Linear free piston combustion engine with indirect work extraction via gas linkage

A linear free piston combustion engine with indirect work extraction via gas linkage, comprising:

• a cylinder having a combustion section located at a closed end of the cylinder;
• a free piston disposed within the cylinder, the free piston comprising a front face facing the combustion section and a back face facing the opposite direction, wherein the free piston is free from mechanical linkages external of the cylinder;
• an extractor piston disposed in its own cylinder at an end of the cylinder opposite the closed end, the extractor piston comprising a front face facing the combustion section and a back face facing the opposite direction;
• and
• a gas linkage comprising a volume sealed between the back face of the free piston and the front face of the extractor piston;
• wherein the extractor piston is connected to a rotary electromagnetic machine without an intervening turbine.

A linear free piston combustion engine, comprising:

• a first cylinder comprising a combustion section;
• a first piston comprising:
• a first front face facing the combustion section, and
• a first back face facing an opposite direction to that of the first front face, wherein the first piston is free from mechanical linkages external of the first cylinder;
• a second cylinder;
• and
• a second piston disposed in the second cylinder, the second piston coupled to an electromagnetic machine without an intervening turbine and comprising:
• a second front face, and
• a second back face facing an opposite direction to that of the second front face, wherein
• an end of the first cylinder is coupled to an end of the second cylinder to form a gas linkage comprising a volume between the first back face and the second front face.