I like your answer Major. It's realy clear!
But I'm interested to know one more thing about DC serie motor.
At a fix given current, maybe 1000A, what determines the capacity of a motor to sustain his max torque over the increasing rpm?
I read someting about resitivity of motor in ohm (mΩ) vs voltage given to the motor vs voltage produce by the motor, but it's not clear for me.
Also, the number of commutator segments can play a role?
Can you explain please.
I need to understand why a motor compare to another one fo the same voltage and the same Amp lose his max torque before the second.
Bellow, an exemple of torque lost at high rpm!
This is sort of two questions here..The ability for ANY motor to sustain a certain torque is a function of how much current it can withstand with out burning up! This has to do with the wiring and how thick the gauge the windings are. also the mass of the motor in its ability to disibate heat. Bigger motor usually can sustain larger torques due to Bigger and heavier winding and more mass for the Heat to go. Larger motors also tend to be more effecient too.
Now If your asking what does it take for a Series or SepEx to sustain torque in an increased RPM that has to do wit the Voltage accross it. The higher voltage with the same 1000 amps will run at a higher RPM. this is a linear realtionship for the most part.
Here is something to think about for given motor:
Volts equates to RPM
Amps equates to Torque.
Volts X Amps equals Watts
Torque X RPM/5252 equals Horse Power