# Acceleration between gears

Say we have a gearing system of the ratio 4:1 is the acceleration of the smaller gear 4 times greater than the acceleration of the larger gear or do they both accelerate in the same way or is it a completely different more complex relationship? Thank you in advance for any help.

## Answers and Replies

I believe the definition is that the gear ratio is the ratio of the angular velocities of both gears (input over output). So the angular velocity of the input is 4 times that of the output in your example and since they would accelerate in step, I believe the ratio would apply to angular accelerations as well.

OldEngr63
Gold Member
grindfreak is correct; the gear ratio gives the ratio of angular displacements, or angular velocities, or angular accelerations, however you want to look at it.