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).
Braking issues such as sponginess and hopping, with suggestions regarding axle rigidity and damping.
| Identifier | ExFiles\Box 5\3\ 03-page256 | |
| Date | 12th March 1927 | |
| To Hs{Lord Ernest Hives - Chair}/RH.{R. Hollingworth} from R.{Sir Henry Royce} To Da.{Bernard Day - Chassis Design} c. to BJ. wor.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} X5420 H3/M12.3.27. EAC.7. BRAKING ETC. X.7420 X.5420 X.7240 I can understand various occurrences of sponginess, but not any material loss of motion due to axle turning over, because the centre of the rope is only just above the centre of the axle. Also we had expected less hopping on the road with this type of control than present torque tube. I always understood that the 20 HP. was good in this respect, and this should be the same. Perhaps something else is the cause of the want of rigidity. I believe on the axle there are two points - (1) Brake drums which can easily be stiffened ring shrunk, on - and - (2) the shafts behind the axle leading to the case might lose much by torsional elasticity. One can understand the car rocking backwards, but all this should not be worse than 20 HP. which seems so much better than torque tube control. I am of the opinion that still more damping is needed especially in recoil. If the above car springs back in coming to rest with the brakes hard on, as we expect may be the case, then this would be less with the positively controlled front axle. For the above anticipated fault it should have several advantages - i.e. smooth running and shunting backwards etc), but our 40/50 has been so much improved since we fit better shock dampers. R.{Sir Henry Royce} | ||