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).
Inter-office correspondence regarding issues with ball and thrust bearing designs on bevel pinions.
| Identifier | ExFiles\Box 49\2\ Scan001 | |
| Date | 4th August 1921 | |
| H.R.A. 25 m. {Mr Moon / Mr Moore} 12-20-20 40842 X4150 INTER-OFFICE CORRESPONDENCE ROLLS-ROYCE OF AMERICA, INC SPRINGFIELD, MASS. CC Mr. Belnap Mr. Nadin Cy9 - G 4821 August 4, 1921 Dear Hives: Re: Ball Bearings Replying Hs {Lord Ernest Hives - Chair} /LG 12.7.21: X4150 Your letters cover so many subjects and raise so many questions that it takes me all my time to answer them. We have cabled Derby that we cannot accept cars without revised thrust bearing design on bevel pinion. I enclose XA-927 showing how we are taking the reverse thrust on the journal bearing for experimental purposes. We had originally considered using a screwed nut and lock wire as you suggest, but, as I have already written you, we came to the conclusion that it would be better not to use a thread at all. The part XA-874 is more expensive to produce than your screwed ring, and if proved unnecessary we should not want to use it; and I notice that on the double thrust, as on the old single thrust scheme, we use a screwed nut and lock wire. But one thinks there is more tendency for the radial bearing to creep round than the thrust bearing, because it is carrying radial load as well as thrust. I realize that the radial load is in one direction relative to the outer race, but the fact remains that the outer race does show signs of having crept round if fitted too loose originally. Also, it will creep round in both directions when carrying reverse thrust, namely, forwards under overrun loads and backwards under reverse loads. Finally, if you run a pair of Gleasons forwards and then backwards on the bevel testing rig, with a brake load on, you will see how the bevel pinion shoots backwards and forwards under the change of direction. This suggests that the shocks to which the reverse and forward thrust devices are subjected are likely to be severe in running conditions, as when the clutch is let in with the engine running too fast or too slow, especially when in low gear. So that one suspects that a threaded device is not so sound as one | ||