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Torque Required To Lift

  • #1

Homework Statement


Question refers to the torque required to lift the nose wheel of an aeroplane

A retracting nose wheel assembly is raised by the application of Torque T applied to link BC through a shaft B. The wheel and Arm AO have a combined mass of 50KG with a centre of mass at G. Find the value of T necessary to lift the wheel when D is directly under B at which position angle θ is 30 degrees

Homework Equations



I have attached the figure that came with this question

T= r x F x Sinθ where T = Torque, r = Length of the Arm, F = Magnitude of the force and θ = the angle between the two arms, but i am unsure if this is what i use to find Torque required to lift

The Attempt at a Solution



I have set up my own free body diagram representing this question however the part i am struggling with is setting up the equations required and getting started.
parts i am having problems with are for the Moment Arm (D) part of the equation, is this length BC and how do i determine the Force part of the equation, I know the mass is 50kg and acceleration is Gravity = 9.8 ? any help that could point me in the right direction would be greatly appreciated
 

Attachments

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Answers and Replies

  • #2
Here is my attempt so far

F = 50 x 9.8
= 490 N

T = 500mm x 490 x sin(30)
T = 122.500

I have no idea to tell if this is on ther right track or not
 
  • #3
Astronuc
Staff Emeritus
Science Advisor
18,706
1,720
One has to determine the force applied by arm CD acting at D, which lifts G through moment arm AG.

The force at D applies an opposite force at C on moment arm BC.

The torque at B must balance FC acting at C of moment arm BC. When D is directly under B, BC and CD are the two legs of an isoceles triangle with base BD.
 
  • #4
Ok so would the Force acting at C Be the Weight of the wheel plus gravity acting to pull CD down? in this case 490 N? therefore the torque must be able to balance 490 N of opposite Force? I am still unsure how to determine the force required by Arm CD acting at D to lift G, and once i determine this Force how to translate it to Torque.
 

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