From: Strandh, Sigvart: The History of the Machine,Dorset Press, New York, 1989
How Ericsson's ultimate caloric engine worked.
The working piston (a) and the feed piston (b) worked
in the same cylinder.
(c) Furnace. A crank mechanism (d) was necessary in order to make a and b move in a suitable way.
(e) Valve regulated by a disk cam on the crank axle and connecting the cylinder space (f) with the outside air.
(g) Air-pressure-regulated valves. (h) Holes connecting cylinder spaces f and (i): uncovered when b moved to the right;
Click on the underlined numbers below to stop the animation in the corresponding
phase; click here to reanimate.
(1) e is closed holes h are uncovered. Since a moves faster than b, g open, and cold air enters the cylinder.
(2) Piston b turns, h are covered, and e is opened so that the air in f can escape.
(3,4) Piston a turns but moves at a slower speed than b, so valves g remain open.
(5) Piston b turns and e is closed. The holes (h) are uncovered, and when the air enclosed in i and f is now heated, its pressure increases, and the valves g close.
(6,7) The increasing pressure of the air, which becomes hotter and hotter, forces a to the right.