A nutating disc engine is a recently patented internal combustion engine comprising fundamentally only one moving part and a direct drive onto the crankshaft. It differs from earlier internal combustion engines in a number of ways and utilizes a type of motion known as nutation.
Power is transmitted directly to the output shaft, (the crankshaft), completely eliminating the need for complicated linkages essential in a conventional piston engine (to change the piston's linear motion to rotating output motion). Since the disc does not rotate, the seal velocities are lower than in an equivalent IC piston engine. However the total seal length is rather long, which may negate this advantage.
The disc wobbles inside a housing and, in its simplest version, half of the single disc (one lobe) performs the intake/compression function, while the other lobe performs the power/exhaust function. Note that the disc lobes can be configured to have equal compression and expansion volumes, or to have the compression volume greater than or less than the expansion volume. This means that the engine can be self supercharged (see supercharger), or operate as a Miller cycle / Atkinson cycle.
A company called McMasters, previously headed by successful American entrepreneur Harold McMaster is also developing a nutating motor burning a mixture of pure hydrogen and pure oxygen that, it claims, will give 200 hp but weigh only one-tenth that of gasoline/air production automotive engines with the same power output. So far the McMasters company claims to have spent $10 million on its development. Plans are also being made to develop a version "the size of a coffee can" that can be built directly into wheel hubs, eliminating the traditional drive train entirely. This concept was first attempted in the British Leyland Mini Moke but was, at that time, severely hampered by lack of reliable synchronization - which is now more commonplace because of ubiquitous miniaturized embedded modern day computer chips. A gasoline-powered version is also planned by McMasters, which is claimed to give substantially cleaner operation than traditional engines .
The same two sons had previously, while still just teenagers in 1794, also invented "The Equalinium", a machine for the preparation of flax for spinning.
Frank Nixon in his book "The Industrial Archaeology of Derbyshire" (1969) commented that "The most striking characteristic of this ingenious machine is perhaps the difficulty experienced by those trying to describe it; the patentees & Stephen Glover only succeeded in producing descriptions of monumental incomprehensibility". Although successful, and a larger model was constructed to drain lead mines at Alport near Youlgreave and many steam versions were subsequently built, the advent of more conventional steam powered machines resulted in the design being largely forgotten.
The same geometry and concept is still used in household water meters.