PURPOSE: To improve resistance to wear and power transmitting ability, by a method wherein a screw groove for coupling to a shaft is formed in a bush coupled to the boss part of an impeller, made of wear resistant white cast iron, by shrink fitting.
CONSTITUTION: An impeller 10 is made of a nickel.chrome series or high chrome series wear resistant white cast iron material, and a bush 20 is coupled to a boss part 12 of the impeller 10 by shrink fitting. A screw groove 21, by means of which a bush is threadely engaged with a shaft 14, is formed in a bush 20. This increases engagement performance of the bush with the shaft by means of the screw groove formed in the bush, and improves resistance to wear thanks to the special material of the impeller.
KAI TOSHIO
HIRATA ISAO
KAMEHARA KENJI
HIRAKAKIUCHI ITARU
