Bob O'Neil Air Engine

[Tom Booth]

One other thing that crossed my mind:

If any of the above speculations are even remotely accurate. That is, if the engine is delivering very cold air to the tank, which seems evident from the patent, (air coming from the tank is described as being below freezing) then I think this might explain how the "equalizer" works.

Liquid air would be around (minus) -196 degrees celsius ( - 320 F ).

If during 1/2/ the cycle the compressor were making liquid air and during the other 1/2 cycle cold compressed air, and these were mixed together and delivered to the tank the temperature of the air going to the tank could be as cold as -150 degrees Fahrenheit. Just to give us something to go on.

At any rate the air going to the tank would be darn cold.

The tank is sitting there surrounded by ambient air, so it would be warming up.

I'll call what goes from the engine to the tank "liquid air" though I doubt that would be the case, more a mix of cold compressed air and possibly liquified air. But any way, this very cold "liquid air" goes through the first check valve of the equalizer at say -100 degrees Fahrenheit. It would, presumably, immediately begin to warm up and expand as the air already in the tank would be considerably warmer. As the cold air, having passed the first check valve gets warmer and expands it would have nowhere else to go but into the tank.

As the air in the equalizer expands and does the "work" of pushing the air out into the tank, the air left behind, still in the equalizer would loose energy. It would tend to cool and contract, drawing more "liquid air" through the first check valve.

In other words it would act like a thermal expansion pump. Cold air goes past the first check valve, warms up, expands and pushes some air through the second check valve, contracts and draws in more cold air through the first check valve. Something like a coffee percolator.

[Motorcoach1]

I stand corrected it's Bob Neil , no O .
Tom I stand with the same anoligy as you on the opperation. As for the exaust porting I'm just as puzzled.
I understand most patents are not complete or things get ommited.
To take the exhaust porting one step farther , I was looking for a weak spot in the piston movement. As the piston moves to mid point in the cylinder , there is chance of netural vaccume on both sides of the piston. So adding in a compressed hot air valve to the bottom of the cylinder would assist the piston in the up stroke , not affecting the evacuation process of the down stroke.
This would mean 2 evaccuation strokes, 1 up, 1 down and 1 compressed air assist , completing the cycle in one cylinder.

[Motorcoach1]

Could not get the McClure file to open , if you have the PDF , please post it . Thanks Mike

[Joe1]

      It takes much less work to pull a vaccume to do work , than try to compress volumes of air to do the same work. Compressed air in this operation is the waist product [exhaust] . This doest not mean we do not use some of this waist exhaust.   
 

Interesting discussion of the Neal machine, thanks Motorcoach.  I have a question about the above statement regarding work to pull a vacuum vs compress air.  Since 1 atm is at 14.7 psi, then any possible vacuum is limited to a pull of less than this amount of psi.  If a compressor is likewise limited, then it seems that the work for either choice would be equal.  Since the amount of energy stored in the air for use in a machine would be measured by how far the air pressure is moved away from 1 atm, it seems that positive pressures would be capable of much higher energy storage, since they are not limited in the extent of pressurization.  If the vacuum or compression are both within 14.7 psi of 1 atm, then either method would be capable of providing the same work.  Does that seem like a correct statement?

[Joe1]

1. There doesn't seem to be any account of any exhaust from the power cylinders. That is, there are inlet ports and an outlet port, but where exactly the outlet port goes is not specified, as far as I can see. After driving the piston, does the compressed air get vented to atmosphere or is it recirculated back to the tank or what ?
2. There is an electric generator that powers some electric heaters situated at the power cylinder inlet, supposedly to bring the incoming air up above freezing ? This seems rather extraordinary to me. Why would the air from the tank be so cold ?
3. There is a water (cooling jacket) surrounding the compressor pistons. There are two water pumps with inlet and outlet pipes shown. It can be assumed, I suppose, that the hot water goes to some sort of external radiator to be cooled by the fan. The first illustration of the engine suggests that the water jacket probably continues to the front and around the power cylinders as there is no step in the side. That is, the jacket appears to be continuous but in the drawing of the power cylinders no water jacket is shown surrounding the power cylinders.

Hello Tom,  this is an interesting discussion on Neal.  Here are some comments, what do you think?
1.  Most likely the power cylinder exhaust exits to the rear of the motor block, to the atmosphere.  It is drawn as the small square shape on figure 3, within the slide valve chamber.  On the left side of figure 3, the number 62 has an arrow leading to it.  This was identifed to me several months ago by a steam engine man, over at the Aircaraccess site.  Apparently this is how steam engines were constructed.
2.  Another explanation might be the use of a pre-heater, as is described in the old texts on compressed air engines.  Supposedly preheating the air produces more engine power with less input energy, as compared to simply compressing the inlet air to a higher pressure.  This method would provide higher efficiency.  Regarding item 3 below, if there is heat generated in the pipes, then that heat will be lost, which will result in a slow cooling of the block since the heating and cooling are no longer equal.  The electric preheater can be used to bring that back into balance.
3.  Since the machine includes both power expansion cylinders and compression cylinders, and each will provide the opposite temperature effect, then possibly the circulating water jacket is self contained within the block with no external radiator.  This would equalize all the temperatures, and save all energy that is flowing via heat within the block.