In an epicyclic gear train, the internal wheels B and A and compound wheels C and D rotate independently about axis O. The wheels E and F rotate on pins fixed to the arm G. E gears with A and C and F gears with B and D. All the wheels have the same module and the number of teeth are : TC = 28; TD = 26; TE = TF = 18.

1. Sketch the arrangement ;

2. Find the number of teeth on A and B ;

3. If the arm G makes 100 r.p.m. clockwise and A is fixed, Calculate the speed of B ; and

4. If the arm G makes 100 r.p.m. clockwise and wheel A makes 10 r.p.m. counter clockwise ; Evaluate the speed of wheel B.