Question

In hydrodynamic lubrication, film thickness remains unaffected by change in speeds.

(a) True

(b) Increase with increase in speed

(c) Decrease with increase in speed

(d) Disappear as the speed tends to infinty

This was presented to me in an online interview.

I would like to ask this question from the Viscosity in Rolling Contact Bearings, Spur Gears and Helical Gears of Machine Design

Answer 1

Optimal answer is (b) Increase with increase in speed

To explain: As speed increases more and more lubricant is forces and pressure builds up thus separating the two surfaces. There is transition from thin film thick film.