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 bearing specifications, clearance, and fit.
| Identifier | ExFiles\Box 84\4\ scan0236 | |
| Date | 15th June 1937 | |
| BRANCHES: LONDON, BIRMINGHAM, MANCHESTER, LEEDS, GLASGOW. AGENTS IN PRINCIPAL COUNTRIES THROUGHOUT THE WORLD. HOFFMANN Registered Trade Mark. 228 or 202. 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.. THE HOFFMANN MANUFACTURING Co. LTD. CONTRACTORS TO THE ADMIRALTY, WAR OFFICE AND INDIA OFFICE. CHELMSFORD. MESSRS. ROLLS ROYCE, LIMITED, DERBY. June 15th 1937. YOUR REF. Rm{William Robotham - Chief Engineer}/Gry{Shadwell Grylls}/11/AP. IN YOUR REPLY PLEASE QUOTE OUR REF. JHW/EH. 99974 A.{Mr Adams} Dear Sirs, We thank you for your letter of the 11th June, reference as above, which has had our close attention. We regret that we cannot suggest a better bearing for this position, and we consider it necessary for the bearing when mounted to have some diametric clearance. We have supplied the bearing with .0003 to .0008" diametric clearance, but we could reduce this to .00025 to .0005". We should expect some creep to take place if the rotating race is not made an interference fit, but your experience may indicate that this is not necessary, possibly due to the use of a hardened shaft. Assuring you of our best attention at all times, we remain, Yours faithfully, THE HOFFMANN MANUFACTURING CO.LTD. | ||