Double acting thermodynamically resonant free-piston multicylinder stirling system and method

A method for operating a Stirling system, comprising:

• positioning each of a plurality of pistons in a different one of a plurality of cylinders;
• allowing each of the pistons to reciprocate within its respective cylinder;
• controlling the reciprocal motion of each of the pistons within its respective cylinder to prevent undesirable travel of the piston within the respective cylinder;
• including portions of a working fluid in the cylinders;
• and
• coupling the reciprocal motion of each of the pistons with the reciprocal motions of a different pair of the pistons solely through the working fluid.

A Stirling system comprising:

• a working fluid;
• a plurality of free pistons;
• a plurality of overstroke preventers, each of the overstroke preventers coupled to at least a different one of the pistons;
• and
• a plurality of cylinders, each of the cylinders coupled to a different corresponding pair of other ones of the cylinders to couple the cylinder to a first cylinder of the corresponding pair to provide for transfer of a first portion of the working fluid therebetween and to couple the cylinder to a second cylinder of the corresponding pair to provide for transfer of a second portion of the working fluid therebetween, each of the pistons positioned in a different one of the cylinders for reciprocal motion therein, the piston positioned in the cylinder being coupled to the piston positioned in the first cylinder of the corresponding pair through the working fluid and coupled to the piston positioned in the second cylinder of the corresponding pair through the working fluid.

A method for operating a Stirling system, comprising:

• allowing each of a plurality of free pistons to reciprocate within a different one of a plurality of cylinders;
• including a working fluid within at least portions of the cylinders;
• controlling the reciprocal motion of each of the pistons within its respective cylinder to limit travel of the piston therein;
• and
• fluidly coupling each of the cylinders to a different corresponding pair of other ones of the cylinders to couple the cylinder to a first cylinder of the corresponding pair to provide for transfer of a first portion of the working fluid therebetween and to couple the cylinder to a second cylinder of the corresponding pair to provide for transfer of a second portion of the working fluid therebetween, with the piston positioned in each cylinder coupled through the working fluid with the piston within the first cylinder of the corresponding pair and through the working fluid with the piston within the second cylinder of the corresponding pair.

A Stirling system comprising:

• a plurality of pistons mechanically disconnected from each other;
• a plurality of overstroke preventers, each coupled to at least a different one of the pistons;
• and
• a plurality of cylinders, each having a different one of the pistons positioned therein for reciprocal motion, each of the cylinders coupled to a different corresponding pair of other ones of the cylinders to fluidly couple the cylinder to a first cylinder and a second cylinder of the corresponding pair;
• a working fluid, portions of the working fluid positioned in the cylinders, the reciprocal motion of each piston being coupled to the reciprocal motion of at least another one of the pistons through the working fluid;
• and
• means for extracting work from the reciprocal motion of the pistons.

A Stirling system comprising:

• a plurality of pistons mechanically disconnected from each other;
• a plurality of overstroke preventers, each coupled to at least a different one of the pistons;
• and
• a plurality of cylinders, each having a different one of the pistons positioned therein for reciprocal motion, each of the cylinders coupled to a different corresponding pair of other ones of the cylinders to fluidly couple the cylinder to a first cylinder and a second cylinder of the corresponding pair;
• a working fluid, portions of the working fluid positioned in the cylinders, the reciprocal motion of each piston being coupled to the reciprocal motion of at least another one of the pistons through the working fluid;
• and
• means for supplying work to the reciprocal motion of the pistons.

A Stirling system comprising:

• a plurality of pistons mechanically disconnected from each other;
• a plurality of cylinders, each having a different one of the pistons positioned therein for reciprocal motion, each of the cylinders fluidly coupled to a different corresponding pair of other ones of the cylinders to fluidly couple the cylinder to a first cylinder and a second cylinder of the corresponding pair;
• and
• a working fluid, portions of the working fluid positioned in the cylinders, the reciprocal motion of the piston positioned in each of the cylinders being coupled to the reciprocal motion of the piston positioned in the first cylinder of the corresponding pair through the working fluid via the fluid coupling of the cylinder in which the piston is positioned to the first cylinder of the corresponding pair, and being coupled to the reciprocal motion of the piston positioned in the second cylinder of the corresponding pair through the working fluid via the fluid coupling of the cylinder in which the piston is positioned to the second cylinder of the corresponding pair.

A free-piston Stirling system comprising:

• a plurality of double-acting free pistons;
• a plurality of cylinders, each having a different one of the pistons positioned therein for reciprocal motion, each of the cylinders fluidly coupled to a different corresponding pair of other ones of the cylinders to fluidly couple the cylinder to a first cylinder and a second cylinder of the corresponding pair;
• and
• a working fluid, portions of the working fluid positioned in the cylinders, the reciprocal motion of the piston positioned in each of the cylinders being coupled to the reciprocal motion of the piston positioned in the first cylinder of the corresponding pair through the working fluid via the fluid coupling of the cylinder in which the piston is positioned to the first cylinder of the corresponding pair, and being coupled to the reciprocal motion of the piston positioned in the second cylinder of the corresponding pair through the working fluid via the fluid coupling of the cylinder in which the piston is positioned to the second cylinder of the corresponding pair, whereby the Stirling system operates without use of a separate displacer piston.

A method for operating a Stirling system, comprising:

• positioning each of a plurality of pistons in a different one of a plurality of cylinders, the pistons being mechanically disconnected from each other;
• allowing each of the pistons to reciprocate within its respective cylinder;
• including portions of a working fluid in the cylinders;
• and
• coupling the reciprocal motion of each of the pistons with the reciprocal motions of a different corresponding pair of the pistons through the working fluid.

A Stirling system comprising:

• a working fluid;
• a plurality of pistons mechanically disconnected from each other;
• and
• a plurality of cylinders, each of the cylinders coupled to a different corresponding pair of other ones of the cylinders to couple the cylinder to a first cylinder of the corresponding pair to provide for transfer of a first portion of the working fluid therebetween and to couple the cylinder to a second cylinder of the corresponding pair to provide for transfer of a second portion of the working fluid therebetween, each of the pistons positioned in a different one of the cylinders for reciprocal motion therein, the piston positioned in the cylinder being coupled to the piston positioned in the first cylinder of the corresponding pair through the working fluid and coupled to the piston positioned in the second cylinder of the corresponding pair through the working fluid.

A method for operating a Stirling system, comprising:

• allowing each of a plurality of pistons to reciprocate within a different one of a plurality of cylinders, the pistons being mechanically disconnected from each other;
• including a working fluid within at least portions of the cylinders;
• and
• fluidly coupling each of the cylinders to a different corresponding pair of other ones of the cylinders to couple the cylinder to a first cylinder of the corresponding pair to provide for transfer of a first portion of the working fluid therebetween and to couple the cylinder to a second cylinder of the corresponding pair to provide for transfer of a second portion of the working fluid therebetween, with the piston positioned in each cylinder coupled through the working fluid with the piston within the first cylinder of the corresponding pair and through the working fluid with the piston within the second cylinder of the corresponding pair.

For a Stirling machine including a first piston rod and a second piston rod, a linear alternator system comprising:

• a first mover configured for coupling to the first piston rod;
• a second mover configured for coupling to the second piston rod;
• and
• a stator shaped to receive both the first mover and the second mover.

For a Stirling machine having a plurality of cylinders, a system comprising:

• an accumulator;
• a first fluid line fluidly coupled to the accumulator and at least a first one of the cylinders;
• a first solenoid valve positioned in the first fluid line, the first solenoid valve configured to be controlled to open and close;
• a first check value positioned in the first fluid line, the first check valve configured to allow fluid flow from the at least first one cylinder to the accumulator and to prevent fluid flow from the accumulator to the at least first one cylinder when the first solenoid valve is open;
• a second fluid line fluidly coupled to the accumulator and at least a second one of the cylinders, the at least first one cylinder and the at least second one cylinder being the same cylinder or different cylinders;
• a second solenoid valve positioned in the second fluid line, the second solenoid valve configured to be controlled to open and close;
• and
• a second check value positioned in the second fluid line, the second check valve configured to allow fluid flow from the accumulator to the at least one second cylinder and to prevent fluid flow from the at least one second cylinder to the accumulator when the second solenoid valve is open.