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).
Flywheel vibration and gear rattle tests for the 25 HP engine.
| Identifier | ExFiles\Box 181\M13\M13.2\ img071 | |
| Date | 8th July 1931 | |
| To R.{Sir Henry Royce} From Ha/Gry.{Shadwell Grylls} c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to R.{Sir Henry Royce} .Da.{Bernard Day - Chassis Design} c. to By.{R.W. Bailey - Chief Engineer} ORIGINAL Ha/Gry.{Shadwell Grylls}1/MJ.8.7.31. 25 HP. FLYWHEEL VIBRATION & GEAR RATTLE. 8634. X5310. Further to our Ha/Grysl/MJ.29.5.31. in which we suggested that we had two alternatives for overcoming the flywheel vibration on the 25 HP. namely the addition of a tail bearing to the existing flywheel, and secondly use of the stiffened flywheel to LeC.2830 in conjunction with a Hardy coupling. We can now report on a test of the latter scheme. This flywheel had previously been tried on the test bed. where it raised the period by 500 R.P.M. and it was also fitted to 18-G4. for the last 10,000 miles test. The engine in this car then had standard valve springs and- we were able to say that the vibration, if it existed, was above the valve bounce. On this occasion the experiments were conducted on a 'Japan' engine fitted with stronger valve springs. We were therefore able to reach the speed of vibration of this flywheel which is at 48 m.p.h. in 3rd.gear, or 3600 R.P.M., instead of 3100 with the standard flywheel. 18-G4. when fitted with a standard flywheel had a noticeable overrun gear rattle from 50 down to 40 m.p.h. The substitution of a flywheel of less inertia would normally make this rattle more pronounced, but on this test with a fabric joint no gear rattle could be detected. The fabric was inserted in the flywheel between the driven plate and the splined driving piece as shown on the accompanying sketch. This experiment is once again further proof of the effectiveness of a fabric joint to eliminate gear rattles. Ha/W.Grylls. Att: Blue print Hs.{Lord Ernest Hives - Chair}374. | ||