Internal combustion engine

• US 4,565,165 A
• Filed: 07/23/1984
• Issued: 01/21/1986
• Est. Priority Date: 02/17/1984
• Status: Expired due to Fees

• Current Assignee: John P.S. Papanicolaou
• Original Assignee: John P.S. Papanicolaou
• Inventors: Papanicolaou, John P. S.
• Primary Examiner(s): Feinberg, Craig R.
• Application Number:
  US06/633,199
• Time in Patent Office: 547 Days
• Field of Search: 123/58 R, 123/58 A, 123/58 AA, 123/58 AM, 123/51 R, 123/51 B, 123/51 BA
• US Class Current: 123/51.0BA
• CPC Class Codes: F01B 3/045 by two or more curved surfaces, e.g. for two or more pistons in one cylinder
• CPC Class Codes: F02B 2075/025 two
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02B 41/04 in main cylinders
• CPC Class Codes: F02B 75/26 Engines with cylinder axes coaxial with, or parallel or inclined to, main-shaft axis; Engines with cylinder axes arranged substantially tangentially to a circle centred on main-shaft axis
• CPC Class Codes: F02B 75/28 Engines with two or more pistons reciprocating within same cylinder or within essentially coaxial cylinders arranged oppositely relative to main shaft F02B75/24

Abstract

A hyper-expansion internal combustion engine operable using a cycle having expansion, exhaust, intake and compression phases comprising at least one pair of opposed pistons which reciprocate in cylinder portions which are in fluid communication with each other via a common combustion chamber, the pistons being coupled to respective cam elements engaged with a common output shaft for converting the reciprocating motion of the pistons into rotational motion, the cylinder portions having intake and exhaust ports in the cylinder walls arranged such that each intake port is engaged by one piston and each exhaust port is engaged by the respective opposed piston; and the cam elements are provided with different cam profiles which are arranged to cause the respective pistons to uncover the respective exhaust and inlet ports so as to produce a sufficient increase in the effective volume of the expansion phase with respect to the intake phase to give hyper-expansion.

Claims

1. In an internal combustion engine operable using a cycle having expansion, exhaust, intake and compression phases, which engine comprises at least one pair of opposed pistons which reciprocate in cylinder portions which are in fluid communication with each other via a common combustion chamber, the pistons being coupled to respective cam elements engaged with a common output shaft for converting the reciprocating motion of the pistons into rotational motion, and the cylinder portions having intake and exhaust ports in the cylinder walls arranged such that each intake port is engaged by one piston and each exhaust port is engaged by the respective opposed piston;

the improvement comprising that the cam elements are provided with different cam profiles profiled at least along those cam portions proceeding the closing of the intake port to cause the respective pistons to uncover the respective exhaust and inlet ports in a timed sequence such that an exhaust stroke length formed between the opposed pistons when the exhaust port is initially opened, is longer than an intake stroke length formed between the opposed pistons when the inlet port is closed, at which time the exhaust port engaging piston has moved from the exhaust port by an amount of at least 10% of a distance from the exhaust port to the center of the common combustion chamber at ignition to produce a sufficient increase in effective volume of the expansion phase with respect to the intake phase to give hyper-expansion.

2. A multiple engine which comprises a least two component engines as claimed in claim 1, a pair of such component engines being positioned in one out of a group of in line, back to back and side by side.

3. An engine as claimed in claim 1 or 2 wherein the exhaust and intake phases overlap to form an idle phase in which both exhaust and intake ports are open.

4. An engine as claimed in claim 1 or 2 wherein a single cylinder forms each respective pair of cylinder portions.

10. An engine as claimed in claim 1 or 5 wherein the cycle is completed during a single reciprocation of each respective piston.

11. An engine as claimed in claim 1 or 5 wherein the cycle is completed in 180 degrees of cam element rotation.

12. An engine as claimed in claim 1 or 5 wherein the cycle is completed in 120°

of cam element rotation.

13. An engine as claimed in claim 1 or 5 wherein the cycle is completed in 90°

or less of cam element rotation.

14. An engine as claimed in claim 1 or 5 wherein, at closure of the intake port by the intake piston, the opposed piston is spaced from the corresponding exhaust port towards the center of the common combustion chamber by at least 10% of the distance between the exhaust port closure position of the exhaust piston and the center of the common combustion chamber.

15. An engine as claimed in claim 14 wherein the opposed piston is spaced by not more than essentially 100% of said distance.

16. An engine as claimed in claim 1 or 5 wherein the cam profile engaged by the exhaust port engaging piston is adjustable by movement of a portion of the cam element relative to the remainder of that cam element enabling an adjustable degree of asymmetricity with respect to the cam profile engaged by the intake position and thereby an adjustable degree of hyper-expansion during running of the engine.

17. An engine as claimed in claim 16 wherein said cam element portion is pivotable attached to said remainder of the cam element.

18. An engine as claimed in claim 16 wherein in one position of the adjustable cam profile the reciprocal movements of the respective pistons are substantially identical, and in another position, the respective pistons uncover the respective exhaust and inlet ports so as to produce a sufficient increase in the effective volume of the expansion phase with respect to the intake phase to give hyper-expansion.

19. An engine as claimed in claim 1 or 5 wherein at least one of the cam elements has an adjustable cam profile.

20. An engine as claimed in claim 19 wherein said adjustable cam profile is adjustable during movement of the engine.

21. An engine as claimed in claim 19 wherein the cam profile is adjustable by movement of a portion of the cam element relative to the remainder of the cam element.

22. An engine as claimed in claim 21 wherein said cam element portion is pivotably attached to said remainder of the cam element.

23. An engine as claimed in claim 21 wherein the cam element has first and second profiles, the second profile including said cam element portion.

24. An engine as claimed in claim 23 wherein the first and second cam profiles are different only at said cam element portion.

25. An engine as claimed in claim 1 or 5 wherein the combustion chamber is provided with fuel injection means and is supplied with pressurized air through the respective intake ports.

26. An engine as claimed in claim 25 wherein said pressurized air is provided by a positive displacement pump.

27. An engine as claimed in claim 25 wherein the pressure of said pressurized air is adjusted in accordance with setting of a throttle means.

28. An engine as claimed in claim 25 wherein said pressurized air is provided by respective stuffing boxes engaged with respective intake pistons.

29. An engine as claimed in claim 25 wherein said pressurised air is provided by a supercharger.

30. An engine as claimed in claim 29 wherein a pressurized air reservoir is provided between the supercharger and said intake ports.

5. A hyper-expansion internal combustion engine, operable using a cycle having expansion, exhaust, intake and compression phases, which engine comprises at least one pair of opposed pistons which reciprocate in connecting cylinder portions having a common combustion chamber, the pistons being coupled to respective cam elements engaged with a common output shaft for converting the reciprocating motion of the pistons into rotational motion, the connecting cylinder portions having an intake and an exhaust port, each port being engaged by a respective opposed piston which controls flow through the port;

the cam elements being provided with cam profiles which are asymmetric to an extent greater than that required for full exhaust and intake port opening and closing such that a ratio of expansion volume when the exhaust port opens to compression volume when the intake port closes is at a value not less than 1.14;

1.

6. An engine as claimed in claim 5 wherein the cam profiles are asymmetric over a cam arc including the whole of the intake phase and at least part of the compression phase.

7. An engine as claimed in claim 5 wherein the cam profiles are asymmetric over a cam arc including substantially the whole of the intake and compression phases.

8. An engine as claimed in claim 5 wherein the cam profiles are asymmetric over a cam arc inclusive of bottom dead centre positions and extending to the full compression position.

9. An engine as claimed in claim 5, 6, 7 or 8 wherein the cycle has an idle phase in which both exhaust and intake ports are open.