What is Steady State Torque? 1

[mselak500]

Can someone tell me what Steady State (Operating) Torque is and how to calculate it?

I'm guessing that it is the troque at operating speed.

Any help would be appreciated.

Thanks,

 

[jimgineer]

Yes you are referring to the torque at operating speed required to essentially keep the motor going at operating speed.

Another way of looking at it would be: If you disconnected your source, you would have a rotational deceleration of your shaft. This deceleration is because of frictional and inherent losses in your motor, much like if you put your car in neutral, it will lose energy and finally coast to a stop.

In linear motion
sigmaF = m * a

in rotational motion
sigmaTorque = Moment of Inertia * alpha

The operating torque is what is keeping the motor rotating at a constant level of speed (the variable omega from physics). The variable alpha that happens is going to shed light on the torque that is required to make the system steady state, ie: sigmaTorque = 0. So all you need to do if you have to measure this out experimentally is to measure the angular acceleration, as well as get the moment of inertia of your motor shaft. This should get you pretty close.

The other option is to look at the motor characteristic curve, if you have it.

 

[TurbineGen]

Torque (lb-ft) = 5252*hp/rpm

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If it is broken, fix it. If it isn't broken, I'll soon fix that.

 

[jimgineer]

I like his answer better -