Help! > Specific Engine Help
4 cyl. steam engine
crueby:
Sounds like some great experiments!
Charles Lamont:
Sounds interesting. One suggestion, in case you had not considered it: driving the oscillatory motion by the piston rod gland is not the best idea for longevity and high performance, a guided crosshead is likely to be an improvement.
This is the sort of thing I mean, from a design I occasionally tinker with.
Jasonb:
I would have thought vibration at 40rpm would be so small to not be worth bothering about. I know all my unbalanced singles sit still at those speeds and it is only when the speeds increase at least 10 fold that vibration is noticeable. Having more than one cylinder shoud see even less vibration.
Many an oscillating engine has a considerably longer guide on the cylinder cover to help guide the rod but if you feel it is an issue then a tail rod is another option rather than the crosshead.
http://www.youtube.com/watch?v=TXKPghq-_S0
http://www.youtube.com/watch?v=ZQl8cqJ17Fc
http://www.youtube.com/watch?v=ToUX_Df6GQ0
paul gough:
Hello Chris, Charles, Jason. Yes it will be a succesion of experiments, obeservations & note taking, contemplation on results and hopefully some sound conclusions. Jason, it will not just be for slow running. It will be a multi purpose experimental tool to be exploited in as many ways I can think of including much higher speeds. The model will be for exploring ideas, some of which I have articulated already, others broader in scope and some I dare say are yet to be formulated. The engine has to fit certain criteria. Quickly, be more or less two separate engines, ie. each capable of being run separately, each must have a simple quickly alterable crankshaft arrangemnt to facilitate changes to crank angles etc. Be easily connected together in line to make a four cylinder unit then a "double" where the two engines sit side by side and coupled through a drive (probably gearing). The slow running is principally for my aesthetic pleasure but also a test and must run effectively at this low speed. Engines of this size, say 12 mm square roughly, are typically run at speeds of hundreds of revs per minute which is far behond full size oscillator operation, eg. usually model boats driving screws. The engine should be readily deployable as a stationary, marine or rail prime mover in one of configurations.
Charles, thank you for bringing this aspect to my attention. A very good point and will explore it for future application.. At the moment a simpler arrangement is of utility for the numerous experiments, the units will not have any intrinsic interest after the experiments, so to some extent their longevity is not of major importance.
Thanks again to those who have shown interest, Regards, Paul Gough.
Michael S.:
Hello Paul,
I understand how you want to design the test engine.
Maybe it's a good idea to allow for some sort of modular design.
In principle 4 individual motors and one motor can be removed or added at any time.
I found a video where someone expanded an engine from a well-known German manufacturer into a 4-cylinder steam engine.
Here the crankshaft is always offset by 90 degrees.
In the video it's not an oscillating motor. But the principle is recognizable.
As Jason mentioned, an extended stuffing box and perhaps a slightly thicker piston rod will suffice.
Greetings Michael
http://www.youtube.com/watch?v=LDyMblyTjco
I found two more videos of oscillating motors.
http://www.youtube.com/watch?v=IITHAHE1GlE
http://www.youtube.com/watch?v=4ldXKDfid1U
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version