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).
Fatigue test report on Phantom III differential housings.
| Identifier | ExFiles\Box 92\5\ scan0068 | |
| Date | 11th June 1936 | |
| To E.{Mr Elliott - Chief Engineer} c. to Sg.{Arthur F. Sidgreaves - MD} c. to Wor.{Arthur Wormald - General Works Manager} c. to By.{R.W. Bailey - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} Hs{Lord Ernest Hives - Chair}/WB.{Mr Brazier/Mr Bell}30/KW.11.6.36. Phantom III Differential Housings. G.54469. These housings were subjected to Wohler fatigue test at 500 r.p.m., the load being regulated by adjusting the extension of a pull rod. The face of the housing was secured to the rig shaft by the eight studs by which it is normally attached, and the load applied via the ball race. Using a .75" dia. S/N loading rod with an extension of .0095", over a length of 6", equivalent to 5240 lbs. approximately, the standard housing G.54469 failed after 1 hr 55 mins - average time for three housings - the fracture occurring along the pitch circle of the lightening holes, and branching into the stud holes. One of these standard housings was fortunately stopped at the commencement of the fracture when it was seen that failure definitely commenced at the lightening holes. A G.54469 without the lightening holes, tested under the same conditions, ran for 10 hrs. 50 mins., failure occurring at the internal change of section forming the differential gear bearing, at which section the securing stud holes break through. Ex.22991. An Ex.22991 housing, similar to the one which originally failed on 22-G-V, when tested under the same conditions failed after 3 minutes. The failure occurred at the undercut at the base of the taper section, thus reproducing the original failure. Tests on other models proceeding. Hs{Lord Ernest Hives - Chair}/W. Bell. | ||