Compound cycle engine

Patent metadata

Field	Value
Publication number	US-10968824-B2
Application number	US-201816156183-A
Country	US
Kind code	B2
Filing date	Oct 10, 2018
Priority date	Jul 20, 2012
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

A compound cycle engine having an output shaft; at least two rotary units each defining an internal combustion engine, a first stage turbine, and a turbocharger is discussed. The first stage turbine includes a rotor in driving engagement with the output shaft between two of the rotary units. The exhaust port of each rotary unit is in fluid communication with the flowpath of the first stage turbine upstream of its rotor. The outlet of the compressor of the turbocharger is in fluid communication with the inlet port of each rotary unit. The inlet of the second stage turbine of the turbocharger is in fluid communication with the flowpath of the first stage turbine downstream of its rotor. The first stage turbine has a lower reaction ratio than that of the second stage turbine. A method of compounding at least two rotary engines is also discussed.

First claim

The invention claimed is:

1. A compound cycle engine comprising:
at least one fuel injector;
an output shaft;
a plurality of rotary engines drivingly engaged to the output shaft, each of the plurality of the rotary engines having at least one igniter for combusting air fuel mixture in a combustion chamber, an intake port for admitting compressed air, and an exhaust port for discharging exhaust pulses to a turbine;
wherein the turbine includes a plurality of turbine inlets;
wherein each of the plurality of the turbine inlets, wherein each of the plurality of the turbine inlets fluidly communicates with a respective exhaust port of the plurality of the rotary engines; and
wherein the turbine is drivingly engaged with the output shaft through a transmission;
wherein the transmission is positioned between a first one and a second one of the rotary engines along the output shaft extending through the turbine and the plurality of the rotary engines.

2. The compound cycle engine as defined in claim 1 , wherein the plurality of the rotary engines and the turbine are disposed in an alternating sequence along a longitudinal axis of the compound cycle engine.

3. The compound cycle engine as defined in claim 1 , wherein the turbine is mounted co-axially with the plurality of the rotary engines.

4. The compound cycle engine as defined in claim 1 , wherein each of the plurality of the rotary engines includes a housing; wherein the housing of said each of the plurality of the rotary engines is angularly offset at 180° from one to another.

5. The compound cycle engine as defined in claim 1 , further comprising a turbocharger including a compressor and a turbocharger turbine, the compressor including a compressor rotor and having an outlet in fluid communication with the intake ports of the plurality of the rotary engines, the turbocharger turbine drivingly engaged to the compressor rotor via a turbocharger shaft.

6. The compound cycle engine as defined in claim 5 , wherein the turbocharger turbine is located downstream of the turbine, an outlet of the turbine being in fluid communication with an inlet of the turbocharger turbine.

7. The compound cycle engine as defined in claim 5 , wherein a reaction ratio of the turbine is lower than a reaction ratio of the turbocharger turbine.

8. The compound cycle engine as defined in claim 7 , wherein the reaction ratio of the turbine is a pressure-based reaction ratio having a value of at most 0.15 and the turbocharger turbine has a pressure-based reaction ratio having a value of at least 0.25.

9. The compound cycle engine as defined in claim 5 , wherein the turbocharger turbine is drivingly engaged to the output shaft.

10. The compound cycle engine as defined in claim 5 , wherein the turbocharger and the plurality of the rotary engines are coaxial.

11. The compound cycle engine as defined in claim 1 ,
wherein said each of the plurality of the rotary engines has an engine rotor; and
wherein the output shaft has an eccentric portion engaged respectively to the engine rotor of said each of the plurality of the rotary engines; and
wherein the eccentric portion respectively to the engine rotor of said each of the plurality of the rotary engines of the output shaft is angularly offset at 180° from one to another.

12. The compound cycle engine as defined in claim 1 ,
wherein said each of the plurality of the rotary engines has an engine rotor; and
wherein the output shaft has an eccentric portion engaged respectively to the engine rotor of said each of the plurality of the rotary engines;
wherein the eccentric portion respectively to the engine rotor of said each of the plurality of the rotary engines of the output shaft is angularly offset at 120° from one to another.

13. The compound cycle engine as defined in claim 1 ,
wherein said each of the plurality of the rotary engines has an engine rotor; and
wherein the output shaft has an eccentric portion engaged respectively to the engine rotor of said each of the plurality of the rotary engines;
wherein the eccentric portion respectively to the engine rotor of said each of the plurality of the rotary engines of the output shaft is angularly offset at 90° from one to another.

14. The compound cycle engine as defined in claim 1 ,
wherein the plurality of the turbine inlets is disposed relatively to one to another on a circumferential surface of the turbine; and
wherein the plurality of the turbine inlets is space apart in a circumferential direction relatively to one to another.

15. The compound cycle engine as defined in claim 14 ,
wherein the exhaust ports of the plurality of the rotary engines are fluidly connected to the turbine via a plurality of exhaust pipes extending separately from each another;
wherein a first one of the exhaust pipes connects to the exhaust port of the first one of the plurality of the rotary engines and extends to a first one of the plurality of the turbine inlets;
wherein a second one of the exhaust pipes connects to the exhaust port of the second one of the plurality of the rotary engines and extends to a second one of the plurality of the turbine inlets; and
wherein each of the first one and second one of the exhaust pipes connects respectively to the first one and second one of the plurality of the turbine inlets.

16. The compound cycle engine as defined in claim 15 , wherein the first and second ones of the exhaust pipes have a main portion extending axially along a longitudinal axis of the compound cycle engine.

17. The compound cycle engine as defined in claim 15 , wherein the exhaust port of the first one of the plurality of the rotary engines and the first one of the exhaust pipes and the exhaust port of the second one of the plurality of the rotary engines and the second one of the exhaust pipes are located on opposite sides of the compound cycle engine.

18. The compound cycle engine as defined in claim 14 , wherein the first one of the plurality of the rotary engines is located on an upstream side of the turbine and the second one of the plurality of the rotary engines is located on the downstream side of the turbine.

19. A compound cycle engine comprising:
a plurality of internal combustion engines;
wherein each of the plurality of the internal combustion engines includes:
a housing defining at least one combustion chamber of variable volume;
intake ports connected to inlet pipes for admitting compressed air;
exhaust ports for discharging an exhaust gas to a turbine;
at least one fuel injector;
at least one igniter for combusting an air fuel mixture in the at least one combustion chamber; and

an output shaft drivingly engaging to the plurality of the internal combustion engines;
wherein the turbine includes a plurality of turbine inlets;
wherein a number of the plurality of the turbine inlets is equal to a number of the plurality of the internal combustion engines in the compound cycle engine;
wherein each of the plurality of the turbine inlets fluidly communicates with a respective one of the exhaust ports of the plurality of the internal combustion engines;
wherein the plurality of the turbine inlets is disposed relatively to one to another on a circumferential surface of the turbine;
wherein the plurality of the turbine inlets is space apart in a circumferential direction relatively to one to another;
wherein the turbine is drivingly engaged with the output shaft through a transmission; and
wherein the transmission is positioned between a first one and a second one of the pl

Assignees

• Pratt & Whitney Canada

Inventors

• Bolduc Sebastien
• Fontaine Mike
• Landry Luc
• Thomassin Jean

Classifications

• F04C2240/30

  Casings or housings · CPC title

• F02C6/12 Primary

  Turbochargers, i.e. plants for augmenting mechanical power output of internal-combustion piston engines by increase of charge pressure · CPC title

• F02B41/10

  in exhaust turbines (use of exhaust turbines for charging F02B37/00) · CPC title

• F01C1/22

  of internal-axis type with equidirectional movement of co-operating members at the points of engagement, or with one of the co-operating members being stationary, the inner member having more teeth or tooth- equivalents than the outer member · CPC title

• Y02T10/12

  Improving ICE efficiencies · CPC title