# US 6,293,103 B1 · Turbocharger system to inhibit reduced pressure in intake manifold > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,293,103 B1 - Document ID: US6293103B1 - Status: Granted - Kind: B1 - Application number: 09/666,634 - Filed: 2000-09-21 - Granted: 2001-09-25 - Earliest claimed: 2000-09-21 - Assignees: Caterpillar Inc. - Inventors: John R. Gladden - Web page: https://patentgrep.com/patent/US6293103B1 ## CPC - F02B 33/446: {having valves for admission of atmospheric air to engine, e.g. at starting} - F04D 17/122: {the individual rotor discs being, one for each stage, on a common shaft and axially spaced, e.g. conventional centrifugal multi- stage compressors} - F04D 27/0223: {Control schemes therefor} - F04D 27/0238: {Details or means for fluid reinjection} - F05D 2220/40: in turbochargers - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract An internal combustion engine is provided with at least one intake manifold and a turbocharger. The turbocharger includes a rotatable shaft; a turbine having 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, 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, a radially extending second outlet associated with the second compressor wheel, and an interstage duct fluidly interconnecting in series the first outlet associated with the first compressor wheel with the second inlet associated with the second compressor wheel. The second outlet is fluidly coupled with the intake manifold. One or more valves are each fluidly coupled with an ambient environment and the interstage duct or intake manifold. Each valve is adapted to open when a pressure of the ambient environment is less than a pressure within the interstage duct or intake manifold. ## Claims ### Claim 1 A turbocharger system for an internal combustion engine, comprising: a turbocharger including: a rotatable shaft; a multi-stage compressor including a first compressor wheel carried by said shaft, an axially extending first inlet associated with said first compressor wheel, a radially extending first outlet associated with said first compressor wheel, a second compressor wheel carried by said shaft, a second inlet associated with said second compressor wheel, a radially extending second outlet associated with said second compressor wheel, and an interstage duct fluidly interconnecting in series said first outlet associated with said first compressor wheel with said second inlet associated with said second compressor wheel; at least one sensor, each said sensor configured to sense a pressure associated with said multi-stage compressor and provide an output signal; a valve fluidly coupled with said interstage duct and an ambient environment; and a controller coupled with each said sensor and said valve, said controller controlling operation of said valve dependent upon at least one said output signal. ### Claim 2 (depends on 1) The turbocharger system of claim 1, each said sensor being configured to sense one of: a pressure associated with said first outlet; a pressure associated with said second outlet; a pressure within said interstage duct; and a pressure difference between said second outlet and said first inlet. ### Claim 3 (depends on 2) The turbocharger system of claim 2, said at least one sensor including a plurality of sensors. ### Claim 4 (depends on 1) The turbocharger system of claim 1, said at least one sensor including a plurality of sensors, said controller receiving an output signal from at least two of said sensors and determining a pressure drop across said multi-stage compressor. ### Claim 5 (depends on 4) The turbocharger system of claim 4, said controller opening said valve upon said determining of said pressure drop. ### Claim 6 (depends on 1) The turbocharger system of claim 1, said valve being a one-way valve allowing flow of air from the ambient environment into said interstage duct. ### Claim 7 An internal combustion engine, comprising: at least one intake manifold; a turbocharger including: a rotatable shaft; and a multi-stage compressor including a first compressor wheel carried by said shaft, an axially extending first inlet associated with said first compressor wheel, a radially extending first outlet associated with said first compressor wheel, a second compressor wheel carried by said shaft, a second inlet associated with said second compressor wheel, a radially extending second outlet associated with said second compressor wheel, and an interstage duct fluidly interconnecting in series said first outlet associated with said first compressor wheel with said second inlet associated with said second compressor wheel, said second outlet being fluidly coupled with said intake manifold; and at least one valve, each said valve being fluidly coupled with an ambient environment and one of said interstage duct and said intake manifold, each said valve being adapted to open when a pressure of the ambient environment is more than a pressure within said one of said interstage duct and said intake manifold. ### Claim 8 (depends on 7) The internal combustion engine of claim 7, including at least one sensor, each said sensor configured to sense a pressure associated with at least one of said multi-stage compressor and said intake manifold, each said sensor providing an output signal; and a controller coupled with each said sensor and each said valve, said controller controlling operation of each said valve dependent upon at least one said output signal. ### Claim 9 (depends on 8) The internal combustion engine of claim 8, each said sensor being configured to sense one of: a pressure associated with said first outlet; a pressure associated with said second outlet; a pressure within said interstage duct; a pressure difference between said second outlet and said first inlet; and a pressure within said intake manifold. ### Claim 10 (depends on 9) The internal combustion engine of claim 9, said at least one sensor including a plurality of sensors. ### Claim 11 (depends on 8) The internal combustion engine of claim 8, said at least one sensor including a plurality of sensors, at least two of said sensors associated with said multi-stage compressor, said controller receiving an output signal from at least two of said sensors associated with said multi-stage compressor and determining a pressure drop across said multi-stage compressor. ### Claim 12 (depends on 11) The internal combustion engine of claim 11, said controller opening at least one said valve upon said determining of said pressure drop. ### Claim 13 (depends on 8) The internal combustion engine of claim 8, said controller independently controlling operation of each said valve dependent upon at least one said output signal. ### Claim 14 (depends on 7) The internal combustion engine of claim 7, one said valve being fluidly coupled with said interstage duct. ### Claim 15 (depends on 7) The internal combustion engine of claim 7, one said valve being fluidly coupled with said intake manifold. ### Claim 16 A method of operating a turbocharger system in an internal combustion engine, comprising the steps of: providing at least one intake manifold; providing a turbocharger including: a rotatable shaft; and a multi-stage compressor including a first compressor wheel carried by said shaft, an axially extending first inlet associated with said first compressor wheel, a radially extending first outlet associated with said first compressor wheel, a second compressor wheel carried by said shaft, a second inlet associated with said second compressor wheel, a radially extending second outlet associated with said second compressor wheel, and an interstage duct fluidly interconnecting in series said first outlet associated with said first compressor wheel with said second inlet associated with said second compressor wheel, said second outlet being fluidly coupled with said intake manifold; fluidly coupling at least one valve between an ambient environment and one of said interstage duct and said intake manifold; and opening at least one said valve when a pressure within said intake manifold is less than a pressure of said ambient environment. ### Claim 17 (depends on 16) The method of claim 16, including the steps of: sensing a pressure associated with at least one of said multi-stage compressor and said intake manifold using at least one said sensor; and providing an output signal from each said sensor corresponding to said respective sensed pressure; said opening step including controlling operation of each said valve using a controller coupled with each said sensor and each said valve, dependent upon at least one said output signal. ### Claim 18 (depends on 17) The method of claim 17, wherein said sensing step includes sensing at least one of: a pressure associated with said first outlet; a pressure associated with said second outlet; a pressure within said interstage duct; a pressure difference between said second outlet and said first inlet; and a pressure within said intake manifold. ### Claim 19 (depends on 16) The method of claim 16, said at least one sensor including a plurality of sensors, at least two of said sensors associated with said multi-stage compressor, and including the steps of: receiving an output signal from at least two of said sensors at said controller; and determining a pressure drop across said multi-stage compressor. ### Claim 20 (depends on 19) The method of claim 19, including the step of opening at least one said valve using said controller upon said determining of said pressure drop. ### Claim 21 (depends on 16) The method of claim 16, including the step of fluidly coupling one said valve with said interstage duct. ### Claim 22 (depends on 16) The method of claim 16, including the step of fluidly coupling one said valve with said intake manifold.