Scotch Yoke Converter

Changes circular motion to linear motion (and vice versa)

Produces a pure sine wave over time given a constant rotational speed

Scotch Yoke Animation

Scotch Yoke Animation

Now add a piston and a crankshaft to get a compressor

Scotchyoke Compressor by Pickett

Scotchyoke. Compressor by John Gilmour

Scotchyoke Compressor by Randy Ward