The nutating engine

[GregLocock]

http://dakeynediscengine.org/default.aspx

Fair enough - but the annoyingly anonymous author says " It's use as a prime mover or if virtually died out after 1850 but today a device based on the original concept is in widespread use in the Western World. If in fact there is a better than even's chance that there is one in your home if you live in Europe or North America. "

and never mentions what he is talking about again.

Any ideas? I'm /guessing/ a gas meter or water meter.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[MikeHalloran]

Water meter.

http://niagarameters.com/products/positive/nutPrinciple.htm

http://www.herseymeters.com/prod_disp_400.html

Mike Halloran
Pembroke Pines, FL, USA

 

[BJC]

It's a water meter.
There have been and still are a number of diesel engines that use pistons in parallel with the shaft. They drive the shaft with a swash plate or neutating disk. The earliest one I have read about were made in the late 20s. The latest was supposed to revolutinize the aircraft industry.
They all looked a little like the GM six cylinder air conditioning compressor.

 

[GregLocock]

Interesting, thanks for the links Mike.

Yeah, swashplate engines. Another way of scamming investors and/or killing engineering companies. The Harrison a/c compressors are lovely things to pull apart, I'm trying to remember how the swash angle was controlled.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[MikeHalloran]

AFAIR, the swashplate angle in a Harrison A6 is fixed.





Mike Halloran
Pembroke Pines, FL, USA

 

[GregLocock]

Nope, it's variable stroke in V5 and V7 at least.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[thruthefence]

I think Vickers makes an aircraft hydraulic pump that the volumn/pressure is controlled by varying the angle of the swashplate according to demand.

 

[berkshire]

Greg,
Is this the beast you are talking about?

http://www.mcmastermotor.com/technical.htm

B.E.

 

[GregLocock]

Yes that's the idea. Waddayerreckon? Power density seems very high.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[IRstuff]

This company has been at it for 9 yrs and still appears productless.

TTFN

FAQ731-376

 

[berkshire]

Greg,
I think you got it right in your second post.
B.E.

 

[btrueblood]

The right question to ask with any motor design (new or old) is, "show me a working example". Subsequent questions would be "how much power does it put out" and "at what efficiency". Websites that don't give any of the above information are wastes of time.

 

[jmw]

Nutating disc isn't much used in Europe for water metering as the commonest types are the rotary piston meter, single and multi-jet inferential meters.
Some suggestion the nutating disc meter pre-dates the rotary piston meter(the rotary piston meter was patented in the UK in the late 1800's).
The same problems that beset the disc meter must surely afect the motor, leakage between the high and low pressure areas at the partition plate.

JMW

http://www.ViscoAnalyser.com

 

[plasgears]

The Wankel engine looked like an inversion of a kind of pump. I didn't have much confidence in it, but it has progressed to production in cars.

Today airplane home builders are installing them with success in small airplanes. One cohort has a two element Wankel that he is gearing down for his RV-6 airplane. The engine is a lot smaller than the equivalent Lycoming.

 

[KENAT]

plasgears, If I recall correctly some UAV use/d wankels.

KENAT, probably the least qualified checker you'll ever meet...

 

[GregLocock]

Wankel is attractive in terms of packaging volume for a given power, and power/weight ratio, to a lesser extent.

However it is not clean or efficient.



Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[plasgears]

One cohort at Curtiss-Wright many moons ago claimed that the Wankel engine ran better with a dose of oil in the fuel. It turns out that oil is still added to the fuel in wankels.

 

[ivymike]

try

http://www.moller.com

for some interesting uses of wankel engines.

 

[gerhardl]

JMV: For watermeters with magnetic impulse transferring rotating movement from spindle/magnet incased in housing to register (outside housing), there is no possibillity of leakage between wet and dry side. See:

http://www.badgermeter.com/Water/Water-Meters/Recordall-Disc-Series-(1).aspx

Now, if the engine version could be equipped with some sort of magnetic clutch....? (How are the US military for RD funds at the moment.. ;-)..???)

 

[jmw]

Gerhardl,
I was referring to the leakage from inlet to outlet without causing rotation/nutation.
The disc is tipped and you have a line of contact between the disc and the chamber that is a radius and which is the separation between the inlet fluid and the outlet fluid. If the disc tips up a bit then this "line of contact" opens up and water can flow through the gap from the inlet to the outlet without causing nutation.
This is, in all positive displacement meters, referred to as slip flow.
The trouble with the nutating disc meter is that a small change in tip angle can open up quite a slip flow path.
What stops the disc form tipping up? the guide bearing.
As the flow rate increases the load on the guide bearing increases and the tenancy of the disc to tip up increases.
If you remove the guide bearing then the disc would tend to tip up until horizontal.
In the rotary or nutating piston meters the slip flow clearances tend to close as the flow rate increases. If you remove the guide roller they perform very poorly at low flows but you won't notice any difference at high flows.

Both principles date from the 1800s.

JMW

http://www.ViscoAnalyser.com