Question

The axes of the two shafts are intersecting and are at 30° to each other. These two shafts are connected by Hook’s joint. At which position of the drives shaft velocity ratio will be minimum?

(a) 90°, 270°

(b) 0°, 180°

(c) 180°, 270°

(d) 90°, 180°

I have been asked this question in examination.

Asked question is from Universal Joints and Differential topic in section Chassis & Transmission System of Automobile Engineering

Answer 1

Correct choice is (a) 90°, 270°

The explanation is: (ωB / ωA) = (cos α) / (1 – cos^2θ sin^2α) where A = driving shaft and B = driven shaft and α is the angle between shaft  A and shaft B. θ is the angle through which the shaft A rotates. Velocity ratio is minimum when θ = m&pi/2 where m = 1, 3, 5, …… i.e. θ = 90° or 270°.