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).
Inspection and failure analysis report on various starter motor components.
| Identifier | ExFiles\Box 165\7\ img039 | |
| Date | 1st January 1950 | |
| -5- Re/RC.{R. Childs}1/PHA. D.1.50. Starter Pinion Gear. In good condition. Brushes. Approx. 40% wear. Clutch and Operating Gear. Clutch not dismantled. The phosphor bronze engagement thrust blocks fitted to the operating fork were considerably worn. This wear probably due to the excessive clutch slip which occurred near the end of the test. See print. Solenoid and Relay. Condition of relay contacts very good considering the number of starts. The main contacts were deeply pitted and burnt but did not give trouble during the 30,000 starts. The motor was returned to Lucas for their examination. Serial No.56. This motor was received from Crewe, having failed on B.40, No.4. slave engine. The cause of failures was due to the rear end-coils of the armature being flung outwards, to such an extent as to foul the poles and field coils. We found evidence to show that the Sinterred iron pinion bush had, at some time, temporarily seized to the shaft. We assumed that this was the cause of the trouble, because the seizure would prevent the pinion from being disengaged after starting the engine, and so, until it freed itself, the armature would be rotated at a speed of 10 times that of the engines. (Fan/RC.{R. Childs}5/DH.{D. Henderson - Showroom} 12.7.49. - 2209 B.) The parts were taken to Lucas and they have now given up the idea of using a Sinterred bush for this application, and have changed back to Bronze. Cont'd..... | ||