Gear Train Application (continued)

 

Step 3:  Calculate Shaft Torques:  (repeated for clarity)

 

Now  T1  =  R1 F,  so  F  =  T1 / R1  =  TA / R1   .   (Torque in Shaft 1)

 

So      T2  =  R2  F  =  TA (R2 / R1)                         (Torque in Shaft 2)

 

In general:  angle of twist  =    φ    =  T L / J G

 

where  T = torque in shaft,  L = length of shaft,  J = polar moment of inertia of shaft

   and   G = shearing modulus of elasticity

 

 

Step 4:  Calculate rotation of gear 2 relative to the fixed end of shaft 2, D.

 

             φC/D  =  T2 L / J G  =   [TA (R2 / R1) L] / J G     where  J  =  π d4/32

 

                          

 

 

For continuity between gears:  R2 φC/D   =  R1 φ gear 1   (The displacements must be equal.)

 

So  φ gear 1  =  ( R2 / R1 ) [TA (R2 / R1) L] / J G  =  [TA (R2 / R1)2 L] / J G 

 

 

Step 5:  Calculate   φA/B:     Here:   φA/B  =  T1 L / J G  =  TA L / J G 

 

Click here to continue with this example.

 


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