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 failure of Bentley III rubber bearings and yoke movement, comparing them to the Packard design.
| Identifier | ExFiles\Box 127\1\ scan0354 | |
| Date | 9th May 1938 | |
| To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} c. Da.{Bernard Day - Chassis Design} c. Da{Bernard Day - Chassis Design}/Ev.{Ivan Evernden - coachwork} 8 1086 also HHD. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale}2/EH.9.5.38. BENTLEY III & PACKARD YOKE MOVEMENT. On the Bumper tests the rubber bearings of the Bentley III have been failing too regularly and too quickly, and they are not as reliable as on the Packard, the design of which is slightly different to the Bentley. With the object of making modifications to prolong the life of these bearings we have obtained detail figures of deflection in the various front suspension components, and Kennington's report gives a clear comparison between our design and the Packard. This report only deals with the axial movement of the upper yoke bearing under bump loads, and does not take into account brake torque. This latter will be dealt with separately. It will be seen that the two portions of our mechanism which are considerably weaker than the Packard are the yoke, and the lower yoke bearing. We propose to stiffen the yoke, but as we cannot easily stiffen the lower bearing we propose to stiffen the lower triangle by a strut (Fig.IV) and thus put ourselves on a par with the Packard. This strut has the additional advantage of reducing the end movement of the rubber bearing at the inner end of the lower lever. An additional cause of failure of the upper bearings has been the breakdown of the front dampers and rubber buffers. Alterations are being made to these items to prolong their life. Should these various modifications not give the desired degree of reliability we may have to employ a metal bearing at the top of the yoke, but in view of the increase of suspension noise which occurs when independent suspension is used, we do not want to do this. Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} | ||