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).
Commutator overheating failures on the Goshawk 11 and proposing further tests on insulating materials.
| Identifier | WestWitteringFiles\I\May1922\ Scan86 | |
| Date | 23th May 1922 | |
| To By.{R.W. Bailey - Chief Engineer} from E.{Mr Elliott - Chief Engineer} c. to Sck. c. to Wor.{Arthur Wormald - General Works Manager} c. to EFO.✓ c. to He. c. to Fr. ORIGINAL RECEIVED MAY 24 1922 X1109 X 4333 GOSHAWK 11. COMMUTATOR. In reply to your Hy{Tom Haldenby - Plant Engineer}15/M18.5.22., the points rais-ed{J. L. Edwards} by you have been noted, but as you now see from the num-ber of commutators broken, the failure is due to overheat-ing of the commutator, and so far as can be seen at the mom-ent, any form of commutator employing bakelite insulation is not likely to be very successful while it has to work at the temperatures apparently reached on Goshawk 11. It is Mr. Royce's opinion that the construction of the commutator should be such as to remain undamaged even when the conductors become unsoldered from the ends of the commutator bars. This occurs with micanite insulation which it is proposed to go on with for production purposes. Referring now to Mr. Clarke's report,(X1109) tests of insulating material, it would be very useful if the 2 forms of asbestos moulded bakelite which you shewed to me in the sample namely, Granula, and Fibrous, could be put through similar tests to those given in the report in question, part-icularly the heating tests as Mr. Royce wishes to know whether it is the gum or the filler that represents the limit of heat resistance in bakelite moulded products, and we particularly wish to find a moulded insulator which possesses great resis-tance to heat. In this connection it would be probably worth while making enquiries of the people who manufacture the moulding materials. We seem to remember reading in one of Mr. Olley's letters of powdered mica being used as a filler for bakelite gum. E.{Mr Elliott - Chief Engineer} | ||