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).
Experiments on torsional vibrations in 20 HP and Phantom engines.
| Identifier | WestWitteringFiles\P\October1926-November1926\ Scan097 | |
| Date | 9th November 1926 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/ACL. c. to BJ. Wor.{Arthur Wormald - General Works Manager}✓ c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer}✓ c. to DA.{Bernard Day - Chassis Design} EY.✓ c. to OY. ORIGINAL Hs{Lord Ernest Hives - Chair}/ACLl/LG9.11.26. TORSIONAL VIBRATIONS ON 20 HP; & PHANTOM X634 X5010 X8010 Further tests have been made on the 20 HP. engine in connection with crankshaft torsional vibrations. The object of the following experiment was to see if it would be possible to eliminate the condition of resonance from the working speed range, or reduce the vibration amplitude, by having the engine flywheel mounted non-rigidly on the crankshaft and still be coupled with sufficient friction to the crankshaft to result in a steady transmission of torque. It is known that reducing the inertia of the system results in raising the speed at which resonance occurs and that friction damping reduces the amplitude, therefore it was thought that the above arrangement, by a combination of the above effects, might prove beneficial. For the purpose of the test the stud holes in the flywheel were slotted and it was mounted between the crankshaft flange and a washer. Bakelite washers were used each side the flywheel flange as friction surfaces and the friction torque could be regulated by the tightness of the securing bolts. In addition rubber buffers were inserted in the stud slots - these being found necessary to prevent 'thrashing' at low speeds due to the firing impulses. The appended sketch shews the method of mounting the flywheel. The friction torque of the flywheel contd :- | ||