means that an inner entry diameter is tapered to the middle region and an inner exit diameter is also tapered to the same. As a result of this design, effective air transfer into the combustion chamber is enabled for high efficient combustion resulting in higher engine power output and reduced emission. Moreover, the moment cancelling four stroke engine favours lean fuel mixture resulting in better fuel economy of the vehicle.
Authored by Dinesh Kumar