Patent ID: 8590300

Claim:
A group of multiple free-piston Stirling (FPS) machines arranged and connected for preventing or minimizing vibration, each FPS machine including an outer housing and internal reciprocating composite masses, including the masses of a prime mover or load connected to the FPS machine, the group comprising: (a) a first set of identical beta FPS machines rigidly connected together, arranged in a mechanically co-directional orientation and configured to reciprocate in thermodynamically synchronous reciprocation with each other, the first FPS machines having axes of reciprocation intersecting a first point, which may be a point at infinity, the axes of the first FPS machines making the same angle with a central axis of motion and equi-angularly spaced around the central axis of motion; (b) a second set of beta FPS machines rigidly connected together and rigidly connected to the first set of machines, the second set of machines arranged in a mechanically co-directional orientation that is the same as the mechanical orientation of the first set of beta FPS machines, the second set of machines configured to reciprocate in thermodynamically synchronous reciprocation with each other but in thermodynamically opposed reciprocation to the first set, the FPS machines of the second set being identical to the FPS machines of the first set and having axes of reciprocation intersecting a point, which may be a point at infinity, the axes of the second FPS machines all making the same angle with said central axis of motion and equi-angularly spaced around the central axis of motion; and (c) wherein each set has three FPS machines.