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 Super Oil Seals Limited investigating the failure of oil seals due to being fitted on shafts larger than their specified diameter.
| Identifier | ExFiles\Box 84\4\ scan0104 | |
| Date | 17th September 1936 | |
| Copy of letter From: SUPER OIL SEALS LIMITED 17th September.1936 Dear Sirs, Confirming the writer's conversation with you yesterday, after which he had an interview with Mr. Mills, Mr Harvey, Mr Bailey, and Mr. Grills regarding three sizes of Oil Seals ordered by you under reference numbers 1751, 1831 and 20616, we wish to place on record the position regarding these. On June 9th last, the writer visited your works and had a conference with Messrs. Harvey-Bailey, Grills and Roberts in response to your request that we investigated complaints that certain Seals were failing due to the leathers becoming burnt or charred. Three sizes of Seals were affected - these being ordered by yourselves under our reference numbers 1751, 1831 and 20616; as clearly indicated in our published list of sizes, of which there are several distributed in your office, the first two sizes mentioned viz: 1751 and 1831 are each made by us to function on shafts of 1" diameter, and the writer found that they were being used on shafts of 1.3/32" diameter, in each case; the third size No. 20616 is made to function on a shaft of 1.3/16" diameter, but it was found that you were using it on a shaft of 1.3/8" diameter. In other words, in two instances the Seals were being used on shafts 3/32" larger than provided for and in the third instance as much as 3/16" larger than intended for. Everyone concerned agreed that this was obviously the cause of the leathers being burnt, as the spring tension was far in excess of what we would apply as manufacturers and designers of this specialised product. To complete the investigation, the writer was taken into your assembly shops by Mr. Bailey and on attempting to fit two seals on the shaft, both Seals were destroyed because the undue interference between the leather diameter and the shaft diameter caused the leathers to be cut by each and every spline despite the fact that you had taken the correct precaution of threading the Seals over a tapered sleeve. (Continued) | ||