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 and investigation of rubber bearings in a bumper chassis front suspension.
| Identifier | ExFiles\Box 119\1\ scan0068 | |
| Date | 11th January 1938 guessed | |
| COPY FOR FILES. 1024 also, 476. RUBBER BEARINGS. B.III BUMPER CHASSIS FRONT SUSPENSION. Jan. 14th. To date 13 bearings have been replaced, 8 in the top of the yoke, 5 in the central pivot of the lower arm. These have been replaced either because of complete failure or incipient failure. Upper Bearings. These have failed because of endwise movement due to either gyroscopic forces as a result of wheel flutter or an axial component due to the vertical movement of the wheel. The cause is now being investigated. By restraining end movement of the bearing the length of the life is indefinitely increased. The angle between the axis of the upper triangle and the C L of the frame is greater on the Packard than on the Bentley (25° to 22 1/2°) There is a tendency for the bearing to move towards the front end of its inner tube. This can only be due to either a couple about the lower needle bearing due to the vertical thrust being off centre or as before an axial component. When there is no load there is no indication of this movement. This phenomenon is also being investigated. One Inlox bearing was tested and on the average life appeared to be slightly inferior to the Silentblocs. It is difficult, however, to determine what stages of disintegration have been reached, as there is no breaking point. More extensive tests are now being carried out. Lower Bearings. These have failed in much the same way except that the "stepped" inner tube has had a shearing effect on the rubber. End thrust should not have been present but actually was in existence owing to the warped condition of the frame. The outside casing has a sharp edge on both bearings; if this was rounded off it would undoubtedly extend their life. Cont'd.{John DeLooze - Company Secretary} | ||