speed question?

Question

Main drive gear = 35 teeth
Speed of main drive gear = 450 r.p.m.
countershaft drive gear = 70 teeth

What is the speed of countershaft drive gear in RPM

Answer 1

The formula for the Gear ratio is:
speed A : speed B = number of teeth B : number of teeth A

Thus, smaller gears turn faster than larger gears when connected.

Let A = main gear, and B = countershaft gear.

450 rpm / countershaft speed = 70 teeth / 35 teeth
countershaft speed = 450 rpm * 35/70
countershaft speed = 225 rpm