I have always found the Aerogen people to be very helpful and they have a good website. I am sure they will supply your new bearings. I have bought spares from other sources but have saved very little after being hit by minimum order charges. The bearings on my rotor are as good as new after 15+ years but I find the vertical axis ones last about 6/7 years. I suspect the grease is washed out of them. Any DIY,er will be able to sort out the repair for you. I tie the thing up to stop it, but mainly it runs 24/7.