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 with variable inertia crankshaft dampers.
| Identifier | ExFiles\Box 138\1\ scan0051 | |
| Date | 21th November 1932 | |
| Y 634 E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} c. to By.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}13/MA.21.11.32. CRANKSHAFT DAMPERS. We have been experimenting with the variable inertia damper LeC.3133, designed for the J.III unit. The friction surfaces were dry Halo which at all, but the high damping loads gives a starting and slipping torque of the same amount. The amount of inertia we tried were 190,82, and 29 lbs.in.2. With the former two the damper eliminated the half torsional period at any sett-ing from 5 to 40 lbs. at 17 3/8" radius. With 4 1/2 lbs damping the half period was just detectable at 2300 R.P.M. Above 40 lbs. the period was lowered to 1600 R.P.M. and 2000 R.P.M. respectively. At 4 1/2 lbs damping the top period suddenly became unpleasant at 4000 R.P.M. With the higher damping loads the engine was run up to 4300 R.P.M. but was generally rough from 3800 upwards. With only 29 lbs.in2 damping the half period was eliminated at any setting from 3 1/2 to 12 lbs. at 17 3/8". We require 13 lbs. damping to drive the fan and hence such a small slipping inertia could not be used. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} | ||