Electric motor with small cross section

Water pump motors used in wells are in that diameter range. See Grainger's catalog or perhaps their www listing.

Hul

Vladimir Vassilevsky wrote:

It can probably be done with fluidics. Once one has gain, such things are possible. For example, here's a fluidic amplifier (triode):

Plenty of other fluidic logic elements available, including a latch, which would be needed for the triac. Admittedly, the triac would be rather complex, probably impractical, and certainly limited in operating frequency, but it would be mechanical.

To illustrate how it works, I built a full size fluidic oscillator from PVC plumbing parts. Power was supplied by a garden hose. It worked, but gave new meaning to the term "circuit leakage".

These daze, microfluidic logic is done with semiconductor processes or micromachining using various gases as the fluid and MEMS devices for switching.

Use a clamp-on amps-guesser to measure power consumption and calculate the power draw.

The biggest I could find that will fit in a 4" well casing (3.75" dia) is 2hp. He needs 5-10hp. There may be longer versions with more horsepower:

I noticed that it's twice as long as the 1hp version, which suggests multiple stages. Reading the description, 16 stages. Yikes.

I set up the equivalant of a fludic power transformer last weekend- it takes air at XX PSI and outputs (a lot less) air at 2.5*XX PSI (which then gets regulated down to 200 PSI).

If you think the 120Hz hum from electrical transformers is annoying...

Best regards, Spehro Pefhany

Hmm.. posting lost its threading.

Here's one (OMM50) with the hoses coming out the back (not that common!) that can produce >3 kW (> 4HP) and is only 60mm (2.36") in diameter (4.4 in^2).

Best regards, Spehro Pefhany

If length isn't a problem then extend the mounting location with a 1:1 extension coupling box.

You didn't indicate the RPMs? you can get gear head motors that are small (series types) that will produce lots of torque. Things like winch motors etc//.

Jamie

That's not a transformer. If it were a transformer, no air would be lost. You can build a fluid transformer, but it would be more like an air motor driving an air compressor with a gear box in between.

Your air pressure regulator is more like a voltage regulator, where the air|voltage pressure is dropped down to a lower value, and the excess air|heat is dissipated elsewhere.

All of the fluidic stuff I built many years ago didn't make much noise. I think the highest frequency I was able to squeeze out of a fluidic multivibrator was about 4Hz.

Ummm... perhaps a muffler?

All the air tools I deal with have them on the exhaust port. Usually, they're sintered bronze or something that will survive getting soaked in oil and water.

A former employer made modules for avionics applications. Sitting directly behind my workbench, was a rather noisy 60Hz to 400Hz motor-generator power line frequency converter. I resisted the urge to defenestrate the monstrosity and tolerated the noise for about 3 months, until a soundproof hiding place was found. By then, I was so accustomed to the noise, that I had trouble thinking without it.

How else do you get 2.5X PSI? You're trading pressure for volume (V for I). Are there no losses in transformers?

No, that's more like a linear regulator (hmm, the names must be coincidental ;-).

That certainly depends on the dimensions and masses, no?

Where does the air go after it exits the motor in your scenario?

That's essentially what these "air amplfiers" are- air-driven reciprocating pistons that have different areas on the driving and driven sides.

They don't really behave like linear regulators-- I have not thought about it much, but it seems they behave more like switching regulators- maybe because air is compressible.

Oh, there's a muffler on there- it's just pretty loud still (and modulated with the load). Louder than the (admittedly pretty quiet)

I might try to see if I can add another one like that though.

Could you think 6-2/3 times faster with the 400Hz converter noise?

Best regards, Spehro Pefhany

Oops. Y'er right. I thought he was going down in pressure as in a regulator and venting the excess. However, other than the air motor driving an air compressor contrivance, or dual pistons with different diameters, I can't think of an easy way to trade air pressure for volume.

Yes. My multivibrator and flip flops were rather huge. About 3"x6" each, as I vaguely recall. I made them out of a four piece sandwich of Lucite plastic, with the ducts gouged into the end pieces with an end mill, and cross connects drilled through the center two pieces. I managed to get two of the flip flops to divide by four, but only if the water pressure was perfect (and all the leaks were plugged).

Fluidic water meter:

Microfluidic oscillator (1Hz)

Or be over 20' long.

That depends on which shelves you're looking at.

You changed the subject to '3'

They took away the bats in your belfry? ;-)

Some kind of subtle PEBKAC issue, no doubt.

Best regards, Spehro Pefhany

To whatever the output is driving, exactly like your device. Instead of two pistons of different sizes, I have two motor/generators of different volumes. The affect is the same.

I was wondering what you were using. That's the double piston method. Sometimes, there's a gear box in between pistons but usually it's a double acting valve as in a locomotive piston to create the necessary oscillations. I played with a home made one in college. I think it got up to about 500 psi. When I released the pressure, I had to wait a while for the ice inside to melt. Oops.

Sigh. All analogies collapse in the end. If air is compressible, then it must be linear, not digital. However, since the same pressure regulator mechanism also works with incompressible water, it could also be digital. Toss a coin?

The noise might be from the pistons banging against the stops at the end of travel. Perhaps a rubber end stopper might help. Use a stethoscope or contact microphone to find the exact source. Or, just bury the monstrosity inside a padded box.

Possibly. My guess(tm) was that my brain waves were phase locked to the 400Hz tone.

Or bad muffler bearings. ;-)

Generators used in micro turbines are quite small and run at quite serious rpm. Maybe such generator could be used as motor.

Regarding hollow shafts, how about using a fixed central stator (with windings) and put the hollow rotor (squirrel-cage construction) around the stator. At least the windings would not suffer from centrifugal forces.

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any

Another advantage that we have is that we can measure things so easily. I can probe almost anything in a live circuit, with a GHz oscilloscope or a PPM-accurate DVM. If some ME wants to know what some temperature or pressure or stress profile is inside some engine, he's in for a lot of work. There must be lots of mechanical stuff that's not optimized because it's so hard to measure stuff.