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).
Gearbox sideshaft failure and proposing design improvements to strengthen the part.
| Identifier | ExFiles\Box 15\5\ Scan310 | |
| Date | 30th May 1932 | |
| HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} C. to DA.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} X7310. R7/M30.5.32. X.7310 P.2. GEARBOX. SIDESHAFT FAILURE. With reference to HS{Lord Ernest Hives - Chair}/LID{A. J. Lidsey}2/KT24532., I understand from HS{Lord Ernest Hives - Chair}/LTD. that the spiral angle in this gear is 40° from the normal parallel with the axis, so that the side pressure on the teeth approaches very nearly the driving pressure. We had hoped to work out a better angle than this and it should be realised that with these large engines the forces at the small radius of the teeth of these wheels is extremely high, and we doubt whether we are going to get the small and light mechanism that the motorcar demands to carry these loads successfully for the long life of the car, both with regard to bearings and other mechanical stresses. We ought therefore to use the smallest spiral angle that we can (for the desired silence) as well as the most favourable angle of action of the actual gear teeth, so as to keep all the forces as low as possible. This matter will be put before DA{Bernard Day - Chassis Design}/HDY.{William Hardy} for his suggestions about the strength of the gear which has broken the web near the hib. To make the work secure we hope to double the strength of the part, and reduce the forces quite possibly 25% by reducing the spiral angle. R.{Sir Henry Royce} | ||