The FairDiesel engine
FairDiesel Limited has combined the barrel and opposed piston engine architectures and applied new patented concepts to them to produce an exceptionally efficient, well-balanced lightweight engine with inherently low emissions for a wide range of applications.
The engine is shown diagrammatically, with opposed pistons acting on shaped cams through rollers.
The use of shaped drive cams enables the motion of each piston to be determined independently, unlike a crank-driven engine, in which the piston motion is constrained to be virtually sinusoidal, and so the combustion cycle can be optimised.
Because the cam has four lobes, The complete cycle occurs twice for each revolution of the drive shaft.
FairDiesel Limited has used the ability to design cam profiles flexibly, to optimise the thermal efficiency of the two-stroke diesel engine.
With a conventional crank-driven diesel engine the injection of fuel continues during the power stroke as the pistons move down the bore, or, in the case of an opposed-piston engine, as the pistons move apart.
Thus full combustion pressure is not generated at Top Dead Centre.
FairDiesel Limited engine, the cams are profiled so as to maintain a constant combustion volume until fuel injection is complete, so that full combustion pressure and temperature are available to drive the pistons along the cylinders, thus maximising thermal efficiency. The engine combines this thermal efficiency advantage of a spark-ignition (gasoline) engine with that of a higher compression diesel engine. The combustion regime thereby reduces CO2 emissions, but can also be tailored to significantly reduce NOx and particulate emissions thus combining the advantages of gasoline and diesel engines.
The illustration below shows a four-cylinder engine although our current baseline engine has seven cylinders.
FairDiesel Limited has patented a technique for ensuring that the forces within the engine are balanced to produce a quiet engine with exceptionally low vibration and even torque delivery without the need for a large heavy flywheel.
Simplicity and Maintainability
In addition to the significant emissions reduction, a striking feature of the cylindrical profile engine is the mechanical simplicity, with far fewer parts than an equivalent engine. Furthermore, the axial combustion forces are carried by the central shaft enabling a lightweight casing. We believe that the engine will therefore be very competitive in terms of price and weight per unit power output.
FairDiesel Limited has patented a modular cylinder assembly approach which enables ready access to main components for maintenance purposes, without having to totally dismantle the engine.
The engine is made in modular form for ease of manufacture and assembley.