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 of dynamos due to water ingress and subsequent rust, with proposed solutions.
| Identifier | ExFiles\Box 46\3\ Scan282 | |
| Date | 11th February 1920 | |
| Ck. {Mr Clark} c. to Hs. {Lord Ernest Hives - Chair} c. to Bn. {W.O. Bentley / Mr Barrington} <c. to Dr.> <c. to Dy. {F R Danby} > X.3014b EP {G. Eric Platford - Chief Quality Engineer} 12/F11.2.20. X.3014b RE. FAILURE OF DYNAMOS IN SERVICE. We recently had a complaint of a dynamo failing on a post-war car whilst in customer's hands. The dynamo was replaced with a new one, and the car was then quite satisfactory. The faulty dynamo was returned to the works and investigated, and when dismantled, it was found that the lower internal parts of the dynamo were caked with rust, showing that it had contained a quantity of water, which had since evaporated. Apart from this, the dynamo was quite satisfactory and further testing confirmed this. This also confirms my complaint of water getting into the dynamos, as per memo. reference EP {G. Eric Platford - Chief Quality Engineer} 11/F2.1.20 and EP {G. Eric Platford - Chief Quality Engineer} /T6/F17.1.20. in which I pointed out that this had taken place, and in view of the fact that the dynamos were not entirely waterproof, a little drain hole could be fixed in the bottom part of the cover to advantage, so as to avoid any pool of water forming, which according to the evidence, has taken place <strikethrough> with the dynamo which failed. I would like to say that part of the final inspection of thecar whilst on test has been for this cover to be removed so as to make sure that the commutator parts are clean and free from dust, etc. also that the dynamo is free from water. It is surprising, however, the amount of water which we have found in these dynamos when inspection has taken place. We have also made a special point of extra precaution being taken in washing and cleaning the car, for water to be kept away from this dynamo. The above failure taking place, however, rather confirms the fact that attention is required to this job, and I trust that some instructions will be given which can be applied to the dynamos at once, and if possible be conveyed to Depots so that they can take advantage of the information in dealing with similar complaints. Some time ago we also asked for a rubber sleeve to be supplied, which can be fixed to the ferrule fixing where the wire passes into the dynamo, as this seems to be the chief place where the water gets in. We think that this, in conjunction with the drain hole, should avoid any further trouble. EP. {G. Eric Platford - Chief Quality Engineer} | ||