Understanding the Tesla Model S Performance Motor

Join me for a deep dive into the details of the 18,000 RPM performance rear motor and drive unit from a 2015-2016 Tesla Model S P90D. This drive unit is similar to the one used in the 2017-2020 P100D. The video is divided into four sections showing: 1. The motor and gears. 2. The high-performance bearings. 3. The lubrication system. and 4. The cooling system.

CORRECTIONS:
Thank you to everyone for catching my errors. There are always errors ;)
1. The Nissan Leaf ring gear is held on with 8 bolts, not 6.
2. The fluid in this drive unit is Dexron 6 transmission fluid.
3. Induction motor rotors do not have poles, just the stator. The 60 slot stator has four poles.
4. Silicon Nitride is a ceramic material.

TIMELINE:
0:00 Start
0:10 Introduction
1:35 Gearbox housing
2:10 Video Section 1 - Gears and Motor Rotor
2:45 The giant differential ring gear with 16-bolts!
4:20 The giant differential case bearings
4:50 The differential case speed at 250 km/h (155 mph) = 1841 RPM
5:15 MUST SEE Comparing the Tesla 213mm x 50mm. ring gear with 78 teeth (Factors 2, 3, 13) to a Chevrolet Bolt EV and Nissan Leaf EV
5:40 A Chevrolet Bolt EV differential 198mm x 34.3mm ring gear with 12-bolts.
6:10 A Nissan Leaf EV differential 200mm x 32mm ring gear with 8-bolts!
7:30 The Counter Shaft (Jack Shaft) with 25 (Factors 5, 5) pinion gear teeth. 78/25 = 3.12:1 Gear ratio from countershaft to the differential case
8:50 The countershaft speed at 250 km/h (155 mph) = 5743 RPM
9:30 The motor shaft with 25 teeth drives 78 teeth on the countershaft for another gear reduction of 78/25 = 3.12:1
10:08 The motor shaft speed at 250 km/h (155 mph) = 17,919 RPM
11:20 See all three gears in the reduction gearbox with an overall gear reduction of (78/25) x (78/25) = 9.7344:1
12:05 MUST SEE The AC Induction Motor Rotor with 74 bars
13:25 Motor specifications for power, torque, and gear ratio
16:22 MUST SEE Close up view of silicon nitride bearing
18:20 The motor rotor speed sensor reluctor wheel (tone ring)
19:22 Must SEE The rotor installed on the drive gear and the functioning gearbox
20:18 Video Section 2 - Specialized Bearings
21:21 The 60 slot four-pole stator and housing
23:05 The oil pump and how it is overdriven by the differential ring gear 23/78 = 0.2948:1 gear ratio (3.339 times faster than the ring gear)
23:55 MUST SEE The function of the oil pump (it may surprise you)
26:27 Motor shaft (Input Shaft) bearing reference speed and limiting speeds
27:30 How to run bearings at higher speeds than their limiting speeds
29:54 Video Section 3 - Lubrication
30:25 Drain and fill plug locations
30:50 Gearbox vent and inverter vents
31:05 Sport model label
31:39 MUST SEE Four different sealed areas in the drive unit
32:46 Video Section 4 - Cooling System
33:30 MUST SEE The coolant inlet port and the two paths coolant takes
33:53 Up for rotor cooling and gearbox cooling
35:03 Down for stator and inverter cooling
36:05 Coolant from the rotor moves to the gearbox heat exchanger and the outlet port
37:25 Stator temperature sensors
38:10 Coolant from the stator to the inverter coolant passages
38:28 Stator coolant temperature sensor
38:35 MUST SEE Insulated-Gate Bi-Polar Transistor (IGBT) module coolant passages and flow through gearbox passages
40:34 Inverter coolant outlet temperature sensor
40:45 The gearbox oil-to-coolant heat exchanger
41:38 Coolant outlet port to coolant pump and onboard charger module under the back seat.
41:55 Drive unit cooling system summary
43:04 IGBT inverter modules installed and inverter cover
43:40 High voltage battery cable connections and low voltage connections at the inverter
44:35 Video summary

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[romang]

2 hours after release, 2000 views, 270 thumbs up and 0 thumbs down. This tells something about the quality of the material. Thank you professor.

[kidcasco]

As an engineer, can't get enough. A fantastic and inspirational mechanical engineering talk for not only seasoned but new engineers. Your experience and humility are inspiring. Thank you for taking the time to share your knowledge and perspective. Much love.

[drvr]

At 9 yrs old I took apart my Grampa's radio cause I wanted to know what made it work. I'm 64 now and still want to know what's inside. Thank you sir for showing me what's inside and how it works. You're the best teacher I wish I'd had.

[quentinvilli]

I'm in a wheelchair too and I love cars. I still was surprised when i saw that you were moving on wheels. We shouldn't stand only to stand and judge the wheelchair. thanks for showing everybody that we are still here and pushing hard to do what we like. You are an example, thank you.

[sandyt]

For years I have wondered what the makeup of the Tesla drive system was built like. I doubt that I have ever seen a more concisely explained explanation of any machine. Done with no showy exaggeration or hype, just as good as anyone could hope for. Thank you for your efforts

[SemihFatihAdem]

Omg we are so lucky to hear these from a professor instead of a youtuber. Thanks for quality content

[mickeyj]

I am a 73 year old retired mechanic with above average knowledge of auto electrics and I really enjoyed the professor's detailed explanation of the drive unit. I have subscribed to the site and look forward to more.

[billmccroskey]

I enjoy the fact the narrator has disassembled (before reassembling) an actual component with explanations that can be understood by a lay person. Great learning tool by teaching that way.

[kevinhansen]

I have wound 3 phase ac motors for a good part of the last twenty years. A 500hp motor typically is around the size of a refrigerator and a 4 pole motor is typically 18 hundred rpm. I am absolutely blown away. Thank you for this video. Very impressive

[DCuzick]

I wanted to mention that, as a potter, I have uses nitride bonded silicon carbide kiln shelves to fire my pottery for years now. I believe that they are made of the same material as the bearings you mention. I fire my kilns to 2, 400°F, though the shelves are only 3/8” thick, 18” X 18”, supported only at the four corners, and holding as much as 100 lb, they do not warp or distort and they are so dense that a molten glaze drip, when cooled, will not stick to the surface of the shelf. Incredible material! Thank you for your very informative and well presented video.

[ehhhhhhhhhh]

I think my favorite part was the explanation of the cooling system. It blows my mind that engineers can manage to get coolant to the right places in the correct amounts such that the system stays stable for so many years of operation. Thanks so much!

[motorvN]

First rate lecture sir! Although I’m not a professional technician I get a huge amount of pleasure watching and learning from your videos. We recently bought an EV (Mini SE) and I’m itching to take it apart. Sadly my family appears less than enthusiastic about the idea so for now I’ll need to live the dream by watching all your EV drive line tear downs.

[sdl]

Thank you, Professor, I wish all my educators were as well-spoken as you. I would not have nodded off in the lecture hall as many times. As an Aviation Maintenance tech in the turbine engine department for 32 years, I say Bravo.

[sonajuma]

This is simply the best of YouTube, demystifying and inspiring. Added to superb content and presentation, audience centred post-production links for easy navigation and reference. Thank you for creating the gold standard for others to follow.

[vkvedam]

Excellent, informative, engaging. You are the sort of teacher every mechanical engineer like myself crave for, take a bow Prof John!

[MrWilliam.Stewart]

Understanding engineering concepts is quite easy for me, though understanding how Professor John Kelly keeps producing such awesome content on the other hand is much harder to grasp.
This man was born to teach!

From a fan in Australia, another bloody good effort mate.

[MrPatdeeee]

Yet another "Gem" from Weber college; through one of THE greatest professors (John Kelly) on this planet; I do believe.

For I can truly say without hesitation that of all the teachers, professors and instructors throughout my life (turn 89 on April 5th); that John is THE greatest. He is a blessing for sure. Thank you kind Sir. Again, If one can't learn under John, they simply can NOT learn, period IMHO.

[razony]

I'm pretty much a DA and don't even own a car. I find this guy so interesting at describing all this with his less than zero eggo. Refreshing and I learned something today!
Loved when he smurked a bit, when he said "Ceramic Balls..."then got all serious. He thought about what he said. Love it!

[marcstumpe]

Dear Professor Kelly,
thank you for this impressive and very well explanatory video.
As an electronics engineer who works in the field of e-mobility, I can confirm that Tesla has done an excellent job here.
(That is one of the reasons why I have been driving a Model 3 with great pleasure for almost 2 years).

[Mixter]

This is one of the best videos I've seen of explaining the Tesla S series engine and transmission details.
I'm studying to become an electric/hybrid car mechanic. Thank you so much for showing me all this.