GB687715A - Improvements relating to gears and gearing - Google Patents

Abstract

687,715. Toothed gearing. NEWTON, J. M., and METROPOLITAN - VICKERS ELECTRICAL CO., Ltd. Jan. 6, 1950 [Dec. 8, 1948], No. 31750/48. Class 80 (i). A metal gear wheel provided with annular inserts to reduce vibrationary noises comprises a hub 3 and a toothed rim 1. Annular recesses 4, 5 in the sides of the rim have therein rings 6, 7 of a metal preferably different from that of the hub and rim, the spaces between the rings 6, 7 and the walls of the recesses being filled with a plastic material 8, which may be rubber, synthetic resin, &c., or a soft metal such as lead or Babbit metal. The recesses may be sealed by flat rings 10 retained by tongues 11. The rings 6, 7 may be recessed at intervals along the inner edge contacting the rim 9, or may be formed of separate segments. Slots may be milled in the under surface of the rim 1 and extend into the recesses 4, 5. In a modification the gear teeth are carried by a ring splined to a rim whose recesses 4, 5 communicate with an annular cavity formed between the ring and the rim. In a modification applicable to narrow gear wheels the recesses are formed concentrically the one within the other. A method of manufacture is described in which the rings 6, 7 have initially an axial length greater than the depth of the recesses and are guided between two annular plates clamped to the gear wheel, outlet holes being provided in the plates to control the pressure produced in the plastic material which is compressed as the rings are inserted. The plastic material may then be treated (e.g. vulcanised) and after removing the plates the projecting parts of the rings may be turned off. The rings may be axially slotted (Fig. 3) so that in the turning operation the connecting portion is iemoved leaving the ring in separate segments.