Hollow piston valve

[Anatol]

I'm exploring all the possible geometries of valving - and finding (unsurprisingly) that most have been tried, and abandoned - often after years or decades of testing.

I *think* I've seen images of a type I'd call a hollow piston valve. I'm thinking of steam use, presumably in a 2, 3 or 4 cylinder inline single acting layout. Steam inlet would be at one end of the valve, and would pass down the hollow center. Drive would happen at the other end. There'd be transverse ports which would line up with cylinder inlet ports, sequentially. Exhaust would be via a separate hollow piston (or possibly uniflow) - maintaining high temp in inlet area.

~Has anyone seen a valve arrangement like this or have any comments?

 

[Blogwitch]

I used hollow piston valves on my 'Paddleducks' engine.

Plans and instructions can be downloaded for free from here.

http://www.machinistblog.com/bogstandards-paddleduck-engine-plans/

John

 

[Anatol]

I used hollow piston valves on my 'Paddleducks' engine.

Plans and instructions can be downloaded for free from here.

http://www.machinistblog.com/bogstandards-paddleduck-engine-plans/

John

Thanks John - so your'e bogstandard? I'm honored. I'm a big fan. I downloaded your piston valve engine pdf, its a really useful document. I appreciate the level of detail in making advice - and the drawings look like mine I had not got in deep enough to see that the engine has hollow piston valves. I will read more deeply. thankyou!

 

[Blogwitch]

Please don't be honoured Anatol, I haven't been very productive for the last five years, but keep your eyes open, after just getting through the worst year of my life, I am hoping to be emerging again in the not too distant future once I get through all the side effects and my strength back, plus workshop tidied up and working again.

John

 

[Anatol]

John,
sorry to hear of your adversity, I hope you're on the mend.
I've had my share and there's no telling who it hits, when, or in what form.
Carpe diem, tempus fugit, ec

 

[lohring]

Here's an oscillating cylinder version that should be easy to build.

Lohring Miller

 

[Anatol]

Interesting! Thanks.
Its a single acting wobbler, and the hollow valve has both exhaust and inlet, correct? That is cool. But what is the 'handle' on the right I the last pic?
Of course, that idea would not scale up to multiple cylinders...I guess you could hang one cylinder each side of the flywheel, and feed steam through a port in the middld of the valve housing....trickier to make.

 

[lohring]

Like it says in the drawing, the lever is the reversing handle. It changes the valve timing.

Lohring Miller

 

[Anatol]

Like it says in the drawing, the lever is the reversing handle. It changes the valve timing.

Lohring Miller

ouch, sorry, shoulda figured that, or looked.