How do automatic transmissions work?

Automatic transmissions are one of the least understood mechanisms, but they are some of the most widely used IN THE UNITED STATES. Almost all cars on the road IN THE UNITED STATES have an automatic transmission. In this video I will use my 3d printed model of an automatic transmission to show you (generally) how they work.

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Happy printing,
Steven

[Joso]

Almost all car on the road in the US are automatic. In Europe it is the other way around.

[Ayvazovsky_kar]

Exactly every tutorial on YouTube showing how “automatic transmission works “ just showing how the planetary gears rotate. No explanation how why and what’s the “automatic “ thing there.
No doubt, great job with 3D printing!

[abdulmuqsit]

While watching, I felt like I understood everything. And then the video ended and I still have no idea how an automatic transmission works

[dbspecials]

That's how the planetary gear set works. but the units themselves are essentially hydraulically driven. you now have to get into the operation of that system with the fluid pump, the valve body and torque converter. the latter being one of the most misunderstood components, not so much the gear box.

[logiclrd]

This explains how the gearing works but not what makes it automatic. How/when are those shifts actually made?

[maciekson]

How do I know author lives in USA?
"Almost all car on the road are automatic" 🤣

[peckergaming]

This is more like a planetary gear transmission rather than how an automatic transmission works.

[Itsdirtnaptime]

I love when people are able to use tools, that people are really getting into, to explain science. Such as this makes it easier for the younger generation to understand this kind of mechanism without needing to go to college for engineering. Younger people already have their 3d printers so this becomes more relatable. Good video.

[TheOpacue]

This didn't explain how an automatic transmission works? Just ow planetar gearing works, no? I mean, how does the gerabox determin which gears to use, isn't that the "automatic" part of it, which you didn't explain at all?

[maratmkhitaryan]

Toque converter is also very important part of automatic transmission, as it allows to make your car stay still without turning off your engine.

[SuchByte]

"Amost all cars on the road are automatic"
Laughs in Germany

[squishy]

Nice. I'm still working on mine. Trying to figure out how to simulate the clutch packs. There's 5 of them and 3 planetary sets, as well as two 1-way clutches. I keep getting distracted with side projects. Will finish sometime this year I hope.

[Nathan-mupz]

Works every time without fail. Just search YouTube and you can fix your own car in no time! Thanks for the tutorial! Saved me thousands of dollars in repairs!

[Ehrlichkeit]

My Hero!
The most important thing noone else mentioned (that easy) until now ist the shared sungear! That was the one thing I needed to finally understand this simply built mechanism! 🙏🏽

[xcoder]

The majority of cars world wide still use manual transmission. Up to 2018, the majority of cars sold in Germany had manual transmission, only in 2019 the automatic ones overtook them (55% automatic), however, this is for new cars sold, not cars on the road. Actually the reason why manual transmission will soon die out is not because of automatic transmission but because of electric cars. Also the majority of German automatic cars don't use an automatic transmission as shown in that video, actually they use the same transmission that a car with manual transmission does use, it's just operated automatically and has two clutches, which allows for very smooth transmission without any noticeable tractive force interruption while doing so.

[james]

Well that's just a planetary gear set which can exist in manual transmissions too but really doesn't explain how automatic transmissions work at all the are hydraulic circuits and steels and frictions and accumulators and all kids of stuff I mean I really have only messed with a 4l60e so I don't know much about others but they are mostly kinda similar

[theresemalmberg]

This is very interesting. Before I retired I worked in a plastic factory that made components for automatic transmissions. Now I understand what the parts I made did.

[jimmyd]

it would be awesome if we could have a model of ravigneaux gearset, which can provide several gear ratios in a compact design.

[michaelchan]

It's worth mentioning that for a reverse rotation output, the planet carrier would have to be the held member of the three. A very good video nonetheless. Now add some other videos of how a torque converter and valve body works to give viewers a complete picture of how an automatic transmission works.

[ilmt]

Nice job! Nevertheless what I'm missing here, is how this works automatically - you still manually select which handle to hold.
This type of gearbox was selected for automatics because it is simpler to control. But how the car choose which gear to select? Was it always computer, or were there some clever mechanical ways (in older cars)?