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).
Crankshaft torsional vibration tests using a Summer's indicator on Bentley II, Wraith III and Phantom III units.
Identifier | ExFiles\Box 132\1\ scan0044 | |
Date | 10th May 1938 | |
By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Mtns. c. Sg.{Arthur F. Sidgreaves - MD} c. Hs.{Lord Ernest Hives - Chair} c. Da.{Bernard Day - Chassis Design} c. Mx.{John H Maddocks - Chief Proving Officer} c. De/Jnr.{Charles L. Jenner} Crankshaft Torsional Vibration Tests. The results obtained so far with the Summer's indicator are mainly confined to full throttle tests with normal damper settings on Bentley II and Wraith III units. This is due to trouble experienced with the indicator at speeds approaching to the top torsional vibration. The indicator was first tried out on P.III unit, but with the normal damper setting no deflection of the crank-shaft was recorded, or at any rate not sufficient deflection for us to take any measurement. When fitted to Wraith, trouble was experienced with recording fingers breaking at speeds in the region of 4,200 r.p.m. Several types of fingers have been tried on Wraith from stiffened type to flexible type and with various forms of balancing. Vibration diagrams have been obtained on Wraith up to 4,400 r.p.m., but on Bentley we have not succeeded in obtaining any diagrams above 4,300 r.p.m. The recording fingers failed again at 4,400 r.p.m., and at the moment the indicator is being repaired. | ||