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).
Letter from Ferodo Ltd discussing the testing and performance of fabric pulleys for a belt drive.
| Identifier | ExFiles\Box 135\4\ scan0069 | |
| Date | 29th April 1940 | |
| FERODO LTD CHAPEL-EN-LE-FRITH STOCKPORT ENGLAND Telephone CHAPEL-EN-LE-FRITH 250 (7 lines) Telegrams FRICTION PHONE CHAPEL-EN-LE-FRITH TECHNICAL DEPT. 29th April, 1940. Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards}4/GH.18.4.40. WES/ET. Messrs. Rolls-Royce Ltd., D E R B Y. Dear Sirs, We would refer to your letter of the 18th instant together with the three prints which you enclosed showing pulleys for a three point "V" belt drive. Quite apart from the practicability of moulding pulleys, particularly to prints Nos. RD.487 and EB.4999, we very much doubt whether any useful purpose will be served in testing fabric pulleys. When our original belt test rig was in operation in which we used one of your fans as a load, we turned up a pair of fabric pulleys and tried these out on this drive. The mechanical strength of the pulleys was quite adequate, and at the commencement of a run when the belt and pulleys were cool the drive required less tension in order to keep within 4% slip at 22 H.P. However, owing to the very poor heat conductivity of the fabric pulleys the belt soon showed signs of overheating and began to disintegrate after 2 3/4 hours running. As this low conductivity is inherent in any moulded fabric, we doubt whether an useful purpose will be served by repeating the test. Admittedly, 16 H.P. at 4,000 R.P.M. is a different matter to 22 H.P. at 4,500, particularly, as under the latter conditions the belt was running right at its limit, under the less onerous conditions fabric pulleys might be more successful, and we could quite easily check up on their behaviour at this lower duty. For the purposes of trial on our test rig we would, however, manufacture two similar pulleys to the same section, as shown on EB.4998, and leave the problem of moulding pulleys with dynamo ventilating blades to be solved later. -continued- | ||