4 ms·

I don't really understand what problem they're trying to solve. Contacts don't really wear out if they are tightened correctly and there was definitely no need

I don't really understand what problem they're trying to solve. Contacts don't really wear out if they are tightened correctly and there was definitely no need for this on the 3-phase side of the driveline. But you add induction coils like this and you're nearly going to need a medium as big as the motor itself to transfer that energy over an air gap. It's also dumb to say 'no wear, we removed the last interface!!'. The motor is full of bearings. It actually seems to have twice as many bearings as a normal motor. So yes, you will need to replace all those bearings and it will be a right pain compared to just tightening a bolt for each of the phases.

tjpd 5y ago
The article states another benefit of the motor is that it doesn’t require rare earth elements, so presumably they’re trying to solve the ecological and supply problems presented by rare earth mining. https://en.m.wikipedia.org/wiki/Rare_earth_industry_in_China https://en.m.wikipedia.org/wiki/Rare_earth_industry_in_China
- elihu 5y ago
  Yeah, it sounds like they're saying they get the efficiency of a permanent magnet motor (which can be around 95% or so) without using magnets. Induction motors I think tend to be in the high 80's. I don't entirely buy the rare earths thing. You can buy permanent magnet EV motors without rare earths, like the Netgain Hyper9 [1] (which I'm using in a conversion I've been working on for awhile). The hyper9 is kind of heavy for its power density, though, so maybe that's the advantage of rare earth magnets. If this company can get the efficiency of a permanent magnet motor but without rare earths and at a high power density, maybe they've got something new and interesting. [1] https://www.evwest.com/catalog/product_info.php?products_id=469 https://www.evwest.com/catalog/product_info.php?products_id=... edit: another advantage of avoiding magnets is that they tend to demagnetize if they get too hot. Not having magnets means you might be able to run the motor hotter without damage. Though, a 95% efficient motor should be pretty easy to keep cool.
slashdot2008 5y ago
the contacts they are referring to are brushes to tranfer energy to the rotating shaft not bolted connections for stator leads

tjpd 5y ago

The article states another benefit of the motor is that it doesn’t require rare earth elements, so presumably they’re trying to solve the ecological and supply problems presented by rare earth mining. https://en.m.wikipedia.org/wiki/Rare_earth_industry_in_China https://en.m.wikipedia.org/wiki/Rare_earth_industry_in_China

elihu 5y ago
Yeah, it sounds like they're saying they get the efficiency of a permanent magnet motor (which can be around 95% or so) without using magnets. Induction motors I think tend to be in the high 80's. I don't entirely buy the rare earths thing. You can buy permanent magnet EV motors without rare earths, like the Netgain Hyper9 [1] (which I'm using in a conversion I've been working on for awhile). The hyper9 is kind of heavy for its power density, though, so maybe that's the advantage of rare earth magnets. If this company can get the efficiency of a permanent magnet motor but without rare earths and at a high power density, maybe they've got something new and interesting. [1] https://www.evwest.com/catalog/product_info.php?products_id=469 https://www.evwest.com/catalog/product_info.php?products_id=... edit: another advantage of avoiding magnets is that they tend to demagnetize if they get too hot. Not having magnets means you might be able to run the motor hotter without damage. Though, a 95% efficient motor should be pretty easy to keep cool.

slashdot2008 5y ago

the contacts they are referring to are brushes to tranfer energy to the rotating shaft not bolted connections for stator leads