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).
Letter to Hoffmann Manufacturing Co. regarding issues with a 25/30 HP steering pivot pin bearing and a proposed change to a needle bearing.
| Identifier | ExFiles\Box 9\7\ 07-page126 | |
| Date | 22th January 1938 | |
| 650 6-50 Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}9/JH. 22nd. January, 1938. Messrs. The Hoffmann Manufacturing Co., Chelmsford, ESSEX. For the attention of C.H. Smith Esq., Dear Sirs, We have recently had some trouble due to partial seizing and excessive friction on the lower journal bearing of our 25/30 HP steering pivot pin. This bearing is at present a plain one 1.125 dia. x 1.00 long with both surfaces hardened steel. The normal load is 1000 lbs. continuously in one direction with occasional loads up to 6000 lbs. during braking and cornering. We wish to try a needle bearing at this point and the enclosed print No.PD.97 shows our proposed arrangement. We should be glad to have your comments on this application. We enclose also prints CW.1961/2 showing the outer race and for your information our pivot pin. We wish to try this arrangement as soon as possible and for experimental purposes wish you to modify some of your standard races NR.17 to suit our housing. For this purpose dimensions A and B will be less than those shown on the print but should be kept as large as possible. The chamfer C will have to be added. The bore of our housing is 1.4062 + 0.0005. Will you please make D to suit, and let us know the limits to which we should machine our pivot pin, and the dimensions D, E, F, G, and H on the outer race. Will you please send us as soon as possible 16 of your standard races NR.17 modified to suit our housing and complete with needles. | ||