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).
Examination and test report on a noisy 40/50 Dynamo UG.13, detailing findings on polarity and mechanical issues.
| Identifier | ExFiles\Box 70\3\ scan0220 | |
| Date | 16th December 1925 | |
| To BY.{R.W. Bailey - Chief Engineer} from EFC. c. Mx.{John H Maddocks - Chief Proving Officer} c. Mr.Brock. X.8783 EFC1/T16.12.25. X.8783 - 40/50 DYNAMO UG.13. Reference MX{John H Maddocks - Chief Proving Officer}/McM3/MC3.12.25 and EY8/H2.12.25, we have now completed the examination and test of this machine which was stated to be noisy. We have noticed on the bench a high pitched note between speeds of 1100 and 1150 r.p.m. and in our opinion this may be due to a slackness which exists in the commutator end bearing, because we do not find any electrical irregularity which might account for this as compared with other machines. As regards other features. This machine was found on receipt by us to have residual excitation of the wrong polarity. Unless the battery (by being put in the rear of frame) was connected with wrong polarity on the chassis, this condition necessitates that the machine has been wrongly excited by the application of an independent battery. The desirability of keeping to the correct polarity lies in the fact that otherwise the cutout contact points on the car may be damaged on the first contact when the battery has to correct the dynamo. Some of the brushes on this machine were not quite .002" clear as now recommended. This should be cured. As regards the electrical performance on the production test, this was found to be satisfactory, and the machine is herewith returned to Mr. Brock. EFC. Suggest new bearing. | ||