Two shafts A and B are co-axial. A gear C having 50 teeth is rigidly mounted on shaft A. As compound gear D-E gears with C and an internal gear G. D has 20 teeth and gears with C and E has 35 teeth and gears with an internal gear G. The gear G is fixed and is concentric with the shaft axis. The compound gear D-E is mounted on a pin which projects from an arm keyed to the shaft B. Find the number of teeth on the internal gear G assuming that all the gears have the same module. If the shaft A rotates at 110 rpm find the speed of the shaft B. -

Mumbai University > MECH > Sem 5 > Theory Of Machines 2

Marks: 7 M

Year: Dec 2014

Na = Nc = 110 rpm

Ng = 0

Also, Te + Td + Tc = Tg

Tg = 35 + 20 + 50 = 105

From table

M+N = 110 ------------ i

-MTd/Tc x Tg/Te +N = 0

-M20/50 x 105/35 +N = 0

-1.2M + N = 0 --------- ii

Solving i and ii

M = 50

N = 60

As the shaft B is connected to arm, It will rotate at the speed same as that of the arm. (from figure)

Hence,

Speed of B = Narm = N = 60 rpm