Question

In a tractor differential, the pinion on the propeller shaft has 12 teeth and the crown gear has 50 teeth. The propeller shaft rotates at 1500 rpm and the right rear axle rotates at 250 rpm while taking a left turn. The rotation of the left axle in rpm will be __________

(a) 470 rpm

(b) 360 rpm

(c) 570 rpm

(d) 600 rpm

This question was addressed to me in an international level competition.

The doubt is from Mechanical Power Transmission in section Mechanical Power Transmission of Farm Machinery

Answer 1

The correct choice is (a) 470 rpm

The best explanation: \(\frac{Nc}{Np}=\frac{Tp}{Tc} \)

Nc=\(\frac{Np*Tp}{Tc}=\frac{1500*12}{50}\) = 360 rpm

Nc=\(\frac{Nll+Nrr}{2} \)

360=\(\frac{Nll+250}{2} \)

Nll = 470rpm.