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).
Page two of a document detailing specifications for armature winding, including coils, wiring, insulation and assembly.
| Identifier | ExFiles\Box 68\4\ scan0204 | |
| Date | 22th March 1920 | |
| Contd. -2- RG{Mr Rowledge}/G22.3.20. In the other case the armature would be wound with 37 coils of eight turns, being wide enough for two wires side by side, and eight wires deep, 16 wires per slot. The grooving of this armature would also be spiral equal to the pitch. Mica is used between the plates to avoid the turning over of the plates due to milling the armature grooves after the armatures are built up. A special caution to prevent the milling cutter running is made by taking about one third of the depth of the groove at a time. The bottom of the groove would have a half-round end. The middle of the armature would be turned down to provide for the fine steel band in the centre of its length. The end wiring should be double helical, and should be fitted on to a support and bound down with steel wire so that the maximum speed of 4500 would not be likely to disturb the coils. The size of the wire to be used on the armature would be .040" or larger if found possible without undue tightness. The insulation would be fine double cotton covered, not adding to the diameter of the wire more than .010". The insulation would be manilla paper troughs fitting into the former, which is temporarily secured by tapes, and after removing from the former the whole coil is taped with fine cotton or silk tape, and well dried and varnished before putting on to the armature. The coils would be wound so as to form two outside ends, one at the bottom and one at the top of the coil. Contd. | ||