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).
Design of timing gears and a double rear bearing to address flywheel vibration.
| Identifier | ExFiles\Box 137\4\ scan0182 | |
| Date | 26th January 1931 | |
| R.{Sir Henry Royce} FROM E.{Mr Elliott - Chief Engineer} X634 F1/M26.1.31. C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} C. to HS.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} JAPAN 3. TIMING GEARS. X.634. X.5010. Please find attached copy of our telegram of even date re. crankshaft pinion at rear end of crank solid with shaft. The drawing we sent to Derby shewed a gear 1.3" wide with a bearing the same width as the intermediate bearings, each side. RHC.{R. H. Coverley - Production Engineer} reports that it is only possible to cut this gear with at least 1" more room between nearest crank web and pinion and then only by employing a specially constructed machine. From an economic point of view Derby would prefer to have the pinion separate to facilitate handling and they also think it necessary to use a hardened gear to avoid lapping away of the teeth of the bronze camshaft gear. We have in hand some designs of different methods of construction with separate pinions as shewn on the attached sketches. Some of these schemes demand a reduction in the dia. of the crank journal. Before we get very far with the double rear bearing we should like to be sure that it is going to be effective in curing the flywheel vibration by actually trying it on an existing engine. We say this because so far as we can see the speed of resonance is not very greatly altered by the change in the construction and the scheme depends for its success on the reduction of the actuating force. We have therefore made a rough design for rigging up a double rear bearing on an existing 25HP. engine by bolting a short extension on the crankshaft and an extra bearing on the crankcase, and suggest that Derby should produce and try this as soon as possible, while we push on with the design. E.{Mr Elliott - Chief Engineer} | ||