Question

question 8
a simple gear train has four gears. the driving gear (a) on the left has 60 teeth. the idler gear b has 24 teeth and idler gear c has 72 teeth.
the driven gear (d) on the right has 60 teeth. will the driven gear turn faster, slower, or at the same speed as the driving gear?
a b c d
faster
slower
at the same speed

Explanation:

Step1: Recall gear speed ratio rule

The speed of gears is inversely proportional to their number of teeth, and idler gears do not change the overall speed ratio between driving and driven gears, only direction. The overall gear ratio $GR$ is $\frac{\text{Number of teeth on driven gear}}{\text{Number of teeth on driving gear}}$.

Step2: Calculate gear ratio

$$GR = \frac{\text{Teeth of D}}{\text{Teeth of A}} = \frac{60}{60} = 1$$
A gear ratio of 1 means the angular speed of the driven gear equals that of the driving gear.

Answer:

At the same speed