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).
Machine coupling methods and analysing discrepancies in motor test results.
| Identifier | ExFiles\Box 34\3\ Scan097 | |
| Date | 16th February 1916 | |
| -2- amount. I used on several occasions for coupling two such machines, a pulley on each machine, one being larger than the other so that the rim of one could fit inside the other with a fair clearance, and the edges were perforated with holes suitable for lacing. This makes a convenient form of flexible coupling, that could be got quickly, or you could use a couple of the leather joints with a piece of tubing between them. I have no objection to using any material for brushes that would run without sparking or cutting the cam and I cannot understand how it is that the carbon brushes are sending out carbon dust at the rate you state. They do not do this on ordinary machines with ordinary carbon brushes. With reference to the test itself, I think you must have some curious arrangement that I do not know of. For instance, it states that the motor absorbs at one end of the list 45 amperes 22volts at 2800 revolutions, then as the test goes on it appears that the volts rise, and yet the current passing through the motor falls. We cannot understand this at all, and can only think that the motor must be separately excited and some error of observation have crept in, or that the voltage is taken inclusive of some resistance which is inserted in the armature circuit of the motor. Amongst other things we particularly started out to try and find what was the flux through the armature of the dynamo for each excitation, and what were the core losses. You can only do this latter by knowing the efficiency of the motor, which under the circumstances could be taken as R.R. 238 A (400) S.C. 83L 16-2-16 G 1646. | ||