Internal combustion engine

Patent metadata

Field	Value
Publication number	US-11118503-B2
Application number	US-201716488811-A
Country	US
Kind code	B2
Filing date	Mar 15, 2017
Priority date	Mar 15, 2017
Publication date	Sep 14, 2021
Grant date	Sep 14, 2021

Abstract

The invention relates to an internal combustion engine comprising a combustion cylinder housing a combustion piston, a compressor cylinder housing a compressor piston, an expander cylinder housing an expander piston, and a crankshaft connected to the combustion piston and the expander piston by a respective connecting rod. The internal combustion engine further comprises a connecting element rigidly connecting the compressor piston and the expander piston such that the compressor piston and the expander piston move in unison.

First claim

The invention claimed is:

1. An internal combustion engine comprising: at least one combustion cylinder housing a combustion piston, said combustion cylinder being configured to be energized by forces of combustion; a compressor cylinder housing a compressor piston, said compressor cylinder being configured to compress a volume of air and transfer the compressed air to the at least one combustion piston; an expander cylinder housing an expander piston, said expander cylinder being configured to receive exhaust gases from the at least one combustion piston; a crankshaft connected to said at least one combustion piston and said expander piston by a respective connecting rod, characterized in that the internal combustion engine further comprises a connecting element rigidly connecting said compressor piston and said expander piston such that the compressor piston and the expander piston move in unison.

2. An internal combustion engine according to claim 1 , wherein said compressor piston is connected to said crankshaft via said expander piston, such that a rotational motion of said crankshaft is transferred into a reciprocating motion of said compressor piston via the expander piston connecting rod.

3. An internal combustion engine according to claim 1 , wherein said crankshaft is driven by said at least one combustion piston by means of the combustion piston connecting rod, and is driven by said expander piston by means of said expander piston connecting rod, wherein said compressor piston is driven by said crankshaft by means of said expander piston.

4. An internal combustion engine according to claim 1 , wherein said expander piston has an expander piston height and an expander piston diameter, and wherein the expander piston height is smaller than ⅓ of the expander piston diameter.

5. An internal combustion engine according to claim 1 , wherein said compressor piston has a compressor piston height and a compressor piston diameter, and wherein the compressor piston height is smaller than ⅓ of the compressor piston diameter.

6. An internal combustion engine according to claim 1 , wherein at least a portion of said compressor piston, at least a portion of said expander piston and at least a portion of said connecting element together forms a compressor-expander arrangement surrounding a portion of said crankshaft.

7. An internal combustion engine according to claim 1 , wherein said expander piston has a circular cross section extending in a first geometrical plane, and said compressor piston has a circular cross section extending in a second geometrical plane, said first and second geometrical planes being positioned in a parallel configuration on opposite sides of a longitudinal axis of the crankshaft.

8. An internal combustion engine according to claim 1 , wherein said expander cylinder and said compressor cylinder are co-axially arranged.

9. An internal combustion engine according to claim 1 , wherein a reciprocating motion of said expander piston inside of said expander cylinder occurs along an expander axis, and a reciprocating motion of said at least one combustion piston inside said combustion cylinder occurs along a combustion axis, and wherein said expander cylinder and said at least one combustion cylinder is arranged inside said internal combustion engine in such way that said expander axis is angled in relation to said combustion axis by between 40 degrees and 90 degrees.

10. An internal combustion engine according to claim 1 , further comprising an expander piston sealing arrangement sealing said expander piston to an inner surface of said expander cylinder, and a compressor piston sealing arrangement sealing said compressor piston to an inner surface of said compressor cylinder, wherein said expander piston sealing arrangement is independent from said compressor piston sealing arrangement.

11. An internal combustion engine according to claim 10 , wherein said expander piston sealing arrangement comprises a liner, comprised in an inner surface of said expander cylinder, and at least one metal ring arranged circumferentially in an outer surface of said expander piston, and wherein said compressor piston sealing arrangement comprises a polished surface comprised in an inner surface of said compressor cylinder, and at least one non-metallic and/or polymeric ring arranged circumferentially in outer surface of said compressor piston.

12. An internal combustion engine according to claim 1 , wherein said at least one combustion cylinder is a first combustion cylinder and said combustion piston is a first combustion piston, and said internal combustion engine further comprises a second combustion cylinder housing a second combustion piston, said second combustion cylinder being configured to be energized by forces of combustion.

13. An internal combustion engine according to claim 12 , wherein said first and second combustion cylinders operate in a four-stroke configuration, and each one of said compressor and expander cylinders operate in a two-stroke configuration.

14. An internal combustion engine according to claim 12 , wherein said compressor cylinder is a first compressor cylinder and said compressor piston is a first compressor piston, said expander cylinder is a first expander cylinder and said expander piston is a first expander piston, and said connecting element is a first connecting element, said internal combustion engine further comprises: a third combustion cylinder and a fourth combustion cylinder housing a respective third and fourth combustion piston, said combustion cylinders being configured to be energized by forces of combustion; a second compressor cylinder housing a second compressor piston, said second compressor cylinder being configured to compress a volume of air and transfer the compressed air to the third and fourth combustion pistons; a second expander piston cylinder housing a second expander piston, said second expander cylinder being configured to receive exhaust gases from the third and fourth combustion pistons; a second connecting element rigidly connecting said second compressor piston and said second expander piston such that the second compressor piston and the second expander piston move in unison, wherein said crankshaft is connected to said third and fourth combustion pistons and said second expander piston by a respective connecting rod.

15. A vehicle comprising an internal combustion engine according to claim 1 .

16. An internal combustion engine according to claim 1 , wherein said expander piston has an expander piston height and an expander piston diameter, and wherein the expander piston height is smaller than smaller than 1/15 of the expander piston diameter.

17. An internal combustion engine according to claim 1 , wherein said compressor piston has a compressor piston height and a compressor piston diameter, and wherein the compressor piston height is smaller than 1/10 of the compressor piston diameter.

18. An internal combustion engine according to claim 1 , wherein a reciprocating motion of said expander piston inside of said expander cylinder occurs along an expander axis, and a reciprocating motion of said at least one combustion piston inside said combustion cylinder occurs along a combustion axis, and wherein said expander cylinder and said at least one combustion cylinder is arranged inside said internal combustion engine in such way that said expander axis is angled in relation to said combustion axis by between 55 degrees and 65 degrees.

Assignees

• Volvo Truck Corp

Inventors

• Andersson Arne
• Lundgren Staffan

Classifications

• F02B2710/025

  with measures for compressing the cylinder charge · CPC title

• F02B41/06 Primary

  in compound cylinders · CPC title

• F02B41/00 Primary

  Engines characterised by special means for improving conversion of heat or pressure energy into mechanical power · CPC title