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).
The testing of two modified motors, detailing failures, diagnoses, and subsequent repairs.
| Identifier | ExFiles\Box 165\7\ img041 | |
| Date | 20th January 1950 | |
| -7- Rm{William Robotham - Chief Engineer}/RC.{R. Childs}1/FMA. 20.1.50. Serial NO.MR.2. This was the second fully modified motor which we received from Lucas 1st Sept., 1949. The motor was fitted to B.40. MK.4.A. engine for type test at Crewe. On examination after the engine had completed 100 hrs., during which time 210 starts had been made under normal temperature conditions, we found that the armature had been rubbing slightly on the poles and also that one of the relay contacts was loose. The motor was taken to Lucas for their examination. The Lucas engineer stated that the loose contact was due to this relay being one of the first samples of the modified type, and that the rolling technique required for these soft silver contacts had not been fully developed. No further trouble is expected now this technique has been perfected. Serial No.2. Landrover. - 12.V. This motor was received 19.10.49. and fitted to engine B.40. MK.II.B for 100 hrs. test at Clan. After 10 hours engine running time, the relay failed after only 20 starts, due to a broken connection to the relay magnet coil. The primary cause of this failure was due to the relay coil being loose on its core, and free to rotate, but for the restricting action of the coil leads; engine vibrations quickly fatigued the lead and broke it at the point where it enters the coil. (See print). In order to get on with the engine test, we repaired the connection and also varnished and baked the coil assembly thereby effectively securing the coil to the yoke. The motor was fitted to the engine and the test continued. No further trouble occurred. At the end of the test, during which, 40 starts were made, we found, on stripping, that the armature had been lightly fouling the poles. Cont'd...... | ||