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).
Failure of a Timken bearing in a semi-floating rear axle and subsequent testing.
| Identifier | ExFiles\Box 114\1\ scan0226 | |
| Date | 13th July 1939 | |
| 1015 To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} c. Da.{Bernard Day - Chassis Design} c. Da{Bernard Day - Chassis Design}/Hdy.{William Hardy} Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}3/MH.{M. Huckerby}13.7.39. SEMI FLOATING REAR AXLE. Some time ago during the assembly of one of these axles, the outer race of a Timken bearing burst. The race outer is .002 loose in its housing to allow it to slide freely when the centre case expands. We took this matter up with Timkens as the 1,000 lb. preload should not burst an unlocated outer race. The outer race which failed had had only one heat treatment, a mistake at the Timken factory. At our request Timkens have tested 100 bearings under 1,000 lbs. load. None burst and the expansion of the outer race was .0004. They then tested six bearings to destruction. These burst at 7 tons and an expansion of .008 to .010. Long before this our housing would support the race. We do not expect any further trouble with these bearings but are, however, going to run on 3.B.50 the larger type shown on OCD.1431. The outer race of this bearing burst at 13 tons. At a later date should it become necessary to have a greater margin of safety, the large bearing will be available. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} | ||