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).
Alteration to the main brush position on the Goshawk dynamo based on performance tests.
| Identifier | ExFiles\Box 50\5\ Scan166 | |
| Date | 30th April 1923 | |
| X4383 To By. {R.W. Bailey - Chief Engineer} } E. {Mr Elliott - Chief Engineer} } from EFC. {E. Fowler Clarke - Electrical Engineer} c. Wor {Arthur Wormald - General Works Manager} /Mr. Brock. c. By {R.W. Bailey - Chief Engineer} /Ds. EFCl/T30.4.23. X.4383 - GOSHAWKAero EngineCodename for 20HP Car / Aero Engine after KestrelAero Engine DYNAMO.- ALTERATION TO POSITION OF X4383 MAIN BRUSHES. We have made an extensive series of careful tests on the performance of the GoshawkAero EngineCodename for 20HP Car / Aero Engine after KestrelAero Engine dynamo with varying main brush position. In each position the control brush has been varied so as to give maximum output consistent with a given degree of heating, and satisfactory commutation. This has been done not only on the standard machines but on a machine with reduced gauge of field winding. The result is that we now definitely require an alteration to the main brush position by which they are retarded 7° from their present position. The present standard position corresponds to a retard of 2° from the no load neutral position, and the amount of retard we find to be best for output and commutation is 9°. This implies that the main brushes require to be moved round 7° in the direction of rotation, or the commutator to be moved this amount in the opposite direction. It is not suitable to allow a retard as suggested of a whole commutator segment, as this amounts to 12.4° and is too much. This alteration should be put through at the earliest possible moment, as we have proved very carefully and definitely that it is correct. The range allowed for the control brush will not need to be altered relatively as we have proved that this same range will give all the Contd. | ||