Thanks Sandy for this motor teardown. I can comment on the winding technology wound vs hairpin. I work with engineers to help them simulate and design these different types of windings and they both come with pros and cons. Wound windings are well known and more flexible in their design, you can make them fill a slot of any shape with a rather good fill factor. The insulation between each separate wire makes that fill factor impossible to reach 80% for instance. Designers usually can go up to 50-60% of copper in the slot. In terms of layout it is also easier to do any sort of connection as you can bend and reposition wires "easily". The cooling of these wires is not very easy as it comes as a large bundle of wire with resin/impregnation around them. Hairpin windings are a recent trend as they provide some benefits. The fill factor can be a bit higher but the slot has to be rectangular. Also as you mentioned Sandy, with higher speeds, you have higher frequency currents and then you can start to have eddy currents and proximity effects going on. It means the current goes mostly on the outside of the section, so you increase your AC losses. Also the conductor closer to the rotor and the airgap sees more varying magnetic flux density which also generate more losses as well as unbalances between wires. The connection of several paths of hairpins also creates unbalances in genral and you can have circulating currents. So in general, it looks easier on paper, or to manufacture and assemble but it means more challenges and less flexibility in the design. I think Tesla kept the wound windings for the simplicity it brings even if it may mean a slightly lower fill factor. They chose initially induction motors over PM motors for the same reason. Regarding the V shape or W shape of the magnets, it is obviously a very sensitive design depending on the performance to achieve, the magnets help for the low speed torque and the V shape acts to create reluctance torque at higher speeds. A tiny change in angle or dimension can change the torque or performance by 10% and the cost of magnet material as well. I work with Altair and we can test and simulate those several multiphysics effects. More than happy to answer any questions.
I don't work in the field, but I thought the difference in layout of the magnets might be due to the different diameters. Magnets that are placed closer to center would need to have a different angle to align to the magnetic field lines than magnets that are placed further out from the center.
Thanks for taking the time to write that. High power high efficiency electric motors are definitely more complicated than what meets the eye. Thank you for the insight ..Take care enjoy 😁
@Sandy Munro, @TheSimong85 Great explanation about the stator wiring options. Can you also comment regarding the stator water circulation that Ford and VW use without a need of a pump, versus the Tesla oil usage requiring an oil filter and a pump? I might be wrong, but does Tesla uses also the oil pressure for dissipating the heat from the rotor bearings?
Yeah he hit Elon (and Jagdeep in the QuantumScape interview) with some tough questions despite his respect for their respective advanced tech. Also even though he worked with some USA OEMs he doesn't shy from talking about their weaknesses. He and his staff have a very objective opinion about EV tech which is refreshing.
It's so rare, people publicly changing their mind when they are proved wrong about their previous public stance. Congratulation on your wisdom, if not on your first stance 😃.
@@dukequack6209 why do you think so? His previous decision doesn’t count anymore and he learned to judge better in the future. This is a good thing. Forgiveness is another 😉
@@DanielDuese he means Recognition for the things that are good does not discount the things that were bad things monkey does bad it’s still as bad it just means it does somethings good
I spent 10 years being a machinist 15 years as a journeyman PatternMaker .. So most of my life in manufacturing. I have a degree in electronics and applied science. So this kind of content is awesome entertainment. Thank you so much.
It seems that someone at Ford finally watched some of Sandy's videos. Even if they didn't build many components themselves at least they are choosing better suppliers and making an effort now.
the Problem with FUD motors and other LEGACY OEM is they are NOT building An Advanced SMART cars , they are ONLY building DUMB Electric car like an OLD FASHIONED gas car with Horse 🐎 & Buggy 🚜 Technology. in many ways TESLA is 5 years ahead of Legacy Auto, and they are pulling away.
BorgWarner investor day presentation claimed it supplies the integrated Drive module which includes gearbox, motor and inverter? Does that mean GKN provides that to BorgWarner?
I really appreciate Sandy's appreciation for why a designer might have done something a certain way, and how he acknowledges that good design is really hard. So many people in their reviews bashing on designs without actually knowing what is required to make a design good, they just know what they don't like. Thanks Sandy - I imagine your employees appreciate being employed by you.
It was fun watching Sandy and his coworker struggle to assemble the inverter. At the factory these more complex electrical sub assemblies use sequential assembly processes, fixtures, special tools and well trained assemblers. They make it look easy.
Thanks to SpaceX, it should be possible around 2030 if they are fortunate. Without them, it would probably have take 10 or 20 more years. So the answer is No, seriously after more than 50 years it should be more than abvious.
@@robdc4829 No Nasa did, I had nothing to do with it. He is right in some ways but you are right as well. Ford choice a good company to do their motors, who already had this motor. So Apple, designs all their stuff, and their Chinese contractor, builds the items. Did Ford design this motor? If not, they at least chose a good supplier to do it for them. Good, but second place, compared to Tesla. Sorry, ask Sandy who is the bench mark for EV's.
I learned that skineffekt comes in play at higher frequenses, so there must be a high frequens based system. It also makes inductiv components more compakt. Ewen the diff. is compact. But maybe "big part" based with exp. repear...? The inwerter looks clewerly designed. Many smaler caps. might be inustrial standard components and therefore cheeper to use. The cooling from the other side is a elegant way to do it. Nice and tidy. They found smart people to design this.
Mr Monroe. The skin effect, I believe, applies to high Frequency power; usually in the upper MHz or GHz rates. DC and low Frequencies use the cross area of the conductor.
This idea is correct. The depth of the skin is inversely proportional to frequency. Motors tend to run at very low frequencies (20 kHz area) where you're right. You'd use the entire cross section of the wires. A couple hundred kHz and you'd go ahead and do the calculations for completeness.
@@jackpalczynski7884 The audio fools will argue this point. I've seen some evidence that even at or just above 20Khz the skin effect can be measured. I know once you reach say 50Khz or so it certainly has some effect. My background is in electronics, however I'm certainly no expert on the subject of the Skin Effect.
It's not that the gears are great, just that forming two gears and a shaft from a single chunk of steel, instead of assembling two gears onto a separate shaft, produces a simple and reliable part.
@@1943vermork Yes, although typical modern construction would probably be to cut the smaller gear on the forged shaft, with only the the larger gear splined on; it looks like the Chevrolet Bolt is an example of that.
@@raroque12 Are you one of those Tesla fanatics. He can praise Tesla up and down but the moment he says something positive about Ford you think he's a Ford puppet? And BTW Ford didn't make the motor in the Mach-E, Magna did, he's praising Magna's engineering work.
Hi Sandy, I don't know where you got your informations with those 70% good/rework parts. The company I am working at sells the production-lines for the hairpin stators with a rate of somewhere +90%. So I think its defenitely the more reliable way to do those stators.
Great job, Sandy! I really like this types of videos where he explains why it's a good or bad design and show it by being able to asembly it back himself without needing an extra pair of hands! I'm sure that all guys there are very knowledgeable, but no one explains it like Sandy's. Also he has grown comfortable in front camera. Not an easy task for an engineer.
True, although the explanations are not always that great. At one point here he said 'this is a good design because, er, I like it'. Which is not exactly a compelling engineering reason :-)
Great teardown! Thanks as always. So, Ford on the Mach-e has 2 different supplier for the front and rear powertrain: Borg warner for the rear unit and Magna for the front.Toughts about this?
Silicone RTV “instant gasket” is (very) old tech. The anaerobic gasket replacements such as Loctite 518 are far better and they cure only when air is excluded. Any excess will not create lumps that can clog oil galleries and it separates like a normal gasket.
Ford shills: “Sandy doesn’t know what he’s talking about”. Sandy: “I love this Mach-E gearbox and differential”. Ford Shills: “Sandy really knows his stuff, he’s a genius engineer”. Sandy: “Tesla were right, a wound stator is better than the Ford stator”. Ford shills: “Sandy doesn’t know what he’s talking about”.
So what you're saying is that the car designers aren't complete idiots and may have done particular things for a reason that sandy isn't aware of. But sandy also isn't a idiot and may make some good suggestions. And keyboard warriors probably know less than either.
What I want to know is did Ford have anything to do with the design of this motor or was it all Magna, and Ford just basically bought this off the shelf. I have a 2017 Ford focus electric, and I believe the powertrain in it was completely designed by Magna.
Magna is a Tier 1 supplier - that means it supplies parts directly to the assembly line in a just-in-time fashion. Ford, GM, and Chrysler got rid of alot of their in-house people and went to suppliers. That's why Magna became such a huge company - it took on the work that the "big 3" in NA were outsourcing. Magna also builds entire vehicles. They are building the Fisker vehicle. They recently entered into a Joint Venture with LG to produce electric drivetrains, inverters, and other systems. The traditional automakers going forward will very much depend on suppliers like Magna for electric systems. That's not a bad thing, Magna employs 169,000 people worldwide and they in turn have their suppliers for stuff, also worldwide. Besides, with Magna building so many different parts for so many different vehicles, they are in a position to draw on their experience on what works best, where. We shouldn't be surprised at seeing some innovative designs from a supplier like Magna.
I have a bunch of experience in Mfg in automotive watching Sandy makes me appreciate what I don’t know and want to catch up somehow. I'm and older guy at 52 but when new tech comes my way I want to get on board.. the younger people may be ahead of me but I am excited to learn and watch. Same with Sandy I think.
Whether to use the hairpin design or wound stator depends on the rotor speed. If you want to make a high rpm motor, you have to use a wound stator in order to retain efficiency. If you make a slow motor you can use the hairpin stator.
In an earlier Mach-E video Sandy referred to the front motor as an induction motor, presumably assuming that it would be. As confirmed in this video, it is not an (asynchronous) induction design - it is a typical interior permanent magnet synchronous motor.
@@harsimranbansal5355 No, "induction motor" has a specific meaning in electric motors, and clearly that's what Sandy meant (and was wrong about). Yes, windings are inductors, but saying "Technically all motors are induction" is as nonsensical as saying "Technically all motors are resistance", because all wires have resistance. In the term "induction motor", the "induction" refers to current induced in rotor conductors (windings or cage) by changing stator magnetic fields, producing a rotor magnetic field for reaction. That is not how this motor works; there are no conductors in the rotor and the motor does not work by inducing rotor current.
@@abraxastulammo9940 Perhaps. One of the VAG platforms uses induction motors at both axles, but he knew that the Mach-E was IPM at the rear. I think he was assuming that everyone would do what Tesla did in the Model 3/Y (which is IPM rear and induction front), but even Tesla doesn't do that in the Model S/X.
Can you imagine being the engineer who designed those systems and having to watch someone tear apart and critique your baby? Glad these designers did an amazing job. Time to buy more Ford stock. 🚀🚀
BorgWarner investor day presentation claimed it supplies the integrated Drive module which includes gearbox, motor and inverter? Does that mean GKN provides that to BorgWarner?
"Skin Effect" is caused by all the electrons in the wire repelling each other. This is why multi-stranded cable can carry more current than a similar mass solid conductor. Stranded wire has more surface area.
Does skin effect matter at EV motor inverter frequencies? So far as I can tell, most EV manufacturers are using frequencies between 2 kHz and 10 kHz. That's pretty low frequency and results in pretty thick skin depth.
So Magna did an amazing job on the front PM motor, but Borg Warner did a not so good job on the rear. Why did Ford contract two different companies? Why not just pick the better design for both front and rear?
Maybe because it's for Ford an new technology that needs an reduancy backup. If the back motor breaks you still have an front motor. And the other way around. So you still get with your car home. They're looking which motor system will last longer? Don't but all your eggs into the same bucket.
Magna's engineering department gets the credit for good engineering. Ford's parts procurement department gets a participation trophy for purchasing a good product.
Magna Powertrain, which is also making similar parts for three other Ford products, Cadillac, and various German makes (VW, Porsche, BMW, etc). I'm guessing there will quite a bit of internal commonality.
@@johnroyal4913 I don't understand how the "Diff" can be shorter than the final drive gear face width? I've worked with Diffs all my working life & have Never come across one that slim. I go to the Racing trade fairs where Diffs of all manners are presented. But this Diff seems to be shorter than the length of spline on the two driveshafts that engage it????? Yet Sandy just Glossed over it ????
You guys are excellent, really enjoy your videos. Wondering about tapered roller bearings on differential gear. Seems like it would be more clearance critical affecting bearing load when squeezed between cases that have composition gaskets. Seems ball bearings would be less critical only concern would be to shaft shift occuring when moving from forward to reverse?
Hi Sandy . Part of the cooling system purpose on the motor is to stop the neodymium magnets from demagnetising due to heat and it is a rather great loss of greater than 95% from just one time of coolant loss. You should do a simple experiment for the audience with a magnet and heat gun . Use a temp sensor on multi meter and have the magnet holding a weight that i can just handle. Heat the magnet and see at what temp it lets go . Once it lets go it will never regain its flux strength again . Probably won’t even hold a paper clip ! It is a very important consideration with electric cars as over time with bad design the magnets will lose strength and some people might only think its the battery losing capacity! 👍🏻
If the rotor gets to the temperature, your bearings would have locked completely and torn apart at that point. If temperature raises too much the computers (inverter or some other module) will not allow the car to continue.
So, Ford's engineers picked these two inverters from suppliers. One is a nightmare, the other is pretty good engineering. What does this tell us about Ford's outsourcing business model? It's hit or miss. Ford is relying on suppliers' expertise. If the supplier doesn't have it, Ford doesn't know enough to avoid that supplier. The other thing I noticed is that the motors seem to be considerably underpowered for such a heavy vehicle. But I was generally pleased by what we saw in today's teardown. *Some* suppliers do seem to be on top of the game. The weakness is in Ford's ability to specify the right parts from the right suppliers. Generally pleased, but I'm still leery of all of the fasteners in the Mach-E. I think Ford needs to scrub out about 80% of them, replace them with snap-fit designs as much as possible. This should save weight and improve the vehicle's reliability. *Probably,* Ford doesn't specify the guts of an assembly like these inverters. *Probably,* Ford uses performance specs; if the part works, it's accepted, fasteners galore or not. If Ford doesn't at least peek inside and look at the quality of the engineering before accepting a part, if Ford doesn't talk to suppliers about their reliability goals and their intention to reduce fasteners, that's a big mistake on Ford's part. They're giving up control over elements of the vehicle's reliability.
This is why I’ve always liked Fiat cars. Their original designs were well considered but over the years have evolved. Thing that need to change are updated but those that work fine stay the same. e.g. Rear wheel spindles and hub-bearings have not really changed since 1970s. They’ve not needed to change. The design is in-house but suppliers (SKF, Magneti Marelli, etc) build to the detail spec.
And to be honest, I’d be amazed if Ford is even making a profit on these vehicles. Feels like they’re just trying to hit some quota, and using whichever parts necessary to make it work. Can’t be too harsh on them cause this is their first run through, but honestly they do seem a *bit* hasty in their decision making on which parts are _sufficient_ and which are actually _superior_ to use. Hopefully someone from Ford watches these videos and is taking notes on what to fix in the future.
Well put, hence why Tesla does most of its design and manufacture in house. Agree the standarad Mach e is considerably under powered, its the coming GT model is where the power is at with a peak of 282 HP (210 kW) and 306 pound feet (415 Nm) although again comparing to whats available from the competition, still average.
Your point is valid. Often for part specification its more of a checkbox / behavioral model. You define fit form and function and are "open" to the variety of implementations. This can be intentional and for the OEM supplier is liberating as it allows them to solve the problems with their IP avoiding violating any one else's patents etc. So the underlying question is does Ford care if the different designs fulfill the requirement? Did they also specify reliability, serviceability, etc. I look at it as the first rounds of R&D as the industry pivots away from ICE. Tesla is ahead of the others and setting the bar but in short order the excellent engineering will dominate, cross-pollinate and we will see interchangeability of multi-sourced parts at the lowest price. Elon is playing the classic Silicon Valley Supply Chain game. He wants quality, interchangeable parts from a plurality of sources and then will negotiate the cost +15% to the winning bidder. Since the EV car has so many fewer parts it will be 20% of the cost of an ICE vehicle. Remember PC's which came out around $7000 - well you get more for $499 today then those original fairly proprietary designs for just this reason. The game is afoot.
Sandy was coy but honest enough to mention briefly that this marvel of an engine was designed and built by .. Magna (who makes the Jaguar EV etc ). So at least Ford chose a good subcontractor. Props to them for that. /s
SANDY , if you guys haven't seen the Ford Mach E 1400 prototype commercial that Ford produced , you guys must watch it. It is pretty pretty amazing and that video really shows that Ford does have some good stuff under that hood. Maybe not the battery advantage but their motors don't mess around.
Once again, great dissection Dr. Munro! So wouldn’t an oil filter in a lubrication system increase the longevity of the device? I imagine Tesla having more electric vehicles on the road than anyone else might have a evaluated this, no?
A gearbox in an EV is similar to a rear diff in an ICE car. They don't have pumps or filters and they last the life of the car. It seems to me Ford has more experience making transmissions than Tesla.
@@davidharris7249 no but they know how to find some one that will make a gearbox that will last for the correct price. They have been doing this for a long time.
The good design of the motors has nothing to do with the Ford engineers and everything to do with the BorgWarner engineers. So out of the two things you mentioned, the Ford engineers only had to design a decent HVAC/coolant system and they couldn't do it. Ford is lucky that it can just purchase off the shelf designs for the most important systems from third party parts suppliers. If they can't even manage to keep some cooling hoses reasonably streamlined they have zero chance of designing a modern high performance electric drivetrain.
I meant to say credit goes to the Magna engineers for the front motor. BorgWarner produces the rear motor which Sandy was not as enthusiastic about. Ford gets credit for the cooling system/HVAC mess.
Ford decided on a spec, decided on the space available, went to suppliers and asked them to tender. Magna won..... The ford designers were happy. No in house design.
The front and rear have two different sets of requirements (for power, space, weight, etc), which were met by two different product, which happened to come from two different suppliers.
Nice IGBT modules. The integrated water cooling fins and contacts are well thought out. The DC input buss bar is also extremely well done. Keeping the positive and negative plate close and parallel minimizes input inductance and RF noise. You can see this pay off because the don't need a DC input filter inductor and capacitor to keep RF noise inside the inverter. Would not be surprised if the power input pins to the IGBT modules alternated + - + - + to minimize inductance as well. Like the intermediate gear in the gearbox too. Adding the long shaft between the large input gear and small output gear provides enough space to fit a standard gear Hob tool. Is the differential a spur-gear planetary design? They have a few more parts than a bevel gear design, but can be extra compact.
I would love to see the thermal pathway in action on that inverter cooled setup. Those pockets look like they could be isolated to not cool off as much as they should.
Water has enormous heat capacity compared to air, so you need far less of it to get the same cooling. The tradeoff is that while {filtered} air is a good insulator, water with stuff dissolved in it cannot safely make contact with any of the live wires. Lots of design conflicts arise here - tricky business...
The industrial motors you might be thinking about are rated for 24x7 operation at 100%, sometimes even more. Also they require no "external parts", ie water cooling system to work. Electric motors in EVs can deliver a huge peak power, but they are not rated to work at 100% all the time. If you see any EV accelerating, it will reach max speed (legal or driver desired), in a few seconds, maybe hitting 100% power output. Once the car is at constant speed, it will consume an smaller amount. An EV at 100~120 km/h consumes about 20~30kW even on a climb, way less than peak power. The EV motors can operate continuously at this "low" power numbers with liquid cooling without issues.
I dont know about Sandy some times, he gets excited over same tech and design that we saw in the Bolt EV years ago???!?!?! But he wasn't excited about it then???? Plus, these designs have way more parts hoses and weight than the Bolt drive unit, the Bolts unit was/is easier to service, most likely less expensive to service, less complicated, lighter and smaller, yet achieves the same result. Yet Sandy was seemingly completely unimpressed??? Victim of brand bias perhaps? (everyone loves to hate GM) Go take a look at Weber Auto's Bolt breakdown, the brilliance of the Bolt design is so simple, ANYONE with a little mechanical capability can completely take it apart. Plus GM is selling 2022 Bolts for 31k and making a profit!!!! NONE of these OEMs are doing that. Good design is not always fancy new and expensive.
GM's stated the drive motor was 100% their tech, LG was simply hired to build it. Like Elon is quick to point out, coming up with the tech is one thing, building it is an entire science unto itself. Most of the Bolt tech was GM design, LG simply implemented it on the build and controls level. Having said that, its irrelevant whose tech it is, Sandy ignored it. Said it was OK and moved on to more exciting versions of the same tech to which he raves over. Oh and its funny you mention the burning batteries because the only batteries suffering from this are the LG/Korea and China made units. The ones made in USA buy Chevy are not experiencing the issues. Also Tesla were bursting into flames long before Bolts were.
One issue I have with the press-in stator: The stator is being pressed into aluminum, and aluminum has nearly double the thermal expansion as does steel. Meaning that the compressive grip of the aluminum on the steel will also loosen as it heats up. The aluminum to steel interface is expected to dissipate the heat from the motor and to withstand the rotational torque from the motor. It looks like there are possibly multiple aluminum keys that mesh with and align the stator - that will help, but time will tell.
The whole cooling system is to have the motor at constant temperature, this is not an ICE. I am aware its temperature will vary more in winter than summer, but the idea is to keep it at low and constant temperature. Part of it is also due to bearing tolerances, might be off if it they too hot or too cold. The higher speed the bearing rotates, and the higher the power, the tighter the tolerances must be, therefore the need to keep temperature extremely constant.
@Sandy you are miss informed on the skin effect on conductors as it is not an absolute sort of thing. As the direction frequency goes faster the electron start to move further and further out to the surface. To spin a 4 pole motor 18,000rpm requires 600hz switching direction. At 600hz the skin effect would mean that conductor would need to be over 5.2mm thick before the skin effect would start to cause issues and that would only be at top speed.
When Sandy says better he means cheaper to build. Tesla chose the wound method because it’s cheaper but the other method offers more fill and is mostly seen as better but more costly and complicated to build.
@@Icayn Better has lots of components, one is cheaper, which is cost of components, ease of manufacture, failure rate. Better also includes; efficiency, durability, predictable characteristics, etc.
@@davidharris7249 I agree, but my point is Sandy only gauges “better” by what is cheaper to manufacture. It’s a fault of his in my opinion, he couldn’t care less about ease of service, long term reliability, cost of repair, or even final cost to consumer. He obsesses over fewer screws, and fewer parts, no matter the cost to the consumer.
@@Icayn Agree, but he does stress that in EVs every gram saved means better efficiency and more range -- and less cost in parts and manufacture, and a better product if done right. Elon: the best part is no part.
@@davidharris7249 not sure that approach is best for the driver/consumer in every case. The Germans say to heck with efficiency and just use a bigger battery. This allows them to give us superior build quality and more traditionally luxurious interiors and higher levels of refinement. All the screws VW likes to use cuts down on noise harshness and vibration. That matters to me. I don’t care if they used one stamp to make the entire car at the factory, I care about comfort, reliability, and cost to own long term.
6:20 gasket vs rtv? Which is more likely to leak after years of service? I’ve had rtv that just stays glued like no tomorrow and would be a better choice for long term service and no issues.
So happy to see other companies improving and getting thins done right. Except for the cooling and some extra weight, the Mach-e seems to be a really good vehicle.
@@neeljavia2965 Mach E descending the Geiranger Fjord in Norway left 6 drivers stranded and there is also a video from USA of Mach E going into panic mode descending a high altitude road. 😱
The greater simplicity of Magna's vs Tesla's the gearbox is interesting, but possibly irrelevant. Tesla's gearbox has been tested to 1 million miles of service. Without knowing the longevity of the Magna gearbox, it's impossible to say which design is best from a durability standpoint. Having said that, the Magna design looks cool.
@@thealienrobotanthropologist True. But few of those vehicles have been on the road for 1 million miles. I'm not so quick to think that Tesla engineers overlooked the possibility of a simpler, lighter differential design. There's a reason they put an oil filter on the gearbox as well. Those gears do wear, and the tiny particles of steel in the oil will accelerate wear. I've seen other innovative differential designs. Check out the Torsen differential. Is this the same idea as the Ford-Magna differential? Hard to tell, but if so, there are a lot of wearing surfaces on this design, th-cam.com/video/JEiSTzK-A2A/w-d-xo.html
Tesla does something new and innovative: "This new thing is great and way better than the old thing!" Ford does something new: "Damn, Ford's new thing is cool but might be more unreliable than the old thing cause it is not proven."
@420KinK well, definitely by not acknowledging Non-binary peoples. Unfortunately with people of Sandy's generation there are still some things they are not aware of.
What kind of fluid? Will it freeze? Who well does it hold up extreme Temps? Now off road in the mud will the wires get torn out? Excavation dirt brush how well will it hold up?
Sandy, you still need more education on "skin effect". No, electricity doesn't only move in the "outside skin" of a conductor. I suggest looking up "skin depth", and then noting that it is not important at the frequency of the power to the motor and the size of the winding conductors.
The harmonics of the chopping drive are up in the Mhz range. Sure this isn't the main power, but it adds some heating. There is also a higher eddy current issue on hairpin designs.
Sandy this looks great as well. But I need to point out the heat from the windings doesn't get into the stator laminations and therefor into the cooling jacket very well. Because the windings are insulated from the laminations its in fact a BED thermal path. This is why many are starting to pot the windings and or are spraying oil on them and the rotor.
4:30 The Ford shafts are much more expensive and Tesla literally manufactured 1,500,000 pcs. of those gears, as rhey are ALL THE SAME in the Model 3! Plus the coaxial Ford is a disadvantage, as it takes away the ground clearance compared to Tesla's spur gear design.
No. A Tesla rear motor shaft is at the same height above the ground as the axles, so it is at the same height (so the same ground clearance if the motor is the same diameter) as a coaxial motor. Tesla front motors in the Model S were originally (I don't know about the latest one) higher in front, but not for ground clearance - they are set up to clear the front of the battery pack. And they're both spur (parallel) gear designs - the difference is only that the output shaft in this case is collinear with the input/motor shaft.
Tesla has probably never made a gear. Like all auto manufacturers, Tesla uses a large number of suppliers to provide components, especially those (like gears) which require specialized manufacturing. Some of the more readily recognized suppliers include Bosch (the iBooster electrically-assisted master brake cylinder), ZF (the electrically-assisted steering rack), and Brembo (the brake calipers), but there are many others... including at least one company which makes reduction gearing for them, Hota Industrial Mfg.
The motor featured in this video is NOT a BorgWarner motor.
Thanks Sandy for this motor teardown.
I can comment on the winding technology wound vs hairpin. I work with engineers to help them simulate and design these different types of windings and they both come with pros and cons.
Wound windings are well known and more flexible in their design, you can make them fill a slot of any shape with a rather good fill factor. The insulation between each separate wire makes that fill factor impossible to reach 80% for instance. Designers usually can go up to 50-60% of copper in the slot. In terms of layout it is also easier to do any sort of connection as you can bend and reposition wires "easily". The cooling of these wires is not very easy as it comes as a large bundle of wire with resin/impregnation around them.
Hairpin windings are a recent trend as they provide some benefits. The fill factor can be a bit higher but the slot has to be rectangular. Also as you mentioned Sandy, with higher speeds, you have higher frequency currents and then you can start to have eddy currents and proximity effects going on. It means the current goes mostly on the outside of the section, so you increase your AC losses. Also the conductor closer to the rotor and the airgap sees more varying magnetic flux density which also generate more losses as well as unbalances between wires. The connection of several paths of hairpins also creates unbalances in genral and you can have circulating currents. So in general, it looks easier on paper, or to manufacture and assemble but it means more challenges and less flexibility in the design.
I think Tesla kept the wound windings for the simplicity it brings even if it may mean a slightly lower fill factor. They chose initially induction motors over PM motors for the same reason.
Regarding the V shape or W shape of the magnets, it is obviously a very sensitive design depending on the performance to achieve, the magnets help for the low speed torque and the V shape acts to create reluctance torque at higher speeds. A tiny change in angle or dimension can change the torque or performance by 10% and the cost of magnet material as well.
I work with Altair and we can test and simulate those several multiphysics effects. More than happy to answer any questions.
I don't work in the field, but I thought the difference in layout of the magnets might be due to the different diameters. Magnets that are placed closer to center would need to have a different angle to align to the magnetic field lines than magnets that are placed further out from the center.
Thank you, that was an excellent overview.
Thanks for taking the time to write that.
High power high efficiency electric motors are definitely more complicated than what meets the eye.
Thank you for the insight ..Take care enjoy 😁
@Sandy Munro, @TheSimong85 Great explanation about the stator wiring options.
Can you also comment regarding the stator water circulation that Ford and VW use without a need of a pump,
versus the Tesla oil usage requiring an oil filter and a pump? I might be wrong, but does Tesla uses also
the oil pressure for dissipating the heat from the rotor bearings?
The hair pin design is patented
I love this channel because it doesn't suffer from brand loyalty: everything these folks tear down is assessed on the merits of the design.
Lets be transparent.. He worked for Ford before soo :-/?
@@kitecattestecke2303 and he bashes Ford when necessary for doing things in a bad way or avoiding to do something riskier like single body castings.
30 years ago... and he quit.
@@MunroLive But keep his mustache !!!
Yeah he hit Elon (and Jagdeep in the QuantumScape interview) with some tough questions despite his respect for their respective advanced tech. Also even though he worked with some USA OEMs he doesn't shy from talking about their weaknesses. He and his staff have a very objective opinion about EV tech which is refreshing.
The mark of a smart person is to realize you were mistaken and to adjust your perspective. Well done Sandy, top notch.
It's so rare, people publicly changing their mind when they are proved wrong about their previous public stance. Congratulation on your wisdom, if not on your first stance 😃.
I really wish our politicians can do the same. It can save us trillions and lives of many.
That’s damn true! „You can always change your point of view because no one can forbid you to get smarter.“ Konrad Adenauer
I mean this doesnt discount his previous criticisms...
@@dukequack6209 why do you think so? His previous decision doesn’t count anymore and he learned to judge better in the future. This is a good thing. Forgiveness is another 😉
@@DanielDuese he means Recognition for the things that are good does not discount the things that were bad things monkey does bad it’s still as bad it just means it does somethings good
Great content Sandy, also it takes a strong person to admit their mistakes (especially publicly)
No. It takes a normal person. Just so many are cowards and weak.
Great character.
@@michaelenglund Huh? You replying to the right person?
@@jasondorfman7979 no. Sorry
@@michaelenglund It also makes for good science.
I spent 10 years being a machinist 15 years as a journeyman PatternMaker ..
So most of my life in manufacturing.
I have a degree in electronics and applied science.
So this kind of content is awesome entertainment. Thank you so much.
It seems that someone at Ford finally watched some of Sandy's videos. Even if they didn't build many components themselves at least they are choosing better suppliers and making an effort now.
the Problem with FUD motors and other LEGACY OEM is they are NOT building An Advanced SMART cars , they are ONLY building DUMB Electric car like an OLD FASHIONED gas car with Horse 🐎 & Buggy 🚜 Technology.
in many ways TESLA is 5 years ahead of Legacy Auto, and they are pulling away.
The car was build before Sandy took it in to pieces 🤣
FUD motors and LEGACY don't listen to Sandy or BUY his Reports, but the Chinese, Japanese, Korean, and Europe does.
@@markplott4820 yes of course, it is just good to see Ford is not shitting the bed on every occasion, only most.
@@krohner5190 ummmm yeah thanks Sherlock... I was talking about Sandy's videos and comments over the past years and how critical he was of Ford.
Thanks for the great tear down analysis, but frankly: This gearbox is not from Magna, but it came from GKN Automotive.
BorgWarner investor day presentation claimed it supplies the integrated Drive module which includes gearbox, motor and inverter? Does that mean GKN provides that to BorgWarner?
I really appreciate Sandy's appreciation for why a designer might have done something a certain way, and how he acknowledges that good design is really hard. So many people in their reviews bashing on designs without actually knowing what is required to make a design good, they just know what they don't like. Thanks Sandy - I imagine your employees appreciate being employed by you.
A good design works even better than it looks.
It was fun watching Sandy and his coworker struggle to assemble the inverter. At the factory these more complex electrical sub assemblies use sequential assembly processes, fixtures, special tools and well trained assemblers. They make it look easy.
I can't believe I'm getting this type of education for free thank you
Very smooth job editing this vid, made for a seamless presentation! Noticable improvement, good job
Much appreciated!
@@MunroLive In previous videos you said the front motor was induction it looks like this is your typical borg warner PM setup
@@joeyscleaninglady2877
Except it's from Magna.
I second that.
This channel should have millions of followers.
Title should read: Sandy is blown away with Fords choice of sub contractor for its electric ⚡️ motors !
Sure. So....the US didn't land people on the moon then?
.... maybe.
Thanks to SpaceX, it should be possible around 2030 if they are fortunate. Without them, it would probably have take 10 or 20 more years. So the answer is No, seriously after more than 50 years it should be more than abvious.
@@robdc4829 No Nasa did, I had nothing to do with it. He is right in some ways but you are right as well. Ford choice a good company to do their motors, who already had this motor. So Apple, designs all their stuff, and their Chinese contractor, builds the items. Did Ford design this motor? If not, they at least chose a good supplier to do it for them. Good, but second place, compared to Tesla. Sorry, ask Sandy who is the bench mark for EV's.
I learned that skineffekt comes in play at higher frequenses, so there must be a high frequens based system. It also makes inductiv components more compakt. Ewen the diff. is compact. But maybe "big part" based with exp. repear...? The inwerter looks clewerly designed. Many smaler caps. might be inustrial standard components and therefore cheeper to use. The cooling from the other side is a elegant way to do it. Nice and tidy. They found smart people to design this.
Sandy no worries the longer the talk the better, video work is getting better and better as shows go on, this is gold dust.
Great to see better design showing up. Thanks for your detailed breakdown and as always great to hear the thoughts of a master engineer.
Glad you enjoyed it!
Great, another dose of Sandy!
Sandy it's great to see that you are a humble man and can change your opinion when new information is provided. Much respect
Retired GM tech... Looks good. As always, need to put some hard miles on it,at least 100,000 then tear it down. Very impressive, love the channel...
Mr Monroe. The skin effect, I believe, applies to high Frequency power; usually in the upper MHz or GHz rates. DC and low Frequencies use the cross area of the conductor.
This idea is correct. The depth of the skin is inversely proportional to frequency. Motors tend to run at very low frequencies (20 kHz area) where you're right. You'd use the entire cross section of the wires. A couple hundred kHz and you'd go ahead and do the calculations for completeness.
@@jackpalczynski7884 The audio fools will argue this point. I've seen some evidence that even at or just above 20Khz the skin effect can be measured. I know once you reach say 50Khz or so it certainly has some effect. My background is in electronics, however I'm certainly no expert on the subject of the Skin Effect.
Hello Sandy.
Im Sorry to correct you but the Gearbox is a GKN desing. Magna has not contributed into these design
Loved the front motor tear down video. The 2nd generation Mach-E is going to be a real winner with all type of design and engineering improvements.
depends if the subcontractors are innovating.
There is a second generation?
I can't wait to see what he says about the plaid motor 😃
would've been really nice to hear more about why these gears were so great with showing a few different kinds maybe
It's not that the gears are great, just that forming two gears and a shaft from a single chunk of steel, instead of assembling two gears onto a separate shaft, produces a simple and reliable part.
Makes me think he is a real Ford puppet!
Combining 2 gears and a shaft on a single forged part is a neat design.
That remove 2 male and 2 female splines.
@@1943vermork Yes, although typical modern construction would probably be to cut the smaller gear on the forged shaft, with only the the larger gear splined on; it looks like the Chevrolet Bolt is an example of that.
@@raroque12 Are you one of those Tesla fanatics. He can praise Tesla up and down but the moment he says something positive about Ford you think he's a Ford puppet? And BTW Ford didn't make the motor in the Mach-E, Magna did, he's praising Magna's engineering work.
I enjoy lessons with professor Munro 😀
Thanks! 😃
Hi Sandy, I don't know where you got your informations with those 70% good/rework parts. The company I am working at sells the production-lines for the hairpin stators with a rate of somewhere +90%. So I think its defenitely the more reliable way to do those stators.
I think this is critical information. I hope it reaches Sandy.
It is weird how hearsay turned his opinion 180 degrees just like that.
The 70% acceptance rate may reflect an early process yield, that should improve as the process gets refined.
Do you use lasers to weld the hairpins?
@@jenniferpedrini4787 Yes, we use Trumpf lasers
Just found your channel yesterday and I can't stop watching it
Very cool!!
Thank you
The longer the video the better
Welcome!
Great examination of the components, I'm gaining more and more respect for Magna as I learn about how well built their EV components are!
Great job, Sandy! I really like this types of videos where he explains why it's a good or bad design and show it by being able to asembly it back himself without needing an extra pair of hands! I'm sure that all guys there are very knowledgeable, but no one explains it like Sandy's. Also he has grown comfortable in front camera. Not an easy task for an engineer.
True, although the explanations are not always that great. At one point here he said 'this is a good design because, er, I like it'. Which is not exactly a compelling engineering reason :-)
What I learned from this video:
Magna knows what they're doing
Great teardown! Thanks as always. So, Ford on the Mach-e has 2 different supplier for the front and rear powertrain: Borg warner for the rear unit and Magna for the front.Toughts about this?
I was thinking the same
The question is why does the car with the big battery consume less?
@@abraxastulammo9940 where did you read this?
@@GiovanniEsposito5 Ford Germany brochure from June 2021 available as pdf. TH-cam is censoring links again...
@@abraxastulammo9940 what "car with the big battery" do you mean?
Silicone RTV “instant gasket” is (very) old tech. The anaerobic gasket replacements such as Loctite 518 are far better and they cure only when air is excluded. Any excess will not create lumps that can clog oil galleries and it separates like a normal gasket.
Ford shills: “Sandy doesn’t know what he’s talking about”.
Sandy: “I love this Mach-E gearbox and differential”.
Ford Shills: “Sandy really knows his stuff, he’s a genius engineer”.
Sandy: “Tesla were right, a wound stator is better than the Ford stator”.
Ford shills: “Sandy doesn’t know what he’s talking about”.
Sandy: tesla quality is worse than 90s kia
tesla shills: I@Y$U@I$HN@$BK$
Sandy: tesla good
tesla shills: sandy good
So what you're saying is that the car designers aren't complete idiots and may have done particular things for a reason that sandy isn't aware of. But sandy also isn't a idiot and may make some good suggestions. And keyboard warriors probably know less than either.
@@sava411 from what i've seen there isn't an overabundance of quality in a tesla... they have many quality control issues...
I would be an engineer if it wasn't for the engineers
While in reality those responses come from different individuals
a newsflash for Fred: "the internet" is not a single person
What I want to know is did Ford have anything to do with the design of this motor or was it all Magna, and Ford just basically bought this off the shelf. I have a 2017 Ford focus electric, and I believe the powertrain in it was completely designed by Magna.
Most likely outsourced engineering
They were in a hurry.
They didn’t have any in-house expertise.
They wanted something that worked.
They didn’t care about the price.
What do you think?
My other car is a Tesla Model 3, and I will be replacing the Ford with another Tesla Model 3 soon lol
Ford's current electric drive components are heavily based on VAG designs.
Magna is a Tier 1 supplier - that means it supplies parts directly to the assembly line in a just-in-time fashion. Ford, GM, and Chrysler got rid of alot of their in-house people and went to suppliers. That's why Magna became such a huge company - it took on the work that the "big 3" in NA were outsourcing. Magna also builds entire vehicles. They are building the Fisker vehicle. They recently entered into a Joint Venture with LG to produce electric drivetrains, inverters, and other systems. The traditional automakers going forward will very much depend on suppliers like Magna for electric systems. That's not a bad thing, Magna employs 169,000 people worldwide and they in turn have their suppliers for stuff, also worldwide. Besides, with Magna building so many different parts for so many different vehicles, they are in a position to draw on their experience on what works best, where. We shouldn't be surprised at seeing some innovative designs from a supplier like Magna.
I have a bunch of experience in Mfg in automotive watching Sandy makes me appreciate what I don’t know and want to catch up somehow. I'm and older guy at 52 but when new tech comes my way I want to get on board.. the younger people may be ahead of me but I am excited to learn and watch. Same with Sandy I think.
Sandy, Just so you understand, groups of smaller caps can discharge quicker than 1 big cap.
That's a more elegant design electrically.
Whether to use the hairpin design or wound stator depends on the rotor speed. If you want to make a high rpm motor, you have to use a wound stator in order to retain efficiency. If you make a slow motor you can use the hairpin stator.
Then it's a good thing that EV motors are all slow.
Did you appraise the relative amount of friction losses under load between the two different gear reduction units?
+1 , please measure this.
Gearbox are GETRAG (German) bought by MAGNA
Hey boss did you see that review Sandy did of my design. Hmm Yeah, I think I’m going to need a raise 🤔
Wow when you've impressed Sandy Munro, it's time to go out for a drink!!! Great work Sandy & team!!!
"It goes thru a tortured path".... Sounds like my life.
You must be married then :-)
14:50 Sandy, let them horses free! 😉
James Watt appreciates that! 😁
In an earlier Mach-E video Sandy referred to the front motor as an induction motor, presumably assuming that it would be. As confirmed in this video, it is not an (asynchronous) induction design - it is a typical interior permanent magnet synchronous motor.
Technically all motors are induction so he wasn’t wrong.
@@harsimranbansal5355 No, "induction motor" has a specific meaning in electric motors, and clearly that's what Sandy meant (and was wrong about). Yes, windings are inductors, but saying "Technically all motors are induction" is as nonsensical as saying "Technically all motors are resistance", because all wires have resistance.
In the term "induction motor", the "induction" refers to current induced in rotor conductors (windings or cage) by changing stator magnetic fields, producing a rotor magnetic field for reaction. That is not how this motor works; there are no conductors in the rotor and the motor does not work by inducing rotor current.
@@brianb-p6586 Maybe it was at a time he still confused the Mach-E with the VW platform which left me puzzled.
@@abraxastulammo9940 Perhaps. One of the VAG platforms uses induction motors at both axles, but he knew that the Mach-E was IPM at the rear. I think he was assuming that everyone would do what Tesla did in the Model 3/Y (which is IPM rear and induction front), but even Tesla doesn't do that in the Model S/X.
@@brianb-p6586 ahhhh, alright thanks for correcting me.
Very impressive from Ford! Shows what many decades of engineering expertise can do. They hired some darned smart peoples.
Can you imagine being the engineer who designed those systems and having to watch someone tear apart and critique your baby? Glad these designers did an amazing job. Time to buy more Ford stock. 🚀🚀
Another Awesome teardown and analysis - marvelous review
Thanks Pablo!
Well done video and explanations! Only one thing to add: the gearbox is designed by GKN not Magna 😊
BorgWarner investor day presentation claimed it supplies the integrated Drive module which includes gearbox, motor and inverter? Does that mean GKN provides that to BorgWarner?
"Skin Effect" is caused by all the electrons in the wire repelling each other.
This is why multi-stranded cable can carry more current than a similar mass solid conductor. Stranded wire has more surface area.
Does skin effect matter at EV motor inverter frequencies? So far as I can tell, most EV manufacturers are using frequencies between 2 kHz and 10 kHz. That's pretty low frequency and results in pretty thick skin depth.
Nice. I’m going to have to watch this another time to get everything I can out of this.
“Really worth talking about” … great detail Sandy
So Magna did an amazing job on the front PM motor, but Borg Warner did a not so good job on the rear. Why did Ford contract two different companies? Why not just pick the better design for both front and rear?
Maybe because it's for Ford an new technology that needs an reduancy backup. If the back motor breaks you still have an front motor. And the other way around. So you still get with your car home. They're looking which motor system will last longer? Don't but all your eggs into the same bucket.
Because FUD motors has NO idea how to build a GREAT Electric car.
Relationships
Also don’t discount the possibility the suppliers couldn’t guarantee enough motors per quarter to use one supplier exclusively….
Cost ?
Good editing, kudos for showing the motor disassembly initially in the video👍
Thank you
Is this indicative of Ford's innovative engineering or Magna's?
Magna's engineering department gets the credit for good engineering. Ford's parts procurement department gets a participation trophy for purchasing a good product.
Magna Powertrain, which is also making similar parts for three other Ford products, Cadillac, and various German makes (VW, Porsche, BMW, etc). I'm guessing there will quite a bit of internal commonality.
My guess is Magna. They bought a lot of former Ford(Getrag) Gearbox plants. They still supply ford but they also supply other manufacturuers.
Working on fords I can tell you it’s definitely magna
@@johnroyal4913 I don't understand how the "Diff" can be shorter than the final drive gear face width? I've worked with Diffs all my working life & have Never come across one that slim. I go to the Racing trade fairs where Diffs of all manners are presented. But this Diff seems to be shorter than the length of spline on the two driveshafts that engage it????? Yet Sandy just Glossed over it ????
Sandy - your analysis is brilliant. Thank you!
You guys are excellent, really enjoy your videos. Wondering about tapered roller bearings on differential gear. Seems like it would be more clearance critical affecting bearing load when squeezed between cases that have composition gaskets. Seems ball bearings would be less critical only concern would be to shaft shift occuring when moving from forward to reverse?
Hi Sandy . Part of the cooling system purpose on the motor is to stop the neodymium magnets from demagnetising due to heat and it is a rather great loss of greater than 95% from just one time of coolant loss. You should do a simple experiment for the audience with a magnet and heat gun . Use a temp sensor on multi meter and have the magnet holding a weight that i can just handle. Heat the magnet and see at what temp it lets go . Once it lets go it will never regain its flux strength again . Probably won’t even hold a paper clip ! It is a very important consideration with electric cars as over time with bad design the magnets will lose strength and some people might only think its the battery losing capacity! 👍🏻
If the rotor gets to the temperature, your bearings would have locked completely and torn apart at that point. If temperature raises too much the computers (inverter or some other module) will not allow the car to continue.
So, Ford's engineers picked these two inverters from suppliers. One is a nightmare, the other is pretty good engineering. What does this tell us about Ford's outsourcing business model?
It's hit or miss. Ford is relying on suppliers' expertise. If the supplier doesn't have it, Ford doesn't know enough to avoid that supplier.
The other thing I noticed is that the motors seem to be considerably underpowered for such a heavy vehicle.
But I was generally pleased by what we saw in today's teardown. *Some* suppliers do seem to be on top of the game. The weakness is in Ford's ability to specify the right parts from the right suppliers.
Generally pleased, but I'm still leery of all of the fasteners in the Mach-E. I think Ford needs to scrub out about 80% of them, replace them with snap-fit designs as much as possible. This should save weight and improve the vehicle's reliability.
*Probably,* Ford doesn't specify the guts of an assembly like these inverters. *Probably,* Ford uses performance specs; if the part works, it's accepted, fasteners galore or not. If Ford doesn't at least peek inside and look at the quality of the engineering before accepting a part, if Ford doesn't talk to suppliers about their reliability goals and their intention to reduce fasteners, that's a big mistake on Ford's part. They're giving up control over elements of the vehicle's reliability.
Exactly.
This is why I’ve always liked Fiat cars. Their original designs were well considered but over the years have evolved. Thing that need to change are updated but those that work fine stay the same. e.g. Rear wheel spindles and hub-bearings have not really changed since 1970s. They’ve not needed to change.
The design is in-house but suppliers (SKF, Magneti Marelli, etc) build to the detail spec.
And to be honest, I’d be amazed if Ford is even making a profit on these vehicles. Feels like they’re just trying to hit some quota, and using whichever parts necessary to make it work. Can’t be too harsh on them cause this is their first run through, but honestly they do seem a *bit* hasty in their decision making on which parts are _sufficient_ and which are actually _superior_ to use. Hopefully someone from Ford watches these videos and is taking notes on what to fix in the future.
Well put, hence why Tesla does most of its design and manufacture in house. Agree the standarad Mach e is considerably under powered, its the coming GT model is where the power is at with a peak of 282 HP (210 kW) and 306 pound feet (415 Nm) although again comparing to whats available from the competition, still average.
Your point is valid. Often for part specification its more of a checkbox / behavioral model. You define fit form and function and are "open" to the variety of implementations. This can be intentional and for the OEM supplier is liberating as it allows them to solve the problems with their IP avoiding violating any one else's patents etc.
So the underlying question is does Ford care if the different designs fulfill the requirement? Did they also specify reliability, serviceability, etc.
I look at it as the first rounds of R&D as the industry pivots away from ICE. Tesla is ahead of the others and setting the bar but in short order the excellent engineering will dominate, cross-pollinate and we will see interchangeability of multi-sourced parts at the lowest price. Elon is playing the classic Silicon Valley Supply Chain game. He wants quality, interchangeable parts from a plurality of sources and then will negotiate the cost +15% to the winning bidder. Since the EV car has so many fewer parts it will be 20% of the cost of an ICE vehicle. Remember PC's which came out around $7000 - well you get more for $499 today then those original fairly proprietary designs for just this reason. The game is afoot.
Sandy was coy but honest enough to mention briefly that this marvel of an engine was designed and built by .. Magna (who makes the Jaguar EV etc ). So at least Ford chose a good subcontractor. Props to them for that. /s
I wish they had sub-contracted the rear motor to them too, it would made the car even better!
Could you please take the Differential apart, I'd be interested to see what that's like inside.
SANDY , if you guys haven't seen the Ford Mach E 1400 prototype commercial that Ford produced , you guys must watch it. It is pretty pretty amazing and that video really shows that Ford does have some good stuff under that hood. Maybe not the battery advantage but their motors don't mess around.
I believe Ken Block was saying the Mach E 1400 prototype has 7 electric motors and produces around 2-4,000Lbs of torque
Once again, great dissection Dr. Munro!
So wouldn’t an oil filter in a lubrication system increase the longevity of the device? I imagine Tesla having more electric vehicles on the road than anyone else might have a evaluated this, no?
A gearbox in an EV is similar to a rear diff in an ICE car. They don't have pumps or filters and they last the life of the car.
It seems to me Ford has more experience making transmissions than Tesla.
@@franciscoshi1968 But Ford didn't make these components.
@@davidharris7249 no but they know how to find some one that will make a gearbox that will last for the correct price. They have been doing this for a long time.
@@franciscoshi1968 Ok, but you original statement did not say that.
Some guy in Germany has a 10 year old Tesla with over 1 million miles driven.
His motor seems to work fine.
Sometimes it feels like I'm not supposed to know this stuff. Like you're sneaking us in behind the scenes at some engineering shop... Thanks!
they put all the good design into that drive unit and didn't have any left over for the HVAC & coolant systems
Big lollllll. Everything is evolving, it won't be the same design forever.
The good design of the motors has nothing to do with the Ford engineers and everything to do with the BorgWarner engineers. So out of the two things you mentioned, the Ford engineers only had to design a decent HVAC/coolant system and they couldn't do it. Ford is lucky that it can just purchase off the shelf designs for the most important systems from third party parts suppliers. If they can't even manage to keep some cooling hoses reasonably streamlined they have zero chance of designing a modern high performance electric drivetrain.
I meant to say credit goes to the Magna engineers for the front motor. BorgWarner produces the rear motor which Sandy was not as enthusiastic about. Ford gets credit for the cooling system/HVAC mess.
Great to see a different engineering on this one
Ford decided on a spec, decided on the space available, went to suppliers and asked them to tender.
Magna won..... The ford designers were happy. No in house design.
I wonder why Ford didn't go with Magna in both front and rear motors? The rear motor is Borg Wagner, which didn't look as nice as the Magna version.
price maybe?
As Sandy mentioned in previous videos: 2 engineers not communicating to each other.
Or Ford just took what they had in the parts bin.
The "transmission guys" might have a hand in it. 🙄
The front and rear have two different sets of requirements (for power, space, weight, etc), which were met by two different product, which happened to come from two different suppliers.
Into the woods with Sandy !!!! Wow !!!
Love that new info changes Sandy’s perspective, does a lot for credibility other than unbiased critique.
Are you suggesting some opinion has been biased?
Nice IGBT modules. The integrated water cooling fins and contacts are well thought out. The DC input buss bar is also extremely well done. Keeping the positive and negative plate close and parallel minimizes input inductance and RF noise. You can see this pay off because the don't need a DC input filter inductor and capacitor to keep RF noise inside the inverter. Would not be surprised if the power input pins to the IGBT modules alternated + - + - + to minimize inductance as well.
Like the intermediate gear in the gearbox too. Adding the long shaft between the large input gear and small output gear provides enough space to fit a standard gear Hob tool.
Is the differential a spur-gear planetary design? They have a few more parts than a bevel gear design, but can be extra compact.
I would love to see the thermal pathway in action on that inverter cooled setup. Those pockets look like they could be isolated to not cool off as much as they should.
Some nice praise for Ford from Sandy and Co. Ford should be very happy about this overview. Interesting stuff Sandy!
I am always amazed at how much more power the liquid cooled car inverters can due compared to air cooled industrial units
Water has enormous heat capacity compared to air, so you need far less of it to get the same cooling. The tradeoff is that while {filtered} air is a good insulator, water with stuff dissolved in it cannot safely make contact with any of the live wires. Lots of design conflicts arise here - tricky business...
The industrial motors you might be thinking about are rated for 24x7 operation at 100%, sometimes even more. Also they require no "external parts", ie water cooling system to work.
Electric motors in EVs can deliver a huge peak power, but they are not rated to work at 100% all the time. If you see any EV accelerating, it will reach max speed (legal or driver desired), in a few seconds, maybe hitting 100% power output. Once the car is at constant speed, it will consume an smaller amount. An EV at 100~120 km/h consumes about 20~30kW even on a climb, way less than peak power. The EV motors can operate continuously at this "low" power numbers with liquid cooling without issues.
Superb videography and documentation of the tear down :)
Hey Sandy, great presentation. Could tell me the manufacturer of those vertical floating connectors?
I noticed Ford had tapered roller bearings on the differential / final drive. Much more robust than ball bearings.
I dont know about Sandy some times, he gets excited over same tech and design that we saw in the Bolt EV years ago???!?!?! But he wasn't excited about it then???? Plus, these designs have way more parts hoses and weight than the Bolt drive unit, the Bolts unit was/is easier to service, most likely less expensive to service, less complicated, lighter and smaller, yet achieves the same result. Yet Sandy was seemingly completely unimpressed??? Victim of brand bias perhaps? (everyone loves to hate GM)
Go take a look at Weber Auto's Bolt breakdown, the brilliance of the Bolt design is so simple, ANYONE with a little mechanical capability can completely take it apart.
Plus GM is selling 2022 Bolts for 31k and making a profit!!!! NONE of these OEMs are doing that. Good design is not always fancy new and expensive.
The tech in the Bolt is mostly done by LG, not GM. Now these cars are known for bursting into flames when charging.
GM's stated the drive motor was 100% their tech, LG was simply hired to build it. Like Elon is quick to point out, coming up with the tech is one thing, building it is an entire science unto itself. Most of the Bolt tech was GM design, LG simply implemented it on the build and controls level. Having said that, its irrelevant whose tech it is, Sandy ignored it. Said it was OK and moved on to more exciting versions of the same tech to which he raves over. Oh and its funny you mention the burning batteries because the only batteries suffering from this are the LG/Korea and China made units. The ones made in USA buy Chevy are not experiencing the issues. Also Tesla were bursting into flames long before Bolts were.
One issue I have with the press-in stator: The stator is being pressed into aluminum, and aluminum has nearly double the thermal expansion as does steel. Meaning that the compressive grip of the aluminum on the steel will also loosen as it heats up. The aluminum to steel interface is expected to dissipate the heat from the motor and to withstand the rotational torque from the motor. It looks like there are possibly multiple aluminum keys that mesh with and align the stator - that will help, but time will tell.
The whole cooling system is to have the motor at constant temperature, this is not an ICE. I am aware its temperature will vary more in winter than summer, but the idea is to keep it at low and constant temperature. Part of it is also due to bearing tolerances, might be off if it they too hot or too cold. The higher speed the bearing rotates, and the higher the power, the tighter the tolerances must be, therefore the need to keep temperature extremely constant.
Hah! A "partridge & a pear tree"? Y'gotta keep that sense of humour Sandy. Critical in your line of work!
For the job you do you have my respect for trying to do in your own beliefs!
I just spoke to Cory this morning. Nice guy to talk to.
Hey Robert! Your new stickers and Magnet are on the way!
Moved to $10 per month from $5 for the tier level
@Sandy you are miss informed on the skin effect on conductors as it is not an absolute sort of thing. As the direction frequency goes faster the electron start to move further and further out to the surface. To spin a 4 pole motor 18,000rpm requires 600hz switching direction. At 600hz the skin effect would mean that conductor would need to be over 5.2mm thick before the skin effect would start to cause issues and that would only be at top speed.
I always wondered why Tesla went with that copper design when you said it wasnt as good. Fair play sandy for saying Tesla was right.
When Sandy says better he means cheaper to build. Tesla chose the wound method because it’s cheaper but the other method offers more fill and is mostly seen as better but more costly and complicated to build.
@@Icayn Better has lots of components, one is cheaper, which is cost of components, ease of manufacture, failure rate. Better also includes; efficiency, durability, predictable characteristics, etc.
@@davidharris7249 I agree, but my point is Sandy only gauges “better” by what is cheaper to manufacture. It’s a fault of his in my opinion, he couldn’t care less about ease of service, long term reliability, cost of repair, or even final cost to consumer. He obsesses over fewer screws, and fewer parts, no matter the cost to the consumer.
@@Icayn Agree, but he does stress that in EVs every gram saved means better efficiency and more range -- and less cost in parts and manufacture, and a better product if done right. Elon: the best part is no part.
@@davidharris7249 not sure that approach is best for the driver/consumer in every case. The Germans say to heck with efficiency and just use a bigger battery. This allows them to give us superior build quality and more traditionally luxurious interiors and higher levels of refinement. All the screws VW likes to use cuts down on noise harshness and vibration. That matters to me. I don’t care if they used one stamp to make the entire car at the factory, I care about comfort, reliability, and cost to own long term.
3:35 - yes this differential seriously kicks ass!
You think you know plenty about engineering until you've watched Sandy. It's like going to night school.
Just love your videos and your view points on engineering...pros and cons!
6:20 gasket vs rtv? Which is more likely to leak after years of service? I’ve had rtv that just stays glued like no tomorrow and would be a better choice for long term service and no issues.
So happy to see other companies improving and getting thins done right. Except for the cooling and some extra weight, the Mach-e seems to be a really good vehicle.
Yes.
It's much better than the overrated VW id4.
However Europeans would choose brand loyalty over value for money.
@@neeljavia2965 But it overheated bad when driving down the mountains. 😱
@@abraxastulammo9940 Which one?
@@neeljavia2965 Mach E descending the Geiranger Fjord in Norway left 6 drivers stranded and there is also a video from USA of Mach E going into panic mode descending a high altitude road. 😱
@@abraxastulammo9940 Can you provide the source for the Mach E problems?
Because most reviewers have mentioned it as quality car.
The greater simplicity of Magna's vs Tesla's the gearbox is interesting, but possibly irrelevant. Tesla's gearbox has been tested to 1 million miles of service. Without knowing the longevity of the Magna gearbox, it's impossible to say which design is best from a durability standpoint. Having said that, the Magna design looks cool.
Its also smaller and likely cheaper. So theres some benefits there.
@@thealienrobotanthropologist True. But few of those vehicles have been on the road for 1 million miles. I'm not so quick to think that Tesla engineers overlooked the possibility of a simpler, lighter differential design. There's a reason they put an oil filter on the gearbox as well. Those gears do wear, and the tiny particles of steel in the oil will accelerate wear. I've seen other innovative differential designs. Check out the Torsen differential. Is this the same idea as the Ford-Magna differential? Hard to tell, but if so, there are a lot of wearing surfaces on this design,
th-cam.com/video/JEiSTzK-A2A/w-d-xo.html
Tesla does something new and innovative: "This new thing is great and way better than the old thing!"
Ford does something new: "Damn, Ford's new thing is cool but might be more unreliable than the old thing cause it is not proven."
@@spacebound1969 True.
However that's after seeing Tesla fail spectacularly trying to automate Model 3 completely.
Almost made them bankrupt.
@@spacebound1969 Reputation speaks volumes.
Great to see something going the right way !!!
I’m 62. Is it to late to change my major to engineering?
Toyota gas been using the hairpin style stators starting with the 4th gen hybrid drivetrain (Prius 4 for example).
Am I the only one who says "Hey boys and girls" at the beginning as soon as I see Sandy? Just gotta love how he always says that!
@420KinK
Only if you're insecure 😉
@420KinK well, definitely by not acknowledging Non-binary peoples. Unfortunately with people of Sandy's generation there are still some things they are not aware of.
What kind of fluid? Will it freeze? Who well does it hold up extreme Temps? Now off road in the mud will the wires get torn out? Excavation dirt brush how well will it hold up?
It's almost like the two inverters were made by totally different companies
LOL yes, the front is Magna and the rear is supposedly BorgWarner
Worth talking about so also worth listening to.
Sandy, you still need more education on "skin effect". No, electricity doesn't only move in the "outside skin" of a conductor. I suggest looking up "skin depth", and then noting that it is not important at the frequency of the power to the motor and the size of the winding conductors.
The harmonics of the chopping drive are up in the Mhz range. Sure this isn't the main power, but it adds some heating. There is also a higher eddy current issue on hairpin designs.
Sandy this looks great as well. But I need to point out the heat from the windings doesn't get into the stator laminations and therefor into the cooling jacket very well. Because the windings are insulated from the laminations its in fact a BED thermal path. This is why many are starting to pot the windings and or are spraying oil on them and the rotor.
4:30 The Ford shafts are much more expensive and Tesla literally manufactured 1,500,000 pcs. of those gears, as rhey are ALL THE SAME in the Model 3!
Plus the coaxial Ford is a disadvantage, as it takes away the ground clearance compared to Tesla's spur gear design.
No. A Tesla rear motor shaft is at the same height above the ground as the axles, so it is at the same height (so the same ground clearance if the motor is the same diameter) as a coaxial motor. Tesla front motors in the Model S were originally (I don't know about the latest one) higher in front, but not for ground clearance - they are set up to clear the front of the battery pack.
And they're both spur (parallel) gear designs - the difference is only that the output shaft in this case is collinear with the input/motor shaft.
Tesla has probably never made a gear. Like all auto manufacturers, Tesla uses a large number of suppliers to provide components, especially those (like gears) which require specialized manufacturing. Some of the more readily recognized suppliers include Bosch (the iBooster electrically-assisted master brake cylinder), ZF (the electrically-assisted steering rack), and Brembo (the brake calipers), but there are many others... including at least one company which makes reduction gearing for them, Hota Industrial Mfg.