Eccentric (mechanism)

An eccentric mechanism is a way to turn a circular motion into a back-and-forth motion.

Imagine holding a spinning top in your hand and sliding your other hand up and down the stem. As the top spins, the stem wobbles back and forth. This is kind of like what an eccentric mechanism does!

The eccentric mechanism has two parts: an eccentric wheel and a rod. The eccentric wheel is like a circle that's been pushed to one side. It's not centered, so as the wheel spins, it makes the rod move up and down in a pattern.

Think of a fancy music box. When you wind it up and it starts playing music, there might be little drum-like things with a bump on them. As they spin around inside the music box, they hit little metal tines, making them vibrate and create sound. Those little drum-like things are an example of an eccentric mechanism.

One common use for an eccentric mechanism is in engines. An engine needs to turn a circular motion (the pistons moving up and down) into a back-and-forth motion (the wheels turning). Inside the engine, there are usually some gears that connect the spinning of the pistons to an eccentric camshaft, which then turns the wheels. It's all very complicated, but the important thing to remember is that an eccentric mechanism is a way to turn a circle into a wobble!