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).
Design features, materials, and challenges for the Comet Rear Axle.
| Identifier | ExFiles\Box 98\1\ scan0097 | |
| Date | 14th September 1940 | |
| 400 Re Rm.{William Robotham - Chief Engineer} c. to Rm{William Robotham - Chief Engineer}/HH. c. to Rm{William Robotham - Chief Engineer}/GB. c. to Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer} c. to Ev.{Ivan Evernden - coachwork} Ev{Ivan Evernden - coachwork}/Tln.6/JH.14.9.40. COMET REAR AXLE. PL.336. We attach to Rm{William Robotham - Chief Engineer}/HH's. copy of this memo. the original of the above scheme. The most unusual feature of this design is the use of dural: tubes and Alum: centre casing. The attachment of tubes to centre casing is a problem which requires solution by experiment. Test pieces representing the mating parts of centre casing and tube, should be detailed and made. Rm{William Robotham - Chief Engineer}/GB. will decide on the design of these to suit his test tackle. Although we have drawn a shrink fit with parts proportioned as on RM.{William Robotham - Chief Engineer}599, we think the stresses, particularly in socket of the centre casing, will be high. Other methods of attachment that have been suggested are : welding around the tube; welding through holes in the socket as on Salisbury axles; expanding the tube into the holes in the socket; and combining the shrink fit with serrations or dowels. Pinion Bearings. We think we have drawn the cheapest combination of bearings by having a Schatz front bearing with a spring ring in the outer race and a type L.L. roller rear bearing. The type L.L. roller (which is eccentrically filled) whilst having sufficient load capacity, may not be rigid enough. In that case we should substitute a bearing of type F or type H, preferably H.{Arthur M. Hanbury - Head Complaints} The Crown wheel bearings are arranged as on present experimental cars. i.e. to take thrust in one direction only. The splitting of the diff. case as shown has advantage in cheap diff. pinion thrusts and rigid diff. case, but involves a large crown wheel forging. The size of centre casing is such that ratios of 10/41, 11/41 and 12/41 can be accommodated. 12/41 should be detailed. Ev{Ivan Evernden - coachwork}/Tln. Original to Rm{William Robotham - Chief Engineer}/HH. Prints to Rm.{William Robotham - Chief Engineer} Ev.{Ivan Evernden - coachwork} Cy. Ashby. | ||