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).
Outlining points for attention regarding the design and manufacture of the Goshawk dynamo.
| Identifier | ExFiles\Box 51\1\ Scan061 | |
| Date | 21th April 1922 | |
| V4383 To E.{Mr Elliott - Chief Engineer} from EFC. c. to Ey. c. to Ey/WER. c. to EP.{G. Eric Platford - Chief Quality Engineer} c. to RHC.{R. H. Coverley - Production Engineer} EFC1/T21.4.22. X.4383 - R.R. COSHAWK DYNAMO - POINTS FOR ATTENTION IN DESIGN & MANUFACTURE Most of the points below, arising out of inspection, bench tests and tests on chassis, have been previously put forward, mostly in writing. (1) The brush terminals on the pig-tail ends are, when in position, rather too close to the end cover. A small inaccuracy in the terminal or in its fixing, or an accidental dent made in the end cover may cause disastrous short circuits. This has occurred. The sleeves into which the pig-tail flex is soldered should be on the inside (radially) in each case, and the brushes should be so arranged that the pig-tails are on the side furthest away from the main body of the dynamo and this position should be considered standard in order to ensure that the brushes will be correctly replaced in their holders when taken out for inspection. This means that the pig-tail end terminal stampings will still be all alike but will be bent to different hands. (2) So far the main connections from the brushes to the terminals or to the field have not been entirely satisfactory in that they have been loose and liable to be chafed when in contact with the stud heads, or in removing and replacing the end cover. There is also a possibility of the brush pigtails being caught by the end cover if left on the wrong side (see above), in fact the space is altogether so limited that a very careful setting of the various parts is necessary. (3) Except that this would interfere with identity with those of the starter motor, we should advocate a slightly deeper brush holder, but in any case we now consider that a deeper brush is necessary and recommend that an addition of .125" be immediately made for future brushes and to the brushes on order if possible. We do not think there will be any tendency of the spring to catch on the brush holder as the brush goes down, as the spring will already just have entered the groove. (4) Trouble has been experienced owing to the brush springs fouling the connections securing nuts, so that an alteration in the spring detail is necessary, but this we think has been done. Contd. | ||