Hi, This is my first post here, so please excuse if its off topic. I am building a model submarine capable of deep submerging, and to provide its buoyancy control I need a pump capable of operating at a pressure of up to 100 million Pascals, (= 1000 atmospheres, ~ 14,700 psi).
It has to push ~0.1 litres of a selected fluid (I get to choose this - probably a non-compressible oil?) in under 15 min.
The power source is not a concern, but the design of such a pump is a little tricky to my non-expert mind.
My inital idea was a simple piston, with a 1mm^2 bore area, running at 10 pumps per second, driven by a cog and hinged shaft, with a stroke length of20 mm. ( A 1mm^2 area at 14700psi gives10Kg, or ~22 LBS weight force.). Valves would control the flow direction. The cog would be driven by worm drive, with possibly one gear reduction in between. Im trying to conserve energy, so need to minimise # of gears.
My concern with this is the compression stresses on the stroke shafts, and the resulting frcture potential, and so I started wondering if a "pulling " pump would be better, so as to put the shaft(s) in tension. Im thinking a very high strrength steel, like lathing back a long 1.6mm dia. drill bit, might be the simplest way to go, but a witha disimilar bore metal, I may run into thermal expansion coeff probs....
Anyway, my questions are...
- Is a piston pump, the best way to go, for simplicity, and practicality?
- Is there any other pump designs (eg turbine, worm?) that could be a better choice?
- For a piston - type, is my initial idea roughly on the right track?
- What kind of source metals should I use? ( I dont have a foundry or anything fancy... so its hardware stores, and maybe some hobbyist lathes / tools to get the job done).
Any comments would be appreciated. TIA.
Dave Merrett, Salisbury, South Australia.