US 12,000,346 B2
Redundant electro-hydraulic servo valve (EHSV) control in a fuel metering system
Carthel C. Baker, Daytona Beach, FL (US); and Andrew D. Splitt, Loves Park, IL (US)
Assigned to Woodward, Inc., Fort Collins, CO (US)
Filed by Woodward, Inc., Fort Collins, CO (US)
Filed on Jun. 23, 2023, as Appl. No. 18/340,508.
Claims priority of provisional application 63/355,841, filed on Jun. 27, 2022.
Prior Publication US 2023/0417193 A1, Dec. 28, 2023
Int. Cl. F02C 9/26 (2006.01); F02C 7/232 (2006.01); F02C 9/46 (2006.01); F23R 3/34 (2006.01)
CPC F02C 9/263 (2013.01) [F02C 7/232 (2013.01); F02C 9/46 (2013.01); F05D 2260/84 (2013.01); F23R 3/346 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A fuel metering system for a multi-stage combustion system having a main combustion stage and at least one secondary combustion stage, comprising:
a main fuel metering system configured to supply fuel to the main combustion stage, the main fuel metering system having a main electro-hydraulic servo valve (EHSV) fluidly coupled to a main system fuel metering valve (FMV) through a transfer valve; and
a secondary fuel metering system configured to supply fuel to the secondary combustion stage, the secondary fuel metering system having a secondary electro-hydraulic servo valve (EHSV) fluidly coupled to a secondary fuel metering valve (FMV) and to the main system fuel metering valve (FMV) through the transfer valve; and
wherein the transfer valve includes a multi-land piston configured to provide control pressures from the main EHSV to the main FMV to control positioning thereof during a normal mode of operation, and to provide control pressures from the secondary EHSV to the main FMV to control positioning thereof during a backup mode of operation.