Gears are some of the most important simple machines we use in the modern world, even with the advances in technology we’ve seen unfold in the past decade. The magic of gears lies in the transference of directional power, and for that to occur as desired, gears need a proper “gear ratio” in relation to one another.
Gear Ratios in a Nutshell
The gear ratio is the ratio between the quantity of teeth on two gears that are turning together. It may also apply to two sprockets connected by the same chain or pulleys connected by a drive belt.
For example, if one gear has 21 teeth, and the gear next to it has 12 teeth, you could write that gear ratio as 12:21 or, simplified, 1:1.75. In a practical sense, for every one time the 12-tooth gear turns, the 21-tooth gear will turn 0.57 times, which is (1/1.75).
Working With Bigger Gear Ratios
If you add more gears to a system, the gear ratio can continue to develop. For example, let’s say there’s a gear at the end with 42 teeth. The gear ratio between gear 2 and gear 3 is then 1:2, so for every revolution gear 2 makes, gear 3 makes half a turn. So for every turn gear 1 makes, gear 3 makes about 0.29 turns (0.57/2). That results in a total reduction of the system of 3.45.
Gear Ratios at Work
Gear ratios are especially important for complex systems, like the gears in your car. For example, “first gear” may have a ratio of approximately 3:1, while “fifth gear” may have a ratio of 0.85:1, utilizing the transmission’s output to control vehicular speed.
If you’re interested in finding the best gear ratio for your system, or manufacturing your next gear project, contact Federal Gear today!