http://www.axminster.co.uk/jet-jet-22-44-osc-oscillating-drum-sander-prod801421/
They are showing that the unit takes 2.2Kw. 746 watts per Horse Power so... It would seem that the main motor is probably around 3HP although it looks too small to be 3HP. I am guessing because, I don't know how many motors the unit has.
Listening to the video, it seems the drive motor is running through a reduction gear box to lower speed and increase torque.