# US 7,610,760 B2 · Two-displacement setting variable displacement pump used as engine over-thrust protection with fuel system thermal benefit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,610,760 B2 - Document ID: US7610760B2 - Status: Granted - Kind: B2 - Application number: 10/592,724 - Filed: 2005-03-29 - Published: 2008-09-25 - Granted: 2009-11-03 - Earliest claimed: 2004-03-29 - Assignees: Argo-Tech Corporation - Inventors: Martin A. Clements - Web page: https://patentgrep.com/patent/US7610760B2 ## CPC - F02C 9/30: characterised by variable fuel pump output - F02C 9/263: {by means of fuel metering valves} - F02C 9/46: Emergency fuel control - 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 fuel delivery system (10) comprises a variable displacement pump (20) for pressurizing fuel. The variable displacement pump has a distinct first pump displacement setting for a first desired mass flow of fuel and a distinct second pump displacement setting for a second desired mass flow of fuel. The variable displacement pump operates in only one of the first and second pump displacement settings. A fuel control (22) with a metering valve downstream of the variable displacement pump selectively regulates fuel delivery. ## Claims ### Claim 1 A fuel delivery system for an associated jet aircraft turbine engine during a control system failure comprising: a pump for pressurizing fuel, the pump having a distinct first pump displacement setting for a first desired mass flow of fuel and a distinct second pump displacement setting for a second desired mass flow of fuel, wherein the pump operates in only one of the first and second pump displacement settings; a metering valve downstream of the pump for selectively regulating fuel delivery; and, means for preventing engine over-thrust operatively associated with the pump for positioning the pump in the second pump displacement setting in response to a control system failure whereby pump flow to the associated engine is limited to provide over-thrust protection. ### Claim 2 (depends on 1) The fuel delivery system of claim 1 wherein the first pump displacement setting is a high mass flow displacement setting. ### Claim 3 (depends on 1) The fuel delivery system of claim 1 wherein the second pump displacement setting is a low mass flow displacement setting. ### Claim 4 (depends on 3) The fuel delivery system of claim 3 wherein the pump is activated to the second pump displacement setting in response to a control system failure. ### Claim 5 A fuel delivery system for an associated jet aircraft turbine engine during a control system failure comprising: a pump for pressurizing fuel, the pump having a distinct first pump displacement setting for a first desired high mass flow of fuel and a distinct second pump displacement setting for a second desired low mass flow of fuel, wherein the pump operates in only one of the first and second pump displacement settings, wherein the pump is activated to the second pump displacement setting in response to a control system failure; a metering valve downstream of the pump for selectively regulating fuel delivery; and, a controller for preventing engine over-thrust operatively associated with the pump for positioning the pump in the second pump displacement setting in response to a control system failure whereby pump flow to the associated engine is limited to provide over-thrust protection. ### Claim 6 (depends on 1) The fuel delivery system of claim 1 wherein the pump includes distinct first and second stops defining operational parameters for pump stroke travel. ### Claim 7 (depends on 1) The fuel delivery system of claim 1 further comprising a controller for positioning the pump in one of the first and second pump displacement settings. ### Claim 8 (depends on 5, 7) The fuel delivery system of claim 5 or 7 wherein the controller is a solenoid valve responsive to an electronic control signal for actuating the pump to only one of the first and second pump displacement settings. ### Claim 9 (depends on 1) The fuel delivery system of claim 1 further comprising a bypass passage downstream of the pump for returning excess flow to a pump inlet. ### Claim 10 (depends on 1) The fuel delivery system of claim 1 further comprising a solenoid valve, the solenoid valve being commanded by the electronic control for positioning the pump to one of the first and second modes of operation. ### Claim 11 (depends on 1) The fuel delivery system of claim 1 wherein the second pump displacement setting contributes less heat to the fuel system. ### Claim 12 (depends on 1) The fuel delivery system of claim 1 wherein the first pump displacement setting permits fuel system heating for avoiding fuel system icing at cold operating conditions. ### Claim 13 (depends on 1) The fuel delivery system of claim 1 wherein the pump is a variable displacement pump. ### Claim 14 A method of delivering fuel for an associated jet aircraft turbine engine comprising the steps of: pressurizing fuel through a pump having first and second fixed displacement settings for a first predetermined, high mass flow of fuel and a second predetermined, low mass flows of fuel; metering the fuel through a metering valve for supply to associated fuel nozzles; setting the pump to only one of the first and second displacement settings; and, positioning the pump in the second pump displacement setting in response to a control system failure whereby pump flow to the associated engine is limited to provide over-thrust protection. ### Claim 15 (depends on 14) The method of claim 14 comprising the further step of controlling fuel system temperature by operating the pump in its fixed high mass flow displacement setting. ### Claim 16 (depends on 14) The method of claim 14 comprising the further step of bypassing fuel exiting the metering valve to recirculate a portion of fuel to the pump. ### Claim 17 A fuel delivery system for preventing engine over-thrust for an associated jet aircraft turbine engine comprising: a variable displacement pump for pressurizing fuel operative in either a first predetermined, high mass flow, fuel displacement setting or a second predetermined, low mass flow, fuel displacement setting; a metering valve downstream of the variable displacement pump for selectively regulating fuel delivery; and, a controller for selectively positioning the pump in only one of the first and second fuel displacement settings, and positioning the pump to operate in the second fuel displacement setting in the event of failure of the controller thereby preventing engine over-thrust. ### Claim 18 (depends on 17) The fuel delivery system of claim 17 wherein the pump includes first and second stops in first and second extremes of pump stroke travel. ### Claim 19 (depends on 18) The fuel delivery system of claim 18 wherein the first and second extremes of pump stroke travel define the respective first and second displacement setting.