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).
Suggested changes and test results for the Wraith 'C' Series Gear Box.
| Identifier | ExFiles\Box 8\11\ 11-page146 | |
| Date | 8th December 1938 | |
| [strikethrough]c. Rm.{William Robotham - Chief Engineer}[/strikethrough] [strikethrough]c. Da{Bernard Day - Chassis Design}/hdy.{William Hardy}[/strikethrough] Handwritten: 628. WRAITH - 'C' SERIES GEAR BOX. Handwritten Signature: AHH The following is what is suggested for 'C' series gear box :- 1st. Motion Shaft. To be to PD.310, with a 35° helix angle. Material S/ZNX. This shaft with a 45° helix angle, has run 44 hours without failure. The lower helix is needed to relieve the bearing. 35° angle gives a relief of 42%. 3rd Speed Gears. Present standard with 45° Helix. 3rd Motion Shaft with increased collar to PD.328, otherwise standard. The present shaft has run 62 1/2 hours, and then pushed off its collar. The increased collar represents 28% increase of shear area. The strengthened 1st Motion shaft to PD.311 with increased clutch splines will either not be used at all or not until the latter part of 'C' series. Handwritten text: F.J.H. How many hours has the shaft to P.D. 310 without the altered helix run. Rms DA.{Bernard Day - Chassis Design} 64 hrs. AHH. 9/12/38 | ||