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).
Letter to Messrs Ransome & Marles Bearing Co. Ltd. regarding experiments on steering rollers, their failures, and design improvements.
| Identifier | ExFiles\Box 153\2\ scan0230 | |
| Date | 18th January 1937 | |
| 1300 Experimental Department 18th January 1937. Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}/AP.9. F.O.Hickling Esq., Messrs Ransome & Marles Bearing Co.Ltd., NEWARK-ON-TRENT. Dear Mr.Hickling, The writer was a victim of the 'flu epidemic during last week with the result that the steering roller experiments were at a standstill during that time. However, we have now got some more information concerning the rollers with 0.312 dia. balls which is as follows. - We examined the rockershaft in which the first roller had been tested and found that the face against which the failed inner abutted was not true, to the extent of 0.004" in the place that mattered. We therefore corrected this and put in the second roller. On test this lasted considerably longer as shewn on the attached table. We are sending to you under separate cover the remains of this roller assembly. This did not fail in the same way and the rockershaft faces were still true at the completion of the test, so we conclude that the cause of the first failure was bad machining of the rockershaft. From the remains of the second roller we conclude that the disintegration of the ball track on the inner and the cracking of the outer have been developing simultaneously. It therefore seems that we have reached the limit of capacity to be obtained from this roller. In any case we think that it is now equal to the duty it will have to perform in service, and, if road tests confirm this, we shall be able to standardise this design. Although this second test has shown that when properly backed up, the inners are satisfactory, we wish to have the extra 0.030 on each inner in future in order to be on the safe side. Before the last test we opened out the gap between the rockershaft faces by an extra 0.060 and made up the difference with packing washers. The test has therefore confirmed that the rockershaft is still sufficiently strong under these conditions. continued. | ||