MECHANISM FOR DRIVING IMPELLER FOR STIRRING ATMOSPHERE IN FURNACE

PROBLEM TO BE SOLVED: To reduce the number of parts, to simplify the structure and to improve cooling efficiency, in a driving mechanism of an impeller for stirring the atmosphere in a furnace. SOLUTION: The impeller 28 arranged in the heat treatment furnace haying the combustible atmosphere is driven with a motor 29 arranged outside the heat treatment furnace. The impeller 28 is directly connected with the tip part of a motor shaft 32 having water-cooling structure. Inert gas is supplied into a motor casing 30 of the motor 29 and the inner part of the motor casing is kept to a higher pressure than the inner pressure in the furnace. A water-cooling jacket 59 is arranged at a through-hole part of the motor casing projecting the impeller connecting side with the motor shaft 32.