Thanks guys.
The fan makes the noise even when not oscillating so it could be the motor or gearbox or just unbalanced blades or cage. I have linked a YouTube video which displays the noise. Any further thoughts would be greatly appreciated.
https://youtube.com/shorts/zzh8mAGzFHM?feature=share
It terms of voltage and frequency I was considering getting a UK to Japanese transformer which would create an output voltage of 100V 50HZ.