Homework Help: Centrifugaleffect on lubricant exerted on small or large gear

1. Aug 2, 2014

klauspetersen

Chain lubricant must be applied to two gears connected by a chain.

The two gears are of different size. The question is now, if it is better to apply the lubricant at the larger or smaller gear, if we wanted to minimize the amount of lubricant lost due to centrifugal force.

The math:

Centrifugal force:

F= V^2 / R

Since the two gears are connected by a chain, V should be the same. Therefore my math intuition says that the larger of the gears would exert less centrifugal force on the lubricant. Am i correct in this analysis?

2. Aug 2, 2014

Simon Bridge

Welcome to PF;
That sounds like safe reasoning for that question: you are saying that since the speed of the outer rim of each gear is the same (due to chain) then the centrifugal force is inversely proportional to the radius of each gear. Therefore: applying lube to the bigger cog minimizes the force. Assuming the lubricant sticks equally hard to each gear, this minimizes the potential loss of lubricant due to the centrifugal effect.