# US 4,392,351 A · Multi-cylinder stirling engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,392,351 A - Document ID: US4392351A - Status: Granted - Kind: A - Application number: 06/124,518 - Filed: 1980-02-25 - Granted: 1983-07-12 - Earliest claimed: 1980-02-25 - Inventors: George J. Doundoulakis - Web page: https://patentgrep.com/patent/US4392351A ## CPC - F02G 1/057: Regenerators - F01C 11/004: {and of complementary function, e.g. internal combustion engine with supercharger} - F02G 1/0435: {the engine being of the free piston type} - F02B 1/04: with fuel-air mixture admission into cylinder - F02G 2254/30: using solar radiation - F02G: HOT GAS OR COMBUSTION-PRODUCT POSITIVE-DISPLACEMENT ENGINE PLANTS (steam engine plants, special vapour plants, plants operating on either hot gas or combustion-product gases together with other fluid F01K; gas-turbine plants F02C; jet-propulsion plants F02K); USE OF WASTE HEAT OF COMBUSTION ENGINES; NOT OTHERWISE PROVIDED FOR - F01C: ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES (internal-combustion aspects F02B53/00, F02B55/00) - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) ## Abstract A multi-cylinder Stirling engine comprises a stationary casing, working fluid, at least one heat source, a first heat exchanger for carrying the working fluid and for transferring heat from the heat source to the working fluid thereby raising the working fluid's temperature, and an output shaft rotatably supported by the stationary casing, which provides reaction surface members in at least one chamber where the working fluid is allowed to expand as the reaction members are allowed to move with respect to the casing. A bi-directional flow regenerator with two chambers, a second heat exchanger for further lowering the temperature of the working fluid to a predetermined temperature, and a compression device for returning the relatively cool and therefore dense working fluid back into the first heat exchanger at a lower expense of work are provided. The casing output shaft with reaction members, expansion chamber and compression device have a rotary engine configuration. This engine configuration operably providing eight power strokes per revolution, thereby greatly increasing the power output of the engine over conventional Stirling engines. ## Claims ### Claim 1 A multi-cylinder stirling cycle engine comprising: heater means for heating a working fluid to a working temperature; a high temperature heat exchanger associated with said heater means for carrying the working fluid past said heater means to bring the working fluid to the working temperature; rotary expansion chamber means having an input connected to said high temperature heat exchanger for receiving the working fluid at the working temperature and reducing the temperature thereof to produce work; a bidirectional regenerator connected to an output of said rotary expansion chamber means for carrying the working fluid in a first path and further reducing the temperature thereof; a low temperature heat exchanger connected to said regenerator for receiving the working fluid and still further reducing the temperature thereof; rotary compressor chamber means connected to said low temperature heat exchanger for receiving the working fluid from said low temperature heat exchanger and compressing it to a working pressure, said rotary compressor chamber means having an output connected to said regenerator; said regenerator receiving the working fluid from said compressor means output and carrying it in a second path in counter current flow relationship with said first path to heat the working fluid from said compressor means and cool the working fluid from said rotary expansion chamber means; said high temperature heat exchanger connected to said regenerator for receiving the heated working fluid; said rotary expansion chamber means being connected to said rotary compressor chamber means, said rotary expansion chamber means and said rotary compressor chamber means having a common rotating shaft on which the work produced is applied and, said regenerator comprising an insulating housing, a heat conductive dividing wall extending in said insulating housing dividing said housing into first and second parallel passages, and a plurality of heat conducting fins extending normally from said dividing wall forming said first and said second parallel passages, the working fluid moving in said first passage in said first path and in said second passage in said second path. ### Claim 2 (depends on 1) An engine according to claim 1 wherein said bidirectional regenerator comprises at least one straight section and at least one bend section connected to said straight section. ### Claim 3 (depends on 2) An engine according to claim 2 wherein said bend section comprises a Y-plane bend section, said regenerator including at least one additional X-plane bend section interconnecting said straight section with at least one additional straight section whereby a plurality of said straight sections can be stacked. ### Claim 4 (depends on 1) An engine according to claim 1 wherein said wall and fins comprise separate wall and fins structures which are interconnectable with each other. ### Claim 5 (depends on 1) A multi-cylinder stirling cycle engine according to claim 1 wherein said fins extending normally from said dividing wall extend parallel to the directional flow of said bidirectional regenerator. ### Claim 6 (depends on 1) A multi-cylinder stirling cycle engine according to claim 1 wherein said fins extending normally from said dividing wall extend normally to the directional flow of said regenerator and wherein said fins including a plurality of apertures therethrough for the passage of the working fluid.