GB864544A - Improvements in centrifugal fan rotors - Google Patents

Abstract

864,544. Centrifugal fans. AIRSCREW CO. & JICWOOD Ltd. June 8, 1959 [July 14, 1958], No. 22462/58. Class 110 (1). In a centrifugal fan rotor of the kind in which the blades are adhesively secured by their extremities to opposing supports, relative outward radial movement of the blades is prevented by interengagement of their extremities with the supports, the interengagement also relieving the adhesive joints of centrifugal load. Fan blades 1 formed with flanges 8 engage in channel-section supports 2, 3 and are secured by adhesive. The fan blades are preferably wider radially than their flanges, Fig. 3, to form shoulders butting on the circumferential edges of the supporting channel 9. One edge of the channel may be turned in as at 13. In alternative constructions a continuous rib 14 may be provided in the support 2, Fig. 5, or spigots 15 on the flanges 8 engaging in holes in the supports 2, 3, Fig. 9. The flanges 8 are shaped so as to be self-locating, even on rotors of different diameter from that for which the blades were designed. For variations of up to Œ20% the gaps between flanges are small enough to be filled with adhesive. The side edges of the flanges 8 may be either truly radial, curved so that adjacent flanges nest into each other, or inclined to the radial where overlapping blades are required.