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).
Inspection and testing procedures for dynamo components including springs and brushes.
| Identifier | ExFiles\Box 62\3\ scan0404 | |
| Date | 31th October 1933 guessed | |
| -2- Test the springs for cracks, by forcing these back as far as possible, when they should not become cracked. Note (1) It is possible that a spring which is noticeably weak is cracked and requires replacing. Note (2) It will usually be found that a spring which is good has a uniformly expanding spiral. (e) The connections of the pigtail conductors are not in any way damaged. (f) The initial bedding of the brush shows partial contact reasonably well distributed over the working surface. (Preliminary bedding of brushes). (2) The insulation resistance of the machine should be taken and should not be less than 1 megohm. N.B. (a) For the running tests it will be necessary to insert a variable resistance in the field circuit of the dynamo. This should be connected between the field terminal and the negative (earthed) brush. A second variable (carbon) resistance is used in the main circuit with which to adjust the terminal volts. (b) Where there is armature end-play it may be necessary to insert washers between the temporary driving pulley and bearing so as to keep the armature up towards this bearing i.e. in the position which it will have when fitted on the chassis. (c) Care should be taken to ensure that sufficient lubricating oil is supplied to the tachometer drive gear at the commutator end of the shaft. | ||