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).
Design and performance of hydraulic dampers, focusing on valve and passage design.
| Identifier | ExFiles\Box 12\1\ 01-page127 | |
| Date | 25th March 1929 | |
| Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} DA{Bernard Day - Chassis Design}/Hdy.{William Hardy} BY.{R.W. Bailey - Chief Engineer} FROM R.{Sir Henry Royce} c. to SG.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} OY. c. to C. CWB. PN.{Mr Northey} E.{Mr Elliott - Chief Engineer} c. to Mr. Claremont. 47420. R3/M25.3.29. HYDRAULIC DAMPERS. SS.{S. Smith} AND OTHERS. X.235 X.7420 As telegraphed, my impression is that dynamic passages as well as leak holes past valves are decidedly wrong, also the effects of viscosity - i.e. spring loaded valves and very free passages, and that the type with low pressure valves in the piston is perhaps the best because the axle can move upwards at the max. rate more freely. The viscosity and dynamic restrictions of the passages is the cause of broken shock damper because at times the resistance to high speed movement of the axle must be enormous. I have watched the car axles over these rough roads, and I believe that we do not want to prevent the axle, moving quickly relative to the body, but we want to damp it and also the movement of the body - (E.{Mr Elliott - Chief Engineer} W points out the slow movement of the body.) Several times we have nearly spoilt the reputation of these dampers, and I am inclined to believe it has been caused by spring lubrication, and other defects. I prefer large free passage valves about 100 lbs. down and 50 lbs. up until I am convinced that this is wrong, i.e. greater freedom over a ridge, and axle held up over pat hole (because it has got to come out.) R.{Sir Henry Royce} | ||