Centreless wheel

Have you ever seen a toy car with wheels? Imagine the middle part of that toy car, where the driver sits, is missing. Now, you just have the two wheels on either side. These two wheels are what we call a centreless wheel.

The centreless wheel is used in machinery like grinding machines, where objects need to be ground or polished evenly. To make sure everything is smooth, the wheel spins very fast on its axis while the object being ground is pushed towards the wheel. But the problem is, a normal wheel with an axle in the middle wouldn't work because the object being ground would just hit the axle and not get ground evenly.

So this is where the centreless wheel comes in - since it doesn't have a centre axle, objects can be pushed against it from any angle and still get ground evenly. This is because the object being ground is pushed between the two wheels, which are spinning in opposite directions.

So to sum it up, a centreless wheel is like a toy car wheel without the middle part, and it's used in machines to grind and polish surfaces evenly. It doesn't have a centre axle, which allows objects to be ground evenly from any angle.