if you an get the model number off it, its probably a DAYTON or FASCO, they make many of the blowers.
Some blowers you can take off the stove and there are 2 little oil holes to lube them up,
Blower fan?or the Squirrel cage sometimes comes loose from the shaft, a little setscrew to hold it in place may be loose too.
You can search EBAY sometimes for these
or
http://www.ElectricMotorWarehouse.com they sell many replacement blowers.