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).
Specification for the inspection and test of a small shunt dynamo.
| Identifier | ExFiles\Box 168a\3\ img091 | |
| Date | 13th December 1938 | |
| ATTACHED TO RM{William Robotham - Chief Engineer}/KC.8/JH.13.12.38 Specification No.E.C.15a. Inspection and test of small shunt dynamo. Type :- Fan machine with rubber drive. Armature : 36 slots, 8 conductors 19 S.W.G. Poles Chamfer 15°, air gap .020" - .105". Brushes angle 8°. Brass brush gear. Weight 24 lbs. 7 ozs. (complete machine). ************ Upon receipt of the machine from the assembling benches :- (1) Inspect the brush mechanism and make sure that - (a) The clearance between brush and holder both axially and circumferentially, is not less than .008". (b) The force extended by the pressure arm measured at the top of the brush is between 13 ozs. and 18 ozs. (c) Corresponding tips of the brushes are on the average, exactly 18 commutator segments apart. (d) The brush pressure arms are free in their bearings, so that the full tensions of the springs are exerted on their respective brushes. (e) The brush flexibles, and their connections, are not in any way damaged. (f) The bedding of the brushes is such that the surface shows signs of making contact, right across its thickness for at least 80% of its width. | ||