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).
Analysis of engine loads and the effect of balance weights on them, with results presented in tables.
| Identifier | ExFiles\Box 115\2\ scan0382 | |
| Date | 10th January 1939 guessed | |
| - 4 - RESULTS. (a) Without balance weights. At Explosion. 2600 2850 179 MEP. 206 179 206 Radial .00081 .00092 ( These are lower ( None of Tangential .000433 .00063 ( than for 2600 ( these is Resultant .000925 .00112 ( and are not ( great enough ( included. ( to cause ( fouling. Radial .000614 .00113 Tangential .000554 .00052 Resultant .000825 .00125 The worst inertia loads occur in the region of crank angles about 570° from 'A' side T.D.C. and at 2850 RPM. The figures below are at 206 MEP. The loads are Radial 10580 11030 11260 11380 Tangential 3650 2940 2130 1320 slopes R.{Sir Henry Royce} .00172 .00178 .00182 .00184 T. .000312 .000251 .000182 .000113 Resultant slopes .00175 .00180 .00183 .00184 None of these will cause fouling, and therefore no fixing couple will be applied by the bearing. (b) Effect of balancing. At the time of the explosion the effect of the balance weights is to increase the deflection, on the other hand where the load is due mainly to inertia the balance weights reduce the slope. Force due to balance weights at 2600 RPM. where the explosion force is most noticeable is 1760 lbs. . The slope (radial) due to this is 1.05 x 10^-7 x 1760 .. = .000184 Applying this to the slopes above 2600 - 179 MEP. 2600 - 206 MEP. Radial .000798 .00094 .001104 .001134 Tangential .000554 .000433 .00063 .00052 Resultant .000974 .001034 .00127 .00125 None of these loads therefore will cause fouling but the slopes up to .0013" per inch are quite considerable and imply edge loading of the bearings. (C) The assumptions in the above case do not meet the requirements of the case as rest of the shaft does exert some constraint on the throw considered (either end throw). It is now assumed that the journal at one end of the throw is constrained to be horizontal - journal 2 or 6 - and that the shaft is supported on the centre this journal while the other end is free and supported on the edge of its bearing. | ||