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).
Causes of 'chunking' in gearboxes and comparing them with American design principles.
| Identifier | ExFiles\Box 104\4\ scan0241 | |
| Date | 14th March 1935 | |
| To E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux} C. to By.{R.W. Bailey - Chief Engineer} C. to WOr.{Arthur Wormald - General Works Manager} x 5310 Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux}19/KW.14.3.35. Gearbox. Causes of Chunking in the Drive. We are more prone to chunking in our transmission of the gearbox than the American cars such as the Buick, Terraplane, Cadillac, because of the following - (1) The synchromesh unit is of such a mass that its inertia when rotated forwards and backwards by either misfires or uneven running of the engine causes a heavy contact in the slackness of the driving splines and slackness in the teeth of the direct drive. (2) The aluminium gearbox when hot allows more slack in the housings of the bearings, thus producing another source of slackness. (3) The aluminium box is more metallic than cast-iron, which amplifies the noise. (4) Thick oils are used in the American gearbox as against thin oil in our boxes. American Principles which cut out Chunking. (1) Very light synchromesh cones and unit. (2) Use of deeper splines and less number, giving more area of contact and less slack. (3) Larger teeth for the direct drive, less number and less slack. (4) Thick gear oil. (5) Small cast-iron boxes, more compact, less liable to amplify noise. (6) Propellor shaft coupling to third motion shaft keyed and on taper. Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux} | ||