Multiple blades in radial direction are setup in inner side of anode barrel. Back end parts of blades are welded to face of inner circumference of anode barrel. Mounting grooves for blades are in perpendicular directions along inner circumference of anode barrel. The Mounting grooves are in use for back end parts of blades to be inserted. When blades are assembled on anode barrel, the invention prevents blades from shake or shift. Further, the invention ensures blades installed inner side of the anode barrel in same angle. |