Gears Don't Have to be Round

Nov 12, 2010 11 Replies

To All:



Had this sent to me and couldn't resist sending it on to my ol' machining buds.


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Is that trick, or what? LOL


-- BottleBob

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That's pretty neat, but somebody needs to have that damned rooster crowing in the background for lunch! :-)

Jim

Just when ya think having a 3-D printer wouldn't be very practical.

A bunch of neat stuff from a recent RCM link

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In a similar vein, my copy of The Metalcaster's Bible shows a sketch of a "positive pressure blower". It consists of two lobe-shaped impellers, geared to each other. They spin in the same direction, and apparently maintain such close contact that air can only flow in one direction.

-- Best -- Terry

Always nice to hear from you Bob. Jerry

Sounds like a Rootes supercharger.

Jim

Yeah, dragsters have been using them for decades. ;-) They work on the same principle as a gear pump.

I've kind of wondered if a blower in reverse could develop torque efficiently; sort of a positive displacement turbine.

Cheers! Rich

The two "lobes" spin in OPPOSITE directions on those. :-) ...lew...

Tons of examples in those mechanisms and linkages books from the turn of the last century.

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has a bunch, I think Henley published them. Square gears, eccentric gears, half gears, anywhere where non-uniform periodic motion was needed. Just takes a different method of thinking besides today's microprocessor programming and stepper motor mentality.

Stan

They will work as an air motor, but not as efficiently as a screw compressor. I had the experience of an 1100 HP gas turbine driven refrigeration screw compressor that stopped suddenly due to blocked fuel filters. The non-return valve on the compressor stuck open and it took off backwards untill the pressure equalised. The power turbine was doing 22,000 rpm when it shut down, and within about 10 second was doing the same speed in reverse. I was standing beside it at the time and it frightened the bejasus out of me! We checked it out pretty carefully then restarted with new fuel filters. No problem. As soon as we could get it off line we put a big equalising valve in that opened as soon as the turbine sht down. So, yes screw compressors work very well as motors!

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Here's one for you Bob

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Wayne...

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