GB636417A - Composite metal articles and the method of making the same - Google Patents

Abstract

636,417. Casting composite articles. WHITFIELD, J. E. Aug. 1, 1947, No. 21107. Convention date, March 27, 1943. [Class 83 (i)] [Also in Group XXIV] A rotor, e.g. of a pump, blower, compressor, motor, or similar machine having shaped interengaging rotors 18, 20, comprising parts having different coefficients of expansion, consists of a shaft, a radially projecting part secured to the shaft, a second radially projecting part movable axially on the shaft, and a member having a higher coefficient of expansion than the shaft secured to both radially-projecting parts. The rotors 18, 20 have the form shown in Specification 558,740, [Group XXVI]. These and the housing 10 may be made of aluminium bronze or other light metal while the shafts 17, 19 are made of steel. The rotor 18 is fixed to its shaft 17 by bolts 30 and dowels 31. The rotor 20 is secured by casting about a flange 46 of the shaft 19 and a flanged sleeve 51, Fig. 6, feathered to slide on said shaft. Both flanges have anchor projections 47 to engage the cast metal and the sleeve 51 is temporarily secured to the shaft by a copper wire 53 which shears as the casting cools. Before the light metal is cast the shaft is cleaned of rust and oil and, if the shaft is of steel and the anchor members are of steel or bronze it is preheated. The rotors are arranged in the casing 10 with the fixed ends adjacent the outlet and the shafts 17, 19 are also driven from this end by a shaft 38 within the shaft 17, which is hollow, and gearing 21, 22.