cam drive engine
cam drive engine
(OP)
The geometry between a piston, piston rod and a crankshaft in an IC engine appear to leave a lot to be desired since the gas expansion only acts on the crankshaft in any usable sense for about 35 to 40 degrees of rotation. And never at a 90 degree angle. The side loads etc would have to be absorded by the casing meaning a more robust structure. It seems to me that a cam arrangement would be more advantageous since the piston thrust would act on the cam at 90 degrees for a much larger part of the crank's rotation. So the question is, are they are more effecient, and if so, why don't we see them in production?





RE: cam drive engine
- entrenched thinking
- millions of hours and dollars spent optimizing emissions
- established service industry
- established suppliers
- etc. etc.
You will not change the establishment unless you can prove substantial advantages.
ISZ
RE: cam drive engine
http://www.prototype-design.com/Camengin.htm
Mike Halloran
Pembroke Pines, FL, USA
RE: cam drive engine
Ted
RE: cam drive engine
http://www.sa.hillman.org.au/TS3.htm
RE: cam drive engine
I think fundamentally the issue is that you don't lose much by 'pushing' at the wrong time. In energy terms over a cycle it doesn't matter whether you push very hard against a short lever arm, or less hard against a longer lever arm.
Not that the nutters ever understand that.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: cam drive engine
Ideal camming probably could help during the ignition stage, and perhaps during the expansion to to make it closer to isentropic than presently done, but I doubt that the designers have overlooked this.
RE: cam drive engine
RE: cam drive engine
Thnx, Bernie