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).
20-HP Dynamo Failures, their cause, and proposed solutions.
| Identifier | ExFiles\Box 47\4\ Scan128 | |
| Date | 2nd October 1923 | |
| EFC. c.BY c.NFT/AEM. For Mr. Brock. 14333 EP{G. Eric Platford - Chief Quality Engineer}9/H2.10.23. X.4333 re. 20-HP Dynamo Failures. Referring to your EFC3/T27.9.23 - the cause of this failure, we take it, was due to the faulty fitting of the new negative brush. The reason for this brush having to be fitted, is apparently fairly obvious - that the old one was worn out, Judging from the condition of the two remaining brushes, which you will notice are now about at their limit, and are in that stage when possibly the old negative brush was probably not making proper contact on to the commutator. Our experience of cars in service is that the brushes do not wear very well, and I hold the view that this is due to the condition the commutator gets into after running for some time. I do not feel that we should charge the customer for the cost of this failure, since as far as we can make out the car has not run more than 2,000 miles. Can BY.{R.W. Bailey - Chief Engineer} please supply instructions and order number for dealing with these failures, as I understand from recent correspondence that the cause of the failure is now somewhat established. I take it that as soon as this is finally settled further instructions will be issued to apply some modifications to the existing dynamos to prevent this trouble taking place, which instructions we should like to put in the hands of our service depots as soon as ever possible. I refer to BY's suggestion of the different sloping of the brush where the spring comes in contact with it, also some protection in fixing the field fuse of similar capacity as referred to in your EFC4/T27.9.23. In view of the controversy which is now going on as regards the importance of bursh failure etc. I am about to supply information to our Depots and others who come in touch with our 20-HP as to the importance of correct brush bedding, and I shall be glad to receive from you or BY.{R.W. Bailey - Chief Engineer} any further information as regards adjustment of even alterations as above suggested which can be embodied with these instructions. The suggested fuse alteration should also deal with the complaints which have taken place due to broken connections, as referred to in BY's memo.BY10/P1.10.23 | ||