Search found 188 matches

by Ferraccio
Fri Aug 19, 2011 3:48 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Crank case pressurization revisited.
Replies: 23
Views: 15017

Re: Crank case pressurization revisited.

The Philips Bungalow Set, the '50 years Stirling. http://www.youtube.com/watch?v=M9UKu-AP02k is a type of "dynamically pressurized" Stirling engine, (NOT closed in a box). The pressurization when the engine is stopped vanishes rapidly, the compressed gas escapes from the seals of the pisto...
by Ferraccio
Fri Aug 19, 2011 3:09 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Crank case pressurization revisited.
Replies: 23
Views: 15017

Re: Crank case pressurization revisited.

The flyweel is not a manufacturer or supplier of energy, is only an energy storage unit, you can not think to earn what you lost.

(This is just to see what happens ...)
by Ferraccio
Thu Aug 18, 2011 1:23 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Crank case pressurization revisited.
Replies: 23
Views: 15017

Re: Crank case pressurization revisited.

You see that I had not understood. My answer is simple and even obvious. any moving parts can not keep up the pressure for more than a few tens of seconds. In short after a few seconds the engine returns to work in atmosferic pressure. It is accentuated in the case of alternating movements, as the p...
by Ferraccio
Wed Aug 17, 2011 12:44 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Crank case pressurization revisited.
Replies: 23
Views: 15017

Re: Crank case pressurization revisited.

I'm sorry that are in Italian:
Not lubricated dry bearings: composed by layers of steel, synterized bronze (porous), and PTFE
see:
http://www.cgboccole.it/cg_boccole.pdf
by Ferraccio
Wed Aug 17, 2011 12:27 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Crank case pressurization revisited.
Replies: 23
Views: 15017

Re: Crank case pressurization revisited.

Aviator and Ian, As always I try to answer trying to understand before all the question, and is not so easy for me. I'm sorry if I'm wrong. In pressurize an engine does not happen anything special, except that the gas is in greater quantity, and is more dense. In fact we live in a pressurized enviro...
by Ferraccio
Thu Aug 11, 2011 10:50 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Design/Build One HP Alpha Stirling Engine
Replies: 33
Views: 23379

Re: Design/Build One HP Alpha Stirling Engine

You've done a question of million dollars. The project od a regenerator for Stirling is one of more diffucult in thermodynamic (not my words). For air may be is net mesh in stainless steel in gauzes stacked (cross flow), wire of order of 1/100 of inch, mesh of order0f 1/30 of an inch. The values hav...
by Ferraccio
Fri Aug 05, 2011 4:00 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 18066

Re: Need help with our gamma school project engine

Sorry again: I had not seen the engine data, but I guess I do not know the stroke, I think piston s. is the same as that for the displacer. Improving the characteristics, the piston engine can be imagined engine 5/8" diameter. The thickness of the cylinder wall must be of the order of 2 mm Stir...
by Ferraccio
Fri Aug 05, 2011 3:36 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 18066

Re: Need help with our gamma school project engine

cooler fins should be 1/16 "thick and 1/4" high, spaced with clearances of 1/8". The reduction of the distance beetween displacer axis and power piston axis, reduce dead space (hole conducting gas is shorter). Taking into account the picture of 1st of August: I think this architecture...
by Ferraccio
Fri Aug 05, 2011 1:03 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 18066

Re: Need help with our gamma school project engine

I apologize for the bad translation: I mean: if the wall thickness is four times higher is as how to use a material that conducts four times less, halving the thickness is like double the conductivity of the metal. Since the Stirling is an external combustion engine, or (with an external source of h...
by Ferraccio
Fri Aug 05, 2011 12:37 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: Need help with our gamma school project engine
Replies: 31
Views: 18066

Re: Need help with our gamma school project engine

Hayman, Ian, my speak. My hunch is excessive strength. With small power, as it is, the strength "necessary" in terms of thickness measurement is of the order of 1 / 100 of an inch, for obvious reasons of workability thicknesses are best to consider the order of 1 / 16, or at least the mini...
by Ferraccio
Sat Jul 30, 2011 12:42 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Displacer/chamber diameter ratio
Replies: 13
Views: 12375

Re: Displacer/chamber diameter ratio

For vlspiano, yes it is, I'm Italian; excuse me for my poor english. For theropod2, anf for vlspiano, yes: copper (very thin foil or wire) are good for low temperature, but for upper temperatures (also if not so good for thermal characteristics) is commonly used stainless steel, (to temperature near...
by Ferraccio
Thu Jul 28, 2011 1:24 pm
Forum: Stirling and "Hot Air" Engine Forum
Topic: Displacer/chamber diameter ratio
Replies: 13
Views: 12375

Re: Displacer/chamber diameter ratio

If I can get into the speech: The origin of the Stirling engine patent is precisely the regeneration. (The hot air engines were already present before Stirling). The displacement obtained from the gas displacer transferred via the cold spot to hot spot, how is greater the difference in temperature b...
by Ferraccio
Sun Jul 10, 2011 5:47 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: best combination for piston and cylinder
Replies: 7
Views: 9374

Re: best combination for piston and cylinder

Of course bronze is the best for hard metallic material.
by Ferraccio
Sun Jul 10, 2011 5:45 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: best combination for piston and cylinder
Replies: 7
Views: 9374

Re: best combination for piston and cylinder

More tradictionally the self lubricating effect is done by bronze, (good), or bronze-graphite loaded (very good) or bronze-graphite sintered (very very good), for piston. Carbon iron or stainless steel for cylinder. The bronze is at all the best for anti-friction material, as it is, a lot more than ...
by Ferraccio
Sun Jul 10, 2011 5:29 am
Forum: Stirling and "Hot Air" Engine Forum
Topic: best combination for piston and cylinder
Replies: 7
Views: 9374

Re: best combination for piston and cylinder

In my opinion is good, (with this range of dimensions and temperatures (low)) to use Rulon sheets as ring seal on piston or Teflon coated needle, all on stanless steel (very) thin piston, for cylinder is good stainless steel, being the very polished surfaces are good for Teflon product, without the ...