Bill, No because you do not heat red hot. Torch used to heat nuts on the outside , no heat applied to shaft and therefore it does not expand as much. I and not sure what the heat would do to windings tho. Overall heat expansion is a very old trick for rusty bolts.
Gerald, he said "hair dryer". Applying heat with a torch may or may not help, but in any case, that would be a last gasp desperation move. The OP hasn't come back to participate in this discussion so we don't know if he has solved the problem with or without our various suggestions.
I mentioned that a torch on the nut may or may not help ... Not because I am skeptical of thermodynamics, but because of one of the few things that I still remember from the course. Starting from where we both agree, the steel does expand when heated. Now let's divide this piece of steel into a bunch of tiny finite pieces ... each of these finite elements that make up the whole will expand in all directions equally.
Suppose that we had a very thin ring composed of a single row of these tiny parts joined together in a large circle. When we heat this ring, each of these tiny pieces expand making the diameter greater. But, there's something else ... since each particle expands in all directions, the inside diameter doesn't expand quite as much as the outer diameter.
Now, let's make this ring a little thicker. What happens when it is heated? It expands, but now the inside diameter expands less than it did previously. We can continue making the ring fatter and fatter until we reach a very interesting critical point where the outer diameter expands as expected, but the inner diameter stays the same. Increasing the thickness of the ring beyond that results in the inner diameter becoming small while the outer diameter grows larger.
The nut is a very complex shape so trying to compute whether this would happen in the case of the jammed nut isn't a back of the envelope type of calculation. Furthermore, I can envision that the expansion of the nut could serve to increase the sidewall wedging of the threads since the thing that is causing the nut to be stuck is the side load against the "bellville" washer.
I have had to use a torch to remove a rusted together fan and motor shaft on an air conditioner condenser unit (twice). The motor was destroyed in the process, but that's what I was replacing and the fan blades are what I wanted to salvage. Heat is great when things are heavily rusted together, but I have serious reservations about it being a prudent solution in this situation.
