Engineering 11
Torque and Gear Ratio Worksheet
Name:
Show your work.
1) Looking at the gear train to the right, if the driver gear was 10 teeth and
the follower gear was 40 teeth, what would be the gear ratio
follower/driver= 40/10=4:1
2) If a motor runs at 200rpm and you have a gear ratio of 50:1, what is the about rpm at the output axle?
200 rpm/w in = 50/1
w in/ 4 rpm
3) You have a vehicle with a 100rpm motor which is attached through gears to an axle. The wheels
attached to the axle have a diameter of 20cm. If the vehicle is capable of travelling 40km/h, what is the
gear ratio?
200 rpm/ 10 rpm= Gr/1
GR=10.1
rpm=(25/3r)
D=2r
rpm=25/3(10cm)(40)=10
4) You have a fan blade that needs to travel at an RPM of at least 2000rpm. A vex motor rotates
at 100rpm.
a) What is the gear ratio needed to achieve this?
w in/w out = 100 rpm/2000 rpm = 0.05:1
b) If an infinite amount of gears available to you are 12, 48, 60 and 84 tooth,
what gears will you use? Draw and label them.