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 stiff grease used in speedometer drives supplied by Smiths.
| Identifier | ExFiles\Box 165\2\ img069 | |
| Date | 15th April 1937 | |
| Rm{William Robotham - Chief Engineer}/Wst 6065 BY.5/G.15.4.37. REV. COUNTERS AND SPEEDOMETER DRIVES ON CHASSIS. Referring to Rm{William Robotham - Chief Engineer}/Wst.11/AP.14.4.37. I am afraid you are wrongly informed as to the actual position in regard to the speedometer drives. The position actually was that Messrs. Smiths supplied drives during the month of December which were filled with a grease much stiffer than the grease which was normally used. We immediately took the matter up with them, and in their reply they stated that no change had been made. I wrote and insisted that the grease was wrong and asked Mr. Arrowsmith to come to our Works and inspect the drives on the spot. The result was that he agreed that the grease was much stiffer than the grease they normally used, and went back to investigate the position. The result of the investigation was that whilst they had not intelligently changed the grease the delivery from which the drives during November and December had been filled was much stiffer in the cold condition. They immediately returned the stock, and corrected the matter for all drives not delivered and for a number which were returned. In the meantime Mx.{John H Maddocks - Chief Proving Officer} who had to keep his production going had found it essential to run some oil through the drives and hang them up to drain. You will observe that there was no question of filling the drive with oil but using oil to soften the grease. Without the use of oil the drive would shear rather than turn the cable. I consider that Mx.{John H Maddocks - Chief Proving Officer} did what appeared to be a reasonable thing at the time in running oil through, but it was evident that they were not drained for a sufficient length of time and ultimately a certain amount of oil which had been associated with the grease started to work back into the dynamo. BY.{R.W. Bailey - Chief Engineer} | ||