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).
Analysis of abnormal wear on a returned axle shaft's splines for chassis B.4-MR, concluding the cause is likely faulty fitting.
| Identifier | ExFiles\Box 131\3\ scan0125 | |
| Date | 25th August 1939 | |
| 1113 Rm{William Robotham - Chief Engineer}/GWH{George W. Hancock - Head Chateauroux}(K) from Mx{John H Maddocks - Chief Proving Officer}/SB.{Mr Bull/Mr Bannister} c. Hy{Tom Haldenby - Plant Engineer} c. Hm{Capt. W. Hallam - Head Repairs} c. Rm{William Robotham - Chief Engineer}/Gry{Shadwell Grylls} MX{John H Maddocks - Chief Proving Officer}/SB{Mr Bull/Mr Bannister}2/MG.25.8.39 CHASSIS NO. B.4-MR Worn Axle Shaft Splines Rm{William Robotham - Chief Engineer}/GWH{George W. Hancock - Head Chateauroux}22/N.18.8.39 The axle shaft returned certainly shows abnormal wear on the splines, but we cannot believe that it is due to any difference in design on M.series. This shaft is of course stiffer than the previous design, and this will have the effect of increasing the intensity of shock loading on the splines. This effect, however, should be more than offset by a 50% increase in the number of splines, and a 10% increase in the effective radius of the splines. Further, the shaft on the other side of the car is presumably all right since no complaint is made, which indicates an abnormal condition on one side. It is observed that the damage to the splines is not ordinary indentation due to loading, but is a form of tearing due to end movement of the coupling. The sides of the splines have distinctly picked up, and this indicates that the coupling piece must have been abnormally tight on the outer serrations, thus concentrating all the end movement on the inner splines. As this is a matter of faulty fitting, we are not worrying unduly about it until we see whether any further trouble develops on other M.series cars. Mx{John H Maddocks - Chief Proving Officer}/SB{Mr Bull/Mr Bannister} | ||