Are the motors bldc motors or ac motors?

I’m curious, the front page says odrive drives brushless motors, are they referring to the bldc motors? or the three phase permanent magnetic ac motors (blac)?

I’m trying to learn the differences between motor types and it seems that the ac motor is better than bldc motor in that its torque output is more stable, hence recommended for high end servo. and this also uses ac motor.

but the open torque and odrive both use bldc motors?

It turns out that most hobby motors are BLAC (sinusoidal back-emf), even though many will still incorrectly call them BLDC. ODrive motors are sinusoidal.


I think it’s not such a simple question because they get mixed up a lot. The thing is, your input DC but you make a kind a 3 phase voltage by using PWM. So you could say they are AC motors but people always call them BLDC motors because BLAC motors are different, maybe the name should have been chosen differently from the beginning but that’s too late now.

After a little search it has become clear that BLAC and BLDC motors are the same motors, it’s just the driving voltage that is different.

The thing is you can still say that the BLDC voltage is AC and I would agree but it’s just the name that has been chosen wrong.


Thank you.

I found a good read on this topic

and yes, according to the above link, some do categorize bldc and blac as the same motor, but the power input and the torque output are different.

I agree that the naming is very bad. I also don’t want to spend too much time on discriminating the definitions, but to look at this question from a practical point of a view. Basically which type is the best for robot actuators? And it seems the sinusoidal type is the best choice.

Yes sinusoidal bEMF is better since it gives a smoother torque profile. ODrive brand motor are sinusoidal.