Pneumatic engine discussion continuation
 

New proposal for pneumatic engine: short stroke, large bore, spring return cylinders in pairs pushing against a one way clutch bearing so that the stroke and lever length can be adjusted independently. Pairs are grouped in threes or fours to cover dead-zones created when the cylinders return to their rest positions. Each pair requires its own bearing. The number of groups needed depends on the power requirement, pairs from all groups should be distributed evenly.
for example:

If we use a pair of numbers ,(G,P) ha ha GP, to name the pairs (G would be the group, P would be the pair, and (2,3) would be the 3rd pair of the second group), a simple, 3-speed, 3-pair configuration would look something like this:

(1,1)(2,1)(3,1)[coupler***](1,2)(2,2)(3,2)[coupler***](1,3)(2,3)(3,3)

***to aid in maintenance, the shaft should be split and joined with couplers after every set*.

* a set is composed of the nth pair of all groups
[The first set includes (1,1), (2,1), and (3,1). The first group includes (1,1), (1,2), and (1,3).]

Cylinders of the same pair fire simultaneously, pairs of the same group fire sequentially, and pairs of the same set can either fire simultaneously or sequentially. when cylinders of the same group fire, there should be a 50% overlap for groups of three, and a 33.33% overlap for groups of four, no such overlap is necessary for sets that fire sequentially, but it is acceptable to do so.

Groups are activated in order as more power is needed.

It is also acceptable to create subsets, or groupings of cylinders that fire simultaneously within a set in which all subsets (which must contain the same number of cylinders) fire sequentially.

If subsets are used, lowercase letters following the last parenthesis of the cylinder's name are used to show the subset, with subscripts to show how many groups are active when the cylinder in question is firing, if subscript cannot be used, normal numbers are fine.

For example: (1,1)a4,6; (2,1)b4,6; (3,1)a4c6; (4,1)b4a6; (5,1)b6; and (6,1)c6 make up the first set of an engine with 6 groups that uses subsets when 4 or 6 groups are active.

High grouped arrangements are generally not used, due to weight. The one above is just a hypothetical example used to demonstrate the proper usage of a naming convention.

This thread was started as a continuation of a topic discussed here

Re: Pneumatic engine discussion continuation
 

Out of curiosity, are we still trying to make this feasible? I do like the concept of spring returns, but the only advantage I see in them would be not having to power them back - which is canceled out, of course, by the necessity of pairing them with more pistons (I checked, 15 ibs is about the max force you can get for a spring return, and that's with a 2" bore - pretty sluggish). Swapping around bore and stroke may give more power for the same air volume, but I'd begin to worry about the chances of such a smaller shaft offset just causing the engine to lock up (not to mention that reducing the torque arm defeats the purpose of increasing the bore).

Re: Pneumatic engine discussion continuation
 

TLDR

draw it or something please.

Re: Pneumatic engine discussion continuation
 

Sorry, I could draw it, and probably will, but you would miss so much fun stuff that can't be drawn, like terminology.