GB1386937A - Impellers of pumps for cooling systems of internal combustion engines - Google Patents

Abstract

1386937 Centrifugal pumps SOC INTERNATIONALE DE MECANIQUE INDUSTRIELLE SA 3 April 1973 [17 April 1972 16 March 1973] 15940/73 Heading F1C An impeller for the water pump of an I. C. engine comprises a metal hub adapted to fit tightly on the pump shaft and embedded in the impeller body, the latter being made from a mixture of a thermosetting resin having a low absorption of water when heated, with a filler which is both water-repellent and not liable to change its dimensions in the presence of water. A phenol-formaldehyde resin may be used, filled with short fibres of asbestos or glass and, it may be, with an elastomer or other flexible material. The metal hub 1, Fig. 2 or 3, which has a castellated periphery 3 embedded by moulding into the impeller body 2, permits the impeller to be force-fitted on to the pump shaft without cracking the impeller body. As a further precaution, a space 23, Fig. 7, may be left between the impeller body 21 and the portion 25 of the metal hub which engages the pump shaft, expansion of the portion 25 relative to the periphery 26 during force-fitting on to the shaft being accommodated by a curved intermediate portion 24. The hub may be machined from bar stock metal so that its thickness can be varied over the cross-section. A sealing ring 9, Fig. 2, may be fitted to the impeller body 2 with the interposition of a flanged rubber ring 10. In Fig. 3, a flanged rubber ring 15 interposed between a sealing ring 13 and an annular rear extension 14 of the impeller body has an annular bead 16 providing a static seal between the impeller body and the shaft 17. In another arrangement, Fig. 4 (not shown) the sealing ring comprises a deposit of refractory or other material deposited on the annular rear extension of the impeller body by a plasma gun.