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).
Clutch failure on model 34-EX, focusing on fabric thickness, rivetting, and weave.
| Identifier | ExFiles\Box 93\3\ scan0127 | |
| Date | 29th May 1936 | |
| Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} from E.{Mr Elliott - Chief Engineer} c. Wor.{Arthur Wormald - General Works Manager} By.{R.W. Bailey - Chief Engineer} Da.{Bernard Day - Chassis Design} Mx.{John H Maddocks - Chief Proving Officer} Roy.{Sir Henry Royce} Hdy.{William Hardy} X 312 Rm{William Robotham - Chief Engineer} E.1/HP.29.5.36. Clutch Failure on 34-EX. Replying to your memo Hs{Lord Ernest Hives - Chair}/Smth.16/KW.27.5.36, we are in agreement with the proposal to increase the thickness of the fabrics from .130 to .165, but to accommodate this increased thickness we do not propose to reduce in any way the thickness of the pressure plate. The present dimension has been shown experimentally to be satisfactory and hence should not be altered. HDY.{William Hardy} is issuing a scheme covering this point. With regard to the rivetting, I think we ought to have 24 fixings instead of 12 as the fabrics which failed definitely show that the span of the friction material between the points rivetted is too great. An examination of the friction material, whether of the present type or the original type which burst shows that the centrifugal force is not satisfactorily resisted by the weave. In the former case the material is on the cross when resisting tension due to C.F. and is, therefore, bound to stretch. In the latter case there are four axes where the material is on the cross and four where the weave definitely tends to disintegrate. It appears to me that for high speed clutches an entirely new method is required for weaving these fabrics to provide that the warp is continuously arranged to resist centrifugal force, the warp being spun round in a continuous layer concentric with the clutch centre; the weft would then run radially to the clutch centre. We are looking into this question to see if it is at all practicable as a future development. E.{Mr Elliott - Chief Engineer} | ||