US6185939B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exhaust gas recirculation system
Assignee: Caterpillar Inc
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Filing: 1999-03-22
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Granted: 2001-02-13
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Expires: 2019-03-22
Abstract
Abstract Past exhaust emission control systems fail to utilize exhaust gas recirculation during all operating parameters of an engine. The present exhaust gas recirculation system reduces the emissions emitted from an engine during all operating parameters of the engine. The engine includes a cylinder, a rotatable crankshaft and a turbocharger defining a compressor section compressing a flow of intake air to a first preestablished pressure and being driven by a flow of exhaust gas having a first preestablished pressure. The exhaust gas recirculation system is comprised of a portion of the flow of exhaust gas being recirculated to the cylinder and forming a flow of recirculated exhaust gas. The flow of recirculated exhaust gas is cooled. A portion of the flow of intake air is compressed to a second preestablished pressure. The flow of recirculated exhaust gas is compressed to a second preestablished pressure being at least as great as the first preestablished pressure of the intake air. And, a quantity of the flow of recirculated exhaust gas is controlled by a valve having an open position in which intake air flows therethrough and a closed position in which the flow of intake air is blocked.
Inventors
- 👤 Gerald N. Coleman
- 👤 Michael J. Evancik
- 👤 Dennis D. Feucht
- 👤 Keith E. Lawrence
- 👤 Jiubo Ma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:30
CPC Classifications
F; F02; F02B; F02B37/00; F02B29/00; F02B29/04; F02B29/0406; F02B29/0425; F02B29/0431; F02M; F02M26/00; F02M26/02; F02M26/04; F02M26/05; F02M26/13; F02M26/22; F02M26/23; F02M26/27; F02M26/34; F02M26/36; F02M26/38; F02M26/42; F02M26/43; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
232 words
An exhaust gas recirculation system for use with an engine, said engine defining a plurality of operating parameters, having a rotatable crankshaft through which an engine speed can be defined and a plurality of cylinders being defined as a part of the engine, said exhaust gas recirculation system comprising: a flow of intake air entering a respective one of said plurality of cylinders, said intake air being pressurized to a preestablished pressure; a supply of combustible fuel entering said respective one of said plurality of cylinders; a combustion process within said respective one of said plurality of cylinders defining a flow of exhaust gas having a preestablished pressure being less than said preestablished pressure of said intake air during at least a portion of said engine operating parameters; a portion of said exhaust gas being circulated to said intake air defining a flow of recirculated exhaust gas, said flow of recirculated exhaust gas being cooled prior to being pressurized to a preestablished level and said pressurization of said flow of recirculated exhaust gas being at least as great as said preestablished pressure of said intake air; and said flow of recirculated exhaust gas being controlled to vary a quantity of recirculated exhaust gas depending on said operating parameter of said engine, said flow of recirculated exhaust gas controlled to vary a quantity of recirculated exhaust gas being controlled by a proportional valve.
Claim 2
Dependent Claim
232 words
An exhaust gas recirculation system for use with an engine, said engine defining a plurality of operating parameters, having a rotatable crankshaft through which an engine speed can be defined and a plurality of cylinders being defined as a part of the engine, said exhaust gas recirculation system comprising: a flow of intake air entering a respective one of said plurality of cylinders, said intake air being pressurized to a preestablished pressure; a supply of combustible fuel entering said respective one of said plurality of cylinders; a combustion process within said respective one of said plurality of cylinders defining a flow of exhaust gas having a preestablished pressure being less than said preestablished pressure of said intake air during at least a portion of said engine operating parameters; a portion of said exhaust gas being circulated to said intake air defining a flow of recirculated exhaust gas, said flow of recirculated exhaust gas being cooled prior to being pressurized to a preestablished level and said pressurization of said flow of recirculated exhaust gas being at least as great as said preestablished pressure of said intake air; and said flow of recirculated exhaust gas being controlled to vary a quantity of recirculated exhaust gas depending on said operating parameter of said engine, said flow of recirculated exhaust gas controlled to vary a quantity of recirculated exhaust gas being controlled by a proportional valve.
Claim 3
Dependent Claim
31 words
The exhaust gas recirculation system of claim 1 wherein a portion of said intake air being further pressurized to a level being greater than said preestablished pressure of said intake air.
Claim 4
Dependent Claim
46 words
The exhaust gas recirculation system of claim 2 wherein said flow of recirculated exhaust gas being pressurized by a blower, said blower being driven at a speed being greater than said speed of said engine and said further pressurized intake air being pressurized by said blower.
Claim 5
Dependent Claim
16 words
The exhaust gas recirculation system of claim 3 wherein said blower being connected to said engine.
Claim 6
Dependent Claim
35 words
The exhaust gas recirculation system of claim 2 wherein said portion of said intake air being further pressurized being controlled by a valve, said valve being operable between an open position and a closed position.
Claim 7
Dependent Claim
43 words
The exhaust gas recirculation system of claim 5 wherein said valve being operable between said open position and said closed position through an infinite number of positions, as said infinite number of positions being operatively controlled by said operating parameters of said engine.
Claim 8
Dependent Claim
23 words
The exhaust gas recirculation system of claim 5 wherein said valve being in said open position defining a minimum flow of recirculated exhaust.
Claim 9
Dependent Claim
23 words
The exhaust gas recirculation system of claim 5 wherein said valve being in said closed position defining a maximum flow of recirculated exhaust.
Claim 10
Dependent Claim
24 words
The exhaust gas recirculation system of claim 1 wherein said flow of recirculated exhaust gas is being cooled by an air to air cooler.
Claim 11
Dependent Claim
29 words
The exhaust gas recirculation system of claim 1 wherein said flow of recirculated exhaust gas controlled to vary a quantity of recirculated exhaust gas being controlled by an orifice.
Claim 12
Dependent Claim
30 words
The exhaust gas recirculation system of claim 1 wherein said flow of recirculated exhaust gas controlled to vary a quantity of recirculated exhaust gas being controlled by an on-off valve.
Claim 13
Dependent Claim
252 words
An exhaust gas recirculation system for use with an engine having a cylinder and a rotatable crankshaft, said engine having a turbocharger defining a compressor section compressing a flow of intake air to a first preestablished pressure and being driven by a flow of exhaust gas having a first preestablished pressure, said exhaust gas recirculation system comprising: a portion of said flow of exhaust gas being recirculated back to said cylinder and forming a flow of recirculated exhaust gas; said flow of recirculated exhaust gas being cooled; said flow of recirculated exhaust gas being compressed to a second preestablished pressure being at least as great as said first preestablished pressure of said intake air during a portion of an operating parameter of said engine; a portion of said flow of recirculated exhaust gas being controlled by a valve, said valve having an open position in which said portion of said flow of intake air being further compressed to a second preestablished pressure flows therethrough and a closed position in which said flow of intake air is blocked; a portion of said flow of intake air being mixed with said flow of recirculated exhaust gas prior to said flow of recirculated exhaust gas being compressed to said second preestablished pressure; and said flow of recirculated exhaust gas and said portion of said flow of intake air passing through said valve each being further compressed to a level being equivalent to that of the second preestablished pressure of said flow of recirculated exhaust gas.
Claim 14
Dependent Claim
252 words
An exhaust gas recirculation system for use with an engine having a cylinder and a rotatable crankshaft, said engine having a turbocharger defining a compressor section compressing a flow of intake air to a first preestablished pressure and being driven by a flow of exhaust gas having a first preestablished pressure, said exhaust gas recirculation system comprising: a portion of said flow of exhaust gas being recirculated back to said cylinder and forming a flow of recirculated exhaust gas; said flow of recirculated exhaust gas being cooled; said flow of recirculated exhaust gas being compressed to a second preestablished pressure being at least as great as said first preestablished pressure of said intake air during a portion of an operating parameter of said engine; a portion of said flow of recirculated exhaust gas being controlled by a valve, said valve having an open position in which said portion of said flow of intake air being further compressed to a second preestablished pressure flows therethrough and a closed position in which said flow of intake air is blocked; a portion of said flow of intake air being mixed with said flow of recirculated exhaust gas prior to said flow of recirculated exhaust gas being compressed to said second preestablished pressure; and said flow of recirculated exhaust gas and said portion of said flow of intake air passing through said valve each being further compressed to a level being equivalent to that of the second preestablished pressure of said flow of recirculated exhaust gas.
Claim 15
Dependent Claim
27 words
The exhaust gas recirculation system of claim 12 wherein said flow of recirculated exhaust gas is at a maximum quantity with said valve in said closed position.
Claim 16
Dependent Claim
27 words
The exhaust gas recirculation system of claim 12 wherein said flow of recirculated exhaust gas is at a minimum quantity with said valve in said open position.
Claim 17
Dependent Claim
22 words
The exhaust gas recirculation system of claim 12 wherein said valve is infinitely movable between said open position and said closed position.
Claim 18
Dependent Claim
25 words
The exhaust gas recirculation system of claim 12 wherein said quantity of said flow of recirculated exhaust gas being further controlled by a proportional valve.
Claim 19
Dependent Claim
22 words
The exhaust gas recirculation system of claim 12 wherein said quantity of recirculated exhaust gas being further controlled by an on-off valve.
Claim 20
Dependent Claim
76 words
An exhaust gas recirculation system for use with an engine, said exhaust gas recirculation system comprising: a flow of exhaust gas and a portion of said flow of exhaust gas forming a flow of recirculated exhaust gas being recirculated to said engine; an exhaust gas recirculation cooler being positioned within a chassis, said chassis defining a frontal portion; and an ambient cooling air passing through said frontal portion and flowing through said exhaust gas recirculation cooler.
Claim 21
Dependent Claim
76 words
An exhaust gas recirculation system for use with an engine, said exhaust gas recirculation system comprising: a flow of exhaust gas and a portion of said flow of exhaust gas forming a flow of recirculated exhaust gas being recirculated to said engine; an exhaust gas recirculation cooler being positioned within a chassis, said chassis defining a frontal portion; and an ambient cooling air passing through said frontal portion and flowing through said exhaust gas recirculation cooler.
Claim 22
Dependent Claim
26 words
The exhaust gas recirculation system of claim 18 wherein said flow of ambient cooling air being in heat exchanging relationship with said exhaust gas recirculation cooler.
Claim 23
Dependent Claim
42 words
The exhaust gas recirculation system of claim 18 further including a radiator being positioned in said chassis and said exhaust gas recirculation cooler being in heat exchanging relationship with said ambient cooling air after said ambient cooling air passing through said radiator.
Claim 24
Dependent Claim
38 words
The exhaust gas recirculation system of claim 20 further including an aftercooler being positioned in said chassis and said ambient cooling air passing through said aftercooler and said radiator prior to passing through said exhaust gas recirculation cooler.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-02-13 | 2004-08-14 | 2005-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-02-13 | 2008-08-14 | 2009-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-02-13 | 2012-08-14 | 2013-02-13 | $7700.00 | Window Closed / Lapsed |