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 to Ferodo Ltd. detailing the results of fan belt testing, including comparisons with American belts and proposed pulley modifications.
| Identifier | ExFiles\Box 135\1\ scan0120 | |
| Date | 4th February 1933 | |
| Messrs. Ferodo Ltd. -2- 4th. February 1933. A third belt was then run and after 1 hour, it performed in an exactly similar manner to the last one - again a distorted region was found and sectioned. We are also returning this belt for your inspection. Care has been taken with both of these belts that no distortion was caused in fitting same. We should be very glad to receive your remarks on these facts. At present it does not look as though your belt is as promising as it first appeared. We have compared your belt with American sections which we have and it appears to differ from these in that their cords are fewer in number and seem to be set in a separate layer of rubber before being built into the belt. In the case of your belt the bonding of the cords to the rubber seems inadequate. Further, the cords appear to be further away from the neutral axis of the belt section than in the case of the U.S.A. belts. We are going to alter our pulley angles in an endeavour to assist matters. At present the pulley angles are as determined by actual measurement of the belt section when bent round a radius equal to that of the pulley. We think that if we increase the angle of Vee of the pulley it will result in less sideways pressure on the top portion of the belt section, containing the cords and possibly reduce the tendency of the cords to break away from their surrounding rubber. We have done a little endurance running on the EW.1518 belts which you have sent us. So far no trouble has been experienced. We look forward to receiving your remarks on this subject. With regard to your Mr.Sutcliffe's query regarding the quantity of fan belts we are likely to order in the next six months, we cannot, of course, give any definite ruling on this matter especially in view of the above test results. We can say that in the event of your belt proving satisfactory (the EW.1518 type) and our deciding to | ||