GB541820A - Improvements in gearing for counter-rotating airscrews, and like transmissions - Google Patents

Abstract

541,820. Toothed gearing. DAY, B. I. June 11, 1940, No. 10184. [Class 80 (i)] [Also in Group XXXIII] Consists in gearing for driving two coaxial elements, e.g. airscrews, in opposite directions at a lesser speed than that of the driving shaft. The driving shaft 1 is connected to a hollow shaft 2 whereon are mounted two gears 3, 4 preferably of identical size and tooth formation. The inner gear 3 meshes with idlers 5 mounted in bearings 6 in the casing 7, the bearings being received in an extension 8 of the casing. The idlers mesh also with an annulus 9 carried on a cone-like extension 10 which itself is carried by a hollow shaft 11 of the inner airscrew 12 mounted in bearings 13. Within the shaft 11 is another shaft 15 of the outer airscrew 16. This shaft extends towards the engine and at its inner end carries planets 17 which mesh with the sun gear 4 and also with a fixed annulus 20. The shafts of the planets 17 are carried at their outer ends by the shaft 15 and, at their inner ends, by an extension 18 of the shaft 15 which takes a bearing at 19 in the structure 8. The shafts of the idlers 5 may be provided with gears 22 for driving engine accessories. When applied to a variable-pitch airscrew, the oil feed for varying the pitch can be sealed between the two shafts 11, 15 with piston rings such as 23.