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).
Component failures, including camshaft bracket studs, a Merlin XX auxiliary driving bevel, and an I.A.E. pump drive.
| Identifier | ExFiles\Box 143\2\ scan0192 | |
| Date | 24th June 1941 | |
| - 7 - Continued: in No.6 journal where the bending moment would be most severe. Previous complaints have been received of camshaft bracket retaining studs pulling out of the block and a special point has been made of this as it is felt that it produces a source of potential danger. It is pointed out that "go" and "not go" gauges must be used for the tapping holes in the block and that these must not be passed oversize. Miscellaneous. One or two peculiar failures have occurred, the most interesting being a failure of the main auxiliary driving bevel which occurred on Merlin XX. 33037 it being finally decided that incorrect meshing was the primary cause of failure as this unit has been completely reliable in the past. The question of the I.A.E. pump drive has also been under consideration and of the four pumps which were sent to Duxford with fitted drives one was returned after 114 hours flying. This one proved to have been originally what was considered the best fit and was now found to be considerably worn but the wear had occurred evenly over the whole length of the splines but failure had not occurred. In view of the fact that 114 hours had been completed satisfactorily as against 15 to 30 hours in previous cases we feel that this shows a distinct improvement. A further coupling with a tighter fit has topped 120 hours and is still operating satisfactorily. We are continuing to run the returned pump and coupling referred to to see what its final life actually will be. BY/HB.{C. E. Harcombe} | ||