Question

While testing a wheat thresher at recommended throughout 80 Nm torque is recorded at 850 rpm at the main shaft of the threshing cylinder, which is operated by a 200-mm diameter pulley. The overload factor and unit mass of V-belt are 1.2 and 0.9 kg/m respectively. At condition of maximum power transfer the maximum tension in V-belt in N is __________

(a) 813.86

(b) 613.86

(c) 413.86

(d) 213.86

I had been asked this question in an interview.

My doubt stems from Mechanical Power Transmission topic in division Mechanical Power Transmission of Farm Machinery

Answer 1

The correct choice is (d) 213.86

Easiest explanation: v=\(\frac{πDN}{60}=\frac{π*0.2*850}{60}\)=8.90 m/s

Tc = mv^2 = 0.9*(8.90)^2 = 71.289 N

Tmax = 3Tc = 3*71.289 N.