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).
Notes on servicing the dynamo at the 15,000-mile interval.
| Identifier | ExFiles\Box 168a\4\ img172 | |
| Date | 15th May 1940 | |
| 6144 Elec. System General. To Rm{William Robotham - Chief Engineer}/AA.{D. Abbot-Anderson} from Rm{William Robotham - Chief Engineer}/RC.{R. Childs} Rm{William Robotham - Chief Engineer}/RC.{R. Childs}8/JMG.15.5.40. Notes on servicing. (15,000 mile) (1) Dynamo. The points to watch on this machine are:- (i) Brush wear. (ii) Commutator wear. (iii) Deposits of brush dust and oil on the commutator and brush-holders. (iv) Bearings. The extent of the work necessary to be done, depends on the way in which the car has been run, i.e., whether at high speeds with headlights etc., on, or at low speeds with very little load on. In most cases it will be found advisable to carry out a complete overhaul. The bearing brackets and armature should be removed, and the field coils, mounted in the yoke, washed in "Trinnings" and afterwards dried out in an oven for about 8 hours in a temperature of about 100°F.{Mr Friese} A check should then be made of the insulation of the field coils by applying through a low C.P. lamp an A.C. voltage of 200, between windings and case. The armature should be cleaned by blowing out with a compressed air gun, especially round the connections to the commutator. After this, the micas between the segments should be cleaned out and, if necessary, undercut and the commutator skimmed. Following this, the armature should be drop tested and the insulation checked. (Photo required showing commutator end of armature in tilted position, with arrows indicating end connections and micas) The bearing brackets and brush-gear should be washed in paraffin and afterwards dried out in the oven. Repack bearings with grease. Replace if necessary. Test for insulation by applying the 200 volt mains through a low C.P. lamp across the insulated brush-holders and the bracket. Newbrushes should be fitted and carefully bedded to the commutator. The pressure exerted by the pressure arm should be measured at the top of the brush to ensure that it is about 1 lb. (Photo required of a brush in its holder, with arrows indicating the curvature of the brush surface) | ||