The maximum torque an electric motor can produce is proportional to the magnetic field in the windings which is proportional to number of turns and current. Inc

The maximum torque an electric motor can produce is proportional to the magnetic field in the windings which is proportional to number of turns and current. Increasing the number of turns means more mass, increasing the current means more heat. More heat is particularly insidious, because as temperature goes up resistance increases, which makes more heat, which increases temperature, and so forth and so on. SCHAFT found a solution to the more current problem with their ultracapacitor driven water cooled motors. Except one cannot drive said motors continuously and alone they still don't have that much torque, so if one wants more torque more windings must be added. You can design motors for higher torques at lower speeds but the torque density suffers. Luckily we have compact high reduction gearing to transform high speed low torque to low speed high torque.