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).
Investigation into the noisiness of Goshawk dynamos, particularly those with two coils per slot and 57 commutator segments.
| Identifier | WestWitteringFiles\L\2Jan1924-March1924\ Scan55 | |
| Date | 29th February 1924 | |
| To R.{Sir Henry Royce} from EFC. c. CJ. & PN.{Mr Northey} c. EY. E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} EP.{G. Eric Platford - Chief Quality Engineer} X.4383 - NOISINESS OF GOSHAWK DYNAMOS. And in particular X.4610. THAT OF DYNAMOS FITTED WITH ARMATURES WITH TWO COILS PER SLOT AND 57 COMM. SEGMENTS. Reference EFC1/T1.11.23 last par. was our last report on noisy Goshawk dynamos. Since that time we have in the intervals of the more important work on commutation and output of these machines, carried out a certain amount of investigation on the reduction of noise, and in particular on the possibility of reducing the noisiness of these dynamos by utilising armatures with two coils per slot and 57 commutator segments. In this connection please find attached copy of my assistant's report AB.104. Machine No.604 therein referred to was one which was handed to us as being, and confirmed by us on an experimental chassis, a particularly noisy one. We have noticed considerable differences on different machines in the variation of the tooth drag on the armature in turning the commutator round by hand, with the brushes lifted and the field separately excited, and it had occurred to us that the extent of this variation might be a measure of the noise producing quality of the machine. As far as our experience goes, this only now appears to be the case to a very limited extent. We have had one very definite result in one dynamo, namely, that an armature with straight slots has been definitely more noisy than any other armature. Contd. | ||