[UK disk drives in the States and vice versa]
Or, if you prefer, a pair of motors with the shafts
connected, and the right
RPM ratings, which will do the frequency conversion for you (certainly at a
much less reasonable efficency).
I did suggest getting a motor-generator set in the first message. It might
be easier to link the motor and generator together with the appropiate
mechanical ratio, say by using a toothed belt or gearing, rather than
trying to find units with the right number of poles to be able to link
them directly
-tony