Rotary valve

This topic has 3 replies, 2 voices, and was last updated 27 September 2015 at 18:53 by Mike Brett.

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27 September 2015 at 16:24 #205860
Mike Brett
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@mikebrett89695
Hi all

I am trying to build a simple single acting steam engine utilising a rotary valve. I have built a simple aluminium mock up to try to understand how the valve works but at present it has got me stumped. The casing of my valve is a block of aluminium with the inlet from the boiler at 3 o'clock , the outlet for the exhaust at 9 o'clock and the feed to the top of the piston cylinder at 12 o'clock. With this configeration what shape should the central rotary valve take. I have tried half moon and many other shapes but always the valve opens or shuts to early before the valve has done its complete 360 deg. rotation. Anybody out there tried to build one of these or could point me in the right direction. Mike
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27 September 2015 at 16:24 #7816
Mike Brett
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@mikebrett89695
building a rotary valve steam engine
27 September 2015 at 16:41 #205866
Neil Wyatt
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@neilwyatt
You can't cut away a full half of the valve without allowing in and out to be open at the same time, so the cylinder can only be open for less than half a rotation.

Instead have the cylinder port on the end of the hole and remove nearly half of the valve so it alternately covers and opens the two in and out ports but the cylinder is al;ways open.

Neil
27 September 2015 at 18:53 #205889
Mike Brett
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@mikebrett89695
Hi Neil

Thanks for reply. Not sure what you mean by have cylinder port on the end of the hole ,but I can see the general concept.

Mike
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Rotary valve

Rotary valve

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