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).
Issues with flats on Goshawk 11 rocker rollers and proposing potential solutions.
| Identifier | WestWitteringFiles\I\May1922\ Scan57 | |
| Date | 19th May 1922 | |
| To Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} c. to CJ. By.{R.W. Bailey - Chief Engineer} c. to Av. H.{Arthur M. Hanbury - Head Complaints} Valves & Fittings GOSHAWK 11. LARGER ROLLERS FOR ROCKERS. V4226 X4229 With reference to the flats on the rollers it has not been clear as to whether these flats are due to the rollers sticking on the pin, in which case they would be curved flats, or whether they are real flats such as might be caused by hammering and a roller not turning with it's pin, but staying with the end of the valve spindle. If by increasing the clearance on the pin, & providing bosses of greater length than the width of the roller, and with ample end clearance, the roller does not creep about, it would appear that the only policy left would be to abandon the roller and use a curved end to the lever that would be forced to revolve. I have suggested to Mr. Elliott the possibility of using a square block or a definite flat on the roller, to enable a large surface to be obtained, and to be reliable so that we do not lose our clearance by moving off the flat. We should however I think prefer to use the round roller if the roller can be relied upon as changing it's position and using the whole surface. It is just possible that due to the closeness of the fit on the pin or due to the fact of some of the surfaces being soft, the hammering and binding occurs, so that the rollers that are used on the experimental test should be carefully noted for hardness, both in the bore and on the outside surface, and on the pin. In the case of ball bearings the polish of the races seems to be important. It maybe that the polish of the pins and the bore is important. As for the degree of slack in the bore and on the faces I should suggest as much as .010 be tried. (1) | ||