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).
Series of tests to investigate and resolve gear rattles on a 25 HP engine.
| Identifier | ExFiles\Box 47\3\ Scan413 | |
| Date | 20th April 1932 | |
| Handwritten: +4117. Handwritten: 20.4.32. Handwritten: x634x GEAR RATTLES ON 25 HP. (CHASSIS G.K.T.22 FROM TEST DEPT.) The above chassis was brought to us at noon 16.4.32., with engine front dismantled. (Scheme Hs.{Lord Ernest Hives - Chair}379 inertia ring) was fitted to the slipper wheel, but the slipper wheel could not be fitted back in place, until the outer diameter of the inertia ring had been modified to clear the Alum lock-nut of the idler wheel, this locking nut had also to be reduced in diameter, and length. The poundage of the slipper was set at 12 lbs. Test 1. The gear rattle with the above fitted, was very pronounced at almost any speed between 500 to 1000 R.P.M., and could only be cut out by heavy loading on dynamo drive. Test 2. The loading of slipper was reduced by taking out 8 of the 16 springs, which would give us a loading of approx 7 lbs. The gear rattle on this test was improved 10% still over the same range, but not so violent, and still required heavy loading on dynamo drive to cut it out. We then fitted a set of (Hs.{Lord Ernest Hives - Chair}477) Valve Springs, but to do this we had to take out the grunmetts from the valve guides, to give us more room for this Valve spring, which is longer compressed, than the springs used on production chassis. Test 3. The gear rattle on this test was much improved, about 30% and the rattle left was easily cut out by braking the dynamo drive, a much less load was required to do this than on the tests Nos. 1 & 2. Test 4. The loading was then removed from slipper, by leaving out all the springs, and in this condition the gear rattles disappeared but this was hardly practical. | ||