[brian_]

Wait what? Did I read that right? Did you say the armature has a fixed winding in it? So does the actual armature spin around this fix winding and the fixed winding is inducing a magnetic field onto the armature...so "sort of reluctance"?

Yes, I had not heard of it before this thread, but that's what 57Chevy described and that appears to be the design of the BorgWarner unit as shown in the YouTube video attached to their product web page. The magnetic coupling between the fixed winding and the rotor surrounding it is radially through the cylindrical area at the open end of the cup-shaped rotor, and axially through the other end. That's a magnetic flux path, with as low reluctance (the magnetic equivalence to resistance) as they could manage.

 

[rishimaze]

Yes, I had not heard of it before this thread, but that's what 57Chevy described and that appears to be the design of the BorgWarner unit as shown in the YouTube video attached to their product web page. The magnetic coupling between the fixed winding and the rotor surrounding it is radially through the cylindrical area at the open end of the cup-shaped rotor, and axially through the other end. That's a magnetic flux path, with as low reluctance (the magnetic equivalence to resistance) as they could manage.

This is kind of interesting...I wonder if there is a weight savings? I'd assume the armature windings are wound onto laminates. I'm betting this motor has multiple internal windings so it can essentially make several magnet poles with them. They probably rotate with the actual armature.

 

[brian_]

This is kind of interesting...I wonder if there is a weight savings? I'd assume the armature windings are wound onto laminates. I'm betting this motor has multiple internal windings so it can essentially make several magnet poles with them. They probably rotate with the actual armature.

Due to the extra rotor mass needed to provide sufficient magnetic coupling between the rotor and the excitation winding, I assume that this is heavier than a typical brush-and-slip ring design.

It appears to have a simple single rotor excitation winding. It's an automotive alternator, so excitation current is controlled to determine alternator output voltage, while the stator phases would feed a simple diode rectifier.