Regenerative internal combustion engine

A thermally regenerated reciprocating cyclic internal combustion engine having a rotating power output shaft composed of a number of similar working units, each working unit comprising:

• a cylinder, closed at one end by a cylinder head with a number of intake valves to draw cool fresh air into the cylinder, and a number of exhaust valves to exhaust the spent combustion gases from the cylinder;
• a first means for opening and closing said intake valves and exhaust valves in a predetermined manner once in each engine cycle;
• a piston inside the cylinder moving along the axis of the cylinder in a reciprocating manner toward and away from the cylinder head between the top dead center position closest to the cylinder head and the bottom dead center position furthest away from the cylinder head, said piston being connected by a second means to the power output shaft, where said second means translates the reciprocating motion of said piston to rotation of the power output shaft;
• a thermal regenerator inside the cylinder between the cylinder head and the piston, capable of being moved in predetermined cyclic reciprocating motion along the axis of the cylinder and comprising a permeable core and other structure to absorb heat from the hot combustion gases when moved in one direction, and to transfer the absorbed heat to the cool fresh air when moved in the opposite direction;
• a cam driven by the power output shaft for imparting periodic motion to said thermal regenerator, said cam acting on the thermal regenerator by linkages through a driving rod which passes through the piston;
• an injection means for injecting combustible fuel into the cylinder;
• and
• an ignition means for igniting the mixture of said air and said fuel in the cylinder.

A thermally regenerated reciprocating cyclic internal combustion engine having a rotating power output shaft composed of a number of similar working units, each working unit comprising:

• a cylinder, closed at one end by a cylinder head with a number of intake valves to draw cool fresh air into the cylinder, and a number of exhaust valves to exhaust the spent combustion gases from the cylinder;
• a first means for opening and closing said intake valves and exhaust valves in a predetermined manner once in each engine cycle;
• a piston inside the cylinder moving along the axis of the cylinder in a reciprocating manner toward and away from the cylinder head between the top dead center position closest to the cylinder head and the bottom dead center position furthest away from the cylinder head, said piston being connected by a second means to the power output shaft, where said second means translates the reciprocating motion of said piston to rotation of the power output shaft;
• a thermal regenerator inside the cylinder between the cylinder head and the piston, capable of being moved in predetermined cyclic reciprocating motion along the axis of the cylinder and comprising a permeable core and other structure to absorb heat from the hot combustion gases when moved in one direction, and to transfer the absorbed heat to the cool fresh air when moved in the opposite direction;
• a cam driven by the power output shaft for imparting periodic motion to said thermal regenerator, said cam acting on the thermal regenerator by linkages through a cylindrical annular sleeve which fits between the cylinder wall and the piston;
• an injection means for injecting combustible fuel into the cylinder;
• and
• an ignition means for igniting the mixture of said air and said fuel in the cylinder.

A process for operating a thermally regenerated reciprocating cyclic internal combustion engine having a rotating power output shaft composed of a number of similar working units, each working unit comprising (a) a cylinder closed at one end by a cylinder head, with a number of intake valves to draw cool fresh air into the cylinder, and with a number of exhaust valves to exhaust the spent combustion gases from the cylinder, said intake valves and exhaust valves communicating with the cylinder between top dead center and bottom dead center;

• (b) a first means for opening and closing said intake valves and exhaust valves in a predetermined manner once in each engine cycle;
• (c) a piston inside the cylinder moving along the axis of the cylinder in a reciprocating manner toward and away from the cylinder head between the top dead center position closest to the cylinder head and the bottom dead center position furthest away from the cylinder head, said piston being connected by a second means to the power output shaft, where said second means translates the reciprocating motion of said piston to rotation of the power output shaft;
• (d) a thermal regenerator inside the cylinder between the cylinder head and the piston, capable of being moved in predetermined cyclic reciprocating motion along the axis of the cylinder and comprising a permeable core and other structure to absorb heat from the hot combustion gases when moved in one direction, and to transfer the absorbed heat to the cool fresh air when moved in the opposite direction;
• (e) a third means for imparting a predetermined periodic motion to said thermal regenerator;
• (f) an injection means for injecting combustible fuel into the cylinder, said injection means communicating with the cylinder near the cylinder head;
• and (g) an ignition means for igniting the mixture of said air and said fuel in the cylinder, said ignition means communicating with the cylinder near the cylinder head, causing fuel to be ignited and combusted in the cylinder between the regenerator and the cylinder head;
• in a four-stroke cycle comprising piston motion from top dead center to bottom dead center back and forth twice and comprising the steps of:
• opening the intake valves with the exhaust valves closed, the piston near top dead center, and the regenerator close to the cylinder head;
• drawing in fresh air through the intake valves into the cylinder by moving the piston from near top dead center to near bottom dead center, while the regenerator remains close to the cylinder head;
• closing the intake valves;
• compressing the air in the cylinder by moving the piston to near top dead center while the regenerator remains close to the cylinder head;
• moving the regenerator from its location close to the cylinder head through the compressed air to a position close to the piston, while the piston is near top dead center, thereby transferring stored high temperature heat from the previous cycle from the regenerator into the compressed air;
• injecting fuel, using the injection means, into the compressed and regeneratively heated air located between the regenerator and the cylinder head;
• igniting and burning the fuel-air mixture using the ignition means to form hot combustion gases with the piston near top dead center;
• extracting work from the hot combustion gases which expand and push the piston to near bottom dead center while simultaneously the regenerator is moved in the same direction and kept close to the piston;
• moving the regenerator from its position close to the piston, through the expanded combustion gases toward the cylinder head, while the piston is near bottom dead center thereby transferring high temperature heat from the combustion gases into the regenerator;
• opening the exhaust valves when the regenerator has passed by the exhaust valves in its motion toward the cylinder head;
• moving the piston from near bottom dead center to close to top dead center while the regenerator remains at or near the cylinder head, thereby exhausting the cooled combustion gases through the exhaust valves;
• and
• closing the exhaust valves.

A process for operating a thermally regenerated reciprocating cyclic internal combustion engine having a rotating power output shaft composed of a number of similar working units, each working unit comprising (a) a cylinder closed at one end by a cylinder head, with a number of intake valves to draw cool fresh air into the cylinder, and with a number of exhaust valves to exhaust the spent combustion gases from the cylinder, said intake valves and exhaust valves communicating with the cylinder between top dead center and bottom dead center;

• (b) a first means for opening and closing said intake valves and exhaust valves in a predetermined manner once in each engine cycle;
• (c) a piston inside the cylinder moving along the axis of the cylinder in a reciprocating manner toward and away from the cylinder head between the top dead center position closest to the cylinder head and the bottom dead center position furthest away from the cylinder head, said piston being connected by a second means to the power output shaft, where said second means translates the reciprocating motion of said piston to rotation of the power output shaft;
• (d) a thermal regenerator inside the cylinder between the cylinder head and the piston, capable of being moved in predetermined cyclic reciprocating motion along the axis of the cylinder and comprising a permeable core and other structure to absorb heat from the hot combustion gases when moved in one direction, and to transfer the absorbed heat to the cool fresh air when moved in the opposite direction;
• (e) a third means for imparting a predetermined periodic motion to said thermal regenerator;
• (f) an injection means for injecting combustible fuel into the cylinder, said injection means communicating with the cylinder near the cylinder head;
• and (g) an ignition means for igniting the mixture of said air and said fuel in the cylinder, said ignition means communicating with the cylinder near the cylinder head, causing fuel to be ignited and combusted in the cylinder between the regenerator and the cylinder head;
• in a two-stroke cycle comprising piston motion from top dead center to bottom dead center back and forth once and comprising the steps of:
• opening the intake valves with the exhaust valves closed, with the piston near bottom dead center, and the regenerator moving toward the cylinder head, and so transferring heat from the expanded combustion gases in the cylinder generated during the previous cycle into the regenerator core and drawing fresh air into the cylinder by the reduction in pressure caused by the transfer of heat;
• closing the intake valves;
• moving the piston upward from the initial position near bottom dead center to a position near top dead center, while keeping the regenerator close to the cylinder head, and thereby compressing the fresh air in the cylinder;
• moving the regenerator from its position near the cylinder head to a position near the piston, thus forcing the fresh air through the regenerator and thereby transferring stored heat from the regenerator to the fresh air;
• injecting fuel using the injection means into the compressed, regeneratively heated air located in the cylinder between the regenerator and the cylinder head;
• burning the mixture of fuel and compressed air, while the piston is near top dead center;
• extracting work from the hot combustion gases which expand and push the piston to near bottom dead center, while simultaneously the regenerator is moved in the same direction and kept close to the piston;
• moving the regenerator back in a direction toward the cylinder head, thereby uncovering the exhaust valve openings in the cylinder wall;
• opening the exhaust valves, causing the expanding combustion gases to flow through and heat up the regenerator and flow through the exhaust valves out of the engine;
• and
• closing the exhaust valves.

A thermally regenerated reciprocating cyclic internal combustion engine having a rotating power output shaft composed of a number of similar working units, each working unit comprising (a) a cylinder closed at one end by a cylinder head, with a number of intake valves to draw cool fresh air into the cylinder, and with a number of exhaust valves to exhaust the spent combustion gases from the cylinder, said intake valves and exhaust valves communicating with the cylinder between top dead center and bottom dead center and located in the piston head;

• (b) a first means for opening and closing said intake valves and exhaust valves in a predetermined manner once in each engine cycle;
• (c) a piston inside the cylinder moving along the axis of the cylinder in a reciprocating manner toward and away from the cylinder head between the top dead center position closest to the cylinder head and the bottom dead center position furthest away from the cylinder head, said piston being connected by a second means to the power output shaft, where said second means translates the reciprocating motion of said piston to rotation of the power output shaft;
• (d) a thermal regenerator inside the cylinder between the cylinder head and the piston, capable of being moved in predetermined cyclic reciprocating motion along the axis of the cylinder and comprising a permeable core and other structure to absorb heat from the hot combustion gases when moved in one direction, and to transfer the absorbed heat to the cool fresh air when moved in the opposite direction;
• (e) a third means for imparting a predetermined periodic motion to said thermal regenerator;
• (f) an injection means for injecting combustible fuel into the cylinder, said injection means communicating with the cylinder near the cylinder head;
• and (g) an ignition means for igniting the mixture of said air and said fuel in the cylinder, said ignition means communicating with the cylinder near the cylinder head, causing fuel to be ignited and combusted in the cylinder between the regenerator and the cylinder head;

A thermally regenerated reciprocating cyclic internal combustion engine having a rotating power output shaft composed of a number of similar working units, each working unit comprising (a) a cylinder closed at one end by a cylinder head, with a number of intake valves to draw cool fresh air into the cylinder, and with a number of exhaust valves to exhaust the spent combustion gases from the cylinder, said intake valves and exhaust valves communicating with the cylinder between top dead center and bottom dead center and being ports located flush in the cylinder wall such that they are open when the piston is near bottom dead center and become closed as they are covered by the piston as it moves toward top dead center;

• (b) a first means for opening and closing said intake valves and exhaust valves in a predetermined manner once in each engine cycle;
• (c) a piston inside the cylinder moving along the axis of the cylinder in a reciprocating manner toward and away from the cylinder head between the top dead center position closest to the cylinder head and the bottom dead center position furthest away from the cylinder head, said piston being connected by a second means to the power output shaft, where said second means translates the reciprocating motion of said piston to rotation of the power output shaft;
• (d) a thermal regenerator inside the cylinder between the cylinder head and the piston, capable of being moved in predetermined cyclic reciprocating motion along the axis of the cylinder and comprising a permeable core and other structure to absorb heat from the hot combustion gases when moved in one direction, and to transfer the absorbed heat to the cool fresh air when moved in the opposite direction;
• (e) a third means for imparting a predetermined periodic motion to said thermal regenerator;
• (f) an injection means for injecting combustible fuel into the cylinder, said injection means communicating with the cylinder near the cylinder head;
• and (g) an ignition means for igniting the mixture of said air and said fuel in the cylinder, said ignition means communicating with the cylinder near the cylinder head, causing fuel to be ignited and combusted in the cylinder between the regenerator and the cylinder head;

In a thermally regenerated reciprocating cyclic internal combustion engine having a rotating power output shaft composed of a number of similar working units, each working unit comprising (a) a cylinder closed at one end by a cylinder head, with a number of intake valves to draw cool fresh air into the cylinder, and with a number of exhaust valves to exhaust the spent combustion gases from the cylinder;

• (b) a first means for opening and closing said intake valves and exhaust valves in a predetermined manner once in each engine cycle;
• (c) a piston inside the cylinder moving along the axis of the cylinder in a reciprocating manner toward and away from the cylinder head between the top dead center position closest to the cylinder head and the bottom dead center position furthest away from the cylinder head, said piston being connected by a second means to the power output shaft, where said second means translates the reciprocating motion of said piston to rotation of the power output shaft;
• (d) a thermal regenerator inside the cylinder between the cylinder head and the piston, capable of being moved in predetermined cyclic reciprocating motion along the axis of the cylinder and comprising a permeable core and other structure to absorb heat from the hot combustion gases when moved in one direction, and to transfer the absorbed heat to the cool fresh air when moved in the opposite direction;
• (e) a third means for imparting a predetermined periodic motion to said thermal regenerator;
• (f) an injection means for injecting combustible fuel into the cylinder;
• and (g) an ignition means for igniting the mixture of said air and said fuel in the cylinder;
• the regenerator in which the permeable core comprises multiple layers of sintered or diffusion bonded screens woven from refractory metal wire.

In a thermally regenerated reciprocating cyclic internal combustion engine having a rotating power output shaft composed of a number of similar working units, each working unit comprising (a) a cylinder closed at one end by a cylinder head, with a number of intake valves to draw cool fresh air into the cylinder, and with a number of exhaust valves to exhaust the spent combustion gases from the cylinder;

• (b) a first means for opening and closing said intake valves and exhaust valves in a predetermined manner once in each engine cycle;
• (c) a piston inside the cylinder moving along the axis of the cylinder in a reciprocating manner toward and away from the cylinder head between the top dead center position closest to the cylinder head and the bottom dead center position furthest away from the cylinder head, said piston being connected by a second means to the power output shaft, where said second means translates the reciprocating motion of said piston to rotation of the power output shaft;
• (d) a thermal regenerator inside the cylinder between the cylinder head and the piston, capable of being moved in predetermined cyclic reciprocating motion along the axis of the cylinder and comprising a permeable core and other structure to absorb heat from the hot combustion gases when moved in one direction, and to transfer the absorbed heat to the cool fresh air when moved in the opposite direction;
• (e) a third means for imparting a predetermined periodic motion to said thermal regenerator;
• (f) an injection means for injecting combustible fuel into the cylinder;
• and (g) an ignition means for igniting the mixture of said air and said fuel in the cylinder;
• the regenerator in which the permeable core comprises a sintered or diffusion bonded felted mat of refractory metal fibers.

In a thermally regenerated reciprocating cyclic internal combustion engine having a rotating power output shaft composed of a number of similar working units, each working unit comprising (a) a cylinder closed at one end by a cylinder head, with a number of intake valves to draw cool fresh air into the cylinder, and with a number of exhaust valves to exhaust the spent combustion gases from the cylinder;

• (b) a first means for opening and closing said intake valves and exhaust valves in a predetermined manner once in each engine cycle;
• (c) a piston inside the cylinder moving along the axis of the cylinder in a reciprocating manner toward and away from the cylinder head between the top dead center position closest to the cylinder head and the bottom dead center position furthest away from the cylinder head, said piston being connected by a second means to the power output shaft, where said second means translates the reciprocating motion of said piston to rotation of the power output shaft;
• (d) a thermal regenerator inside the cylinder between the cylinder head and the piston, capable of being moved in predetermined cyclic reciprocating motion along the axis of the cylinder and comprising a permeable core and other structure to absorb heat from the hot combustion gases when moved in one direction, and to transfer the absorbed heat to the cool fresh air when moved in the opposite direction;
• (e) a third means for imparting a predetermined periodic motion to said thermal regenerator;
• (f) an injection means for injecting combustible fuel into the cylinder;
• and (g) an ignition means for igniting the mixture of said air and said fuel in the cylinder;
• the regenerator in which the permeable core comprises a large number of granules of refractory metal or ceramic which have been closely packed together and which may be sintered or otherwise bonded together to form a cohesive porous body.

In a thermally regenerated reciprocating cyclic internal combustion engine having a rotating power output shaft composed of a number of similar working units, each working unit comprising (a) a cylinder closed at one end by a cylinder head, with a number of intake valves to draw cool fresh air into the cylinder, and with a number of exhaust valves to exhaust the spent combustion gases from the cylinder;

• (b) a first means for opening and closing said intake valves and exhaust valves in a predetermined manner once in each engine cycle;
• (c) a piston inside the cylinder moving along the axis of the cylinder in a reciprocating manner toward and away from the cylinder head between the top dead center position closest to the cylinder head and the bottom dead center position furthest away from the cylinder head, said piston being connected by a second means to the power output shaft, where said second means translates the reciprocating motion of said piston to rotation of the power output shaft;
• (d) a thermal regenerator inside the cylinder between the cylinder head and the piston, capable of being moved in predetermined cyclic reciprocating motion along the axis of the cylinder and comprising a permeable core and other structure to absorb heat from the hot combustion gases when moved in one direction, and to transfer the absorbed heat to the cool fresh air when moved in the opposite direction;
• (e) a third means for imparting a predetermined periodic motion to said thermal regenerator;
• (f) an injection means for injecting combustible fuel into the cylinder;
• and (g) an ignition means for igniting the mixture of said air and said fuel in the cylinder;
• the regenerator in which the permeable core comprises stacked or wound sheets of refractory metal foil, which have been embossed or otherwise shaped to form axial gas flow passages.

In a thermally regenerated reciprocating cyclic internal combustion engine having a rotating power output shaft composed of a number of similar working units, each working unit comprising (a) a cylinder closed at one end by a cylinder head, with a number of intake valves to draw cool fresh air into the cylinder, and with a number of exhaust valves to exhaust the spent combustion gases from the cylinder;

• (b) a first means for opening and closing said intake valves and exhaust valves in a predetermined manner once in each engine cycle;
• (c) a piston inside the cylinder moving along the axis of the cylinder in a reciprocating manner toward and away from the cylinder head between the top dead center position closest to the cylinder head and the bottom dead center position furthest away from the cylinder head, said piston being connected by a second means to the power output shaft, where said second means translates the reciprocating motion of said piston to rotation of the power output shaft;
• (d) a thermal regenerator inside the cylinder between the cylinder head and the piston, capable of being moved in predetermined cyclic reciprocating motion along the axis of the cylinder and comprising a permeable core and other structure to absorb heat from the hot combustion gases when moved in one direction, and to transfer the absorbed heat to the cool fresh air when moved in the opposite direction;
• (e) a third means for imparting a predetermined periodic motion to said thermal regenerator;
• (f) an injection means for injecting combustible fuel into the cylinder;
• and (g) an ignition means for igniting the mixture of said air and said fuel in the cylinder;
• the regenerator in which the permeable core comprises a monolithic body of high temperature resistant metal or ceramic provided with multiple perforations.

In a thermally regenerated reciprocating cyclic internal combustion engine having a rotating power output shaft composed of a number of similar working units, each working unit comprising (a) a cylinder closed at one end by a cylinder head, with a number of intake valves to draw cool fresh air into the cylinder, and with a number of exhaust valves to exhaust the spent combustion gases from the cylinder;

• (b) a first means for opening and closing said intake valves and exhaust valves in a predetermined manner once in each engine cycle;
• (c) a piston inside the cylinder moving along the axis of the cylinder in a reciprocating manner toward and away from the cylinder head between the top dead center position closest to the cylinder head and the bottom dead center position furthest away from the cylinder head, said piston being connected by a second means to the power output shaft, where said second means translates the reciprocating motion of said piston to rotation of the power output shaft;
• (d) a thermal regenerator inside the cylinder between the cylinder head and the piston, capable of being moved in predetermined cyclic reciprocating motion along the axis of the cylinder and comprising a permeable core and other structure to absorb heat from the hot combustion gases when moved in one direction, and to transfer the absorbed heat to the cool fresh air when moved in the opposite direction;
• (e) a third means for imparting a predetermined periodic motion to said thermal regenerator;
• (f) an injection means for injecting combustible fuel into the cylinder;
• and (g) an ignition means for igniting the mixture of said air and said fuel in the cylinder;
• the regenerator in which the permeable core comprises layers of felt composed of high temperature resistant ceramic fibers.

In a thermally regenerated reciprocating cyclic internal combustion engine having a rotating power output shaft composed of a number of similar working units, each working unit comprising (a) a cylinder closed at one end by a cylinder head, with a number of intake valves to draw cool fresh air into the cylinder, and with a number of exhaust valves to exhaust the spent combustion gases from the cylinder;

• (b) a first means for opening and closing said intake valves and exhaust valves in a predetermined manner once in each engine cycle;
• (c) a piston inside the cylinder moving along the axis of the cylinder in a reciprocating manner toward and away from the cylinder head between the top dead center position closest to the cylinder head and the bottom dead center position furthest away from the cylinder head, said piston being connected by a second means to the power output shaft, where said second means translates the reciprocating motion of said piston to rotation of the power output shaft;
• (d) a thermal regenerator inside the cylinder between the cylinder head and the piston, capable of being moved in predetermined cyclic reciprocating motion along the axis of the cylinder and comprising a permeable core and other structure to absorb heat from the hot combustion gases when moved in one direction, and to transfer the absorbed heat to the cool fresh air when moved in the opposite direction;
• (e) a third means for imparting a predetermined periodic motion to said thermal regenerator;
• (f) an injection means for injecting combustible fuel into the cylinder;
• and (g) an ignition means for igniting the mixture of said air and said fuel in the cylinder;
• the regenerator in which the permeable core is an axially perforated ceramic board composed of ceramic fiber felts sintered together by heat with the possible addition of colloidal ceramic binders.

In a thermally regenerated reciprocating cyclic internal combustion engine having a rotating power output shaft composed of a number of similar working units, each working unit comprising (a) a cylinder closed at one end by a cylinder head, with a number of intake valves to draw cool fresh air into the cylinder, and with a number of exhaust valves to exhaust the spent combustion gases from the cylinder;

• (b) a first means for opening and closing said intake valves and exhaust valves in a predetermined manner once in each engine cycle;
• (c) a piston inside the cylinder moving along the axis of the cylinder in a reciprocating manner toward and away from the cylinder head between the top dead center position closest to the cylinder head and the bottom dead center position furthest away from the cylinder head, said piston being connected by a second means to the power output shaft, where said second means translates the reciprocating motion of said piston to rotation of the power output shaft;
• (d) a thermal regenerator inside the cylinder between the cylinder head and the piston, capable of being moved in predetermined cyclic reciprocating motion along the axis of the cylinder and comprising a permeable core and other structure to absorb heat from the hot combustion gases when moved in one direction, and to transfer the absorbed heat to the cool fresh air when moved in the opposite direction;
• (e) a third means for imparting a predetermined periodic motion to said thermal regenerator;
• (f) an injection means for injecting combustible fuel into the cylinder;
• and (g) an ignition means for igniting the mixture of said air and said fuel in the cylinder;
• the regenerator in which the permeable core comprises inner surfaces with catalytic activity, such as deposited selected metal oxides to burn off any fuel or lubricant residues which might deposit in the pores.