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).
Synchromesh Gearbox issue regarding insufficient clearances on the driving dogs.
| Identifier | ExFiles\Box 15\5\ Scan294 | |
| Date | 9th May 1932 | |
| GRY{Shadwell Grylls} X7310. H.{Arthur M. Hanbury - Head Complaints} from E.{Mr Elliott - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} Hor. Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} Da.{Bernard Day - Chassis Design} E.1/HP.9.5.32. re Synchromesh Gearbox. Referring to Hs.{Lord Ernest Hives - Chair}5/WJ.7.5.32 reporting that the top gear on Hancock's car is working out; we attach herewith a blueprint showing what is actually fitted to 19-EX. We are of the opinion that apart from the question of removing the driving splines on the shaft to a remote position, the question of the clearance of the sleeve with shaft at point "A" on the blueprint is of vital importance to secure that the driving dogs shall be floating and evenly driving all the way round instead of being hard on one side, and driving like an annular gear, which latter condition it is thought causes the engagement to work out spirally. We think this clearance was insufficient, being only 1 to 3 thousandths at point "A" whereas on the improved scheme last made for the 20/25, a blueprint of which we sent you, this clearance was made 6 to 7 thousandths, and the control of the sleeve when it is in either top or third gear is taken entirely by the dogs. We think this may account for the trouble which has been experienced. E.{Mr Elliott - Chief Engineer} | ||