Air turbine start system

Abstract

An air turbine starter device includes a gear assembly, a rotor arranged in a cavity of a housing and operably connected the gear assembly, a first manifold having a cavity with a first manifold port operative to direct compressed air to the rotor, and a second manifold having a cavity with a second manifold port operative to direct compressed air to the rotor. The first manifold is larger than the second manifold, the second manifold is fluidly connected in parallel with the first manifold, and the first manifold port and the second manifold port are operative to drive the rotor in a common direction for starting a gas turbine connected to the gear assembly. Air turbine starter systems and methods of starting gas turbine engines are also described.

1 . An air turbine starter device comprising:
 a gear assembly;   a rotor arranged in a cavity of a housing, wherein the rotor is operably connected the gear assembly;   a first manifold having a cavity with a first manifold port operative to direct compressed air to the rotor; and   a second manifold having a cavity with a second manifold port operative to direct compressed air to the rotor,   wherein the first manifold is larger than the second manifold, wherein the second manifold is fluidly connected in parallel with the first manifold, and wherein the first manifold port and the second manifold port are operative to drive the rotor in a common direction.   
     
     
         2 . The device of  claim 1 , wherein the first manifold includes a greater number of ports than a number of ports in the second manifold. 
     
     
         3 . The device of  claim 1 , wherein the cavity of the first manifold defines a first compressed air flow path that flows through the cavity of the first manifold, through the port of the first manifold, and through a nozzle that is communicative with the cavity of the housing. 
     
     
         4 . The device of  claim 1 , wherein the cavity of the second manifold defines a second compressed air flow path that flows through the cavity of the second manifold, through the port of the second manifold, and through a nozzle that is communicative with the cavity of the housing. 
     
     
         5 . The device of  claim 1 , wherein the rotor is operative to rotate when compressed air impinges on the rotor. 
     
     
         6 . The device of  claim 1 , wherein the rotor is mechanically linked to a gas turbine engine such that the rotation of the rotor rotates components of the gas turbine engine. 
     
     
         7 . The device of  claim 1 , wherein the air turbine starter is communicatively connected to a compressed air source. 
     
     
         8 . An air turbine starter system, the system comprising:
 air turbine starter device as recited in  claim 1 , wherein the rotor is mechanically linked to a gas turbine engine such that the rotation of the rotor rotates components of the gas turbine engine;   a first control valve operative to control a flow of compressed air to the first manifold; and   a second control valve operative to control a flow of compressed air to the second manifold.   
     
     
         9 . The system of  claim 8 , wherein the first manifold includes a greater number of ports than a number of ports in the second manifold. 
     
     
         10 . The system of  claim 8 , wherein the cavity of the first manifold defines a first compressed air flow path that flows through the cavity of the first manifold, through the port of the first manifold, and through a nozzle that is communicative with the cavity of the housing. 
     
     
         11 . The system of  claim 8 , wherein the cavity of the second manifold defines a second compressed air flow path that flows through the cavity of the second manifold, through the port of the second manifold, and through a nozzle that is communicative with the cavity of the housing. 
     
     
         12 . The system of  claim 8 , wherein the rotor is operative to rotate when compressed air impinges on the rotor. 
     
     
         13 . The system of  claim 8 , wherein the air turbine starter is communicatively connected to a compressed air source. 
     
     
         14 . The system of  claim 8 , wherein the system is operative to drive the air turbine starter at a first speed when the first valve is in a closed position and the second valve is in an open position, and the system is operative to drive the air turbine starter at a second speed when the first valve is in an open position. 
     
     
         15 . The system of  claim 14 , wherein the first speed is lower than the second speed. 
     
     
         16 . The system of  claim 8 , wherein the air turbine starter device is controlled by a controller. 
     
     
         17 . A method for controlling an air turbine starter system, the method comprising:
 at an air turbine starter device including a gear assembly; a rotor arranged in a cavity of a housing, wherein the rotor is operably connected the gear assembly; a first manifold having a cavity with a first manifold port operative to direct compressed air to the rotor; and a second manifold having a cavity with a second manifold port operative to direct compressed air to the rotor, wherein the first manifold is larger than the second manifold, wherein the second manifold is fluidly connected in parallel with the first manifold, and wherein the first manifold port and the second manifold port are operative to drive the rotor in a common direction   closing a first valve that is operative to control a flow of compressed air to a first manifold of an air turbine starter device;   opening a second valve that is operative to control a flow of compressed air to a second manifold of an air turbine starter device, such that the flow of compressed air to the second manifold is operative to drive a rotor of the air turbine starter system to a first speed.   
     
     
         18 . The method of  claim 17 , further comprising:
 opening the first valve that is operative to control a flow of compressed air to the first manifold of the air turbine starter device, such that the flow of compressed air to the first manifold is operative to drive a rotor of the air turbine starter system to a second speed.   
     
     
         19 . The method of  claim 18 , wherein the second speed is greater than the first speed.