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).
The failure of hydraulic shock absorbers during a bump rig test.
| Identifier | ExFiles\Box 68\2\ scan0106 | |
| Date | 25th November 1925 | |
| R.R. 493A (50 H) (D.D. 31. 12-6-25) J.H.D. EXPERIMENTAL REPORT. Expl. No. 48520 REF Hs{Lord Ernest Hives - Chair}/Bml/LG25.11.25. To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to CJ. BJ. c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to WCr. R-R HYDRAULIC SHOCK ABSORBERS. /x235 The original RR. hydraulic shock dampers have been run for 11 hrs. on the bump testing rig. Both shock absorbers were cooled during the test by means of a trickle of water on the outside casing. After 2 1/2 hrs. the O.S. shock absorber commenced to lose efficiency and rapidly became almost ineffective. After 5 hrs. the N.S. shock absorber lost about 50% of its efficiency. A very slight oil leak was observed between the outside casing and the N.S. damper. This was the only leak which occurred during the test. After 6 hrs. both shock absorbers were removed and examined. It was found that the aluminium back plates had distorted somewhat in each case allowing oil to leak passed the rotor. After re-bedding the back plates, the dampers were re-erected and the test continued. After 2 hrs. of the second test the O.S. shock absorber again lost efficiency. After 5 hrs. the N.S. shock absorber also showed signs of lost efficiency. Both were removed and on examination the back plate was found to have again distorted slightly. We have not made steel back plates for these shock absorbers to overcome the trouble experienced owing to the fact that we understand an improved type has already been designed. Hs{Lord Ernest Hives - Chair}/W.A. Robotham. | ||