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 bench testing of a Rotax AT.4 dynamo sample for the Goshawk II engine, detailing its mechanical and electrical performance.
| Identifier | WestWitteringFiles\G\September1921\ Scan79 | |
| Date | 19th February 1931 | |
| R.R. 235A (50 T S.H. 986. 19-2-31) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 3008 To R.{Sir Henry Royce} from EFC. c.c. to C.J.S & P.N. c.c. to Ry. & EP.{G. Eric Platford - Chief Quality Engineer} c.c. Rs.{Sir Henry Royce's Secretary} & Ds. c.c. R.R. of America Inc. ORIGINAL EFC4/TEL9.21. X.4359H - ROTAX AT.4 DYNAMO FOR "GOSHAWK II". A week ago we received from the Rotax Co. the sample Rotax small AT.4 dynamo, which they have made up for us for the Goshawk in accordance with our requirements mechanically, and as nearly as possible in accordance with our requirements electrically. The dynamo is a nice little job and has run consistently well on the bench tests which we have carried out upon it. The machine is fitted with Skefko self-aligning bearings (not Hoffmann), and there seems very little magnetic hum, and owing to the way the dynamo would be fixed on the Goshawk engine, we do not anticipate any trouble whatever from this cause. The brushes, however, seem to make rather a noise on the bench though we do not think this will be noticeable on the car. The machine is a 4-pole single field winding third brush control. The output curve is slightly variable, according to the exact condition of the control brush bedding on the commutator. On the attached photostat, two curves of output, taken on our schedule volt-ampere characteristic, one taken before and one after the heating test, are given. It will be seen that each of these curves (which are for the fully hot condition) complies reasonably well, though not absolutely, with our specification of output. Ca. | ||