3.1. CHANGES IN SPEED + 3.2. SPEED RATIOS

3.1. Changes in speed

If we want to increase speed of a rotary system, first wheel (input motion) has to be bigger than second wheel (output motion), and vice versa.

3.2. Speed ratios

The relationship between the speed of the two wheels is inversely propotional to their sizes.

                                                        N2 / N1 = D1 / D2

This relationship is called the ratio of transmition, where N is the speed of rotation and D is the diameter of the wheel.