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).
Historical and recent oil leakage issues with the Bentley tachometer drive on dynamos.
| Identifier | ExFiles\Box 168a\3\ img359 | |
| Date | 18th March 1937 | |
| 6142 To Rm{William Robotham - Chief Engineer}/Wst. A.W.R. BY.4/B.18.3.37. BENTLEY TACHOMETER DRIVE ON DYNAMOS. With reference to Rm{William Robotham - Chief Engineer}/Wst.6/AP.16.3.37., the breathing device referred to, was issued to the Expl. Dept. 2.4.36. May we remind you, that you were fully aware of oil leakage on the commutators from the rev. counter drive, and a test was made and reported upon 13.2.36, and a further report on a similar subject 26.6.36. [Handwritten note: Where is report?] In March 1936 the output of Bentley Dynamos stopped, because of the rapid transference of oil from the rev. counter drive on the commutator, and it was at this time that tests were made which illustrated that a pressure built up inside the rev. counter drive, due to the temperature rise, and the provision of a ventilator, successfully prevented any oil leakage whatsoever. This test was carried out on production dynamos in the production shop, and your assistant was fully aquainted with the proceedings as they happened. He in turn was conducting experimental tests in the Expl. Lab. on a similar subject at that time. The recent epidemic of oil on the dynamo commutators is an entirely different issue. [Handwritten note: This was never approved] In November last the makers of the flexible rev. counter drive were filling these drives with a very stiff grease which almost prevented the drive rotating, during the very cold weather. An attempt was made to remove this grease and oil was substituted. Whilst this oil gave the drive freedom, it was found that when it became hot the surplus drained down the drive into the dynamo, and the surplus escaped on to the commutator. The batch of cars involved are all known, and very few have got into customers' hands. Cont'd.{John DeLooze - Company Secretary} | ||