GB601962A - Machine for bending the vanes of rotary impellers - Google Patents

Abstract

601,962. Making centrifugal impellers ; angular bending. POWER JETS (RESEARCH & DEVELOPMENT), Ltd., and TAYLOR, T. A. June 17, 1944, No. 11597. [Classes 83 (ii) and 83 (iv)] A machine for bending the blades 3 of a rotary impeller 1 or the like as at 3A is arranged to be heated, at least as regards a part thereof, together with said impeller and to be operated by fluid pressure. The impeller 1 is mounted on a table or truck, not shown, for placing in an oven, a stubshaft 7, with a circular flange 8, is fixed in its hub 9, a frame 5 carrying an airoperated cylinder 11 is mounted to turn on the shaft 7, and a former block 24, shaped to the form of blade required, is placed behind the blade 3 in line with the cylinder and so held by a clamp 25. The cylinder has nipples 20A, 21A for engagement by unions 208, 21B of a compressed air supply and exhaust 22, 23, 32. The piston-rod 12 carries a detachable die 15 supported by a guide 36 and if desired limited in movement by stops 42. The guide may also engage a hook 26 of the block 24. A thin flap 27, Fig. 7, of easily deformable metal is arranged between the blade 3 and the die 15. All the parts except the air supply pipes &c. 22, 23, 32 are made of such material that they can withstand the temperature to which the impeller is heated and they are lubricated with graphite from which the bush 13 also is made. After heating for 3-4 hours to 400-500‹ C., the machine is removed from the oven, the air supply is connected and operated to bring down the die 15 against the blade 3 and bend it to conform with the block 24. The die is then raised, the block 24 is detached, the machine is rotated on the shaft 7 to bring the die over the next blade, the block 24 is reinserted and clamped, and the operation is repeated until all upper blades have been treated. The frame 5 and shaft 7 are now removed from the impeller and, if this is double sided, it is turned over and the whole operation is repeated. In a modification, the blades on both sides are operated on simultaneously by a duplex machine. If desired, the temperature of the work may be maintained during bending by electric heaters or by enclosing the parts not actually being worked upon in an asbestos tent supplied with hot air. The flange 8 may have means for indexing the frame 5.