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).
Examination report on a 20 HP Dynamo, No.1307, detailing issues with stiff brushes, overheating, and excessive lubrication.
| Identifier | ExFiles\Box 57\2\ Scan082 | |
| Date | 16th May 1927 | |
| To EY. from EFC. c. SFT{Mr Swift}/Mr. Bröck.{Mr Clark} X578sdo EFC6/T16.5.27. 20 HP. DYNAMO NO.1307 - EX CRICKLEWOOD. (57 segs) We have duly examined this machine handed to us by Mr. Bröck{Mr Clark}'s Dept. It is noted that the commutator solder has only just begun to run in one or two places, so that the heating has not been serious. We find the brush angles to be correct but that the brushes are rather stiff in their holders - this appears to have been caused by excessive lubrication, oil getting on to the brush holders and mixing with carbon dust. The negative brush in particular seems to jam in its holder, and we consider this to be sufficient reason for overheating by poor running contact of this particular brush. We query whether the clearance of the brush holders is correct as given by the drawing. Owing to the use of bevelled brush tops the clearance of the non-pressure side of the brush is supposed to be a relatively large amount, so much so that circumferential jaming of the brushes should not be possible. We return the dynamo herewith to EY. EFC. | ||