Single shaft dual expansion internal combustion engine

Patent metadata

Field	Value
Publication number	US-9574491-B2
Application number	US-201514610393-A
Country	US
Kind code	B2
Filing date	Jan 30, 2015
Priority date	Jan 30, 2015
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A single-shaft dual expansion internal combustion engine includes first and second power cylinders and an expander cylinder. The cylinder head fluidly couples the first and second power cylinders and the expander cylinder. First and second power pistons reciprocate in the first and second power cylinders and connect to a first crankpin of the crankshaft. A multi-link connecting rod assembly includes a rigid main arm supporting a first pivot pin, a second pivot pin and a third pivot pin. The first pivot pin connects to an expander piston reciprocating in the third cylinder. The third pivot pin couples to a first end of a swing arm, and a second end of the swing arm rotatably couples to a fourth pivot pin that couples to a distal end of a rotating arm that attaches to a rotating shaft coupled to rotation of the crankshaft.

First claim

The invention claimed is:

1. A single-shaft dual expansion internal combustion engine, comprising: an engine block, a cylinder head, a single crankshaft and a multi-link connecting rod assembly; the engine block including first and second power cylinders and an expander cylinder; the cylinder head fluidly coupling the first and second power cylinders and the expander cylinder; first and second power pistons reciprocating in the first and second power cylinders, respectively, and connected to respective first and second crankpins of the crankshaft; the multi-link connecting rod assembly including a rigid main arm extending orthogonally to a longitudinal axis of the crankshaft and supporting a first pivot pin located on a first end of the main arm, a second pivot pin located on a central portion of the main arm and a third pivot pin located on a second end of the main arm; the first pivot pin coupled via a connecting rod to an expander piston reciprocating in the third cylinder; the second pivot pin coupled to a third crankpin of the crankshaft, the third crankpin having a throw that is rotated 180 degrees around the longitudinal axis of the crankshaft from a throw of the first and second crankpins; and the third pivot pin coupled to a first end of a swing arm, and a second end of the swing arm rotatably coupled to a fourth pivot pin that couples to a distal end of a rotating arm that attaches to a rotating shaft coupled to rotation of the crankshaft; wherein the first pivot in and the second pivot in of the multi-link connecting rod assembly define a first linear distance, the second pivot in and the third pivot in of the multi-link connecting rod assembly define a second linear distance, and wherein a magnitude of linear travel of the expander piston reciprocating in the third cylinder is defined based upon the first linear distance and the second linear distance.

2. The single-shaft dual expansion internal combustion engine of claim 1 , further comprising a phaser inserted between the rotating arm and the rotating shaft, the phaser effecting phasing control of the rotating arm in relation to the rotating shaft coupled to rotation of the crankshaft.

3. The single-shaft dual expansion internal combustion engine of claim 2 , wherein the expander piston reciprocates in the third cylinder at a maximum distance between TDC and BDC during each revolution when the phaser controls the rotating element to a first relative phasing, and the expander piston reciprocates in the third cylinder at a minimum distance between TDC and BDC during each revolution when the phaser controls the rotating element to a second relative phasing.

4. The single-shaft dual expansion internal combustion engine of claim 1 , wherein the first and second power pistons synchronously reciprocate in the first and second power cylinders, respectively, and the expander piston reciprocates in the expander cylinder 180° out of phase with the first and second power pistons.

5. The single-shaft dual expansion internal combustion engine of claim 1 , wherein the first pivot pin and the second pivot pin of the multi-link connecting rod assembly define a first linear distance, the second pivot pin and the third pivot pin of the multi-link connecting rod assembly define a second linear distance, and wherein a magnitude of linear travel of the expander piston reciprocating in the third cylinder is defined based upon the first linear distance, the second linear distance and a linear length of the swing arm connected between the third pivot pin and the engine block.

6. The single-shaft dual expansion internal combustion engine of claim 1 , wherein the first and second power cylinders and the expander cylinder have longitudinal center axes that are parallel, and wherein the longitudinal center axis of the expander cylinder is offset from a plane formed between the longitudinal center axes of the first and second power cylinders.

7. The single-shaft dual expansion internal combustion engine of claim 1 , wherein the cylinder head comprises a first exhaust port, a first exhaust runner and a first expander cylinder intake port fluidly connecting the first power cylinder to the expander cylinder and a second exhaust port, a second exhaust runner and a second expander cylinder intake port fluidly connecting the second power cylinder to the expander cylinder.

8. The single-shaft dual expansion internal combustion engine of claim 1 , wherein the first power cylinder operates in a four-stroke combustion cycle and the second power cylinder operates in a four-stroke combustion cycle.

9. The single-shaft dual expansion internal combustion engine of claim 7 , wherein the four-stroke combustion cycle of the first power stroke executes 360 rotational degrees out of phase with the four-stroke combustion cycle of the second power cylinder.

10. The single-shaft dual expansion internal combustion engine of claim 1 , wherein the expander cylinder operates in a two-stroke combustion cycle.

11. A single-shaft dual expansion internal combustion engine, comprising:
an engine block, a cylinder head, a single crankshaft and a multi-link connecting rod assembly;
the engine block including first and second power cylinders and an expander cylinder;
the cylinder head fluidly coupling the first and second power cylinders and the expander cylinder;
first and second power pistons reciprocating in the first and second power cylinders, respectively, and each connected to a first crankpin of the crankshaft;
the multi-link connecting rod assembly including a rigid main arm extending orthogonally to a longitudinal axis of the crankshaft and supporting a first pivot pin, a second pivot pin and a third pivot pin;
the third pivot pin coupled to a first end of a swing arm, and a second end of the swing arm rotatably coupled to a fourth pivot pin that couples to a distal end of a rotating arm; and
a phaser coupling the rotating arm to a rotating shaft coupled to rotation of the crankshaft;
wherein the phaser effects phasing control of the rotating arm in relation to the rotating shaft coupled to rotation of the crankshaft.

12. The single-shaft dual expansion internal combustion engine of claim 11 , wherein the expander piston reciprocates in the third cylinder at a maximum distance between TDC and BDC during each revolution when the phaser controls the rotating element to a first relative phasing, and the expander piston reciprocates in the third cylinder at a minimum distance between TDC and BDC during each revolution when the phaser controls the rotating element to a second relative phasing.

13. The single-shaft dual expansion internal combustion engine of claim 11 , wherein the first pivot pin and the second pivot pin of the multi-link connecting rod assembly define a first linear distance, the second pivot pin and the third pivot pin of the multi-link connecting rod assembly define a second linear distance, and wherein a magnitude of linear travel of the expander piston reciprocating in the third cylinder is defined based upon the first linear distance and the second linear distance.

14. The single-shaft dual expansion internal combustion engine of claim 11 , wherein the first and second power pistons synchronously reciprocate in the first and second power cylinders, respectively, and the expander piston reciprocates in the expander cylinder 180° out of phase with the first and second power pistons.

15. The single-shaft dual expansion internal combustion engine of claim 11 , wherein the first and second power cylinders and the expander cylinder have longitudinal center axes that are parallel, and wherein the longitudin

Assignees

• Gm Global Tech Operations Llc

Inventors

• Durrett Russell P
• Najt Paul M
• Andruskiewicz Peter
• Miller Steve
• Whiteside Ian
• Anstey Steve

Classifications

• F02B75/228

  with cylinders arranged in parallel banks · CPC title

• F02B75/18 Primary

  Multi-cylinder engines (scavenging aspects F02B25/00) · CPC title

• F02B2075/1812

  three · CPC title

• F02B41/06 Primary

  in compound cylinders · CPC title

• F02B75/12

  Other methods of operation · CPC title