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).
Suggested points of improvement for the Goshawk Dynamo.
| Identifier | ExFiles\Box 50\5\ Scan019 | |
| Date | 6th February 1922 | |
| X4383 X.4383 1/2 EFC4/T6.2.22. X.4383 - GOSHAWK DYNAMO - SUGGESTED POINTS OF IMPROVEMENT. (1) The brush terminals on the pigtail ends are, when in position, rather close to the end cover. An accidental dent made in the end cover may cause disastrous short circuits. The sleeves into which the pigtail flex is soldered should be made on the inside (radially) in each case. (2) Where the main connections from the brushes pass through the end plate to go to the terminals or to the field, insulating bushes appear to be desirable. The wires constituting these connections also should be protected against chafing through where they come into contact with stud heads. (3) There appears to be room for a slightly deeper brush holder and corresponding longer brush. This would give an extra degree of stability to the brush and might also make for a little more allowance for wear. (4) The insulation between the brush holders and the end plate should completely cover the machined area, which itself should give a margin all round as compared with the corresponding surface of the brush holder. This increases the length of leakage path in case of accumulation of brush dust. It has been found that the continental bakelite plates shrink a little, so that there is a tendency for the brush holders to become loose, even after some little time. To avoid this it may be necessary to revert to mica for this purpose | ||