We don’t know who invented the first wheel, but we do know that it was one of our most important inventions. Wheels allow us to go places and allow products to be delivered to us. Gears are another important invention. Gears are wheels with teeth. They are simple machines that harness force. Bicycles, non-digital clocks, wind-up toys, and many other machines work with gears.
- Machines typically use two or more gears of different sizes; one gear is often larger than the other.
- The smaller gear usually rotates faster than the larger one. The larger gear typically has more teeth than the smaller one.
- Beveled gears include one gear that sits at an angle to another gear.
Gear: A toothed wheel
Harness: Control or use
Rotate: turn or move in a circle
Q and A
Question: Why would I use gears of different sizes?
Answer: One reason is to save energy. When a big gear is connected to a smaller gear (a gear train), the bigger gear drives the smaller one, making it go faster. Yet, the bigger gear continues to move at a slow pace, saving energy and effort.
Watch this video to learn more about gears.