MOVABLE-VANE SUPPORTING STRUCTURE FOR VARIABLE MOVABLE-VANE TYPE AXIAL-FLOW FAN

摘要

PURPOSE:To prevent the reduction of the fatigue strength of a screw part by installing a holding member for holding a movable-vane shaft between a thrust bearing and a fastening nut and allowing only the lightened centrifugal force to act onto the screw part of the movable-vane shaft having the fastening-nut arranged. CONSTITUTION:A ring 60 is shrink-fitted onto a straight frictional fastening part 27C formed in the shaft part 27 of a movable vane, and a fastening nut 34 is arranged in a screw part 27D, and the ring 60 is fastened onto a thrust bearing 30. Since the movable-vane shaft part 27 is certainly fixed in the radial direction of the shaft part in the straight frictional fastening part 27C through the shrink-fit ring 60, the bending moment generated on the movable vane is transmitted to the thrust bearing 30 through the shrink-fit ring 60, and the bending moment transmitted to the screw part 27D becomes little, and further a part of the centrifugal force is born by the contact surface between the straight frictional fastening part 27C and the shrink-fit ring 60, and therefore, also a part of the centrifugal force acting onto the screw part 27D is lightened, and the reduction of the fatigue strength of the screw part 27D can be prevented.