PURPOSE: To facilitate positioning of parts, and speedily assemble an impeller by sequentially superposing discs formed with holes which are engaged with corresponding steps of circular cones or pyramids on a specified base plate, while engaging the holes with the corresponding stepped portions.
CONSTITUTION: A plurality of superposed circular cones 3b or pyramids are installed on an upper surface of the disc-like base plate 3a through lapped flat seam, connection or integral forming. Discs 3c1 to 3c3 formed with holes holes 3d1 to 3d3 which are engaged with corresponding stepped portions 3b1 to 3b3 of the circular cones 3b or the pyramids are sequentially superposed while engaging the holes 3d1 to 3d3 with the corresponding stepped portions 3b1 to 3b3. After completion of the superposing the discs 3c1 to 3c3, a top of the circular cone 3b or the pyramid which is projected from the hole 3d3 of the outermost disc 3c3 is caulked. Since the discs 3c1 to 3c3 are fixed to the base plate, members are easily fixed to each other. Positioning of the members are facilitated, while the impeller 3 is speedily assembled.
AKAMATSU KATSUSHI
ARIMA YASUHIRO
NISHI TOMOHIRO
YAMAMOTO SO
