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 Co. regarding combined ball and roller bearings for the Bentley rear axle.
| Identifier | ExFiles\Box 84\4\ scan0352 | |
| Date | 18th November 1937 | |
| COPY OF LETTER RECEIVED FROM ;- THE HOFFMANN MANUFACTURING CO. LIMITED, CHELMSFORD. November 18th 1937. Messrs. Rolls-Royce Ltd., Derby. Da{Bernard Day - Chassis Design}/Hdy.{William Hardy}6/G.{Mr Griffiths - Chief Accountant / Mr Gnapp} Your Ref. CHS/AMB.102676A. Dear Sirs, FOR THE ATTENTION OF Mr. W.G. HARDY. We are in receipt of your letter of the 15th inst. and have carefully noted your remarks about the combined ball and roller bearing for the Bentley rear axle. Independent axial adjustment external of the bearing would, we agree, probably result in some reduction of the cost of manufacture, but we do not think this would be very large. As you point out, a gap could be left between the open faces of the outer races of the ball and roller components but as the latter would not be held endways, there would always be a possibility of its being in contact with one race, leaving a double gap at the other side. Our drawing No. 41-477K section 96, of which we enclose a print, shows an arrangement using individual bearings with a standard bearing No. RLS 12 1/2 in the centre. The increase in the bore from 30 m/m.{Mr Moon / Mr Moore} to 1 3/8" has the effect of reducing the ball races to the fullest extent we consider safe. There is also the disadvantage, compared with a one-piece inner race, that any errors of eccentricity, within our manufacturing limits, of the two ball tracks, may be aggravated if the races happen to be mounted so that the worst points are diagonally opposite. Yours faithfully, THE HOFFMANN MANUFACTURING CO. LTD. (signed) C.H. Smith. Encl. Drawing 41-477K sec.96. Technical Manager. | ||