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).
The construction of an outer generator and inner motor armature, including a hand-drawn sketch.
| Identifier | ExFiles\Box 52\3\ Scan370 | |
| Date | 1st August 1919 | |
| (2) Dispensing with flywheel, due to high moment of inertia of the outer (or generator) armature. (3) Lines of force run in closed circuits within a steel drum, a place of greatest density being at the middle of the drum, with a decrease of density towards the outside. Hence low magnetic leakage. (4) Armatures run in the same direction, one tending to distort the fields one way, and the other the opposite way. Hence low field distortions and little trouble from sparking at the commutator. (In practice, at no speed could any sparking be detected). (5) Reverse is obtained by reversing the connections of one set of brushes, without the use of a sliding reverse gear. 12. Details of the construction are as follows: (1) The outer or generator armature is coupled direct to an aluminum disc, bolted to the engine crankshaft, replacing both flywheel and clutch. It is former, wound of taped copper strip, and has laminated teeth mounted on the inside of a pressed steel drum, which with the aluminum intermediate pieces forms an integral cylindrical box, covering the whole of the mechanism and supported at its outer end on a ball bearing running on the stationary hollow shaft, which holds the fields. The windings are impregnated with a Bakelite solution under, first vacuum and then pressure. (2) The inner or motor armature is built up of formed strip, having clasped between each pair of strips opposite the pole pieces, sector-shaped laminated iron conductors for the lines of max force. These are ingeniously formed of little pieces of low hysteresis iron sheet, pressed out thus:- and built up thus:- After building up, each assembly of iron pieces is pressed together endways into what is practically a solid block, the iron Us holding each other by friction. The resulting sector-shaped blocks are built up into the armature assembly, projecting considerably above and below the windings, thus: [Handwritten text] [In section 1, above the word 'strip'] Copper [To the left of the sketch] Driving teeth & end plate see general arrangement sketch [Above the sketch] Projecting teeth before grinding. [To the right of the sketch] Piano-wire banding. Face-commutator segments | ||