Another approach
Created November 10, 2006, at 11:33 pm by manolis
Increasing more and more the con-rod length, you finally get a harmonic or pure sinusoidal piston motion. Such a piston motion increases the constant volume portion of combustion and so increases the efficiency and the pick power at high revs. What actually the long rod makes is to keep the piston around TDC for more time. But the height of the engine would be enormous and the long con-rod would bend immediately.
At the [URL="http://www.pattakon.com/pre/index.html"]http://www.pattakon.com/pre/index.html[/URL]it is presented the pattakon PRE engine.
The following slide explains PRE differences from convnetional
and here is a combact Junkers-PRE in section view (two stroke power concentration and at the same time four stroke lubrication, built-in scavenging pumps, four stroke like torque curve, through scavenging, improved efficiency due to the slow motion of the piston at TDC, etc). An electric power station based on this single cylinder Junkers-PRE is absolutely free from vibrations,making it ideal for Hybrid cars, Hybrid vehicles, autonomous robots etc.
[INDENT]In general, to see the relevant animations enter into the http://www.pattakon.com/pre/index.html , click on an image to download the 'exe' file and then open it.[/INDENT]
The conventional engine offers a sub-sinusoidal piston motion around TDC. This PRE engine offers an over-sinusoidal piston motion around TDC, i.e. it increases a lot the constant volume portion of combustion. The shorter the con-rod length, the longer the time the piston stays near TDC. The PRE engine can be overquare, square or undersquare.
In the plot below what you see is the piston travel versus the crank angle for a conventional engine, the PattakonPRE (both using conrod to stroke ratio equal to 1.65) and the Harmonic engine.
see also the rest plots.
The PRE as regards TDC is nothing but a conventional revving at significantly slower revs, and as regards the BDC, the PRE is nothing but a conventional revving at significantly faster revs.
It is obvious that the valve lift profiles (if valves are used) have to be change to suit to the PRE piston motion, as well as the spark advance (or the injection advance in case of Diesel). If necessary, the PRE can use Pattakon’s Variable Valve Actuation (or VVA) system in order to optimize breathing along the whole rev range (you can see details for this breathing system at [URL="http://www.pattakon.com/"]http://www.pattakon.com/[/URL] as well as the pattakon’s prototype cars).
A vibration free, lightweight, simple and efficient engine like Junkers-PRE seems ideal for Hybrid cars. Doesn't it"?
I’ll be glad to hear your objections and answer your questions.
Thanks
Manolis Pattakos
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A reasonable way to improve a hybrid car is by improving the constituent subsystem.
Compared to Prius, i.e. the present state of the art Hybrid car, this
approach seems to gather a few advantages. Doesn't it?
And a question: when the gasoline engine of Prius is switched off and the car is running on the road with, let say, 70 Km/h, the generator has to rev quickly at the "reverse" (than charging) direction. Do I miss something?
Thanks
Manolis Pattakos
Hello from Greece.
The second prototype of the Opposed piston Pulling Rod Engine (OPRE) is now running on Diesel fuel.
Video and photos at http://www.pattakon.com .
Thanks
Manolis Pattakos
You said:
when the gasoline engine of Prius is switched off and the car is running on the road with, let say, 70 Km/h, the generator has to rev quickly at the "reverse" (than charging) direction. Do I miss something?
Yes, the Prius has no reverse and nothing runs in reverse (the car backs up by running the electric motor backwards, this is the only time).
The car has 2 electric motors that can power the car. One can power the car or start the engine while the other can power the car or charge the system. The engine seldom stops turning at above 50kph speed and usually turns with 'open valves' at high speeds without compression to prevent start up kick, even in electric mode. The car has many modes and explaining them all can take a book and is very time consuming. From what I've learned, i'm pretty sure this is correct but nobody has seen a tech manual for the car that covers this. Besides, the car has 7 computers and I don't want to figure them out. The important thing is that the car works and you don't have to know why. 130,000 miles shows great dependability with my 2001 Prius.
Prius Owner
Hope this helps
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