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).
Material and design of first speed teeth for the senior gearbox, referencing a 30,000-mile test.
| Identifier | ExFiles\Box 136\2\ scan0297 | |
| Date | 11th October 1940 | |
| Handwritten: 1/53 Rm{William Robotham - Chief Engineer} | Wyman. Parker 47634 Did not the box do 50,000 miles? I thought it was not changed until the other day. Rm{William Robotham - Chief Engineer} 47,654 Typed: To Rm.{William Robotham - Chief Engineer} c.c. to Rm{William Robotham - Chief Engineer}/HH. c.c. to Ev.{Ivan Evernden - coachwork} Ev{Ivan Evernden - coachwork}/Tln.9/JH.11.10.40. PL.368 8 DP. FIRST SPEED TEETH. SENIOR GEARBOX. 30.G.VII. ran for nearly 30,000 miles with a gearbox having 9 DP. first speed teeth in S/ZNX. These did not fail even though subject to regular use whilst the car was on bus work. If we are justified in taking this as a fair test of first speed, then the 7.2 DP. teeth on the Senior Rationalised box are unnecessarily strong, and we ought to compromise on a quieter but more highly stressed set of teeth. This we have done on PL.368. The reverse pinion meshing with the first speed wheel is naturally involved and the other reverse pair becomes involved in order to match the end thrusts on the reverse layshaft. All layshafts and reverse layshafts for the whole Senior Range should be made in S/ZNX. Third motion shafts should also be in S/ZNX with the possible exception of shafts drilled for second speed anti rattle. The only gearbox centres that are altered are those between the main shaft and reverse lay-shaft; and here the alteration is so small that actuation pieces are not altered and the gearbox need not be redrawn. Thn. Ev{Ivan Evernden - coachwork}/Tln. Original to Rm{William Robotham - Chief Engineer}/HH. Prints to Rm.{William Robotham - Chief Engineer} Ev.{Ivan Evernden - coachwork} Rm{William Robotham - Chief Engineer}/HH. Olley & Ashby. | ||