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 Wellworthy Pistons Ltd. discussing bearing failures at Leyland's, comparing materials and suggesting lubrication system improvements.
| Identifier | ExFiles\Box 115\4\ scan0075 | |
| Date | 9th June 1940 | |
| Hole 1020A Rm.{William Robotham - Chief Engineer}1/ML. 9.6.40. J.Howlett,Esq., Wellworthy Pistons Ltd., Lymington. HANTS. Dear Howlett, I called in at Leyland's on Friday to discuss their bearing failures with them. They seem to feel that the lead bronze they have tried out has less tendency to suffer from failure than A.C.9. As we pointed out to them, until the bearing has been in service for a long time it is impossible to get an average picture of the failures really likely to occur and any new bearing tried out is always likely to impress one favourably. They do not have a very complete service record of exactly what failures have taken place. We pointed out to them that in our experience, any bearing capable of carrying really high loads was likely to be extremely oil sensitive i.e. even a momentary starvation of lubricant would most probably cause a failure; this was true of lead bronze as well as A.C.9. Therefore it was necessary to re-design the lubrication system if these high load carrying capacity materials were to be used successfully. There were a number of features on the lubricating system which we actually consider are out of date. As an example, they have a gauze strainer on the suction side of their pump which is not likely to be an effective filter but which may very easily cause oil starvation under cold starting conditions. Again, they have interrupted oil feeds into the crankshaft. They do not have 2 supply holes in the pin, which we have found to be desirable. Their oil pump size has not been stepped up to the extent that we have found necessary. - Continued - | ||