Apple Car research focusing on use of Tesla-style induction motor

Posted:
in General Discussion
Apple is working on a three-phase AC induction motor suitable for an Apple Car, implementing the same basic engineering and motor design principles that Tesla uses.

Tesla motor windings
Tesla motor windings (source: Windell Oskay


Apple will still not say that it is making a car, despite filing legally-required documentation, and also countless patents regarding the interior and exterior. Now, though, those countless patents include one that details how Apple intends to use an electrical motor that is designed for cars.

Titled "Electric motor with bar wound stator and end turn cooling," US Patent No 10,630,127, discusses the technology that Apple has chosen, and has now been granted, for a potential Apple Car.

The patent details specifically a three-phrase AC induction motor, which is only one of several possible electrical motor systems for cars. However, it uses the same squirrel cage motor technology that Tesla does.

Apple will have chosen this technology specifically for the same reasons that Tesla has. It can generate a high starting torque when the voltage/frequency is controlled, it's cheaper, and is also useful over rugged terrain. These motors can be also be expected to have a longer life, and need less maintenance, than, for instance, a permanent magnet drive.

In comparison, hybrid vehicles from Ford and Nissan use permanent magnet synchronous motors. They are more efficient than induction motors, but they also cost more and need greater maintenance. Plus their magnets tend to wear out and need replacement over time.

Three-phase induction motors are likely chosen because the technology is relatively cheap to build, requires little maintenance, and can generate a high starting torque when voltage/frequency is controlled. When properly controlled, a three-phase AC induction motor can be made to be 90% efficient. The problem is in the complexity of that control, though the patent does not explicitly detail Apple's systems for handling this.

Instead, Apple's patent concentrates on the motor technology paired with a method for dissipating heat from the engine. "[A] cooling structure [is] disposed in a thermally conductive relationship with at least one of the upper exterior ring surface or the lower exterior ring surface for receiving heat from the end turn ring," it says.

Detail from the patent showing a three-phase AC induction motor
Detail from the patent showing a three-phase AC induction motor


The patent is credited to five inventors, Dillon J. Thomasson, Kan Zhou, Rui Guan, Yateendra B. Deshpande, and William M. Prince. Thomasson, Zhou, and Guan are all previously credited on the related patent "Electric motor with shielded phase windings."
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Comments

  • Reply 1 of 42
    willettwillett Posts: 25member
    The other important advantage of induction motor: no need for rare earth materials.  I bet Apple can handle the more complex motor drive (power electronics).
    Rayz2016GeorgeBMacjbdragondysamoriaAndy.Hardwakejony0rundhvidqwerty52watto_cobra
  • Reply 2 of 42
    XedXed Posts: 1,030member
    willett said:
    The other important advantage of induction motor: no need for rare earth materials.  I bet Apple can handle the more complex motor drive (power electronics).
    Yeah, the lack of rare earth metals (and other benefits mentioned in the article) sound promising.
    SpamSandwichwatto_cobra
  • Reply 3 of 42
    melgrossmelgross Posts: 33,035member
    I use three phase induction motors in some of my equipment. To control them, because they work either over single phase 120, or single phase 240, depending on the motor, I use what are called VFDs. These convert either single phase 120 or 240 to three phase 240 (at the outlet in most places we see 220 measured). VFD stands for variable frequency drive. By varying the frequency the speed of the motor can be varied by a wide range, often from zero to possibly 3600, as with my motors. These are complex devices. They have control over every parameter of the motor, and monitor motor characteristics and health. They have reverse, jog, degree of turn, and most importantly, constant torque.

    there are special “inverter duty” motors for this purpose, because motors don’t like to run off their designed frequency of either 50 or 60 Hz. If they do, they get too hot. The VFD will then shut them down. So while a drill press can use a regular (cheaper) 3 phase motor with this, its very disconcerting to have the mill or lathe shut off in the middle of a long cut.

    this technology the article is taking about is almost the exact same technology we use. But our equipment isn’t meant to be bumping along the road while in use.
    edited April 2020 GeorgeBMacdysamoriarazorpitAndy.Hardwakejony0qwerty52Carnagewatto_cobra
  • Reply 4 of 42
    jbdragonjbdragon Posts: 2,246member
    melgross said:
    I use three phase induction motors in some of my equipment. To control them, because they work either over single phase 120, or single phase 240, depending on the motor, I use what are called VFDs. These convert either single phase 120 or 240 to three phase 240 (at the outlet in most places we see 220 measured). VFD stands for variable frequency drive. By varying the frequency the speed of the motor can be varied by a wide range, often from zero to possibly 3600, as with my motors. These are complex devices. They have control over every parameter of the motor, and monitor motor characteristics and health. They have reverse, jog, degree of turn, and most importantly, constant torque.

    there are special “inverter duty” motors for this purpose, because motors don’t like to run off their designed frequency of either 50 or 60 Hz. If they do, they get too hot. The VFD will then shut them down. So while a drill press can use a regular (cheaper) 3 phase motor with this, its very disconcerting to have the mill or lathe shut off in the middle of a long cut.

    this technology the article is taking about is almost the exact same technology we use. But our equipment isn’t meant to be bumping along the road while in use.
    We h ave tons of motors where I work and a number of VFD's. Most of ours are 480V 3 phase. VFD's do come in handy.
    watto_cobra
  • Reply 5 of 42
    Good news! Soon we can stop the insanity of going to a gas station once or twice a week! :)

    watto_cobra
  • Reply 6 of 42
    red oakred oak Posts: 888member

    Can't wait for that Apple Car launch

    edited April 2020 watto_cobra
  • Reply 7 of 42
    Apple will be doing a lot of 're-inventing of the wheel' with all this.  Getting rid of the heat from the motors is easily solved. Tesla, Jaguar, VW and others have solved it already. Some of the solutions will be patented but there is always room for innovation.
    It is not unknown for EV's to have radiators and heat pumps.
    boxcatcherelijahgprismatics
  • Reply 8 of 42
    dysamoriadysamoria Posts: 3,430member
    Good news! Soon we can stop the insanity of going to a gas station once or twice a week! :)

    How often will we have to pay to charge at charging stations, rather than just charging after use at home?
  • Reply 9 of 42
    neilmneilm Posts: 902member
    In fact the Tesla Model 3, a newer design than the S or X, uses a switched reluctance 3-phase permanent magnet motor. 

    According to Tesla’s Chief Motor Designer, Konstantinos Laskaris:
    “So, as you know, our Model 3 has a permanent magnet machine now. This is because for the specification of the performance and efficiency, the permanent magnet machine better solved our cost minimization function, and it was optimal for the range and performance target.”

    Although permanent magnet motors are more expensive from a material content standpoint, they are also more efficient due to the lower I^2R losses in the rotor. This also reduces rotor heating, and may allow a reduction in the motor's overall size and weight for a given power output. The switched reluctance type of permanent magnet motor that Tesla uses in the X does require more complex electronic controls, but delivers higher efficiency in return.

    There's no real limit to motor rpm in a variable frequency drive system other than the obvious mechanical constraints. (Centrifugal force increases with the square of a rotating part's radius, so beyond some size and rpm limit everything just wants to fly apart.) Tesla's Model S induction motors turns at up to 18,000 rpm, but at the other end of the size/output spectrum you can buy tiny ultra-high speed electric motors that hit 500,000 rpm or more (https://www.celeroton.com/en/products/motors.html).
    edited April 2020 iqatedoroundaboutnowrundhvidqwerty52watto_cobra
  • Reply 10 of 42
    kamiltonkamilton Posts: 281member
    Hopefully, I’m driving my last care with an internal combustion engine!
    techwarriorminicoffeeiqatedoRayz2016watto_cobra
  • Reply 11 of 42
    XedXed Posts: 1,030member
    dysamoria said:
    Good news! Soon we can stop the insanity of going to a gas station once or twice a week! :)
    How often will we have to pay to charge at charging stations, rather than just charging after use at home?
    That depends on one's specific driving needs, but for the majority of drivers they simply aren't needed, and for those that do need them, it's only occasionally. If the range of a modem EV doesn't suit one's needs then one should consider ICE for the foreseeable future.
    StrangeDaystechwarriorwatto_cobra
  • Reply 12 of 42
    XedXed Posts: 1,030member
    kamilton said:
    Hopefully, I’m driving my last care with an internal combustion engine!
    Me, too. I preordered a Tesla CyberTruck. I really like the look of the Rivian and some of the features, like Tank Turn, but they're an unproven company and their starting cost and cost for a giving distance isn't as good.


    watto_cobra
  • Reply 13 of 42
    StrangeDaysStrangeDays Posts: 11,584member
    dysamoria said:
    Good news! Soon we can stop the insanity of going to a gas station once or twice a week! :)

    How often will we have to pay to charge at charging stations, rather than just charging after use at home?
    Tell us, how often?

    Most people commute a short distance on a regular basis. I don’t having dwelling data to indicate how many of those people have houses or driveways, but if they do it’s promising. Workplace charging too. 

    Most of the time, our vehicles are sitting around near us. 
    watto_cobra
  • Reply 14 of 42
    sreesree Posts: 139member
    dysamoria said:
    Good news! Soon we can stop the insanity of going to a gas station once or twice a week! :)

    How often will we have to pay to charge at charging stations, rather than just charging after use at home?
    If they start hitting the 500-600miles range on a single charge, I figure it would be only required for inter-state road trips. That would be pretty rare.
    watto_cobra
  • Reply 15 of 42
    avon b7avon b7 Posts: 5,904member
    dysamoria said:
    Good news! Soon we can stop the insanity of going to a gas station once or twice a week! :)

    How often will we have to pay to charge at charging stations, rather than just charging after use at home?
    Tell us, how often?

    Most people commute a short distance on a regular basis. I don’t having dwelling data to indicate how many of those people have houses or driveways, but if they do it’s promising. Workplace charging too. 

    Most of the time, our vehicles are sitting around near us. 
    My sister-in-law charges once a day to top up.  Normally 20-30 min on the way home. It is free and she does some shopping while waiting. There is an app to reserve the charging point. The commute is around 120km, round trip. 

    She has a charging point in the garage but that isn't free. Neither is charging at motorway service stations (5€).

    Currently tolls are free from Mon-Friday. Doesn't pay local parking fees either. 

    Some supermarkets have free charging but you need your own charging cable on hand.

    If you live in a block, the community has to install charging equipment if a resident requests it.

    HYUNDAI IONIC 100% Electric. About three years old now. 
    techwarrior
  • Reply 16 of 42
    macxpressmacxpress Posts: 5,175member
    Good news! Soon we can stop the insanity of going to a gas station once or twice a week! :)

    If you're going to the gas station 2x a week then you need a different vehicle or something. If it's because a long commute it will be no different with an electric vehicle. You'll just be paying to charge your vehicle instead of paying for gas. Either way, you're paying. 
    razorpittht
  • Reply 17 of 42
    StrangeDaysStrangeDays Posts: 11,584member
    macxpress said:
    Good news! Soon we can stop the insanity of going to a gas station once or twice a week! :)

    If you're going to the gas station 2x a week then you need a different vehicle or something. If it's because a long commute it will be no different with an electric vehicle. You'll just be paying to charge your vehicle instead of paying for gas. Either way, you're paying. 
    Nearly all aspects of modern living require the exchange of currency for resources. I don’t personally see “free” as being the appeal of EVs. 
  • Reply 18 of 42
    razorpitrazorpit Posts: 1,796member
    Good news! Soon we can stop the insanity of going to a gas station once or twice a week! :)

    Hope not. Not looking forward to having to spend 20-30 minutes at a minimum every 150 miles on some of my drives. Would rather spend the 5 minutes every 400 miles to so, gas up and get back on the road.

    macxpress
  • Reply 19 of 42
    macxpressmacxpress Posts: 5,175member
    razorpit said:
    Good news! Soon we can stop the insanity of going to a gas station once or twice a week! :)

    Hope not. Not looking forward to having to spend 20-30 minutes at a minimum every 150 miles on some of my drives. Would rather spend the 5 minutes every 400 miles to so, gas up and get back on the road.

    Exactly! I just don't see the appeal of an EV just yet other than just trying to be cool. 
  • Reply 20 of 42
    macxpressmacxpress Posts: 5,175member

    macxpress said:
    Good news! Soon we can stop the insanity of going to a gas station once or twice a week! :)

    If you're going to the gas station 2x a week then you need a different vehicle or something. If it's because a long commute it will be no different with an electric vehicle. You'll just be paying to charge your vehicle instead of paying for gas. Either way, you're paying. 
    Nearly all aspects of modern living require the exchange of currency for resources. I don’t personally see “free” as being the appeal of EVs. 
    Never said it would be free (because its not). I was just making the point that they may not really be saving much in the end versus a vehicle that gets better gas milage. And if you have to recharge every 150 or so miles how is that any better than going the gas station 2x a week?
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