The original Energy Storage Piston designs were tested in a Suzuki 125cc motorcycle engine in GADL's workshop at Sidcup, in a fabricated test rig constructed around the rear end of the motorcycle. The rear wheel brake assembly was utilised as a load for the motorcycle and the assembly contained instrumentation to read rpm, torque, time and fuel flow through burettes. These tests were fully video recorded and clearly show fuel savings of up to 40% when compared with a motorcycle fitted with a standard piston arrangement. This design of the Energy Storage Piston benefited from a corrected heat treatment which extended its longevity to enable extensive testing.
Limitations of the Standard Engine
The fundamental limitation of any existing reciprocating internal combustion engine is that it is at best only 30% efficient, with a diesel engine being around 40%. Clearly there is much scope for improvement.
The problem with existing crank mechanisms is that a conventional internal combustion engine employs a crankshaft to convert the reciprocating motion of the piston(s) into output torque to propel a vehicle or act upon any other load.
The crankshaft is inefficient in terms of converting the power available from the fuel combustion into useable output torque. This is because combustion of the fuel/air mixture takes place before top dead centre position of the piston. Not only the crank pin but also the crankshaft main bearings are consequently subjected to periodic heavy stresses.
What is of greater significance, however, is that with an internal combustion engine provided with conventional drive gear the ignited fuel/air pressure forces cannot produce torque when the piston is either before or at top dead centre or bottom dead centre as the connecting rod and the crank pin are practically in a straight line, so there is no force component tangential to the crank circle.
This results in most of the available energy being lost as heat. The torque necessary to carry the crankshaft through these two dead centre positions is supplied by the inertia of the flywheel of the engine.
Furthermore, by the time the crankshaft has rotated through about 80 degrees past top dead centre, where the turning effect is at maximum, the pressure on the piston is greatly reduced, so the resulting torque is relatively small.
Product Achievements
The Energy Storage Piston uses an energy storage device which is a Titanium Alloy spring assembly, contained within a piston, the final specification of which will be capable of operating for 200,000 miles without failure.
By changing the existing pistons in a standard engine (any fuel, any type), with Energy Storage Pistons, the fuel consumption will reduce dramatically by up to 30% for no loss in power. The lower fuel consumption will also reduce overall total exhaust emissions, particularly CO2, unburned hydrocarbons and "green house" gasses.
Fitting Energy Storage Pistons modified with a raised crown design, such that the existing cylinder clearance volume is halved (therefore doubling the compression ratio), is now standard practise in all Energy Storage Pistons applications. This is imperative in diesel engines to ensure that the compression reaches the level necessary for diesel fuel combustion.
All Energy Storage Piston applications with doubled compression ratio further improves the engine's performance due to 50% more exhaust gasses being scavenged, which could allow the exhaust to be left closed for a longer period. This utilises the energy that would otherwise have been wasted to the exhaust.
Efficiency is further improved due to the inherent delay in spring release producing more power available to drive the load, as the crank will then be advantageously positioned at an angle after top dead centre which will generate more torque.
This efficient piston spring and flywheel design also enhances the engine efficiency by arranging that the spring / inertial mass resonant peak is at a car engine's average RPM, about 2000.
The Energy Storage Piston can be used in any existing or new internal combustion engine running on any fuel, to replace its standard pistons.
Galvin Automotive Design Ltd
Energy Storage Pistons
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