Disc Engines

Updated: 29 Mar 2023

Newton Engines added
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The disc engine was was highly ingenious variation on the rotary engine. A disc rotated and wobbled- for want of a better word- in a closed chamber with the working fluid entering alternately on either side of the disc. Most people have some difficulty in visualising how this works- it's very much a 3D process.


The roots of steam disc engines go back a long way. In 1820-something (the exact date appears to be obscure) the mill-owners Edward & James Dakeyne commissioned a a hydraulic or water engine to make use of high-pressure water available near their factory site. The basic design was similiar to the Davie engine below, but with the shaft vertical.

This remarkable device now can be seen in the water engine gallery: The Dakeyne hydraulic disc engine.


Left: Davie's Disc Engine: 1836.

"A disc b, is fixed to an oscillating shaft,a, which swings in a circuit pivoted in the disc crank,c. The cylinder heads are cones in the apex of which the ball bearing of the shaft oscillates. The outer shell of the cylinder,d, is spherical over which the disc moves. Steam enters alternately on either side of the piston." Through valves which are not shown, presumably? Or are no valves required, as in the Dakeyne engine?

This figure and the one below comes from "Mechanical Movements, Devices and Appliances" by Gardner D Hiscox, published by Sampson Low, Marston & Co in 1899. For each design the title, and the parts of the captions that are in quotes, are taken from the original book.

Left: Reuleaux Engine or Pump.

"A disc on a fixed shaft. The cylinder swings on a central spherical bearing, carrying an arm pivoted in a crank."

In this case the disc is fixed and the casing rotates around it; the opposite of the Davie engine above.

The name applied by Hiscox is misleading. Reuleaux certainly did not invent this engine, he merely analysed it in his book on kinematics.

Left: The Ericsson Engine: 1840.

Section from the side. Note the principle is not quite the same as the disc engines above. This engine was originated by John Ericsson, who was also involved in hot-air engines, and many other engineering endeavours.

An engine of this sort is believed to have driven the printing presses of the Times newspaper in London for some years. It is possible that it was particularily suitable for this job because the torque was more constant than that of a conventional piston-and-crank steam engine, but at the moment this is pure speculation.

Left: The Ericsson Engine: 1840.

Section looking from one end.

This engine was compared with The Tower Spherical Engine.

Left: The Newton Engines: 1865

In 1865 Engineering published a long account of 'Newton's Improvements in Rotary Engines'. These were in fact, according to Museum terminology, actually wobbling-disc engines.

Here Fig 1 shows an engine in where power can be taken from the shaft at either end. Fig 3 shows a single-ended engine where the power is taken from the pulley F at right.

The Museum Staff soon tracked down Mr William Edward Newton, who received British patent No 2308 in 1860 for 'Improvements in Rotary Engines and Rotary Pumps'; from the text a drum-type rotary machine is described that seems to have no relation to these disc engines. The patent is said to be "a communication from abroad" but where is not said.

Source: Engineering 15 Sept 1865, p168

Left: The Newton Engines: 1865

Fig 9 shows a compound disc engine. The disc thing at the bottom is not an engine but an air-pump for the attached condenser. It was driven by belt from the pulley l next to output pulley L.

Googling 'William Edward Newton' gets several hits, but apart from the patent none that are obviously associated with steam engines. There is no sign that these engines met with any success.

Source: Engineering 15 Sept 1865, p168

Left: The Newton Engines: 1865

Fig 10 shows a section of the compound disc engine. There are two disc of differing sizes, the steam from the smaller passing to the larger. Power is taken from the pulley L at right.

Source: Engineering 15 Sept 1865, p168

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