# US 2014/0150440 A1 · Gas turbine engine with a low speed spool driven pump arrangement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0150440 A1 - Document ID: US20140150440A1 - Status: Published application - Kind: A1 - Application number: 13/705,462 - Filed: 2012-12-05 - Published: 2014-06-05 - Earliest claimed: 2012-12-05 - Assignees: United Technologies Corporation - Applicants: United Technologies Corporation - Inventors: Gabriel L. SUCIU; Christopher M. DYE - Web page: https://patentgrep.com/patent/US20140150440A1 ## CPC - F02C 7/236: Fuel delivery systems comprising two or more pumps - F02C 7/32: Arrangement, mounting, or driving, of auxiliaries - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) ## Abstract A gas turbine engine includes, among other things, a propulsion assembly situated to rotate about an engine central axis. Operation of the propulsion assembly requires a first amount of fluid during a first operating condition and a second, greater amount of the fluid during a second operating condition. A first pump is operatively associated with a low speed spool that rotates with a low pressure turbine. The first pump has a first fluid delivering capacity corresponding to at least the first amount. A second pump has a second fluid delivering capacity configured to correspond to at least a difference between the first amount and the second amount. The first pump provides the fluid for propulsion assembly during the first and second operating conditions and the second pump provides the fluid for propulsion assembly operation only during the second operating condition. ## Claims ### Claim 1 A gas turbine engine, comprising: a propulsion assembly including at least a high pressure turbine and a low pressure turbine, the turbines being situated to rotate about an engine central axis, operation of the propulsion assembly requiring at least one fluid including requiring a first amount of the fluid during at least a first operating condition and a second, greater amount of the fluid during at least a second operating condition; a low speed spool configured to rotate about the engine central axis with the low pressure turbine; a first pump that is operatively associated with the low speed spool such that operation of the first pump is dependent on rotation of the low speed spool, the first pump having a first fluid delivering capacity configured to correspond to at least the first amount; and a second pump having a second fluid delivering capacity configured to correspond to at least a difference between the first amount and the second amount; the first pump providing the fluid for propulsion assembly operation during the first and second operating conditions and the second pump providing the fluid for propulsion assembly operation only during the second operating condition. ### Claim 2 (depends on 1) The gas turbine engine of claim 1, wherein the second pump is inactive during the first operating condition. ### Claim 3 (depends on 1) The gas turbine engine of claim 1, comprising a controller configured to: determine at least one of the operating condition of the propulsion assembly or an amount of the fluid needed; and control the second pump to provide a corresponding amount of the fluid to the propulsion assembly. ### Claim 4 (depends on 1) The gas turbine engine of claim 1, wherein the fluid comprises fuel. ### Claim 5 (depends on 1) The gas turbine engine of claim 1, wherein the fluid comprises a lubricant. ### Claim 6 (depends on 1) The gas turbine engine of claim 1, wherein the second pump is driven by a power element distinct from the low speed spool. ### Claim 7 (depends on 6) The gas turbine engine of claim 6, wherein the power element comprises an electric motor. ### Claim 8 (depends on 1) The gas turbine engine assembly of claim 1, wherein the second fluid delivery capacity is lower than the first fluid delivery capacity. ### Claim 9 (depends on 1) The gas turbine engine assembly of claim 1, comprising a power extraction module that is an interface between the low speed spool and the first fluid pump. ### Claim 10 (depends on 9) The gas turbine engine assembly of claim 9, comprising at least one other pump operatively associated with the power extraction module such that the other pump is driven based on rotation of the low speed spool. ### Claim 11 A method of operating a gas turbine engine that includes a propulsion assembly including at least a high pressure turbine and a low pressure turbine, the turbines being situated to rotate about an engine central axis, operation of the propulsion assembly requiring at least one fluid including a first amount of the fluid during at least a first operating condition and a second, greater amount of the fluid during at least a second operating condition, comprising the steps of: driving a first pump using rotation of a low speed spool configured to rotate about the engine central axis with the low pressure turbine for providing the fluid for propulsion assembly operation during the first and second operating conditions; and driving a second pump for providing the fluid for propulsion assembly operation with the first pump only during the second operating condition, an amount of the fluid provided by the second pump corresponding to a difference between the first amount and the second amount. ### Claim 12 (depends on 11) The method of claim 11, comprising inactivating the second pump during the first operating condition. ### Claim 13 (depends on 11) The method of claim 11, comprising determining at least one of the operating condition of the propulsion assembly or an amount of the fluid needed; and controlling the second pump to provide a corresponding amount of the fluid to the propulsion assembly. ### Claim 14 (depends on 11) The method of claim 11, wherein the fluid comprises fuel. ### Claim 15 (depends on 11) The method of claim 11, wherein the fluid comprises a lubricant. ### Claim 16 (depends on 11) The method of claim 11, comprising driving the second pump using a power element distinct from the low speed spool. ### Claim 17 (depends on 16) The method of claim 16, wherein the power element comprises an electric motor. ### Claim 18 (depends on 11) The method of claim 11, wherein the first pump has a first fluid delivering capacity configured to correspond to at least the first amount; and the second pump has a lower, second fluid delivering capacity configured to correspond to at least a difference between the first amount and the second amount.