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
into the steam age
 
  
Many inventors and engineers in the early 18th century regarded the rotary steam engine as the Holy Grail.  It's perceived advantages of light weight, low cost, compact size,  high-speed, and   superior efficiency compared very favourably with heavy beam engines which had hardly evolved since the days of James Watt.
 
Three patentees followed one another in developing disc engines based on the design of the Dakeyne engine. They were to realize the ambitions of Edward and James who had recognized that potential in their patent. 
 
The first were George Davies and Henry Taylor who patented their engine as early as 1836.  As well as being fitted with valves to control the admission of steam, it differed from the Dakeyne prototype in other ways. The drive rod was fixed to a bracket on the main engine frame at the maximum angle of tilt.  This meant that the axis of the engine was horizontal instead of vertical and that because of the rod was fixed, it was the casing that rotated around  the disc - the reverse of the original disc engine.     
 
This arrangement avoided the need to couple the end of the rod that was flailing around to a crank and therefore the engine could be fitted into a smaller envelope.  It would also look a lot neater . All that you would see would be a horizontal cylinder - the casing - rotating smoothly round and round.
 
The disc had to rotate with the casing and to allow this the drive rod  was mounted in a bearing on the engine mainframe bracket.
 
It may not be immediately obvious that this is a Dakeyne type engine. It just requires a little imagination! 
 
 
That it had a horizontal output shaft was clearly a major improvement on the Dakeyne prototype - not many machines require a vertical drive!  It looked fairly conventional and would clearly appeal to anyone looking for a small but powerful engine - even if they did not understand how it worked. It was not quite as simple as the hydraulic engine since valves were required to allow for expansive working.
 
More patents were to follow over the next eight years directed to introducing expansive working and improving sealing - in the latter case going as far as the machining of radial slots in the disc which intermeshed with similar slots in the conical ends of the casing.
 
Davies and Taylor (although it was Davies that took the leading role) had nine years in which to exploit their design before a competitor of significance entered the market. That competitor was
George Daniell Bishopp of Edgbaston, formerly Locomotive Engineer on the Birmingham and Gloucester Railway.
 
Bishopp went to the highly reputed engineering company of Donkin & Co based in Bermodsey, London, to build his first engine in 1840. Although again a horizontal engine, it was closer in design to the original Dakeyne engines. However, because it was horizontal, the way of locating and supporting the disc inside the casing had to be redesigned - the sphere could not sit on a spherical bearing on a vertical pillar. So Bishopp extended the drive rod on both sides of the sphere. The ends of the rod fitted into a yoke extending over the top of the casing. The yoke was supported at its centre on a pivoting bearing mounted on slider fitted in a radiused track on top of the casing. This allowed the yoke  (and hence the drive shaft/sphere /disc assembly) to tilt in the vertical and in the horizontal plane.
 
The drive rod was coupled to a large flywheel mounted on the output shaft.
 
 
 
Considerable lengths were taken to improve the sealing. Radial strips were mounted around the conical ends of the casing and these were spring loaded to hold them tightly against the disc as it rolled over them in turn. There were adjustable packings to seal the sphere and casing interface and a seal around the rim of the disc.
 
A Patent for the engine was granted in 1845.  
 
There were other patentees subsequently such as partners Barnard William Farey and Bryan Donkin (Jr) who claimed further improvements to the basic design directed to, for example , expansion valve gear and sealing. Bryan Donkin, the son of the founder of the eponymous company, had worked with Bishopp on the latter's original engine. Farey, the nephew of the
eminent engineer and polymath John Farey, was employed by Donkins.
 
To see a working model go to:-
 
 http://www.youtube.com/watch?v=ZBUQKHgxQuA&feature=related