This is number two Ross yoke engine. The Ross yoke is named after its inventor, Andy Ross. The mechanism allows for a dual connection on one crank, and also has the benefit of reducing side load because the connecting rods have almost no sideways movement. This particular engine uses the conventional Ross linkage, with a retaining connecting rod mounted perpendicularly to the axis of movement. The Ross yoke has the effect of magnifying the crank throw, so to end up with a total piston motion of 7mm we only need a crank throw of 2.5mm.
Main dimensions:
Crank throw: 2.5mm
Piston diameter: 9.5mm
Piston stroke: 7mm
Chamber height: 12.5mm
Chamber internal diameter: 74mm
Displacer height: 8mm
Flywheel diameter: 82mm
This engine operates on the heat from my hand, and will do anywhere from 40 to 160rpm, depending on the temperature differential.
