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 failure analysis of a 40/50 Dynamo from chassis 18-RC.
| Identifier | ExFiles\Box 70\3\ scan0334 | |
| Date | 1st December 1927 | |
| To Mr. Brock. K.{Mr Kilner} BY.{R.W. Bailey - Chief Engineer} V8/Jdo EFC4/T9.12.27. 40/50 DYNAMO RO.{C. C. Rose - Export Manager}25 EX CHASSIS 18-RC.{R. Childs} As in the previous case, this machine has the early control brush setting of 120° and the reason for the melting of the solder from the commutator connections appears to have been the same one. As a consequence, an open circuit in the armature winding was caused which led to brush flashing and consequent excessive wear of the brushes. It was noted that the positive brushes had been exchanged in the holders. The brushes were partially re-bedded only, but we think this was done as a result of, and was not the cause of, the failure. The control brushes were found to be sluggish in the holders and badly worn, and this sluggishness may have been a contributory cause of the overheating in the first instance. Machine herewith sent to BY.{R.W. Bailey - Chief Engineer} EFC. | ||