| 摘要 |
1,085,343. Centrifugal and axial-flow fans. G. WOODS and W. K, PEYTO. June 9, 1965 [Feb. 26, 1965], No. 8465/65. Heading F1C. In the manufacture of an impeller for an axialflow or centrifugal fan, the blades and hub are of plastics material and are secured together by a synthetic plastics bonding material. A jig may be employed and may be used to set the stagger angle of the blades. The blades and hub may be of glass fibre reinforced polyester resin. The hub may comprise two discs each having complementary recesses 12 for the blade roots and an opening 11 for a steel insert for the driving- shaft, or a single moulding having an internal cavity which after assembly of the impeller parts, is filled with the bonding material and closed off by a mould plate for curing. The recesses 12 may be of dovetail or conical form and grooved to assist bonding. The stagger angle of the blades is preferably set by providing at the bottom of each recess 12 a key, Figs.4 and 5 (not shown), having a protuberance engaging a slot in the blade root (see Specification 1, 085, 344). Holes 32 are provided for rivets. The opening 11 has recesses 13 the surfaces 14 of which are coned for reception of complementary coned lugs on the steel insert. |
