How does an Oscillating Fan Work?
Some fans have a dial in the middle to make it move up and down, and a pin on top to make it move back and forth. On those old fans, they have 4 buttons, three speeds, and a white button that turns it off. When you press another button, the others get released. The white button however doesn’t move. Each button has a spring underneath that wants to push the button backup. Inside there are a few metal plates that have a few jagged cuts going down. The metal plates get pushed by a spring. By pushing the buttons, the plates slide left. Push down far enough, and it clicks into place, preventing the button from coming back up. Press another button and the plate slides enough to release the first button. The reason for the white button is to release any of the other buttons. There’s no notch to hold the button down. Coming out the back there are three color-coded wires. Whichever button is pressed, it will send a signal up a wire to the top of the fan, and into the motor to start the fan spinning at what speed you chose. If you want to cool off more room, press the pin, and the fan starts oscillating, or moving back and forth.
The idea here is to make the spinning motion of the fan into a side-to-side motion. This is called a four-bar mechanism. There are 4 bars, and each bar is connected by pins which allow them to rotate freely. One of the bars is usually fixed in place, so it can’t move. Attached to the left of the bar is called a crank. It is usually rotated by a motor. The top and right bars are called coupler and follower. They just follow the crank’s motion. Changing the length of the bar changes the rotations. The bars are in the upper middle of the fan. That’s how the fan rotation’s work. The way the fan works is inside the gearbox. Inside the gearbox, there is a piece that sticks out the back that rotates along with the fan. The piece is called a worm. When it spins, it kind of looks like it’s moving even though it’s not. Right next to the worm is the worm gear. Down below is another gear that is directly attached to the crank. The pin is what connects all these gears together. Towards the top of the pin, there’s a spring with two ball bearings. They come out just far enough to catch the worm gear and spin with it. The fan is on, which spins the worm and the worm gear. This spins the pin, which spins the next gear, which turns the crank causing the four-bar mechanism to oscillate the fan back and forth. This only works when the pin is down. When the pin is up, it doesn’t rotate along with the worm gear so nothing else below it will move. This means the fan will continue to point in the same direction. But if we press the pin down, the fan starts to oscillate again.
Comments