The Romping Lion

The story of the Dakeyne Disc Engine
in the beginning
the lion that roared
the dakeynes and their mills
the search for power
the disc engine
driving the mill
down the mine
the last water engine
into the steam age
disc engines at work
made by the million
explosive force
reborn in america - 1996
back to the mill
the legacy in the dales
NEW -animation of engine
contact
NEW - book in publication
the disc engine
 
Imagine taking an orange and a piece of cardboard.  Cut a circle in the cardboard about twice the diameter of the orange.  The cut the orange in half and place the disc between the two halves.  You will now have something that looks like the planet Saturn with its rings. Now push a cocktail stick into the top of the orange say half an inch deep. Place the orange on top of a napkin ring. By placing your finger on the end of the cocktail stick you'll be able to tilt the orange until the disc comes into contact with the napkin ring.  You can of course do this in any direction and the orange simply tilts and when viewed from above does not rotate.
 
The next stage in the experiment is to rotate the top of the cocktail stick in a circle making sure that the disc is always a maximum tilt - that is, touching the napkin ring.  You will see that, again, the orange does not need to rotate to allow the end of the cocktail stick to move in a a circle.
 
If you understand that you are half way to understanding the operation of the disc engine.
 
The schematic drawing of the disc engine above clearly resembles the imaginary orange and cardboard disc. It differs in that the disc is now enclosed within a tight fitting casing, although the top and the bottom of the sphere protrude above and below the casing.  The crank ensures that the disc is always at the maximum tilt angle so that the disc is held firmly against the top and the bottom of the casing.  Although it is not too apparent in the drawing, the top and bottom of the casing are actually shallow cones whose angle is exactly the same as the maximum tilt angle of the disk. therefore there is always a line of contact between the lower side of the disc and the bottom of the casing and (diametrically opposite) the upper side and casing top.
 
Another feature is a radial web or partition across the casing (coloured blue).  A radial slot was cut in the disc to allow for this.  On either side of the web there was a hole in the the casing circumference allowing water to flow in through what was actually a port and out through the other.  In the drawing above the right hand port is shown as the inlet.
 
Now imagine you were able to look into the ports from the side and that the disc was tilted towards you.  High pressure water would force its way through the right hand port on to the top of the disc.  This would force the disc downwards and to the right, moving the tilt angle around the casing.  As this happens you would see that the edge of the disc as viewed through the ports starts to rise.  When the crank has turned through 180°and the disc is at maximum tilt away from the ports, water is being admitted to the bottom side of the disc, continuing the rotation of the crank.  As they desk again starts to tilt towards you the upper surface of the disc is exposed to the exhaust port allowing the water to be discharged from the engine.
 
It may be helpful to think of slugs of water travelling around the casing one above the disc followed by a second one below the disc.  Of course in practice they are not slugs because the rate of flow changes as the disc tilts. It will be appreciated that no valves were required, the flow of water to the upper and lower sides of the disc being controlled by the position of the disc itself. 
 
There were other features of the design essential to make the engine work.  Seals had to be fitted to prevent loss of water around the sphere to the outside and to the circumference of and slot in the disc to prevent leakage of water from one side of the disc to the other.  To avoid crushing the seals and minimize the friction within the engine the disc and sphere had to be located centrally and its weight supported.  This was achieved in three ways.  Firstly, the sphere, which was hollow, was supported on a spherical bearing at the top of a pillar which extended from the base of the machine to the centre of the sphere.  Secondly there was a yoke (M)mounted on the casing by what were effectively gimbals. The drive rod was locked into the yoke.Thus the weight of the sphere and disc was tranmitted via the drive rod to the yoke and from the yoke to the casing..  Finally holes were drilled through the casing which allowed water from the side of the disc under pressure to enter the space between the casing and the sphere on the opposite side of the disc.  Obviously this is intended to help balance the hydraulic forces acting on the disc.
 
The drawing is shown in the 1830 Patent. The spherical bearing is "C" and the stirrup bracket is "M". The ends of stirrup are mounted on swivel bearings on a ring around the casing, none of which arrangement is shown. The ring is in turn mounted on the casing with swivels at 90 degrees (in plan view) to the other pair.
 
 
Hopefully you will now have some idea of how the disc engine worked. What will be never understood is how the Dakeyne brothers conceived of such an arcane design. And how, having come up with the concept, they actually made it, and made it work. And that it ever worked at all is miraculous.
 
 
 - and now read my book "The Romping Lion  - the story of the Dakeyne Disc Engine" , published in 2011. Click on the book cover below for more information.




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