Compressor Construction

[lilrex]

I was wondering what stresses a radial compressor is exposed to, I dismantled a Vacuum cleaner impeller. Its construction was basically a steel back plate with retro-curved blades with protrusions at the root of the blade fitted through holes in the plate which were peined to rivet them to the plate, the spacing of the "rivets" were about 1 in 5/8 inch and were about 1/16 inch in diameter. There was a cover plate on the other side of the blades much the same a Shrecklings plywood compressor. Obviously the forces enacting on the compressor are of a sheering nature on the pins riveting the blades to the plates. My question is has anyone experimented with this type of construction? What method would you use to calculate the ultimate strength of the wheel? And how close to the ultimate strength would you consider?

[lilrex]

What I was thinking of doing is to make a .125 thick flat plate made of 6061 T6 Aluminum holes will be drilled in the plate in a retro curve. The blades will be made of the same stuff as the plate with pins fashioned every .375". Then a contour spun out of .0625 plate aluminum and placed in the center of the plate with slots cut to fit the blades. Then finally a shroud spun out of .0625" plate to fit the outer contour of the compressor also with the riveted pins attaching it to the blades.

I will try to draw a picture of the construction.

[lilrex]

Here is a Drawing done in paint :evil:
anyway it shows basic non dimensional construction

[Mike Everman]

Nice. Worth trying. 'twer me, I'd spot weld in all those rivet locations.

[lilrex]

spot weld? hmm. do you mean weld the ends of the pins or actualy spot weld the blads on usind a "L" at the root of the blad. I like the idea of welding the ends of the pins that way I could possibly make it flush.

I think I will try making a few simple renditions of a compressor, do a distructive test by balanceing the best I can. Then put a little bit of imbalance into it. Then rotate the crap out of it untill is flys apart, and finnaly compair it to my calculations. After a few of them I should have a good idea of the capability of this type of construction.

[lilrex]

here is a pic of the XLS spreadsheet that I have been working on to calculate the streangth of the compressor wheel I am planing on constructing. I would be willing to share the spreadsheet if anyone wants it.