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).
The material, dimensions, and fitting process for glands FB.3436/7.
| Identifier | ExFiles\Box 99\3\ scan0061 | |
| Date | 19th January 1938 | |
| -8- HPS{Horace Percy Smith - Experimental Factory Mgr}/WB.{Mr Brazier/Mr Bell}1/EP.{G. Eric Platford - Chief Quality Engineer}19.1.38. Glands FB.3436/7. The material and dimensions of the glands is already being reconsidered, the faults being that the rubber is not sufficiently flexible, also the onus of compression of the rubber is upon the outer diameter instead of being equally disposed between the inner and outer diameters, to conform to the general principle of "DUPRENE" glands. Actually the glands proved to be the most awkward feature of the assembly. The glands must be fitted into position before the shaft is fed through, and owing to the compression on the outer diameter the inner diameter is reduced considerably. Although the situation was relieved by fitting a detachable "leading cone" on to the small end of the shaft, and providing a pot to receive the end of the shaft as it protruded through the small diameter gland(and at the same time preventing the rubber from being forced outwards), the serrations cut into the large diameter gland and also sheared off a circlet of the rubber. It was eventually found necessary to press the shaft partly home, press it out again, remove the surplus rubber and then press home finally. Since it is necessary to feed the shaft through two bushes, two glands, the press fit serrations in the rocking lever, and at the same time locate the master serration, it will be realised that the operation cannot be performed as rapidly as required on a production basis. It would be far preferable to fit the glands into position after assembling the shaft. This could be made possible with the squared end type of shaft fitted in the first set, by deleting the lips of the gland housings in the casing, but might entail either reducing the square, or increasing the bearing diameter to allow a "leading" bush to be fitted to prevent the rubber being cut against the existing shoulder. With the serrated type of main lever however, this method would not be possible after the lever had once been pressed on to the shaft. An increase in the length of the gland section of the main shaft is required(specially with the double serrated type shaft) since the present gland rubbers overflow their housings. continued | ||