Help, what type of motor is this?

[Bluefang]

Hey guys,
I was asked by a friend to increase the power to a motor he had, i had a look at the controller and it was only rated for 16V caps so i said i would replace it with a brushless controller i had and increase it to 36V as he wanted to go 2x as fast compared to his 12V lead system was able too.

I installed a Ecrazyman controller i had and went thru all the combinations and it does almost nothing on all the combinations. I opened the motor and found something alot different then what i was expecting. It seems to have 3 phases and 3 halls but it does not seem to have any magnets and the halls are not responding normaly when i tested them.

So, What type of motor is this, and can i run it with a E-crazyman controller or a sensorless controller?

 

[amberwolf]

I recall seeing a picture of a wheel laced like that somewhere here on ES before, but not what the name or thread was.

If it has no magnets, then it is using field coils that must be run by a separate controller or a separate FET bridge within teh same controller (or the field coils are simply wound in alternating pole patterns and energized with a constant current, rather than being PWM'd, but that would make having them be pointless, as magnets would be easier to use if all you want is a constant field).

If those coils are all in series, you can then wire them up to a current source, and power them with varying levels of current until the motor begins to respond to controller inputs on the phase wires. Might take some serious experimentation to determine correct current levels for various motor usage/speed.

But it is probably easier to use the original controller. It might be upgradable to a higher voltage, but I don't know what components you'll have to change--probably a fair amount of stuff besides just the caps, such as resistive dividers, maybe transistors or FETs, low-voltage-regulators, etc. Best to reverse-engineer the controller to see what it is actually doing first, and then start upgrading it.


Keep in mind that the motor is going to be using brushes for either the field windings or the phases (probably the field; it seems logical that it would be attached to the hub itself, but I can't tell from the pics which set rotates with it). Those brushes will run hotter with more current from higher voltage.


Another possibility for faster speed is to use field-weakening, by running less current thru the field once it reaches normal running speed. I don't know what this will do to current/power usage in the rest of the motor though, so you'd want to watch for overheating/etc., and possible bad feedback into the controller itself.


So the very easiest way is to replace motor, controller, and batteries, though that is not as fun a challenge.

 

[Bluefang]

blehh, I was not looking for a challange lol, I think i am going to source a replacement hub

 

[bearing]

Looks like an axial flux motor to me. The magnets are probably in a disc shaped rotor located behind the stator in the picture, or between two mirrored stators. If this is the case, I think it should be able to run from a standard brushless controller.

You write that the halls doesn't respond normally, could it be that one of them is inverted? (60° hall spacing)

 

[Miles]

Seems to be the Avanti motor.
See: http://www.endless-sphere.com/forums/viewtopic.php?p=35307#p35307

http://www.imtmotors.com/ebike.htm

 

[parabellum]

Isn't that ring on the stator a magnet ring that got unglued/unscrewed from rotor?

 

[Miles]

Isn't that ring on the stator a magnet ring that got unglued/unscrewed from rotor?

Looks like it.

 

[bearing]

I think it's the back of the stator (there are magnets on only one side). It would be the side attached to the dark cover disc in the first two photos below.

 

[Bluefang]

Awesome, thanks for the pics, now that i actually understand the motor i have gotten it running on a sensorless controller, cept its not running very fast and with very little power on 6s200amp controller. The normal controller is only 14V and it manages 40km/h unloaded so i would have thought running it on 5s would be reasonable for 40km/h loaded speed, but it barely seems to freewheel at 15km/h drawing 50W only. And my sensored controllers dont even move it at all anymore. Such a simple thing it making my head spin