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).
Experimental bench trial report for the Goshawk Dynamo.
| Identifier | WestWitteringFiles\J\March1923\ Scan1 | |
| Date | 12th March 1923 | |
| To R & E.{Mr Elliott - Chief Engineer} from EFC. c. CJ. & PN.{Mr Northey} c. By & EP.{G. Eric Platford - Chief Quality Engineer} c. Da.{Bernard Day - Chassis Design} [STAMPED: ORIGINAL] X.4383 - R.R. GOSHAWK DYNAMO. An experimental bench trial of an R.R. Goshawk dynamo wound with a finer field winding, namely, 20 S.W.G. D.C.C. in place of 19 S.W.G. D.C.C. wire, has now been completed, as referred to in our last dynamo report EFC2/T23.1.23. At the same time, however, owing to satisfactory results as regards output and heating with greater retard of control brush having been experienced on a number of dynamos on experimental cars, further retard has been allowed on the specification of production test, to give increased output, so far with perfectly satisfactory results (also referred to in above mentioned report). Reverting to the dynamo with 20 S.W.G. field winding, this was done with a view to reducing the field current and increasing the output at high speeds, utilising, of course, at the same time, a greater retard of the control brush and a greater span of armature flux operating upon the field winding. The maximum output cold (18°C) was just over 14 amperes at 1600 r.p.m., the output falling to 8 amperes at 3000 r.p.m. Running on the bench rig for four hours at maximum output, the final temperature attained was 68°C. Balancing speed at this temperature corresponding to 13.6. battery E.M.F. being 730 r.p.m. as compared with 680 r.p.m. Contd. | ||