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).
Torsional vibration diagrams for the Goshawk III crankshaft without damper wheels under various conditions.
| Identifier | ExFiles\Box 6\1\ 01-page031 | |
| Date | 7th April 1933 | |
| DIAGRAM 1: STANDARD CRANKSHAFT 3100 R.P.M. STD PISTONS WITH HEAD (CYL) REMOVED 3 OSCns PER REV AMPLITUDE 8 3/4° DIAGRAM 2: 12% STIFFER CRANKSHAFT 3370 R.P.M. DIAGM WITH ENGINE RUNNING UNDER POWER LIGHT LOAD AMPLITUDE 6° DIAGRAM 3: STD CRANKSHAFT 3100 R.P.M. RESULTING VIBRATION UNDER ACTION OF THE THREE REAR PISTONS ONLY. ENG. MOTORED WITHOUT CYL. HEAD AMPLITUDE 2 3/4° DIAGRAM 4: STD CRANKSHAFT. 1550 R.P.M. FULL LOAD. VIBRATION UNDER LOWER HARMONIC OF GAS PRESSURE. WHEN ENG. MOTORED WITHOUT CYL HEAD THE DIAGRAM BECOMES APPROX. A CIRCLE. DIAGRAM 5: 12% STIFFER CRANKSHAFT. 1680 R.P.M. FULL LOAD. NOTE OSCILLATION IS LESS THAN WITH STD. CRANKSHAFT. DIAGRAM 6: 12% STIFFER CRANKSHAFT 1120 R.P.M. FULL LOAD. BOTTOM LEFT: DIAGMS 1, 2, & 3 TAKEN WITH SHORT SCRIBE FINGERS 1.125 & 1.300 R.P.M. 4, 5, & 6 " LONG " 2.250 & 2.125 R.P.M. BOTTOM RIGHT: GOSHAWK III CRANKSHAFT. TORSIONAL VIBRATION DIAGS. NO DAMPER WHEELS. | ||