Design considerations for motor connections, starter construction, and armature cores.
| Identifier | WestWitteringFiles\I\July1922\ Scan37 | |
| Date | 19th July 1922 guessed | |
| (2) standard practice, but being anxious that my pigheadedness should not be correct, I suggested that our motor should be connected 2 in series, 2 in parallel, to make it equivalent to the American requirements. I do not think this is a serious matter as the demand on the battery though rather greater, is probably of less duration. But my opinion is that for the sake of silence of starting and reliability the equipment is best as our present standard, without this alteration. My views on this latter point have been modified somewhat owing to the fact that we have now a better starting carburetter which seems to give a start even turning very slowly. (3) The third point, concerning the building up of the starter motor I also think is doubtful. I quite agree that considering the tests shew no difference between carefully insulated armature plates, and those insulated with oxide only, there was never any need to use the mica insulation between armature plates unless the grooves for the wires were to be milled in the core, and it was never intended to be done in the expensive way it was even then carried out. Therefore as regards building armature cores I maintain that small pieces of thin scrap mica should be placed between the plates when it is intended to mill the grooves, but the plates with stamped grooves require no such precaution, and can depend on the oxide only, or in the absence of oxide, varnish. (4) As regards the poles, experiments have shewn that there is no advantage in making these of separate plates. At the same time it was thought that to build them up of stamped sheet steel plates was a convenient way of producing them. I still think that if well organised, and with plates of an economical thickness. | ||
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).