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).
Interference fit tolerances for an assembly involving bearings and gears on a threaded shaft.
| Identifier | ExFiles\Box 104\4\ scan0168 | |
| Date | 12th September 1932 | |
| - 2 - BY.8/G.12.9.32. some positive interference fit, that is we must not be below size and size, otherwise as the parts are secured by locking through a series of five parts i.e. two bearings and three gears, there will be rotation of the inner races of the bearings which will cause slack to develop in the system and the threads on the shaft may be 'dithered' away. By the limits we are now trying out as a result of discussion with Works Inspectors, we just keep on the minimum limit on interference fit, while on the upper limit we have only + .0004 instead of plus .001 as with the Hoffmann limits. Further the Works prefer the new method of limiting as they find that they cannot selectively fit and obtain the results required as in any batch of bearings delivered the number of bearings is too small to give the required variation in production. BY.{R.W. Bailey - Chief Engineer} By | ||