Abstract: An improved technique for balancing inertia forces and rocking couples of a Ross-type Stirling machine (U.S. Pat. Nos. 4,138,897; 4,532,819 and 4,738,105). Two counter-rotating balance masses are used, one on the crankshaft and one on a separate balance shaft. These balance masses lead the throw of the crankshaft by more than 180 degrees of rotation. The axis of the balance shaft is positioned so that a line connecting it and the axis of the crankshaft is inclined with respect to the cylinder axes toward the heavier piston of the machine. The new technique is also applicable to other machines having separate parallel cylinders in which pistons of unequal mass reciprocate out of phase.

Abstract: A compression piston and cylinder mechanism for the V type two piston Stirling engine which substantially reduces engine dead volume without increasing complexity or decreasing mechanical efficiency. A stepped piston is attached at its smaller outer portion to a relatively long connecting rod. The piston seal is located at the larger inner portion of the piston, thereby permitting a short passage of low dead volume to connect the volume swept by the compression piston to the engine's heat exchangers. A stepped cylinder corresponds to the shape of the piston, having a smaller outer portion that sustains the side loading resulting from connecting rod angularity, and a larger inner portion that the piston seals against.

Abstract: A balanced crankshaft mechanism for the two piston Stirling engine which permits the use of a single crankpin and eliminates side forces on the pistons. A triangular yoke has connected to its respective apexes the connecting rods for each piston and the crankpin. One end of a rocking lever is connected to said yoke at a point between the points at which the connecting rods are attached. The other end of said rocking lever is connected to the base of the machine. As the crankpin rotates, the separate connecting rods and their respective pistons are moved with a phase relation appropriate for a two piston Stirling engine, and side forces are absorbed by the rocking lever, rather than by the pistons. A simple means of balancing the reciprocating inertial forces is described, which is also applicable to other types of Stirling engines.