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 notes on the performance of armatures after fitting new bearings.
| Identifier | ExFiles\Box 165\6\ img129 | |
| Date | 29th June 1920 | |
| RR 236.(150 BKS.)(SHS7.29-6-20.) MP 224356 ROLLS-ROYCE LTD. INSTRUCTIONS. To Order No. Customer's No. 9 very strong. New bearings were fitted to this machine and with its own armature. Seemed to improve the quietness of running. No 702. Hum at tooth frequency and also at 1/2 times tooth frequency (unusual). Tooth drag strong. Slight slack in driving end bearing. Side pressure on shaft has little effect. Air-gaps not quite equal. Pole-tip spacing fairly uniform. 57 coil armature hums usually badly. 28 slot armature hums slightly at about 1000 rpm. but is better than the other armatures. No 1025. Tooth frequency hum above 1200 rpm. Slight slack in both bearings. Side pressure on shaft has no effect. 57 coil armature seems to be a little better. 28 slot armature fairly good. Air gaps fairly equal. Pole tip spacing not. (cont) Signed This Sheet must be filed on completion of the work. | ||