Second Entry: Parts

We are about a week into the project so far and we are just finishing up making our basic parts before we begin assembly. As of now we have a ring stand attached to the bottom of our pressure vessel. This will eventually be attached to a wooden block, because if it is not mounted we fear that the movement of the legs (i.e. the ring stand) would cause the system to loose too much energy. Next, we have a bottom and a top to our displacer. Finally, we have a top to our pressure vessel. Here are some pictures with brief explanations:

1) Ring Stand and Pressure Vessel Bottom:

The three legs of the ring stand support the pressure vessel. If they are bent and then nailed down, we can bring the engine closer to the flame (increase the heat in) and minimize any energy lost from the engine shaking. The pressure vessel bottom is essentially the case for the engine. It contains the air which will move to do work, as well as the displacer necessary to assist in that work.

2) Displacer Top and Bottom:


The displacer has two parts, a top and bottom, that will eventually seal together to create one hollow, airtight object. The displacer serves two functions. First, it controls the air flow from the hot and cold sources by narrowing the gap through which the air can pass and essentially dividing the engine into hot and cold compartments. Secondly, as the displacer moves up and down due to the motion of the hot and cold air, an attached needle (yet to be displayed) will be attached to the crankshaft.

Although we have not attached the top and bottom yet, here are some pictures of the top portion resting on the bottom portion. Notice how the diameters are nearly equal and the fit is very tight.









We want to be sure that the displacer creates minimal friction with surrounding components and moves properly (i.e. up and down at the right heights), so we cut the displacer's height as accurately as possible. Then once we attach the displacer top from the inside, we are going to sand all the edges down so that the rim of the displacer top is flush with the rim of the displacer bottom.

3) Pressure Vessel Top:














The pressure vessel top simply seals off the entire engine so that no air can get in or out of the chamber. It also will contain a hole through which the needle will pass and attach to the crankshaft. Mostly though, the top simply keeps the number of air molecules at a relatively constant level.

That is all we have for now. Stay tuned and we will have some more pictures up, including the final versions of the displacer top and pressure vessel top, as well as the crankshaft and crankshaft supports.

Thanks,

Keith Berquist
Mike Reher