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 from a bearing manufacturer regarding the analysis of two noisy bearings found to contain foreign matter and distortion.
| Identifier | ExFiles\Box 93\3\ scan0293 | |
| Date | 25th March 1937 | |
| HOFFMANN Registered Trade Mark BRANCHES: LONDON, BIRMINGHAM, MANCHESTER, LEEDS, GLASGOW. AGENTS IN PRINCIPAL COUNTRIES THROUGHOUT THE WORLD. TELEPHONE: 3151 (5 lines) TELEGRAMS: HOFFMANN, CHELMSFORD CODES USED: A.B.C. 5th EDITION, BENTLEY PHRASE, BENTLEY 2nd PHRASE, MARCONI AND WESTERN UNION 5 LETTER. BALL AND ROLLER BEARINGS STEEL BALLS AND ROLLERS THE HOFFMANN MANUFACTURING Co. LTD. CONTRACTORS TO THE ADMIRALTY, WAR OFFICE AND INDIA OFFICE. CHELMSFORD. MESSRS. ROLLS-ROYCE LTD., EXPERIMENTAL DEPT., DERBY. 312 25th March 1937. YOUR REF. Rm{William Robotham - Chief Engineer}/Smth.6/JH. IN YOUR REPLY PLEASE QUOTE OUR REF. PEC/WAH. Rm{William Robotham - Chief Engineer} th Dear Sirs, Further to your letter of the 15th March, we have now examined the two bearings, our N.2001, which we found to be noisy in the condition as received, but in this connection we would respectfully point out that they were found to contain a quantity of foreign matter, as shown by the filter paper which we attach herewith. May we also point out that both outer races show the effect of uneven loading, this being slightly heavier at two opposite points and agreeing with heavier fit marks on the outside diameter of the race. It seems evident therefore that some distortion has been present. As you will be aware, the section of the races is slight and consequently will readily distort unless fitted to a housing which is bored truly circular. Both bearings can be suitably re-conditioned and we shall be glad to hear whether we are to proceed with the work. The outer races are slightly out of round due to the distortion, but they will take on their correct shape when applied to a truly cylindrical housing. We await your further instructions in the matter and in the meantime, We remain, Yours faithfully, THE HOFFMANN MANUFACTURING CO. LTD. Ph III Clutch thrust race. ENC. Filter paper. | ||