Planetary Gear Set Operation - AUSV 2520

See a demonstration of the basic mechanical operation of a planetary gear set

TIMELINE:
0:00 Introduction
0:45 The parts of a simple planetary gear set
1:50 Possible gear ratios of a single planetary gear set
2:18 Underdrive gear ratios
2:54 Overdrive gear ratios
3:50 Reverse gear ratios
4:00 Direct drive ratio
4:16 Usable gear ratios
6:18 The physical size of gears is related to their torque capacity
7:35 How power is transferred through a planetary gear set
8:58 Reverse
9:12 Underdrive
10:00 Overdrive
10:25 Direct drive
11:32 The three Allison 1000 transmission planetary gear sets
12:53 Parking gear and pawl
27:05 Function of Five Allison transmission clutch packs
31:25 Allison 1000 Clutch application chart
33:40 Universal transmission operation theory
38:34 Powerflow through the Allison 1000 planetary gear sets
40:37 First gear
42:19 Second gear
43:38 Third gear
44:21 Fourth gear
45:12 Fifth gear
46:10 Sixth gear
46:35 Reverse
47:48 Troubleshooting
50:32 Video summary

This video is intended for students in the online AUSV 2520 Automatic Transmissions class at Weber State University in Ogden, Utah. This class is normally taught face-to-face, but due to the COVID-19 Pandemic in 2020, I am attempting to offer the class material online. Suggested quiz questions are shown below the video timeline.

Questions for teachers:
1. What are the three main pieces of a simple planetary gear set?
2. How many underdrive gear ratios are possible with a simple planetary gear set?
3. How many overdrive gear ratios are possible with a simple planetary gear set?
4. How many reverse gear ratios are possible with a simple planetary gear set?
5. How many direct gear ratios are possible with a simple planetary gear set?
6. How many usable/practical gear ratios are possible with a simple planetary gear set?
7. How is power typically transferred through a simple planetary gear set?
8. How does the parking gear keep the vehicle from rolling in the park position?
9. What does the term "Compound simple planetary gear set" mean?
10. What is the function of the clutch packs in the Allison 1000?
11. What component in a transmission causes clutch packs to apply?
12. What component controls the valves in the valve body?
13. What component controls the electronics in the valve body?
14. Use the Allison 1000 clutch application chart download from below for the remainder of the questions
15. Which clutches are used to provide first gear? Choose two: C1, C2, C3, C4, C5
16. Which clutches are used to provide second gear? Choose two: C1, C2, C3, C4, C5
17. Which clutches are used to provide third gear? Choose two: C1, C2, C3, C4, C5
18. Which clutches are used to provide fourth gear? Choose two: C1, C2, C3, C4, C5
19. Which clutches are used to provide fifth gear? Choose two: C1, C2, C3, C4, C5
20. Which clutches are used to provide sixth gear? Choose two: C1, C2, C3, C4, C5
21. Which clutches are used to provide reverse gear? Choose two: C1, C2, C3, C4, C5
22. Tell me one thing you learned or found interesting in this assignment?

ABOUT US:
Weber State University (WSU) - Automotive Technology Department - Automatic Transmission Lab. A technical description and demonstration of the basic mechanical operation of a planetary gear set in an automatic transmission or transaxle. Components from the Allison 1000 Transmission were used in the majority of this video.

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[darwinrosete]

after watching this..my overall knowleged as human being is completed I can now rule the world..thanks to this guy..👍👍👏👏👏

[preinstalleduser]

There are people who teach and there are people who have the inherent ability to open the minds of other to allow them to see through the otherwise unknown with clarity. Anyone who has the opportunity to sit in the same room with this man should sit quietly with eyes, ears wide open in hopes to absorb as much as possible. Thank you for your contribution to the automotive industry.

[MrPatdeeee]

I studied auto mechanics in Fenger HS in Chicago, in 1949, by a VERY knowledge teacher named "Mr Loizo". Truly the greatest teacher I have EVER known. He was a former GM engineer.

I am 84 now and it took me this long to find a teacher I could call "second" ONLY to my beloved and late Mr Loizo". Thank you so much for making an old man's day in my waning years.

Note: Automatic transmissions were in the VERY infant stages then; and obviously little was able to be taught to HS students. However, we WERE introduced to planetary gears using GM's Hydormatic Transmissions. As I recall, it had 3 sets of PG's. But that is ALL we were shown.

But I never lost my craving for more. So I thirsted for more and more in various and sundry places all these ensuing years. But NOTHING helped me like your unprecedented video. I am blown away.... Wow! I understand it now. Wow! I feel like I could run down the road and "eat the bark off of trees". Yippee!

May Jesus richly bless you and yours always dear sir.

carl dixon

[E-M-Power]

I don't usually post comments. However, I have to say that this Teacher is great. He breaks it down to the basics so well. This demo is the best so far.

[jeffreystroman]

I've been that way too eager student asking questions not necessarily to garner information rather to show others my interest. Sucks I probably came across the same way, great teachers have great patients and I'm thankful I've had many.

[mjbirdClavdivs]

I was watching this because I always wanted to know how planetary gears work, and how they're used in transmissions. So, I'm watching this and my wife, in another room, heard the man's cadence, his self-confidence, and his obvious expertise with the material. She also picked up enough to know that it was about transmissions. This is a great talk and this man is a fantastic teacher.

[ChrisS-xk]

Always wanted to be an engineer, but couldn't do maths and became a lawyer! Never understood how an AT works, but this video is an absolute model of clarity even for the uninitiated, so now I do. Thank you professor.

[Novalrd]

God!! Finally a proper explanation!! Sir you the best. After digging into the internet for 2 months, I finally landed up here to learn the automatic transmission perfectly. The best explanation I have come across.
And for god sake kick that annoying kid out of the class!

[lazylizard]

This is the planetary gears in an automotive transmission explanation I've wanted for 30 years. Thank You!

[pingpong]

I will probably never work on a transmission but this is the best teacher by a mile - I got so many of the concepts from this. Super fascinating.

[jebpab]

BEST TEACHER EVER! I'm an IT guy just surfing for the hell of it and he was able to make even ME understand how it worked. Wow, hats off to him!!!

[hrandhayrapetian]

Thank you professor. You are a very knowledgeable man and a class A teacher. At age 72 I finally learned from you how does an automatic transmission system work and I have learned a lot more from you. Thank you a lot and please accept my best wishes.

[ismaelumpierrez]

It amazes me how simple are in fact those machines, there's a lot of creativity on them. Those are the wonders of engineering in my opinion. Superb explanation professor, thank you very much.

[makeown]

I tried to understand automatic transmission in the past 2 days watching other videos and only until I watch this one when I can totally grasp the concept. This great teacher not only explained how one set of planetary gear set worked but how the whole transmission system operated.

My salute this this great teacher.

[KyleMontanaro]

I always enjoy the videos from Weber State Uni. I don't know how or why they're allowed to put their lessons online, but I sure am happy they do! Excellent lecturers too!

[johnturnbull]

This takes me back to when i was an apprentice 55 years ago, we were sent down to solihul in the midlands to the rover factory for tuition on the Borg Warner auto trans boxes, and the tutor told us always to fit jaguar clutches if possible to obtain them, his reason was because jaguar fitted GM boxes which were the best in the world at that time and the clutches were of top quality materials and therefore the customer would get a good job well done and value for money, We took his advise and continued to do so until i retired with the rest of us.Anyway congratulations i have enjoyed watching and look forward to more of it in the future Regards J.T

[ΦωτεινήΣαριδάκη]

Hi! I'm a Mechanical Engineer and this year, it's my first time teaching Automotive Technology at a Technical Vocational School in Greece. Thank you for teaching me - your help is priceless!!!

[henryjoevenosa]

If I had a teacher like you, who taught in details like you do, I would be dismantling and rebuilding gearboxes like a pro but all I got most was the engine. Your teaching skill is absolutely amazing. Your students should have no excuse of not understanding cos my teacher never came close to your teaching not even an ⅛th. Thanks a lot n God bless your heart

[henryt]

So far, the best tutorial in explaining how an automatic transmission work. The automatic transmission and its inner working was like a black box to me until after seeing this video, everything becomes clear. I have always been pretty mechanical minded, but the workings of the automatic transmission has always been a mystery to me. It is just amazing how simple the principle is and by building multiple clusters, it all works exponentially in its gearing. Brilliant !!!!

[jjmhilu]

Mzee Kelly, is one of the gift from God, imgine audible, clear and brilliant pronounciations which not only make my hand skill job better but also I can understand the american english as well. I wish you visit Tanzania one day. These kind of people in anient times were termed Prophets.