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).
Tests on variations of brush bedding in 20 HP Dynamos and the resulting effect on output and heating.
| Identifier | WestWitteringFiles\K\October1923\ Scan6 | |
| Date | 1st October 1923 | |
| To R.{Sir Henry Royce} & E.{Mr Elliott - Chief Engineer} from EFC. c. CJ. & PN.{Mr Northey} c. WOR.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} EP.{G. Eric Platford - Chief Quality Engineer} c. DA.{Bernard Day - Chassis Design} OY. s. EYB. ORIGINAL EFC1/T1.10.23. X.4383 - 20 H.P. DYNAMOS. Y4383 Further to our EFC1/T26.9.23, EFC4/T27.9.23 and EFC5/T28.9.23, and now regarding more particularly the variations of brush bedding which are or may be experienced on dynamos even though the bedding is made in the first instance with all possible care and appears to be perfectly correct, and which subsequent development of irregular bedding may possibly be the cause of some of the dynamo failures, we have now made tests to discover the range of variation of output and heating possible, due to such variations artificially made. For this purpose we have, on an experimental machine, caused the brushes to bed only on one quarter of their width at one side, which side could be made either the leading or the trailing edge by reversing the brush, and each of the eight combinations of the three brushes in their two positions have been tried. The position of the control brush holder had been previously set with normally bedding brushes to suit the specification of production test, i.e. to give a peak output of 11 amperes, after 20 minutes running. With these artificially made variations of brush bedding, the peak outputs and the heatings have varied considerably. Contd. | ||