You can see the cooler in the video right on the motor casing. Not sure if its pumping coolant through it or just oil. It actually looks very similar to what's on my Volvos. Those run coolant through to cool the oil.

 

The motor is cooled with oil, and then there's an oil chiller to transfer that heat from the oil to the coolant powertrain circuit, this way they don't have to run coolant inside the electric motor and there's a dielectric liquid (oil) that touches working parts directly to cool them better.

 

So cool! Love it! A shoe box with 238Hp !

 

They had a short section on motor efficiency in a Nissan White Paper before they launched the Ariya. I believe X Axis is the motor RPM, whereas I’m not sure of the Y axis…


View attachment 5855

Y axis is demanded torque.

Funny you should mention that. I was just reading that paper before you posted. I was searching for information about oil cooling of the motor, as I was thinking about earlier. And found the answer. The rotor is NOT surrounded by oil it is just sprayed with oil:

"The oil that accumulates in the oil pan below the motor is pumped using an electric pump, transferred through the channels in the motor casing, and sprayed over the stator and rotor. For the stator, oil is supplied from the outer periphery primarily to cool the core. For the rotor, the supplied oil cools the front and rear coil end portions, and oil is simultaneously supplied to the bearings and oil seals to ensure lubrication. The oil circulates only inside the motor, and the generated heat is discharged to the water-cooling circuit of the vehicle side through a heat exchanger attached to the side of the motor. The discharge quantity of the oil pump can be varied according to the temperatures of the stator and rotor. Thus, the electrical power consumed by the pump is suppressed. Additionally, the oil is used to cool the high-voltage components."

So oil can be used to lubricate and also cool the components, but without creating resistance/drag on the components. The rotor spins mostly in air. My next question would be if they are taking advantage of that heat in the HVAC system for heating the cabin in cold weather.

I was going to explain that the motor isn't oil sunk or fully filled but sprayed instead.

For the last question, the Ariya doesn't have heat scavenging capability on the electric powertrain cooling circuit BUT, the new Leaf does.

It also doesn't appear to have a sealed oil cooling system. I don't see oil coming out which means it was emptied prior to opening it up which means it is replaceable. Based on what was mentioned above about the oil cooling/lubricating it must be the same reduction gear oil.

According to official procedures the motor oil isn't replaceable, due to dust and moisture concerns once the motor is opened, it has to be a new or reconditioned motor from a factory clean room.

 

For the last question, the Ariya doesn't have heat scavenging capability on the electric powertrain cooling circuit BUT, the new Leaf does.

Well that is strange/stupid. I mean, they are pumping the coolant up to the front radiator, I assume. Adding a heat transfer shouldn't have been all that difficult or costly. They did it for the battery coolant, afterall. Oh well. Thankfully it doesn't get all that cold where I live (winter lows usually hover around freezing point, sometimes lower). I am not sure how much heat would be offered by the motor assemblies, anyway. They are pretty efficient. But Tesla scavenges heat all over the place.

 

It also doesn't appear to have a sealed oil cooling system. I don't see oil coming out which means it was emptied prior to opening it up which means it is replaceable. Based on what was mentioned above about the oil cooling/lubricating it must be the same reduction gear oil.

 

They had a short section on motor efficiency in a Nissan White Paper before they launched the Ariya. I believe X Axis is the motor RPM, whereas I’m not sure of the Y axis…

 

They had a short section on motor efficiency in a Nissan White Paper before they launched the Ariya.

Funny you should mention that. I was just reading that paper before you posted. I was searching for information about oil cooling of the motor, as I was thinking about earlier. And found the answer. The rotor is NOT surrounded by oil it is just sprayed with oil:

"The oil that accumulates in the oil pan below the motor is pumped using an electric pump, transferred through the channels in the motor casing, and sprayed over the stator and rotor. For the stator, oil is supplied from the outer periphery primarily to cool the core. For the rotor, the supplied oil cools the front and rear coil end portions, and oil is simultaneously supplied to the bearings and oil seals to ensure lubrication. The oil circulates only inside the motor, and the generated heat is discharged to the water-cooling circuit of the vehicle side through a heat exchanger attached to the side of the motor. The discharge quantity of the oil pump can be varied according to the temperatures of the stator and rotor. Thus, the electrical power consumed by the pump is suppressed. Additionally, the oil is used to cool the high-voltage components."

So oil can be used to lubricate and also cool the components, but without creating resistance/drag on the components. The rotor spins mostly in air. My next question would be if they are taking advantage of that heat in the HVAC system for heating the cabin in cold weather.

 

The parts where he shows the service door for the brush seems easy enough to access. I saw the Renault Zoe brush listed for around $100, as it was the previous generation EESM motor.

One forum post on BMW claimed they were told by BMW the life was 8000 hours. So at 30mph that is 240k miles, then 60mph is twice that. I would suspect constant speed change is worse on wear, versus highway cruise speed.

 

Cool video. Is Ariya's motor actually more efficient at highway speeds than the competition, like Ioniq 5, ID.4 or Mach-E?

 

Cool video. Is Ariya's motor actually more efficient at highway speeds that the competition, like Ioniq 5, ID.4 or Mach-E?

Yes. At least, that is what the information I have read affirms. It is more efficient at higher speeds and less efficient at lower speeds. And since most range requirements are for highway/higher speeds, it is a better choice. Having no large, rare-earth magnets makes the motor less expensive and less susceptible to supply-chain issues as well (since prices and supplies are constantly in turmoil). The downside is that it needs additional electronics needed to control it, and it has wearable brushes. But if designed well, the brushes should last the life of the vehicle (requiring no service).

That little motor produces 238hp/221ft-lb, which is pretty amazing. I am not sure why with two of them in the AWD models, the horsepower isn't doubled (the torque does, to 442ft-lb, but hp is only 389 when it "should" be 476?) **.

** Update: Ah, I bet the limit is how much electricity can be sent in the amount of time. Torque is instant, horsepower is not.

 

I don't have much mechanical knowledge so a lot of the video is lost on me, but it's cool to see what's actually inside my car and that it gets kudos from at least one engineering source. Thanks for posting the link!

 

Yeah, I find such videos strangely fascinating. I am pretty technical and love to know how everything works. Sometimes things get too "deep" but, whatever, still interesting. I watched a bunch of these type of videos a year ago on Tesla teardowns. I remember the one on the HVAC and it was really interesting how much Tesla works to gain heat for heating the cabin. They pull it from all over the place, not just the motors and batteries. I am hoping there will be more on the Ariya as time goes on.

Glad you enjoyed it.

 

The efficiency at high speed is what makes this a winner. Consider the weight of these vehicles and the average aero score they are very efficient!

 

Not sure how rare it is, but it is an interesting motor. BMW, Mercedes, and of course Renault (who shares platforms with Nissan) all use EESM.

 

Yeah but all the others use permanent magnets (including Nissan before now), and that is a lot of manufacturers. So maybe more than 99% of EV's sold use magnets? That does make it pretty rare. I hate the idea of the wearable brushes. But I guess most everything that is mechanical has some wear parts, somewhere (bearings, seals, connectors, fasteners, etc). As long as it is designed well, it shouldn't matter.

I was hoping for a longer, more detailed motor teardown. We know it is sealed in oil, for example, but which portions? Is the rotor in oil too? Wouldn't that create a tremendous drag?

The Ariya is still young. I think this might be the first such video.