engineering recuitment Cochin Shipyard Executive Trainee Mechanical Mock Test Theory of Machines Gear Trains
If t and T are the number of teeth on pinion and gear, G is gear ratio, Ap is the fraction by which the standard addendum of one module is multiplied and ϕ is the pressure angle, the expression minimum number of teeth on the pinion to avoid interference when pinion and gear have an equal number of teeth is given as
1
t = 2 Ap/ (1 – 3 sin2ϕ)1/2 + 1
2
t = 2 Ap/ (1 + 3 sin2ϕ)1/2 + 1
3
t = 2 Ap/ (1 – 3 sin2ϕ)1/2 – 1
4
t = 2 Ap/ (1 + 3 sin2ϕ)1/2 – 1