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).
Test procedures for an armature operated switch, including insulation and brush bedding.
| Identifier | ExFiles\Box 62\1\ scan0183 | |
| Date | 24th October 1933 guessed | |
| -2- (f) Verify that the armature operated switch makes contact when the armature has moved .475" + .025 from the rest position. (g) Ascertain that the armature motion operated switch contact gap is .030" ± .010 with the armature at rest. (h) By placing the motor with its axis vertical and pinion uppermost verify that the set of the pinion spring is such that the initial load applied to the pinion to begin to move this from its max outermost position lies between the limits 2.5 to 3.0 lbs. wt. Also, with the motor axis horizontal, verify that the pinion spring returns the pinion satisfactorily to its normal position without any signs of undue fricton on the splines after the pinion has been pushed in to its full extent. (i) Ascertain that the pinion rebound motion lies between the limits .085" to .115". (1) INSULATION TESTS. Lift the two pairs of earthed brushes and test the insulation of the machine (i.e. all windings etc. together) which should not be less than 1 megohm. A test should also be made of the insulated terminal and switch contact with the armature in the out of gear position in which the contact gap is open. (3) BRUSH BEDDING. The brushes should now be suitably bedded to the commutator, or inspected for O.K. bedding if such has already been performed. | ||