I am a passionate engineer with interests in automobiles (5 patents), HPV - Human Power Vehicles (5 patents), variable power transmission (1 patent), gears (1 patent) and many other projects in various fields. Projects My patents presents some stroke variation mechanisms realized by modification of the basic configuration of the mechanism, keeping constant the crank radius with the change of TDC position and displacement during operation, and with the position adjustment of BDC (and the volume of the chamber in relation to the adjusted displacement to maintain the prescribed compression ratio and the optimum conditions for combustion. My solutions could be realized by classical technologies, with the variation of the compression ratio and the displacement (0-100%), generating high power and low consumption ! An industrial version of an engine with variable displacement mechanism (pending patent ) is under development, with perfect dynamic balance realized by classical crankshaft, rods, rotational or translational joints. Other projects FOUR STROKE ENGINE, WITH DOUBLE CYCLE OF IGNITION TWO STROKE ENGINE, WITH VALVES ENGINE MECHANISM WITH LINEAR CHARACTERISTIC ENGINE MECHANISMS WITH FAST COMBUSTION STROKE If you are interested in any of the projects, please contact me in order to discuss details. TZ0QO_NgNow NAM9zKEAQ6E Best regards Adrian
The only place I can see variable engine displacement useful is when the engine was under little or no load. There is no free lunch under load conditions. Gearing accomplishes whatever is needed. But I could see how it might be useful for other things such as a pump.
I believe they do not work in the automotive field .... The auto industry has many challenges in the field of compression but very few or no variables in the displacement varabile. Important variable compression is demonstrated by laboratory tests. Here are some references: http://autospeed.com.au/cms/title_Saabs ... ticle.html PtvEFUqs ... re=related http://capellossiiv.*.com/2009/02/mce-5 ... ngine.html DdM2VbbdtB4 2pW78Bmn0ts o0I4-_xm ... re=related fIG9pWld ... re=related 7_18_lrF ... re_related http://starpsi.free.fr/TIPE/ressources_ ... oteur1.pdf Best regards Adrian
I do like the variable compression ratio achieved by tilting cylinder/head unit away from crank assembly, and I see the solid value of variable compression. But here is another way to achieve the goal of reduced consumption under little or no load scenarios, instead of reducing cylinder volume why not reduce functional idle speed of engine? Instead of say 800 minimum idle speed, make it 400 rpm. This takes the task away from the load bearing structures and to valve timing.
I understand your idea. But if a gasoline engine, a lower speed means less explosions in the combustion chamber and therefore a much lower power - with the possibility of engine shut down. Tests have shown that to maintain a reasonable power at low engine loads, it takes increasing compression ratio, reduction of displacement and increasing the speed
That's your opinion. Others have a different opinion: CHANGING THE SQUEEZE The technologies and control of variable compression ratio engines. by Julian Edgar http://www.autospeed.com/A_110204/cms/article.html
Its not just my opinion, its common sense. I'm 47 and I can tell you variable displacement is a dumb idea. Prove me wrong. I think this site is a great idea and I think disagreement should be encouraged.
SAAB tests and concludes : "Fuel consumption can be reduced by up to 30 percent - while still retaining existing performance levels Due to its variable compression ratio, the SVC engine can be run at the optimum compression ratio of 14:1 at low load (ie steady highway speed) in order to put the energy in the fuel to best possible use. The compression ratio can then be reduced to 8:1 at high load (ie under hard acceleration) to enable the engine performance to be raised by supercharging without the problem of engine knocking occurring. The variable compression ratio also gives the engine great fuel flexibility. Since the compression ratio can be varied and adjusted to suit the properties of the fuel, the engine will always run at the compression ratio best suited to the fuel. The various functions of the SVC engine are controlled by a special version of Saab's Trionic engine management computer" ALVAR (by Massachusetts Institute of Technology, U.S.A.) tests and concludes: "• Variable compression ratio renders a possibility for increasing the efficiency at part load conditions. • At high compression ratio: It is not critical in terms of efficiency if the spark advance has to be reduced from MBT timing to avoid knock. It will bring the benefits of lower NOx – emissions. • Variable compression ratio gives a possibility to increase the maximum power output through lower compression ratio and high boost pressure. • The Alvar engine is a possibility in achieving variable compression ratio and it has shown to give the expected benefits of such a engine. • The Alvar engine does not give higher HC-emissions than a standard engine, contrary to what was expected." MCE tests and concludes: "The benefits of having a variable compression ratio is that you can control much more precisely combustion and adjust the variable to get the best performance for each situation (acceleration, cruising, deceleration, etc). It becomes especially potent - in theory - when combined with other technologies like turbochargers, direct injection, variable valve timing and lift, etc. At the upcoming 79th International Motor Show in Geneva, France-based MCE-5 Development will showcase its first vehicle application (a Peugeot 407) of a prototype 1.5-liter MCE-5 VCRi (variable compression ratio) gasoline engine. The four-cylinder 1.5L VCRi, equipped with a two-stage turbocharger, develops 220 hp (164 kW) of power (comparable to that of a 3.0L V6 engine), and 420 Nm (310 lb-ft) of torque at 1,500 rpm (comparable to a V8 gasoline engine). Fuel consumption on the NEDC is 6.7 L/100 km (35 mpg US) with 158 g CO2/km. The technology can be applied to smaller displacements, MCE-5 notes. What's interesting is that this prototype is not "equipped with GDI (gasoline direct injection) or optimized combustion chambers." The 2010 version of the engine should have these improvements and bring fuel economy to 6.0 L/100 km (39 mpg US) while producing 50 hp more!" This is the difference: My solution may be applied to larger variations of displacement !!!
