GB1031949A - Improvements in or relating to axial-flow blowers - Google Patents

Abstract

1,031,949. Axial-flow blowers. R. A. LISTER & CO Ltd. Oct. 5, 1964, No. 40497/64. Heading F1C. An impeller for an axial-flow blower has an annular hub 13a to 13d carrying, in axiallyspaced relation, a pair of flat annular discs 15 clamped axially on to blade roots 23 lying between the peripheries of the discs, which roots are circumferentially-extending to form a substantially complete annulus radiallyspaced from the hub and are retained radially by means not loaded by the clamping means. Each blade root 23 is clamped between the discs 15 by bolts 25 and recessed washers 26 bridging the ends of four hollow dowels 24 which secure the root radially. Some of the washers may be oversize for impeller balancing purposes. The roots 23 may have radiallyinwardly projecting portions which can be machined away for initial weight adjustment. The discs 15 and a spacer ring 16 are secured between a flange 13c and an extension 17 of the impeller hub by bolts 18. The impeller hub is mounted on bearings 14 carried by a shaft 10 bolted through a flywheel 11 to the crankshaft of an I.C. engine. Holes 13d in the hub provide access to studs 10c. A centrifugal clutch 19, 20 carried by the shaft 10 internally of the hub extension 17, engages to drive the impeller before the engine reaches its idling speed. Outlet straightener vanes 30 are bolted at 31 to an outer casing 34 and at 32 to a diaphragm 29 which carries a shroud 33 and a bearing 28 the inner race of which, during normal running, clears the shaft 10.