Describing the design of a direct drive nose, including propeller shaft bearings and casing.
| Identifier | ExFiles\Box 42\1\ Scan119 | |
| Date | 18th November 1925 | |
| COPY FROM AJS. 43829 C. to G.L. HS. {Lord Ernest Hives - Chair} RR. E.16. DIRECT DRIVE NOSE. X4114 X.3829 AJS1/M18.11.25. We send herewith drawing LeC.2167. shewing the propeller shaft bearings and direct drive nose casing etc. You will note that a plain floating bush bearing has been used for supporting propeller end of shaft. No whitemetalling grooves have been shewn onthis as the bush is mild steel and we do not wish to add them unless absolutely necessary. A New Departure No.313. medium type 65 mm. bore double row bearing has been used for taking the thrust in either direction. This bearing is arranged to take no radial load. The lubrication of the plain bearing is effected through a special type of bush at the rear end of shaft pressed into a 1 in 20 taper in the bore, which taper is continuous throughout the rear portion of shaft. It is intended that this bush should be .003 oversize before pressing into position and its bore made such that after pressing in it will be a good fit on the supporting spigot fixed in crankshaft end. The bush, after pressing in to an exact longitudinal position is secured from being pushed out by the internal oil pressure through the split ring sprung into position as shewn. It should be noted that no timing of the bush relative to the shaft is required. With a view to relieving pressure due to oil leakage from the supporting spigot to the inside of bush a hollow bolt has been used for securing the spigot in crankshaft. The internal oil pressure of shaft lubricates the plain bearing at front, and this bearing incidentally acts as an oil check. The ball bearing it is intended should be lubricated by oil exuded radially from the inner end of floating bush. The surface in which the floating bush runs it is intended should be casehardened, and this steel piece is spigoted in a disc which it is intended should have its final boring operation done when clamped into position on the end of casing already bolted to engine, and so secure alignment with the crankshaft. The snug riveted into this plate on the top is to prevent the plate being accidentally turned over and throwing the bearings out of line after dismantling at any time, should the eccentricity of its bore not be on the vertical centreline. The dimensions for shaft flange and those of flange on casing for securing faring, we are not certain about, and should be glad if RG. {Mr Rowledge} would check these up as we do not know what propeller would be used. AJS. | ||
From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).