Two-stroke diesel engine

• US 6,182,619 B1
• Filed: 12/24/1998
• Issued: 02/06/2001
• Est. Priority Date: 12/24/1998
• Status: Expired due to Term

• Current Assignee: General Atomics Aeronautical Systems Incorporated (General Atomic Technologies Corporation)
• Original Assignee: General Atomics Aeronautical Systems Incorporated (General Atomic Technologies Corporation)
• Inventors: Spitzer, Jeffrey J., Manzke, Clifford A.
• Primary Examiner(s): Kwon, John
• Application Number:
  US09/219,964
• Time in Patent Office: 775 Days
• Field of Search: 123/51.B, 123/51.BD, 123/51.BA, 123/193.5
• US Class Current: 123/51.00B
• CPC Class Codes: F01P 2003/021 Cooling cylinders
• CPC Class Codes: F02B 2075/025 two
• CPC Class Codes: F02B 2275/14 Direct injection into combustion chamber
• CPC Class Codes: F02B 25/08 Engines with oppositely-moving reciprocating working pistons
• 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 75/282 the pistons having equal strokes
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A two-stroke, opposed piston, diesel engine is provided herein. The engine includes a thermal shield and a fluid gap which surround the exhaust ports to shield the engine block from an exhaust fluid from the cylinder assembly. Additionally, a cooling fluid is transferred to a plurality of helical shaped passageways which encircles the cylinder housing. These features allow the engine to operate at a cooler temperature and allow for more uniform cooling of the engine. Preferably, the engine also includes a first injector which injects a combustion fluid into the cylinder chamber between the pistons in the same direction as a swirl created within the cylinder chamber. This increases the distribution of the combustion fluid in the cylinder chamber and enhances the efficiency of the engine.

Claims

1. A diesel engine comprising:

a tubular cylinder housing including a cylinder wall which at least partly defines a cylinder chamber, the cylinder housing having an exhaust port which extends through the cylinder wall, the exhaust port being adapted to release exhaust fluid from the cylinder chamber;

first and second opposed pistons which are adapted to move within the cylinder chamber;

an engine block which at least partly encircles the cylinder housing proximate the exhaust port; and

a thermal shield positioned substantially between the exhaust port and the engine block to thermally shield the engine block from the exhaust fluid.

2. The diesel engine of claim 1 including a fluid gap positioned between the exhaust port and the engine block to reduce heat transfer to the engine block.

3. The diesel engine of claim 2 wherein the fluid gap is positioned between the thermal shield and the engine block.

4. The diesel engine of claim 1 wherein the cylinder housing includes a plurality of exhaust ports and the thermal shield substantially encircles the cylinder housing and the exhaust ports, the thermal shield being positioned between substantially all of the exhaust ports and the engine block to thermally shield the engine block from the exhaust fluid.

5. The diesel engine of claim 1 including a cooling passageway having a substantially annular, cooling section which substantially encircles the cylinder housing and a coolant inlet which is adapted for delivering a cooling fluid substantially tangential to the cooling section.

6. The diesel engine of claim 5 wherein the cooling section includes a cooling outlet which is adapted to receive the cooling fluid substantially tangential to the cooling section.

7. The diesel engine of claim 1 including a cooling passageway having a plurality of helical shaped passageways which substantially encircle at least a portion of the cylinder housing.

8. An engine which is adapted to be cooled by a cooling fluid, the engine comprising:

a tubular cylinder housing defining a cylinder chamber, said cylinder housing including a plurality of exhaust ports which are adapted for releasing an exhaust fluid;

an engine block which at least partly encircles the cylinder housing proximate the exhaust ports;

a thermal shield positioned substantially between at least one of the exhaust ports and the engine block to thermally shield the engine block from the exhaust fluid; and

a cooling passageway including a substantially annular cooling section which substantially encircles the cylinder housing and a cooling inlet which is adapted for delivering the cooling fluid substantially tangential to the cooling section.

9. The engine of claim 8 wherein the cooling passageway includes at least one helical shaped passageway which substantially encircles at least a portion of the cylinder housing and is in fluid communication with the cooling fluid.

10. The engine of claim 9 wherein the helical shaped passageway includes a groove in a housing outer surface of the cylinder housing.

11. The engine of claim 9 including a plurality of helical shaped passageways which substantially encircle the cylinder housing, the plurality of helical shaped passageways being in fluid communication with the cooling fluid.

12. The diesel engine of claim 8 wherein the cooling section passageway includes a cooling outlet which is adapted to receive the cooling fluid substantially tangential to the cooling section.

13. The engine of claim 8 including a fluid gap positioned between the thermal shield and the engine block to reduce heat transfer from the exhaust ports to the engine block.

14. A two-stroke engine which is powered by a combustion fluid, the engine comprising:

a tubular cylinder housing having a cylinder wall defining a cylinder chamber;

a pair of pistons positioned within the cylinder, the pistons being adapted to move between a first position in which the pistons are spaced apart and a second position in which the pistons are proximate each other, movement of the pistons between the first position and the second position being accompanied by a swirl in the cylinder chamber in a swirl direction; and

a first injector which is adapted to inject the combustion fluid into the cylinder chamber between the pistons, the first injector being adapted to direct the combustion fluid in the cylinder chamber in substantially the swirl direction.

15. The engine of claim 14 wherein the first injector is adapted to direct the combustion fluid at between approximately a thirty degree (30°

) angle and a eighty degree (80°

) angle relative to a tangent of the cylinder housing at where the first injector enters the cylinder housing.

16. The engine of claim 14 wherein the first injector comprises a first hole and a second hold wherein the first hole is adapted to direct the combustion fluid at approximately a sixty degree (60°

) angle and wherein the second hole is adapted to direct the combustion fluid at approximately an eighty degree (80°

) angle relative to a tangent of the cylinder housing at where the first injector enters the cylinder housing.

17. The engine of claim 14 including a second injector positioned substantially opposite from the first injector in the cylinder housing, the second injector being adapted to direct the combustion fluid into the cylinder chamber in substantially the swirl direction.

18. A two-stroke cycle diesel engine comprising:

an engine block;

a tubular cylinder housing positioned within the engine block and including a cylinder wall which at least partly defines a cylinder chamber, the cylinder housing having a plurality of exhaust ports which extend through the cylinder wall to release exhaust fluid from the cylinder chamber;

a pair of opposed pistons positioned within the cylinder housing, the pistons being adapted to move between a first position in which the pistons are spaced apart and a second position in which the pistons are proximate each other, movement of the pistons between the first position and the second position being accompanied by a swirl in the cylinder chamber in a swirl direction;

a first injector which is adapted to inject the combustion fluid into the cylinder chamber between the pistons, the first injector is adapted to direct the combustion fluid in the cylinder chamber towards the swirl direction;

a thermal shield positioned between the exhaust ports and the engine block to thermally shield the engine block from the exhaust fluid;

a fluid gap positioned between the thermal shield and the engine block to thermally shield the engine block and reduce heat transfer between the exhaust fluid and the engine block; and

a cooling passageway including a substantially annular cooling section which substantially encircles the cylinder housing and a coolant inlet which is adapted for delivering a cooling fluid substantially tangential to the cooling section.

19. The diesel engine of claim 18 wherein the cooling passageway includes a plurality of helical shaped passageways which substantially encircle at least a portion of the cylinder housing, the helical shaped passageways being in fluid communication with the cooling fluid.

20. The diesel engine of claim 18 wherein the cooling section includes a cooling outlet which is adapted to receive the cooling fluid substantially tangential to the cooling section.