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).
Investigation report into a faulty Bentley Dynamo W.S.BK, detailing issues with erratic charging and an oil leak.
| Identifier | ExFiles\Box 168a\3\ img406 | |
| Date | 24th June 1937 | |
| WST What does R.H.C. think about this? Rm{William Robotham - Chief Engineer} 6142 MEMO. from Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} S. Rm.{William Robotham - Chief Engineer} Kingsbury. June 24th, 1937. BENTLEY DYNAMO - W.S.BK.{A. Birkett - Commercial Manager} We wish to draw your attention to the above dynamo the history of which is as follows:- The dynamo was first fitted to B.30.GA. Minchin's Bentley. On the 4th May 1937 it was taken off this car because of erratic charging and sent straight to the Works. It was returned to Kingsbury on the 10th May 1937 and put in the Stores this morning. June 24th it was withdrawn from the Stores to replace another faulty dynamo. I was asked to examine it before being fitted as I am watching for oil on the commutators. I noticed half the commutator was oiled up, the remaining portion being dry. I had the reduction gear cover removed to ascertain the quantity of oil therein. Upon looking at the fixing it was discovered there were only three screws holding the reduction housing, also that this housing was incorrectly drilled, the position of the gears being such that one screw could not be got in. In my opinion it had been turned half a turn in the jig when being drilled. The hole in the aluminium casing for this screw had not been tapped, so apart from the screw being left out, it was not possible to fit one. The oil in the reduction housing had escaped through this hole on to the commutator. The drive for the dynamo claimed my attention. The three drilled bosses for the reception of the rubber blocks have got two sharp indents in each boss. I at first said they were chisel marks, and went thoroughly into the matter of how this drive was removed etc. but I can vouch that these cuts have not been caused by anyone here. They are too evenly spaced to have been caused haphazard, and in my opinion after thinking the matter over I came to the conclusion that a three chuck claws had been used probably for skimming the commutator or testing purposes. I am sorry this report is lengthy but I have done everything to get to the bottom of the cause. Sketch enclosed shews wrong drilling of the reduction housing Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} | ||