Power plants – Fluid motor means driven by waste heat or by exhaust energy... – With supercharging means for engine
Reexamination Certificate
2000-09-21
2001-10-16
Denion, Thomas (Department: 3747)
Power plants
Fluid motor means driven by waste heat or by exhaust energy...
With supercharging means for engine
C060S612000, C416S16800R, C417S407000, C417S409000, C415S120000
Reexamination Certificate
active
06301889
ABSTRACT:
TECHNICAL FIELD
The present invention relates to turbochargers for use in an internal combustion engine, and, more particularly, to a turbocharger having a turbine and a multi-stage compressor.
BACKGROUND ART
An internal combustion engine may include one or more turbochargers for compressing a fluid which is supplied to one or more combustion chambers within corresponding combustion cylinders. Each turbocharger typically includes a turbine driven by exhaust gases of the engine and a compressor which is driven by the turbine. The compressor receives the fluid to be compressed and supplies the fluid to the combustion chambers. The fluid which is compressed by the compressor may be in the form of combustion air or a fuel and air mixture.
A turbocharger may also include a two stage compressor with two separate compressor wheels which are carried and driven by a common shaft. U.S. Pat. No. 4,344,289 (Curiel et al.) discloses a supercharger with a two-stage compressor having two compressor wheels which are disposed in a back-to-back orientation relative to each other and carried by a common shaft. The hub portions of the two compressor wheels are configured differently relative to each other, but the overall diameter of the compressor wheels at the outside diameter of the blades is the same. The two compressor wheels and the common shaft appear to be monolithically formed with each other. Since the compressor wheels have the same diameter, the stress capacity of the compressor wheels is limited by the common material from which they are constructed. Moreover, the rotational inertia of the entire compressor assembly can only be altered by changing the geometry of the compressor wheels since they are constructed from a common material.
An exhaust gas recirculation (EGR) system is used for controlling the generation of undesirable pollutant gases and particulate matter in the operation of internal combustion engines. Such systems have proven particularly useful in internal combustion engines used in motor vehicles such as passenger cars, light duty trucks, and other on-road motor equipment. EGR systems primarily recirculate the exhaust gas by-products into the intake air supply of the internal combustion engine. The exhaust gas which is reintroduced to the engine cylinder reduces the concentration of oxygen therein and increases the specific heat of the mixture, which in turn lowers the maximum combustion temperature within the cylinder, decreasing the formation of nitrous oxides (NOx). Furthermore, the exhaust gases typically contain unburned hydrocarbons which are burned on reintroduction into the engine cylinder, which further reduces the emission of exhaust gas by-products which would be emitted as undesirable pollutants from the internal combustion engine.
It is known to recirculate the exhaust gas within a turbocharger in an internal combustion engine. For example, U.S. Pat. No. 4,250,711 (Zehnder) discloses a supercharger for an internal combustion engine with exhaust gas recirculation. The supercharger includes a single turbine wheel and a single compressor wheel. The turbine is in the form of an axial turbine which is driven by exhaust gas from an exhaust manifold of the internal combustion engine. A portion of the exhaust gas may be recirculated from the turbine side to the compressor side of the supercharger. More particularly, the exhaust gas is recirculated to the discharge side of the single stage compressor either immediately prior to the diffuser section or within the volute section. A single stage compressor as shown in Zehnder,
711
has limited compression capabilities, primarily dependent upon the configuration and rotational speed of the compressor wheel.
The present invention is directed to overcoming one or more of the problems as set forth above.
DISCLOSURE OF THE INVENTION
In one aspect of the invention, a turbocharger for an internal combustion engine is provided with a rotatable shaft; a turbine including a turbine wheel carried by the shaft; and a multi-stage compressor. The multi-stage compressor includes a first compressor wheel carried by the shaft, an axially extending first inlet associated with the first compressor wheel, and a radially extending first outlet associated with the compressor wheel. A second compressor wheel carried by the shaft includes an axially extending second inlet associated with the second compressor wheel, and a radially extending second outlet associated with the second compressor wheel. An interstage duct fluidly interconnects in series the first outlet associated with the first compressor wheel and a second inlet associated with the second compressor wheel. An exhaust gas recirculation duct fluidly interconnects the turbine with the interstage duct. A valve is positioned within the exhaust gas recirculation duct.
In another aspect of the invention, an internal combustion engine includes an intake manifold and a turbocharger. The turbocharger includes a rotatable shaft; a turbine including a turbine wheel carried by the shaft; and a multi-stage compressor. The multi-stage compressor includes a first compressor wheel carried by the shaft, an axially extending first inlet associated with the first compressor wheel, and a radially extending first outlet associated with the first compressor wheel. A second compressor wheel carried by the shaft includes an axially extending second inlet associated with the second compressor wheel, and a radially extending second outlet associated with the second compressor wheel. The second outlet is in fluid communication with the intake manifold. An interstage duct fluidly interconnects in series the first outlet associated with the first compressor wheel and the second inlet associated with the second compressor wheel. An exhaust gas recirculation duct fluidly interconnects the turbine with the interstage duct. A valve is positioned within the exhaust gas recirculation duct.
In yet another aspect of the invention, a method of operating a turbocharger in an internal combustion engine is provided with the steps of: providing a turbine including a turbine wheel carried by the shaft; providing a multi-stage compressor including a first compressor wheel carried by the shaft, an axially extending first inlet associated with the first compressor wheel, a radially extending first outlet associated with the first compressor wheel, a second compressor wheel carried by the shaft, an axially extending second inlet associated with the second compressor wheel, and a radially extending second outlet associated with the second compressor wheel; fluidly connecting in series the first outlet associated with the first compressor wheel with the second inlet associated with the second compressor wheel using an interstage duct; fluidly interconnecting the turbine with the interstage duct using an exhaust gas recirculation duct; positioning a valve within the exhaust gas recirculation duct; rotating the turbine wheel, the first compressor wheel and the second compressor wheel carried by the shaft; and selectively actuating the valve to recirculate exhaust gas from the turbine to the interstage duct.
REFERENCES:
patent: 1213889 (1917-01-01), Lawaczek
patent: 3941506 (1976-03-01), Robb et al.
patent: 4082477 (1978-04-01), Kronogard
patent: 4250711 (1981-02-01), Zehnder
patent: 5937650 (1999-08-01), Arnold
patent: 6145313 (2000-11-01), Arnold
patent: 6209324 (2001-04-01), Daudel et al.
patent: 6216459 (2001-04-01), Daudel et al.
patent: 998179 (1952-01-01), None
patent: 1155263 (1958-04-01), None
patent: 60-162050-A (1985-08-01), None
Gladden John R.
Houtz Phillip J.
Caterpillar Inc.
Denion Thomas
Taylor Todd T.
Trieu Thai-Ba
LandOfFree
Turbocharger with exhaust gas recirculation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Turbocharger with exhaust gas recirculation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Turbocharger with exhaust gas recirculation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2551699