Air horn mount (again)

[lragan]

Since the compressor I got home from MOOTMAG with was inoperable, I decided to take this little pump apart to see what gives.  It is sort of a cheapo inverse Wankel engine, for want of a better term. 

The shaft that comes up from the DC motor to the pump chamber is off center.  The black round piece (rotor) with the four slots fits on the keyed shaft, and rotates rapidly when the motor is running.  The vanes are made of what appears to be .062 FR4 (printed wiring board epoxy-fiberglass) without metallization.  They are the same length as the height of the rotor, so they drag both the top and bottoms of the chamber ever so slightly.  Centrifugal force causes them to wipe the side of the chamber.  As they pass the intake, air is moved along to the output, about 5/8 of a turn away.  A little silicone grease facilitates this action.

The reason mine was inoperative, by the way, was that the chamber contained a substantial quantity of road grit -- some black, obviously asphalt, other pieces of various colors and consistencies.  When I cleaned the chamber of grit, relubricated it, and reassembled it, it works like a charm!

The output opening may wear more heavily on the vanes when the pump is mounted with the chamber below the motor ("upside down" if you will), but other than this possibility, I see no reason to mount it with the pump chamber on top.

My conclusion -- it is more important to mount the compressor pump somewhere where the ingestion of road grit is minimized than to mount it "right side up". 


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[Magnum Magna]

This is a guess not even an educated guess but could it be lubrication. I believe you are to remove the tube and drop in some oil in the hole for maintenance. 

[lragan]

That is a good guess, Robert.  One can also add lubrication through the intake -- they both are open to the chamber.  The intake should take lubrication in either orientation.

It had a dab of clear grease in it, that I took to be silicon grease.  That is what I put back. 

Where I have mounted the new one, lubricating it will be a bit of a trick.  Maybe I better hang on to the one I cleaned out.

[Chad in Michigan]

at work i repair some vacuum pumps that operate like that, with carbon vanes. they are around dust and debris all day long, and part of my maintenance that i do is clean the intake and exaust filters on them. is there a way you could fit a filter at least on the intake side? that would cut down on cleaning and replacing the vanes and or the pump.

[Magnum Magna]

I think I will try to squeeze my pump in behind the battery case like you did Robert....Looks good..Thanks Again....

I put my pump on the frame by the radiator.

Lawrence put it at the battery