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).
Providing feedback and suggestions for improving the test of a self-starter motor.
| Identifier | ExFiles\Box 34\3\ Scan096 | |
| Date | 19th April 1915 | |
| To Wor.{Arthur Wormald - General Works Manager} for Mr. Ellis from R.{Sir Henry Royce} c. to J.{Mr Johnson W.M.} -1- RS{Sir Henry Royce's Secretary}/IB19415. April 19th. 1915 Re R.R. Self Starter. With reference to the test of the R.R. starter motor, I fear you have not got this job sufficiently well rigged up to be of much value. Referring to your description of the apparatus, I make out that the motor you are using has 192 armature conductors, it is lap wound, and compared with the wave wound one would be equivalent to 96 armature conductors, wave wound. There is therefore about 6% difference between them in the electro motive force which should be generated. You do not say how many turns of wire you have on the dynamo field, which reads that this one is separately excited, and that the motor is self excited. I should think you would get better results if both were separately excited, and in the case of the motor the excitation could be kept constant or varied slightly to keep the speed constant if you supply the motor with a constant electro motive force. It would be as well to use for the dynamo experimentally the armature which has 45 slots. and two conductors per slot.. This could be put in and run with a few of the useful excitations of about 40,45, 50, 55, 60, to see whether the flux through this armature was greater than the one with three coils per.slot, and whether the core losses were any less. You do not say whether, in your test, the two machines were coupled together directly, or whether they have a belt drive. They ought to be direct coupled, as the loss in the belt is a very uncertain | ||