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).
Progress and design choices for gearboxes, comparing a simple design with Maybach and epicyclic options.
| Identifier | ExFiles\Box 15\5\ Scan194 | |
| Date | 9th March 1931 | |
| HS.{Lord Ernest Hives - Chair} DA{Bernard Day - Chassis Design}/HDY.{William Hardy} ) FROM R.{Sir Henry Royce} X7310 E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} ) (At Le CanadelHenry Royce's French residence.) c. to - SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} GEARBOXES. R2/M9.3.31. X.7316. X.5310. X.523. So far we have got on slowly with the above to make any definite improvement from our simple box well made with helically driven side shaft. It is a good practical scheme but we realise that some progress is needed. If we had not made such a good piece of work with this and other parts we should have been earlier forced into something more novel, so that our very virtue becomes our disadvantage and forces others to become more progressive: we have also quite a few things in hand. Now we are quite convinced that in its ordinary form the Maybach is not suitable for the ordinary box, and the special box as made by Maybach, Mercedes, etc, is not satisfactory to our requirements because there are too many wheels running in constant mesh at higher than engine speeds under many conditions - i.e. idling, and on top gear, so that I do not favour buying the Maybach box, but to continue our struggles on our own lines. I am in great hopes that you will like our own double top - i.e. the vacuum operated epicyclic with Maybach or ordinary jaws, and I am very pleased that works are making such a splendid effort to get this going. I believe that ordinary jaws will be preferred for the box - i.e. 2nd. and top in the box. As regards J.{Mr Johnson W.M.} 3. we shall be able to decide what jaws are to be used for this and whether the 4 speed box with silent 3rd. (i.e. two single helicals) as designed is to be made, or whether you will keep the present (I hope not), or whether you will have the epicyclic double top on this also. Anyway it should be the best selling proposition and made at the least possible cost. Mr. Sidgreaves is quite right: we are working at the designs for a new box because everyone thought that at least a very silent 3rd. was wanted. One other point in this memo. is that P. 2. with double top should have at least one, and perhaps two more teeth, in the back axle pinion - i.e. both 3rd. and top about 15% higher. R.{Sir Henry Royce} | ||