Re:Boeing CEO Dennis Muilenburg Addresses the Ethiopian Airl...
by salawat on Saturday April 06, 2019 @10:15PM
(#19594369)
Okay. So after a bit of chewing on the screw jack equations, I settled on using an M24 screw as the basis just for convenience. Eyeballed a video of jackscrew of a 737NG, and figured a 6 inch lever arm. In the form of a pulley of some sort as the input for the screw jack from the trim wheel in the cockpit.
Dropping in the previously calculated wind load of 1015087 N, we end up with an effort force of 3182 N, which through a 6 in pulley would be 485Nm (357 ft-lbs) of torque,
Note, we're in automobile engine levels of torque output to actuate this screw jack against the wind load on the horizontal stabilizer.
Give me a bit to come up with some estimates on the trim wheel and play around with some gear trains to see if I can come up with an arrangement that does the trick.
It should be doable, but with the gear ratios I'm thinking will be required to generate the requisite torque, the actual rate of actuation is going to be pretty slow.
Dropping in the previously calculated wind load of 1015087 N, we end up with an effort force of 3182 N, which through a 6 in pulley would be 485Nm (357 ft-lbs) of torque,
Note, we're in automobile engine levels of torque output to actuate this screw jack against the wind load on the horizontal stabilizer.
Give me a bit to come up with some estimates on the trim wheel and play around with some gear trains to see if I can come up with an arrangement that does the trick.
It should be doable, but with the gear ratios I'm thinking will be required to generate the requisite torque, the actual rate of actuation is going to be pretty slow.