Inside the Skywell EV Motor: Lessons Learned from BYD’s 10-Year-Old Design

Comments · 218

• EL

  @ElSwissCanardo · 1 year ago

  Did not know Geroge Lucas had a second job

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• SH

  @shazam6274 · 1 year ago (edited)

  Great examination and explanation. &nbsp;A couple of fine points: &nbsp;1) &nbsp;@ <a href="https://www.youtube.com/watch?v=Rbdd5KWS9Mk&amp;t=1506">25:06</a> &quot;IGBT&quot; is an INSULATED Gate Bipolar Transistor, not &quot;integrated&quot;. &nbsp; These are a large bi-polar transistors with a built in FET (aka IG-MOS-FET, Insulated Gate Metal Oxide Field Effect Transistor) to minimize the drive current needed to activate them. This is more efficient and has several beneficial characteristics than just a Bi-Polar transistor. &nbsp;These are all Silicon based semiconductors. &nbsp;Nowadays, they have been replaced by GAN (Gallium Nitride) or SiC (Silicon Carbide) semiconductors, which are more efficient to make and have better characteristics overall. &nbsp;The ~800V drives all use SiC because they have an inherently higher breakdown voltage. &nbsp;2) @<a href="https://www.youtube.com/watch?v=Rbdd5KWS9Mk&amp;t=1644">27:24</a> the capacitor is as described and needs to be close with short electrical connection to the Inverter transistors. &nbsp;Not only is it faster to charge / discharge than the battery, but those very thick cables may have very low resistance, but considerable inductance, which is dependent on the length, not the thickness. &nbsp;The Inductance along with the Resistance limits the speed and efficiency of the current pulses required by the motor. &nbsp;@ <a href="https://www.youtube.com/watch?v=Rbdd5KWS9Mk&amp;t=1715">28:35</a> &nbsp;the Ferrite is a combination inductor and resistor for high frequencies and is also usually used with an inductor (choke) to limit high frequency (i.e. the edges of the current pulses) to acceptable levels to reduce EMI. &nbsp;Otherwise those long orange wires act as antennas to make your EV a rolling EMI jammer !

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• EL

  @electricvehiclesug256 · 1 year ago

  Absolutely love these ev lessons. Thanks munro

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• GE

  @georgecostanza2695 · 3 months ago

  “BYD today, is making some of the most sophisticated electric motors on the market… this is not one of those motors.” Omg, the way you said it just had me rolling on the floor😂😂

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• KE

  @kennethprocak5176 · 1 year ago

  Excellent video, should make US people realise the meaning of what parts supply chain can be. Almost no one produces a 100% in house vehicle. New model Toyota hybrid and EV’s made in Japan are now using BYD drivelines and batteries, a partnership deal done back in 2019.

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• AR

  @ArneVanhove · 1 year ago

  I was looking with great interest and then suddenly .... LOOOOUD NOISES. Brilliant 😀 !

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• KI

  @KiwiMechEng · 1 year ago (edited)

  The made-up problems with assembly of the bearing retainer are easy to avoid with simple tooling and assembly processes and that would have been considered in detail before signing off the design. &nbsp;This method provides end float control of the intermediate shaft as much as eliminating outer race spin.<br>As for the four motor and input shaft bearings, the reason more designs use three these days is not because of cost reduction but because the four-bearing arrangement is a poor choice being geometrically overconstrained when combined with a splined coupling under high torque. &nbsp;Three-bearing designs also would use &apos;wet&apos; motors and so don&apos;t need a seal to keep oil out of the motor.<br>Some areas you could look at closer for future interest are how rotor stray currents are kept under control, what type of bearings and mounting styles does the motor use and how are wear particles sequestered in the gear reducer. &nbsp;Thanks for another great video!

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• NE

  @new-zealand-clippy · 1 year ago

  Frankly, I will happily watch any video from Paul, but I pass on every one with Sandy now days. Keep up the good work Paul!

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• DI

  @DiedLiu · 1 year ago

  The noise part was fun.

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• AN

  @andersjuul7038 · 1 year ago

  I absolutely love these motor tear down videos. Maybe because i do not know a lot and have a feeling i go away learning a lot. In addition <a href="https://www.youtube.com/watch?v=Rbdd5KWS9Mk&amp;t=515">8:35</a> is cool 😂

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• KE

  @kennethprocak5176 · 1 year ago

  I bolted thousands bearing blind retainers for years, never had a problem. Fitting assembly was the first place l started in my trade apprenticeship at 16yrs old. &nbsp;In the early 70’s.

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• LO

  @Loasdrums2 · 1 year ago

  I wonder if BYD used guide rods during the assembly of the bearing retainer. Such rods are used by VW/Audi/Porsche owners when mounting their wheels. Those cars use bolts instead of studs. So, the guide rod holds the wheel in place so the first few bolts can be threaded in.

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