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 performance and mileage testing of the N.B. type 40/50 dynamo on experimental cars.
| Identifier | WestWitteringFiles\Q\2April1927-June1927\ 93 | |
| Date | 9th May 1927 | |
| To R.{Sir Henry Royce} from EFC. c. BJ. PN.{Mr Northey} c. E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. Wor.{Arthur Wormald - General Works Manager} CWB. c. RG.{Mr Rowledge} BY.{R.W. Bailey - Chief Engineer} c. EP.{G. Eric Platford - Chief Quality Engineer} ORIGINAL 40/50 DYNAMO OF THE N.B. TYPE, i.e. ARRANGED WITH NARROWER BRUSHES THAN STANDARD, AND ALTERED ANGULAR ARRANGEMENT OF BRUSHES TO SUIT. It has been previously reported that these N.B. machines produce far less self-heating for the same output than the present standard machine with the wider brushes, also that the commutation is equally good and the brush wear is not materially increased. Three of the machines have done large mileages on experimental cars. One machine, designated J, has done a total of 22,350 miles, and the only complaint has been a slight noisiness of the brush gear, such as sometimes occurs on standard machines. Otherwise entirely satisfactory. A second machine, designated L, has done 10,600 miles on your car 7-EX (still on) and the only reported complaint in this instance is a slight magnetic noise. (N.B. Experimental 28 slot armatures are also in preparation for this 40/50 dynamo and can be used equally with the N.B. type machine as with the standard). A third machine, designated I, has done 7,780 miles on chassis 10-EX and no complaint has been reported. The margin of safety of the standard machine in respect of self-heating and melting of commutator solder (without an open or bad circuit) is too small; the N.B. Contd. | ||