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Electric motors with no rare earths

renaultgroup.com

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Re: Electric motors with no rare earths

#221

Post by sellmesoap »

adev_ wrote: post #214
whazor wrote: post #124

Earlier quoted context omitted.

Not sure how familiar you are with Renault, but “maintenance problems” pretty much sums up a lot of older Renaults.

> maintenance problems” pretty much sums up a lot of older Renaults. It was in the 2000s but not anymore. If you go to eastern Europe, specially in the Balkans, you will see a lot of taxi drivers with Renault with milages over 500k km. They do hold the space with the usual Toyota Prius. The current brands in the EU with bad reliability issues are Stellantis with infamous Puretech engine. And BMWs, not so much for the…

The brand new BMW I last drove has network issues, it's been to the shop 10+ times the infotainment system glitches worse then skrillix and adjusting the side mirrors crashed and the car had to be turned off and on again to regain functionality. My friend is pulling teeth to get a new replacement, I had nightmares that it would glitch and emergency break us to death on the highway, not confidence inspiring!

Re: Electric motors with no rare earths

#222

Post by MisterTea »

chipsa wrote: post #190
MisterTea wrote: post #189

Earlier quoted context omitted.

> so such motors require frequent maintenance for changing the brushes. Define frequent. I maintain machinery with brushes so I have a decent idea of what life span should be depending on the environment. If the housing for the slip ring setup is well protected from dirt and the slip rings aren't cleaned by a cave man you can get a few years of life from the brushes.

If the desired location for this is a car, then a few years of life that requires half disassembly of a motor isn’t going to work.

They do not need to be half disassembled. That's hyperbole.

Brushes are usually easily assessable from a cover at one end of the motor or dedicated brush holders accessable from the outside.

Re: Electric motors with no rare earths

#223

Post by regularfry »

dmurray wrote: post #191
regularfry wrote: post #185

Earlier quoted context omitted.

25% of cars. It was... not good.

So like... One in four cars would break down at the side of the road before it was otherwise EOL? One roadside breakdown every 800,000 miles or so? That really doesn't sound bad.

Not in the first 800,000. Maybe in the first 8,000. They really struggled with reliability early on the E65, they introduced a lot of new (to them) technology all at once.

Re: Electric motors with no rare earths

#224

Post by mjanx123 »

psd1 wrote: post #167
mjanx123 wrote: post #114

Earlier quoted context omitted.

It does not bond to polypropylene and other low surface energy plastics

Terminology question - I understood those to be "high-energy" surfaces, because the chains are strongly bound. Is it a typo, or am I wrong?

It is really called low energy, it refers to the low attractive force of the surface, liquids bead up and do not wetten, in epoxy that results in small contact area and a weak bond, on a high surface energy material it flows into all the crannies and has enormous contact area and a strong bond.

Re: Electric motors with no rare earths

#225

Post by AngryData »

halper wrote: post #201
wolfi1 wrote: post #196

Earlier quoted context omitted.

150kkm - wouldn't that be 150 Mm?

Yes, you are correct. As the SI brochure states: "Compound prefix symbols, i.e. prefix symbols formed by the juxtaposition of two or more prefix symbols, are not permitted." Unfortunately, almost no one uses SI units and/or prefixes correctly.

Meh, units should be used at the convenience of us, they are all arbitrarily defined to start with. We still use lots of non-si units, like AUs, minutes seconds and hours, degrees and arc units, or whatever else. Conversion is easier than ever today so I think units should be adapted to the application and use more fractional units when appropriate.

Re: Electric motors with no rare earths

#227

Post by superxpro12 »

torginus wrote: post #176
adrian_b wrote: post #120

Unfortunately, their Web page does not say a single word about the important problems of their motors. The electrically excited synchronous motors have been known forever, but they had not been used in EVs because of 2 disadvantages. The first is that traditional EESMs require brushes, i.e. sliding electrical contacts, which are worn out by friction, so such motors require frequent maintenance for changing the brushe…

Munro took apart a Nissan Ariya which has this exact kind of motor. The maintenance is basically removing a tiny cover and replacing the tiny and cheap carbon brushes every 100k km or more. It's basically cabin filter level maintenance. And they said that PMSM motors are more efficient at low RPM, but their coils get saturated at higher RPMs meaning they lose efficiency at highway speeds (which actually affect the ra…

im surprised they make it so simple considering all these EV's are operating at lethal voltage levels. I would hope there's some kind of interlock that prevents service.

Re: Electric motors with no rare earths

#228

Post by mech998877 »

superxpro12 wrote: post #227
torginus wrote: post #176

Earlier quoted context omitted.

Munro took apart a Nissan Ariya which has this exact kind of motor. The maintenance is basically removing a tiny cover and replacing the tiny and cheap carbon brushes every 100k km or more. It's basically cabin filter level maintenance. And they said that PMSM motors are more efficient at low RPM, but their coils get saturated at higher RPMs meaning they lose efficiency at highway speeds (which actually affect the ra…

im surprised they make it so simple considering all these EV's are operating at lethal voltage levels. I would hope there's some kind of interlock that prevents service.

Maybe they've got a big ol warning sticker. or maybe not. Automative maintenance is generally dangerous anyway.

Re: Electric motors with no rare earths

#230

Post by [deleted] »

superxpro12 wrote: post #227
torginus wrote: post #176

Earlier quoted context omitted.

Munro took apart a Nissan Ariya which has this exact kind of motor. The maintenance is basically removing a tiny cover and replacing the tiny and cheap carbon brushes every 100k km or more. It's basically cabin filter level maintenance. And they said that PMSM motors are more efficient at low RPM, but their coils get saturated at higher RPMs meaning they lose efficiency at highway speeds (which actually affect the ra…

im surprised they make it so simple considering all these EV's are operating at lethal voltage levels. I would hope there's some kind of interlock that prevents service.

[deleted]
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