Integrated linear generator system

A frame for a linear generator, the linear generator comprising two free-piston assemblies, the frame comprising:

• at least one axial member extending along an axis parallel to a center line of the linear generator;
• at least one lateral member affixed to the at least one axial member;
• a first end member arranged at a first axial end of the at least one axial member;
• a second end member arranged at a second axial end of the at least one axial member, wherein the two free-piston assemblies are to move along the center line, wherein a first gas spring cylinder is affixed to the first end member without mechanical linkage to the two free-piston assemblies, wherein a second gas spring cylinder is affixed to the second end member without mechanical linkage to the two free-piston assemblies, and wherein the at least one axial member is to counteract axial forces from pressure in the first and second gas spring cylinders;
• and at least one tie rod configured to be tension to provide a compressive pre-load on the frame along the axis.

A linear generator comprising:

• a frame comprising a plurality of structural members;
• two linear electromagnetic machines (LEMs) affixed to the frame and laterally aligned to each other, wherein each of the two LEMS are arranged to interact with a respective free-piston assembly;
• a central cylinder affixed to a center of the frame between the two LEMs and laterally aligned to the two LEMs;
• two gas spring cylinders affixed to the frame and that form respective gas springs without mechanical linkages to the respective free-piston assembly, each laterally aligned to a respective LEM of the two LEMs, wherein each respective free-piston assembly are to move along an axis relative to the laterally aligned central cylinder and two gas spring cylinders, and wherein at least one structural member of the plurality of structural members is to counteract axial forces from pressure in the respective gas springs caused by the respective free-piston assembly;
• and at least one tie rod in tension to provide a compressive pre-load on the frame along an axis of the frame.

A frame for a linear generator comprising:

• a plurality of structural members to mount and laterally align:
• a central cylinder arranged along an axis;
• two linear electromagnetic machines (LEMs), each arranged along the axis on a respective opposing side of the central cylinder;
• and two gas spring cylinders that form respective gas springs in contact with respective free-piston assemblies without a mechanical linkage, each arranged along the axis outboard of a respective LEM;
• and at least one tie rod to provide an axial compressive pre-load on the at least one structural member of the plurality of structural members to counteract forces generated by the respective gas springs.