I was playing around with the Odrive Motor spreadsheet and noticed that changing bus voltage did not change the torque for each of the motors. When I have used brushed DC motors in the past, I believe that their stall torque was proportional to bus voltage. Is this not the case for brushless motors? I am trying to size motors for use in a drivetrain, but I am not running the motors at their rated voltage. Instead, I am trying to run them at 12v and I don’t understand how this will affect torque.

Looking at the equation v = IR + wK, where K is the back emf constant and w is angular velocity, consider when w = 0. This should be at stall. Then, v = IR. Since I is proportional to torque, stall torque is proportional to bus voltage. If this is the case, I am failing to understand why the stall torque doesn’t change.

Any help would be great. Thank you!