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).
The strength of helical gears in S. M. gearboxes, stating that angles up to 33° are acceptable.
| Identifier | ExFiles\Box 15\5\ Scan319 | |
| Date | 4th June 1932 | |
| Hs.{Lord Ernest Hives - Chair} FROM DA{Bernard Day - Chassis Design}/HDY.{William Hardy} X7310 DA{Bernard Day - Chassis Design}/HDY{William Hardy}1/M4.6.32. X.7310 C. to R.{Sir Henry Royce} SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} E.{Mr Elliott - Chief Engineer} S. M.{Mr Moon / Mr Moore} GEARBOXES. STRENGTH OF HELICAL GEARS. With reference to the remarks in HS{Lord Ernest Hives - Chair}4/KT2632., about the increase of helical angle on S. M.{Mr Moon / Mr Moore} gearboxes, in case it is thought that the helical gears on these may be weak we should like to point out that we have anticipated the need for increased lateral strength with increased helical angle, and that if our N. schemes have been followed correctly there need be no apprehension with helical angles not exceeding 33°. DA{Bernard Day - Chassis Design}/HDY.{William Hardy} | ||