Rotary engines

[delta]

This (less than technically aware) pongo visited RAF Halton last week and had the chance of visiting the Apprentice Museum. Tis superb place has been developed ona self help basis and is rarely open to visiors but my guide picked up on my WW1 inetersts.

As we went round the WW1 exhibits; my guide explained that rotary engines were desigend in such a way that the whole engine would rotate thereby aiding cooling.

Thinking about it, I am most unclear - for example how would the fuel have reached the cylinders? also how would the engine has delivered powered when they were not working against a solid mounting

Was I being wound up? I think I was but..............

Stephen

[Tom Morgan]

No - you were told right!

Mind you - the engines weren't called rotary engines, but radial engines.

Instead of the traditional cylinder block remaining stationary and turning a shaft, the cylinder bank itself revolved around the shaft. So the shaft became a main bearing and was fastened direct to the plane, and the propeller was bolted to the front of the cylinder bank, and they both turned together, with the cylinder bank acting as a flywheel.

There was no carburetter and the fuel (at least in the earlier engines) was sprayed into the spinning engine, with the rotating engine creating the "mixture."

There was no accellerator - the ignition was either on or off. To vary speed when landing, the ignition was switched on and off as needed. Of course the engine continued to rotate for some seconds even with the ignition switched off. When you see an old movie where the pilot shouts "contact" before his mechanic swings on the propeller to start a radial, he is giving a safety warning that he has switched the ingition on, since when the propeller is spun the engine is going to fire up and immediately run at full speed.

Tom

[PhilB]

No - you were told right!

Mind you - the engines weren't called rotary engines, but radial engines.

Tom

Weren`t radial engines similar but had rotating crankshaft and stationary cylinders? Phil B

[delta]

There was no carburetter and the fuel (at least in the earlier engines) was sprayed into the spinning engine, with the rotating engine creating the "mixture."

Curiouser and curiouser....

How does the fuel get into the ingtion chamber if the cylinder block is rotating?

[Redradial]

This Link shows how the rotary engine worked. The radial appears to be the same, that is it has the cylinders around the crankshaft but they do not rotate. See this link. radial

Red

[delta]

That's truly remarkable - thank you; so the petrol-oil mix not only lubricated the workign parts of the engines but also was fed into the chambers by a value in the piston - how clever

[MikB]

That's truly remarkable - thank you; so the petrol-oil mix not only lubricated the workign parts of the engines but also was fed into the chambers by a value in the piston - how clever

That still happens in modern 2-strokes, although the valves are just apertures that line up at the right point in the cycle.

Thanks again to Red, those links clarified my understanding too, no end. Anybody know why there was a master rod - I'd have thought it's be easier to make 'em all the same connecting to a multi-crankpinned boss in t'middle. Ah, but you have to make this rotate with the pots, so a master rod must be the easiest way...?

Regards,

MikB

[AndyHollinger]

Where else except on this board! Thanks ... and thank whomever for their excellent little seminar on Rotary/Radial Engines

[Redradial]

If you get the chance to visit the Shuttleworth Collection (and all WWI aviation Buffs should) then make sure you visit the workshops where there is an ingenious - to say the least - working cutout model of a Rotary/radial engine. If you pull on a lever it works as a Rotary, if you push, it works as a Radial.

Of course, the entire Shuttleworth Collection Link is superb.

Red

[Adrian Roberts]

In the Grahame-White shed of the RAF Museum at Hendon, you can get up close to several types of rotary engines, including a cut-away rotating one.

Shortly before I last went I had come across the Keveney link in Red's post above - I think I more or less worked it out at one time, but I'd have to think about it all over again now!

As the link says, for power to weight, it was the most effective engine of its day. The idea may be fiendishly complicated, but the device itself is very simple. Given that it was designed only a few years after the first petrol engine of any kind, the designer must have been an absolute genius. I believe the first ones were designed by the Anzani firm in about 1908, but I've now idea who actually invented the concept.

Adrian