Nutating disc engine

A nutating disc engine, sometimes called a disc engine, is an internal combustion engine built around essentially one moving part, a disc that wobbles without rotating and drives the crankshaft directly. The centre of the disc hub sits in the middle of a Z shaped shaft, one part of the disc area handles intake and compression, another seals against the casing and the rest handles expansion and exhaust, with compressed air passing through an external accumulator and combustion chamber, which lets small engines burn diesel fuel. A modern version was patented in 1993 by Leonard Meyer of Illinois and one prototype ran briefly, while McMaster Motor pursued a hydrogen and oxygen variant. The idea descends from the Dakeyne hydraulic disc engine of the 1820s and the steam disc engines of Davies and Taylor and of George Bishopp in the 1830s to 1850s, which were used on canal tugs and gunboats before faster conventional steam engines displaced them. The same geometry survives in the nutating disc water meter.