What Is A Balance Wheel?
The balance wheel regulates the time with a weighted device that swings back and forth inside the watch mechanism. With every swing there will be a tick or beat that stimulates the gears to forward the hands of the watch.
The balance wheel is part of the rotary (harmonic) oscillating mechanism that also includes the balance spring, often referred to as the hairspring. It is this hairspring that brings the balance wheel back to the watch centre after each tick.