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).
The development and issues with the Bentley V gearbox, including synchro mesh, gear selection, and overdrive options.
| Identifier | ExFiles\Box 161a\3\ scan0130 | |
| Date | 21th April 1939 | |
| - 8 - BY.1/G.21.4.39. BENTLEY V.{VIENNA} (cont'd) GEARBOX. (a). We are introducing the universal gearbox with Bentley V.{VIENNA} Incorporated in it is a helical first gear, as we have satisfied ourselves that the straight gear was such in regard to noise that it would have been a cause of serious complaint. (b). Synchro Mesh. The synchromesh gave trouble because it was not functioning, but similar boxes into which the spring control had been replaced show no faults in this direction. The particular box about which complaint was made was one that the control springs have been removed from to see whether they proved to be necessary or otherwise. (c). Change speed - stickiness of gear selection. A rubber washer has been applied at the gearbox end, which appeared to be satisfactory when run in France, and a metal cover has been arranged to protect the shaft which would otherwise be exposed on the lever end. (d). With reference to Cx.{Major Len W. Cox - Advertising Manager}6/KW.14.4.39, that direct drive boxes or overdrive boxes should be optional, this position is not practicable under our new production proposals, as obviously if the matter were optional we should have to obtain the customer's decision, and this is not compatible with producing boxes regularly on a line. We are satisfied that the first essential we require is reliability. The necessity for this has been forced into prominence since we introduced high performance by low axle ratios. The overdrive box makes both conditions possible, i.e. a man can use his direct drive on town and cross country work, and has an overdrive available for the open road. A certain amount of gear sing is unavoidable with gears transmitting the load, as in the case of the overdrive. This, however, will have to be expected, it is not noticeable unless a man misuses his overdrive by running on it at relatively low speeds. | ||