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).
Summary of test findings on crankshaft oscillation and vibration, including the effectiveness of slipper dampers and plans for future experiments.
| Identifier | WestWitteringFiles\P\2July1926-September1926\ Scan143 | |
| Date | 4th September 1926 guessed | |
| contd :- -16- (3) One free period of oscillation of the standard crankshaft assembly is between 167.5 and 172.5 oscillations per second. (4) Belt drive tests - without cylinder head - indicate the critical vibration is not so severe with lightened pistons. (5) Lower harmonics of the explosion pressures seem responsible for the lower speed vibrations. (6) Increasing the stiffness of the crankshaft raises the critical speed. (7) Added inertia to the crankshaft lowers the critical speed. (8) The standard slipper damper is effective in damping out the lower speed vibrations so that they are not noticed by feel and sound. (9) Erosion of the crankshaft can be caused by running on the critical speed. Our next experiments will be made with the object of finding out the effect of piston and big end weights, the fit and support given by the bearings and various degrees of damping afforded by the slipper wheel. Hs{Lord Ernest Hives - Chair}/A.C. Lovesey. | ||