Vafn systems with improved drive coupling assemblies and brakes

Abstract

An actuation system is provided for a variable area fan nozzle assembly of an aircraft. The actuation system includes a motor configured to generate a torque; a nozzle; and a drive coupling assembly coupled to the motor and the nozzle. The drive coupling assembly includes a first position in which the torque from the motor is transferred to the nozzle to translate the nozzle and a second position in which the torque from the motor is not transferred to the nozzle. The drive coupling assembly includes a first end portion and a second end portion, the first and second end portions mating with one another in the first position and disengaged from one another in the second position.

What is claimed is: 
     
         1 . An actuation system for a variable area fan nozzle assembly of an aircraft, the system comprising:
 a motor configured to generate a torque;   a nozzle; and   a drive coupling assembly coupled to the motor and the nozzle, the drive coupling assembly having a first position in which the torque from the motor is transferred to the nozzle to translate the nozzle and a second position in which the torque from the motor is not transferred to the nozzle,   wherein the drive coupling assembly comprises a first end portion and a second end portion, the first and second end portions mating with one another in the first position and disengaged from one another in the second position.   
     
     
         2 . The actuation system of  claim 1 , wherein the drive coupling assembly is mounted on a transcowl such that the drive coupling is in the first position when the transcowl is stowed and in the second position when the transcowl is deployed. 
     
     
         3 . The actuation system of  claim 2 , wherein the drive coupling assembly comprises
 a first drive shaft coupled to the first end portion;   a second drive shaft coupled to the second end portion; and   a nozzle actuator coupled to the second drive shaft and mounted on the transcowl such that deployment of the transcowl moves the nozzle actuator and the second drive shaft away from the first drive shaft such that the first and second end portion disengage.   
     
     
         4 . The actuation system of  claim 3 , further comprising a fixed structure gearbox coupled to the first drive shaft. 
     
     
         5 . The actuation system of  claim 3 , wherein the nozzle actuator comprises a gimbal that couples the second drive shaft to the nozzle such that rotation of the second drive shaft translates the nozzle. 
     
     
         6 . The actuation system of  claim 3 , wherein the first end portion includes a first end face with pins extending therefrom. 
     
     
         7 . The actuation system of  claim 6 , wherein the second end portion includes a second end face with tabs extending therefrom that define gaps between adjacent tabs. 
     
     
         8 . The actuation system of  claim 7 , wherein, in the first position, the pins of the first end portion extend into the gaps to engage the tabs of the second end portion to transfer torque between the first drive shaft and the second drive shaft. 
     
     
         9 . The actuation system of  claim 8 , wherein the first end portion further includes recesses to house the pins in a retracted position and springs to bias the pins into an extended position. 
     
     
         10 . The actuation system of  claim 9 , each of the pins is configured to retract into the retracted position upon initial engagement with one of the tabs until rotation of the first drive shaft aligns each of the pins with the gap to enable extension of each of the pins into the gap. 
     
     
         11 . The actuation system of  claim 3 , wherein the nozzle actuator includes a braking assembly to prevent rotation of the second drive shaft when the drive coupling assembly is in the second position. 
     
     
         12 . The actuation system of  claim 11 , wherein the braking assembly includes
 a rotor mounted on the second drive shaft,   a stator mounted proximate to the rotor, and   a spring that biases the stator against the rotor with a spring force to prevent rotation of the second drive shaft when the drive coupling assembly is in the second position.   
     
     
         13 . The actuation system of  claim 12 , wherein the first end portion is configured to mate with the second end portion in the first portion to overcome the spring force, separate the rotor and the stator, and enable rotation of the second drive shaft. 
     
     
         14 . The actuation system of  claim 11 , wherein the braking assembly includes
 a first knurled surface mounted on the second drive shaft,   a second knurled surface mounted proximate to the first knurled surface, and   a spring that biases the second knurled surface against the first knurled surface with a spring force to prevent rotation of the second drive shaft when the drive coupling assembly is in the second position.   
     
     
         15 . A drive coupling assembly for driving variable area fan nozzle with a motor of an aircraft, the assembly comprising:
 a first portion coupled to the motor; and   a second portion coupled to the nozzle, the second portion having a first position engaging the first portion in which the torque from the motor is transferred to the nozzle to translate the nozzle and having a second position decoupled from the first portion in which the torque from the motor is not transferred to the nozzle.   
     
     
         16 . The drive coupling assembly of  claim 15 , wherein the first portion includes a first end face with pins extending therefrom. 
     
     
         17 . The drive coupling assembly of  claim 16 , wherein the second portion includes a second end face with tabs extending therefrom that define gaps between adjacent tabs. 
     
     
         18 . The drive coupling assembly of  claim 17 , wherein, in the first position, the pins of the first end portion extend into the gaps to engage the tabs of the second end portion to transfer torque between the first portion and the second portion. 
     
     
         19 . The drive coupling assembly of  claim 18 , wherein the first end portion further includes recesses to house the pins in a retracted position and springs to bias the pins into an extended position. 
     
     
         20 . The drive coupling assembly of  claim 19 , each of the pins is configured to retract into the retracted position upon initial engagement with one of the tabs until rotation of the first portion aligns each of the pins with the gap to enable extension of each of the pins into the gap.