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 overheating failure of the Goshawk 11 commutator and potential insulation solutions.
Identifier | WestWitteringFiles\I\May1922\ Scan83 | |
Date | 23th May 1922 | |
To Hy.{Tom Haldenby - Plant Engineer} from E.{Mr Elliott - Chief Engineer} c. to G.I. c. to Wor.{Arthur Wormald - General Works Manager} c. to Wmg. c. to Hs.{Lord Ernest Hives - Chair} ORIGINAL REC'D MAY 24 1922 Seen HS{Lord Ernest Hives - Chair} X. 4353. GOSHAWK 11. COMMUTATOR. X. 4333. In reply to your Hy{Tom Haldenby - Plant Engineer}15/M18.5.22., the points raised by you have been noted, but as you now see from the number of commutators broken, the failure is due to overheating of the commutator, and so far as can be seen at the moment, 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, particularly 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 resistance 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} | ||