3.1 Changes in speed

If we want to increase the speed of a rotary system, we must transmit motion from a larger (input) element to a smaller (output) element. However, when we increase the speed we also decrease the rotary force, or torque.

The opposite is true if we want to decrease the speed of a rotary system. We must transmit motion from a smaller (input) element to a large (output) element. At the same time, we also increase the torque. If the input and output elements are the same size, the rotary speed remains constant. The rotary force will also remain constant.