@oskar,
Check your local for sale site, craigslist, kijij, or equivalent.
I have picked up two treadmills for no cost........the owner just wanted to get rid of them.
One was working perfectly, the other had a bearing gone in one belt axle (the motor and controller worked fine).
Of course they are always in the basement.......take some tools, dis-assemble and make many trips.
(I forgot allen wrenches for one and had to use vise-grips on the heads)
So these motors can be free, for the effort of hauling the treadmill machine away!
-brino