Alain G a écrit :Bon j'ai revisionné le vidéo et il semble bien que les pistons sont lubrifié entre les 2 segments et on voit clairement 2 tuyaux de circulation d'huile sur le couvercle du moteur coté piston, il existe tout de même un plat sur la partie intérieure des pistons d'ou l'étanchéité a quand même du créer un problème mais pas insurmontable.
On a déjà évoqué ce moteur sur le site mais je ne me souviens plus ou!
Voici la bête qui ne semble pas avoir été inventé par les russes, il s'apelle MYT(Massive Yet Tiny):
http://www.youtube.com/watch?v=qfE8eiZv ... re=related
http://www.youtube.com/watch?v=wPc06A8F ... re=related
http://www.youtube.com/watch?v=vfjAqxVi ... ature=fvwp
http://www.youtube.com/watch?v=kARq0mUcXu0&feature=fvw
http://www.youtube.com/watch?v=zp-PJXIj ... re=related
http://www.youtube.com/watch?v=YEbztw3p ... re=related
Sur le même principe par un français et je crois déjà posté par Pascal ou Raymond:
http://www.youtube.com/watch?v=YwWnSJl5 ... re=related
Alain G a écrit :Malheureusement pour certain, c'est encore américain!
http://peswiki.com/index.php/Directory: ... %29_Engine
Site officiel:
http://www.angellabsllc.com/ME Theory
* 1. The Mighty Engine ™ (“ME”) design is very small and simple. The prototype has a 14 inch diameter and is 14 inches long. It weighs 150lbs. There are only 26 moving parts, 31 parts total. These are simple, physical facts. The first prototype uses diesel or biodiesel for fuel. (The ME design accommodates dramatic reductions in size depending on the application of the engine.) Through two revolutions of its crankshaft, the ME firing cycle is equivalent to a 32 cylinder reciprocating engine, that is, it fires 32 times. As a result, its displacement is equivalent to an 848 cubic inch reciprocating engine, despite its compactness. This displacement comparison is derived as follows: (3.1416*(3)(3)*3.75)/4*32 = 848 cubic inches, with a 3” bore and 3.75” stroke, four stroke cycle and thirty two firings. The design is also modular. Additional units can be connected to increase power. The ME is actually a large (extremely efficiently organized) displacement internal combustion engine; therefore its high horsepower output. Moreover, with the high number of cylinders firing in close order, a high number of pulses are generated for high torque, but without the friction and parasitic losses discussed below. (ME efficiency and the ability to use biofuels reduces our dependency on foreign oil.)
* 2. At 150lbs, the basic ME design needs only to produce 3,000 hp from 848 cubic inches to produce a 20 to 1 power to weight ratio. (We are assuming less than 4 hp per cubic inch of displacement. Racing engines based on conventional design perform up to 5+ hp per cubic inch of displacement with Super/Turbo Charge. With Normally Aspirated, it will generate minimum 850 horse powers.) To our knowledge, only the latest jet engine has finally attained a 20 to 1 power to weight ratio. By replacing the rear cover of the ME and connecting another ME chamber assembly (adding two inches in length and little additional weight) the ME now becomes a 64 cylinder engine with 1,695 cubic inches raising the power to weight ratio up to 40 to 1.
* 3. Since the ME lacks the 80% of the parts normally found in a reciprocating internal combustion engine that is responsible for high friction and parasitic losses, this normally dormant horsepower is now available and would increase the total deliverable output of the ME.
* 4. Normally, in a compression ignition (diesel) engine, combustion begins @ TDC (Top Dead Center) @ 0 degree crankshaft position. The expanding gases push the piston down on the power stroke, rotating the crankshaft 180 degrees. The piston then returns to TDC pushing the exhaust at the exhaust stroke, rotating the crankshaft another 180 degrees. This is the burning time in a standard engine, a total of 360 degrees duration.
* 5. On a dynamometer, an engine’s combustion temperatures is typically measured 2” from the exhaust ports, on the premise that the combustion temperature is very close to exhaust temperature. This is due to the zero degree duration @ TDC and the 360 degrees running duration of a standard engine. However, if @TDC, the piston is allowed to stay for a longer duration, it will burn a greater percentage of the fuel and air mixture in the combustion chamber until oxygen or fuel theoretically runs out at the end of the power stroke, thereby totally completing the combustion process and drastically lowering the exhaust temperature at the end of the exhaust stroke.
* 6. The ME design permits the piston dwell @TDC to be adjustable and the prototype ME is currently set at approximately 12 degrees of the crankshaft rotation, thereby approaching the perfection of a complete burn of all fuel. Its exhaust gases are much cooler. As a result:
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* More energy is harnessed for the same amount of fuel and air input.
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* There is less left over fuel to continue to burn at the exhaust stroke.
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* There is less waste and pollution
* 7. The higher compression ratios used in diesel engines result in greater thermal expansion of gases in the cylinder. The end result is a high percentage of fuel energy being converted into useful power. (When running the ME with Bio fuels, the same fuel is used to lubricate the crankcase.) In the ME design, a compression ratio as high as 70:1 can be attained due to the absence of the restrictive reciprocating components. Specifically:
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* The combustion chambers in the ME have no design limitations due to the absence of valves. (The internal combustion engine is an air pump. Airflow through intake and exhaust ports are normally restricted by valves. The ME has no valve --just open ports with no restriction. Air flow action is one way.)
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* There are no odd or brand new parts within the cylinder. All the parts are proven designs used in reciprocating engines.
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* The entire engine acts as a heat sink and a radiator. It is both air and oil cooled.
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* There is no thrust loading on piston skirts.
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* Pistons do not touch the cylinder walls, only the rings do.
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* Pistons travel only the same direction. No reciprocation, only stop and go.
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* There is high rpm potential for all of these reasons.
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* There are no cylinder heads, no cam shaft, no valves (the ME is equivalent to the bottom end of a reciprocating engine).
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* Intake compression and power stroke and exhaust stroke events are happening all at the same time, so there are no load strokes.
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* AND THE ME DESIGN IS NOT A ROTARY OR WANKEL
*
Source: http://www.angellabsllc.com/ME%20theory.html
oiseautempete a écrit :En tout cas ce concept à pistons pendulaires tient bien mieux la route que la Quasiturbine que je n'imagine pas pouvoir fonctionner de façon correcte en mode thermique notamment à cause des problèmes de lubrification et d'encrassement (= blocage des segments) ainsi que de forme trop allongée des chambres de combustion et d'évacuation de la chaleur (et les déformations résultantes), les mêmes problèmes que sur un Wankel avec les mêmes solutions donc...sauf que sur un Wankel les ingénieurs de Mazda ont trouvé pas mal d'améliorations...
sherkanner a écrit :Ils ont la même forme que sur un moteur classique (d'après ce que je vois sur les images).
Christophe a écrit :Pourquoi tu trouves le concept "pistons pendulaires" mieux? Tu peux développer un peu plus? Pour moi y a les même probleme d'étanchéité non?
Mazda a mis combien de temps pour faire une version "acceptable" de son moteur? Il y a une version moderne qui passe les normes anti pollution Euro4 ou 5?
Christophe a écrit :
Oui sauf que l'étanchéité ne se fait pas sur un cylindre mais sur un tore ! Il y a donc une "légère" courbure qui risque de poser bien des problèmes, quand on sait, par exemple, que les pistons conventionnel sont légèrement coniques pour compenser les dilatations...
+1 pour le concept du moteur toroïdal qui n'a pourtant rien de nouveau car il fut développé par BSA dès 1938.
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