Your fan might be slightly different but the mechanisms I'm about to show you are probably very similar, unless it's a box fan or one of those tower fans or a bladeless fan. These are pretty cool. I might have to do a future video on this. But for now, let's focus on this fan over here. Taking one apart is pretty simple. Several screws in the bottom and plastic pieces to take off. The coolest parts are at the top.
At first, the fan will only be pointed in one direction. If we wanna cool off more of the room, then press the pin and the fan starts oscillating, or, in other words, moving back and forth. We already have and electric motor and you don't wanna add another one. The idea here is to convert the spinning motion of the fan into a side-to-side motion.
First, let's get acquainted with the main clutch components. The primary drive shaft typically contains a stationary electromagnet which is fixed with a flange or torque tab. A rotor is fixed to the primary driving shaft with a key or other connection. Next, an armature is riveted to a flat spring. The flat spring is then riveted or screwed to a hub, or in this case, a pulley, which is then connected to a secondary shaft with a belt.
This is a shaded pole motor and currently as viewed from the output shaft, it's turning clockwise these motors use magnetism and feel to determine which way they run there are no contacts or brushes running on the armature in order to reverse the rotation on this motor. We need to reverse this field this motor is designed to run on AC. The voltage is reversing itself 50 60 times a second depending on where you're at and as long as the motor is made to where you can flip this field.
I also wanna point out that the speed of the crank is much slower than the speed of the fan. If it was spinning as fast as the fan, well, it probably would break before that point. The right combination of gears helps to slow the speed down so the oscillation happens at just the right speed.
This actually happened to me the first time I took apart the fan. Don't worry, I found them again. Just be warned if you try this yourself. What normally prevents this is the gear box lid. Pull the pin up and you can see the ball bearings are forced back in. This is what keeps the pin up. Otherwise it would just fall back down. Press the pin down again and the spring forces the ball bearings out and in contact with the worm gear.