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 Hoffmann Manufacturing concerning bearing clearances, specifications, and supply for gearboxes.
| Identifier | ExFiles\Box 136\2\ scan0045 | |
| Date | 4th February 1939 | |
| 1153 BRANCHES: LONDON, BIRMINGHAM, MANCHESTER, LEEDS, GLASGOW. AGENTS IN PRINCIPAL COUNTRIES THROUGHOUT THE WORLD. HOFFMANN Registered Trade Mark BALL-AND-ROLLER-BEARINGS STEEL-BALLS-AND-ROLLERS THE HOFFMANN MANUFACTURING Co. LTD. CONTRACTORS TO THE ADMIRALTY, WAR OFFICE AND INDIA OFFICE. TELEPHONE: 3151 (Five Lines) TELEGRAMS: HOFFMANN, CHELMSFORD CODES USED: A.B.C. 5TH EDITION, BENTLEY PHRASE, BENTLEY 2ND PHRASE, MARCONI AND WESTERN UNION 5 LETTER. CHELMSFORD. LA{L. A. Archer} Please return. MESSRS. ROLLS-ROYCE LTD. DERBY. February 4th. 1939. YOUR REF. Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls}6/MH.{M. Huckerby} IN YOUR REPLY PLEASE QUOTE OUR REF. CHS/AMB2 110688A. Rm{William Robotham - Chief Engineer}/GRY.{Shadwell Grylls} Dear Sirs, FOR THE ATTENTION OF MR. GRYLLS. We are in receipt of your letter of the 1st. instant, from which we note that you wish to test bearings which have the minimum diametric clearance, in one of your gear boxes. As you know, it is your standard practice to specify bearings with diametric clearance of .00075" for your gear boxes, compared with our standard "O" fit of 0.0" to 0.0002". This would give a mean end play as follows :- Hoffmann Bearing No. LS 12 .004" end play. " " " MS 12 .005" " " Hoffmann Special Bearing No. N.2592, Your Part No. GW 789 .0045" " " Hoffmann Special Bearing No. N.2591, Your Part No. GW 788 .0055" " " Hoffmann Special Bearing No. N.3022, Your Part No. GW 1881 .004" " " As requested, we are arranging to send you one of each of the aforementioned bearings with the reduced clearance, except bearing No. N.2592, and as this is given twice in your list, we will send two of this size. Yours faithfully, THE HOFFMANN MANUFACTURING CO. LTD. [Signature: C. A.{Mr Adams} Smith] TECHNICAL MANAGER. | ||