How Torque Converters Work! (Animation)

The torque converter is often seen as the most complicated part in vehicles of today. It is, however, a very important component of automatic transmissions. This animation explains the theory behind this complex component.

Contents
1) Torque converter impeller
2) Blades and fluid of impeller
3) Centrifugal forces caused by rotation of impeller
4) Torque converter turbine
5) Fluid flow between impeller and turbine
6) Fluid coupling
7) Torque converter stator
8) Housing, lock-up clutch and shaft
9) Stages of operation: stall, acceleration, coupling

[Pretermitted]

The genius behind this is so undervalued. Imagine having to come up with this on your own where would you start?

[deusexaethera]

The stator assembly never seems to be explained adequately, so I will explain it now:

The stator redirects fluid flow exiting the input turbine, so the fluid impacts the output turbine more forcefully. This allows the fluid to transfer its kinetic energy to the output turbine more effectively. However, the stator also creates a lot of turbulence in the fluid, and therefore wastes some amount of energy in the process.

To minimize this effect, the stator is mounted on a one-way bearing that allows it to spin freely in one direction, so it stops interfering with fluid flow when the torque converter is spinning at high speed. This "unlocking" occurs once the entire torque converter is spinning fast enough that the forward rotation of the torque converter overwhelms the force of the fluid trying to spin the stator backwards.

Since the force trying to spin the stator backwards depends on the total amount of force being transmitted through the torque converter, that means the exact moment when the stator unlocks and starts spinning depends on how hard the vehicle is accelerating.

In layman terms, the stator is always locked when the car first starts accelerating, and it unlocks when you finish accelerating and start cruising at your intended speed. You can re-lock the stator by stomping on the gas pedal, and you can unlock the stator again by easing off the gas pedal or coasting. There's no reason for you to do this on purpose, though, because locking the stator is only useful during hard acceleration, and the extra efficiency from unlocking the stator only matters at high speeds. Just let the stator do its job and drive the car normally.

[Bassotronics]

In short, my car is moving due to the kinetic force of a liquid. It's amazing how much force is applied to a liquid which can move tons of metal up a hill.

[AspectOfTheStorm]

Ah! He said the magic words. "Because the fluid flows back more slowly". I just watched over an hour of videos on torque converters and kept failing to realize the relationship between the stator, when the clutch engages and its purpose, and how the torque is physically multiplied. But now it makes sense. Since the pump is constantly spinning at engine speed and there's pressure being built up at the stator, adding more "leverage", if you will to the pump. And when this leverage is no longer needed at high speed the clutch is engaged essential making it 1 synchronized mechanism.

[TheRobDog]

Just discovered these videos and as an engineering student I think you're doing an incredible job man! It's interesting how little people know about a vehicle that they use on a daily basis and by explaining components with exploded views and your steady voice it is extremely helpful it providing people with valuable information that will let them understand their pride and joy (cars) better. Great job, man. Keep it up! :)

[haraldgrnvold]

This might be the best video on the subject on youtube. Perfect animation on the principle in place. - Norwegian mechanical engineer

[egustafson]

Best interpretation of a torque converter I've ever seen. I've always pictured in in my head but but you've made my dreams come true!

[johngraham]

outstanding, precise, sufficient detail and concise, many others could learn technical presentation from you.

[AutOdometer]

literally the BEST torque converter explanation ive seen on the web thank you!

[devilinblue]

Ah YouTube, 139, 865, 329 cat videos...
But for every 1000 cat videos, there is one really useful video like this one. Great job!!

[baptizedbyfire]

I am impressed with this video. What I am even more-so impressed with is the majority of intelligent YouTubers responding to this video. Seriously, I could spend all day reading the observation and responses and complimenting on many. Some real bright individuals who simply "get it". Now if only I could surround myself with people like this in my real life. My colleagues here at work are a joke.

[olivor_h]

This video is excellent, a perfectly clear and understandable explanation of a fairly complex device.

[akrish]

this is by far the best explaination of torque converter in youtube

[GeneralCuster]

Can't even being to imagine how long it took someone to figure all of this out... wonderful explanation! Thank you!

[YouTubestopsharingmyrealname]

This is the Best animation I have seen for torque converter operation. Great work!

[slashusr]

Brilliantly presented and explained! A much more complicated an invention than say, the wheel; yet demonstrated with such clarity that even a Sumerian might understand. Thank you, Thomas Schwenke!

[fawkesash]

Amazing ! I never comment on videos but I am mechanical engineer who design engines and I was fascinated. This is how you create videos / presentations !! Kudos Sir !

[DaBoogie]

Die Animationen und der Kommentar, das ist ganz tolle Arbeit! Sehr durchdacht und sehr anschaulich erklärt!

[msnmath]

It’s amazing that a team of mechanical engineers and physicists came up with this genius device. To just sit there and brainstorm this is amazing to me

[waverlh]

I've been looking for a video that would quickly demonstrate the fluid flow of a converter. Well done!