How does an Oscillating Fan work?

Summary

In this educational video, Jared explores the inner workings of a household fan, highlighting its gears, levers, and oscillation mechanism. He explains the fan's speed control buttons, pitch adjustment dial, and oscillation pin, and uses 3D animations to illustrate the fan's operation. Jared delves into the four-bar mechanism that enables the fan's side-to-side movement and the gear system that converts the fan's rotation into the crank's slower oscillation. He also shares a personal mishap with the fan's ball bearings, offering a cautionary note for viewers who might disassemble their own fans.

Takeaways

• 🔧 The household fan features intricate mechanisms, including gears and levers, which enable it to oscillate.
• 🎥 Jared, the creator of 3D animations, explains the fan's workings through a detailed video.
• 🔘 The fan has four buttons at the bottom: three for speed settings and one white button to turn the fan off.
• ⚙️ Each button operates a mechanism with a spring and metal plate to toggle the fan speed.
• 🔌 Pressing a button sends a signal through color-coded wires to the motor, controlling the fan's speed.
• 🔄 The oscillation feature is achieved by converting the fan's spinning motion into a side-to-side motion using a four-bar mechanism.
• 🔄 The four-bar mechanism includes a fixed bar, a crank, and two other bars that follow the motion to create oscillation.
• 🐛 The gear box contains a 'worm' that, when spun by the fan, engages with a worm gear to initiate oscillation.
• 🔩 The pin with ball bearings connects the gears and, when pressed down, allows the fan to oscillate; when released, it stops the oscillation.
• ⚖️ The gear combination inside the gear box is designed to slow down the crank's speed, ensuring the fan oscillates at a functional rate.

Q & A

What is the main focus of Jared's 3D animations?

Jared's 3D animations focus on demonstrating how various things work, particularly the mechanisms and inner workings of objects.

What is the purpose of the buttons at the bottom of the fan?

The buttons at the bottom of the fan are used to set the fan speed, with three buttons for different speeds and a white button to turn off the fan.

How does the pitch adjustment dial on the fan work?

The pitch adjustment dial on the fan is used to change the angle of the fan blades, allowing for different air distribution patterns.

What is the function of the pin on top of the fan?

The pin on top of the fan is used to engage the oscillation feature, making the fan move back and forth to cool more of the room.

How does the button mechanism inside the fan control the speed and operation?

Each button has a spring underneath it and a metal plate inside that slides to the left when a button is pressed, clicking into place to hold the button down and control the fan speed. The white button releases any of the other buttons, turning off the fan.

What is the role of the color-coded wires coming out of the back of the fan?

The color-coded wires are used to send a signal up to the fan's motor, initiating the fan to spin at the selected speed when a button is pressed.

Can you explain the concept of a four-bar mechanism as it relates to the fan?

A four-bar mechanism is a system of four bars connected by pins, with one bar fixed in place. The lengths of these bars determine the motion they produce. In the fan, this mechanism is used to convert the spinning motion into a side-to-side oscillating motion.

What is the function of the worm and worm gear in the fan's gear box?

The worm and worm gear in the gear box are part of the mechanism that converts the spinning motion of the fan into the oscillating motion. The worm gear is connected to a pin that, when engaged, causes the fan to oscillate.

How does the pin's position affect the fan's oscillation?

When the pin is down, it engages with the worm gear, allowing the fan to oscillate. When the pin is up, it disengages, causing the fan to stop oscillating and point in one direction.

What is the purpose of the ball bearings and spring in the gear box?

The ball bearings and spring in the gear box are part of the mechanism that connects the pin to the worm gear. When the pin is pressed down, the spring forces the ball bearings out to engage with the worm gear, enabling the fan to oscillate.

Why is the speed of the crank slower than the speed of the fan?

The speed of the crank is slower than the fan to ensure the oscillation happens at a practical and controlled speed. If the crank spun as fast as the fan, it could lead to mechanical failure.

Outlines

00:00

🛠 Exploring the Household Fan's Mechanisms

In this segment, Jared introduces the inner workings of a household fan, focusing on its oscillating feature driven by gears and levers. He invites viewers to his YouTube channel for more educational animations. The fan's features are outlined, including speed settings, pitch adjustment, and oscillation control. Jared notes that while fans may vary, the mechanisms are likely similar, with exceptions for box, tower, or bladeless fans. He dismantles the fan to reveal its top components and uses 3D animation to illustrate the fan's operation. The fan's control buttons are detailed, explaining the spring mechanism that releases previous button presses when a new one is selected. The white button is unique in its function to release all buttons and turn off the fan. The video transitions to discuss the fan's oscillation, introducing the concept of a four-bar mechanism and how it's adapted in the fan to create a side-to-side motion. The gear box's role in converting the fan's spinning motion into the crank's rotation is highlighted, with a focus on the worm and worm gear's interaction.

05:01

🔩 Understanding the Oscillation Gearbox

This part of the video delves into the gearbox's role in the fan's oscillation. The worm, worm gear, and pin with ball bearings are central to this mechanism. The worm's rotation, driven by the fan, spins the worm gear, which in turn spins the pin connected to other gears. This action causes the crank to rotate, initiating the four-bar mechanism and making the fan oscillate. The pin's position dictates whether the fan oscillates or remains stationary. When the pin is up, the fan points in one direction; when pressed down, the fan oscillates. The segment also addresses the importance of the gearbox lid in keeping the ball bearings in place when the pin is up, preventing them from flying out. Lastly, Jared points out the necessity of gear ratios to slow the crank's speed for proper oscillation, ensuring the fan doesn't break due to excessive speed.

Keywords

💡Mechanism

A mechanism refers to a system of parts working together in a machine to produce motion or perform a function. In the video, the term is used to describe the various parts and their interactions within the household fan, particularly the gears and levers that enable the fan to oscillate. The script mentions exploring the 'neat mechanisms' of the fan, highlighting the intricate design that allows for its functionality.

💡Oscillate

To oscillate means to swing back and forth regularly around a central point. In the context of the video, the fan's ability to oscillate refers to its movement from side to side, which helps distribute air more evenly across a room. The script describes how the fan's design incorporates a mechanism to achieve this oscillating motion.

💡3D Animation

3D animation is a technique of creating three-dimensional, computer-synthesized images that appear to move over time. The video's narrator, Jared, specializes in making 3D animations to illustrate how things work. The script mentions that the 3D animation will 'do all the hard work' of explaining the fan's mechanisms, providing a visual aid to the viewer.

💡Fan Speed

Fan speed refers to the rate at which a fan rotates, which affects the volume of air it moves. The script describes a feature of the fan that allows users to set different fan speeds using buttons at the bottom of the device, demonstrating how the fan's functionality can be adjusted to user preference.

💡Pitch

In the context of a fan, pitch refers to the angle at which the fan's blades are set, which can affect the direction and distance of the air being moved. The script mentions a dial to adjust the pitch of the fan, indicating another way users can customize the fan's performance.

💡Four-bar Mechanism

A four-bar mechanism is a basic mechanical system consisting of four bars connected by pivots, often used to convert rotational motion into linear motion or vice versa. The script explains how this mechanism is used in the fan to convert the spinning motion of the fan into a side-to-side oscillating motion.

💡Worm Gear

A worm gear is a type of gear used in a gearbox to convert rotational motion into a slower rotational motion or to change the direction of rotation. In the script, the worm gear is described as part of the gear box that interacts with the worm to enable the fan's oscillation.

💡Crank

A crank is a lever or a rod that is pivoted at one end and used to turn a wheel or to perform work. In the video, the crank is one of the bars in the four-bar mechanism that is connected to the fan's motor and is responsible for the fan's oscillating motion.

💡Ball Bearings

Ball bearings are rolling-element bearings that reduce rotational friction and support radial loads. They are mentioned in the script as part of the mechanism that connects the worm gear to the crank, allowing the fan to oscillate when the pin is pressed down.

💡Gearbox

A gearbox is a transmission device that changes the speed and torque of a rotating system. In the video, the gearbox is where the magic happens, as it contains the worm and worm gear that interact to convert the fan's spinning motion into the oscillating motion of the fan.

💡Spring

A spring is a mechanical device that stores energy and returns it when released, often used to maintain tension or to return parts to a position. The script describes springs in the fan's button mechanism that push the buttons back up and in the gearbox that helps control the oscillation.

Highlights

Jared introduces the household fan's internal mechanisms, focusing on gears and levers that enable oscillation.

The fan features buttons for speed control, a dial for pitch adjustment, and a pin for oscillation.

Jared's 3D animations demonstrate the fan's workings, inviting viewers to explore more on his YouTube channel.

The fan's bottom section houses the control buttons, each with a spring mechanism for automatic release.

A metal plate with jagged cuts is pushed by a spring, sliding left when a button is pressed.

The white button is unique, serving to release other buttons and turn off the fan without holding a position.

Three color-coded wires transmit button-press signals to the fan's motor for speed control.

Oscillation is achieved by converting the fan's spinning motion into side-to-side motion using a four-bar mechanism.

The four-bar mechanism's configuration is detailed, with one bar fixed and others moving to create oscillation.

The gear box contains a worm and worm gear, crucial for converting fan rotation into crank rotation.

The pin's gear teeth connect the gears, with a spring and ball bearings allowing it to engage or disengage with the worm gear.

When the pin is down, the fan oscillates; when up, it remains stationary due to the pin's disengagement from the worm gear.

Ball bearings in the gear box prevent the pin from falling and keep it in the up position when not in use.

The fan's oscillation speed is controlled by a combination of gears to ensure a slow, steady motion.

Jared shares a personal anecdote about losing and finding ball bearings, cautioning viewers if they attempt to disassemble the fan.

Transcripts

- [Jared] The inside of this household fan

has some neat mechanisms

especially the gears and levers

that cause it to oscillate back and forth.

Let's take a closer look.

(electricity whirring)

My name is Jared

and I make 3D animations (metal thudding)

on how things work.

After this video, make sure to visit my YouTube channel

to see more animations.

(upbeat music)

First, a quick tour of the features of this fan.

At the bottom are the buttons to set the fan speed,

a dial to adjust the pitch of the fan,

and then the pin on top to make the fan move back and forth.

You know the drill by now.

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.

So sit back and relax and we'll let the 3D animation

do all the hard work.

Okay, let's start at the bottom

and go through this in detail now.

Four buttons, three speeds,

and then the white one turns off the fan.

Each time you press down a button,

the previous ones are released.

The white button turns the fan off.

It also doesn't stay down like the other buttons do.

And if you've been following my YouTube channel,

you know that I like to explore different mechanisms.

And there is definitely a mechanism here.

Let's take a look.

Each button has a spring underneath

that wants to push the button back up.

Inside is a metal plate

with a few jagged cuts going down.

This metal plate is being pushed to the right

by this spring.

By pushing down a button, the plate slides to the left.

Push down far enough and it clicks into place

preventing the button from coming back up.

Press down another button and the plate slides enough

to release the first button.

The sole reason for the white button

is to release any of the other buttons.

You'll notice that there's no notch to hold

the white button down.

Releasing the other buttons will then turn off the fan.

Coming out the back here is three color-coded wires.

Whichever button is pressed will send a signal

up the wire to the top of the fan

and into the motor to start the fan spinning

at whatever speed we choose.

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.

Let's take a step back so we can understand

the concepts behind this.

This is called a four-bar mechanism.

Each bar is connected by pins

which allow them to rotate freely.

One of the bars is usually fixed in place

so that it can't move.

This one is called the crank.

Usually a motor is causing it to rotate around.

These other two bars are forced to follow the motion.

By changing the lengths of these bars,

we can get some different motions.

Let's focus in on this configuration.

Normally the green bar is the one that's fixed in place.

Watch what happens when instead the small blue bar

is fixed in place.

Now watch the motion of the green bar.

Notice how it goes back and forth about the same amount.

And this is how we get that oscillating motion

for the fan.

Now let's go back and see how all this works on a fan.

So the four bars on a fan are right here.

This is the short bar that's fixed in place.

There's a long bar here.

And another long bar, which in this case is the motor.

And then the last bar which is the crank.

This is the one that has to rotate to get the fan

to start oscillating.

But there's still a missing piece.

How do you convert the rotation of the fan

to the rotation of the crank?

The magic happens inside of the gear box.

There's a piece that sticks out the back

that rotates along with the fan.

This is called the worm.

When it spins, it kind of looks like it's moving

even though it's not.

Right next to it is the worm gear.

Down below is another gear which is directly attached

to the crank.

The pin is what connects all of these gears together.

You can see it has some gear teeth on it.

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.

Let's walk through the whole thing now.

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.

Let's look at the ball bearings again.

When the pin gets pulled up,

the ball bearings would go flying in each direction

if there was nothing to stop them.

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.

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.