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 into a Bentley dynamo with a complaint that the armature was fouling and causing knocks.
| Identifier | ExFiles\Box 168a\3\ img224 | |
| Date | 23th August 1935 | |
| 76142 F.{Mr Friese} From Ha/Wst. c. to By.{R.W. Bailey - Chief Engineer} c. to K/KC. c. to Bd{Mr Berend}/SB.{Mr Bull/Mr Bannister} Ha/Wst.3/MA.23.8.35. BENTLEY DYNAMOS. We have had for investigation a dynamo No.0.8.BM returned from K.{Mr Kilner} with the complaint that the armature fouled somewhere causing knocks. It was found that by knocking the armature it could be moved forward into the commutator end bracket sufficiently to cause the riser of the commutator to foul the backing plates of the bush holders. When pulled up firmly against the pulley end bearing, apart from a harshness in the tachometer drive gearing, the armature rotated smoothly. The machine is wrong in so far as it is possible to move the armature in its bearings so much, as to cause parts to foul each other. But apart from this, we have stated, in the dynamo test specification, that for running the machine, the armature should be pulled up against the pulley end bearing, and where necessary, packing washers should be inserted between the pulley and the bearing to ensure this being done. Further, it is implied that the armature should be in this position when on the car. It would seem, therefore, that packing washers were necessary, but were not used, in fitting the dynamo coupling, resulting in the armature being thrust slightly forward. We recommend that action be taken in respect to the design of the dynamo to prevent recurrence of this trouble which has been with us for so long. Apparently it is not possible to change over a dynamo on any of our chassis without expert assistance. Ha/Wst. | ||