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).
Tests and a modification to prevent knocks in hydraulic shock dampers.
| Identifier | WestWitteringFiles\Q\2April1927-June1927\ 148 | |
| Date | 2nd June 1927 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to BJ. Wor.{Arthur Wormald - General Works Manager}✓ c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer}✓ c. to BY.{R.W. Bailey - Chief Engineer} DA.{Bernard Day - Chassis Design} c. to OY. EP.{G. Eric Platford - Chief Quality Engineer}✓ c. to Mx.{John H Maddocks - Chief Proving Officer} Hm.{Capt. W. Hallam - Head Repairs}✓ c. to Pt. ORIGINAL Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}1/LG2.6.27. X235 HYDRAULIC SHOCK DAMPERS. (A) MODIFICATION TO PREVENT KNOCKS. We have been carrying out a number of tests on the hydraulic shock damper. We found that one source of an audible knock which occurred on a large number of dampers was the high pressure valve returning to its seat. Investigations shewed that with a piston velocity of 16 ft/sec [handwritten correction: ins/sec], the high pressure valve under the standard front shock absorber conditions lifts .025". An examination of the seats shewed that in some cases the valves were hammering into the aluminium. We could reproduce this failure on our rig endurance tests as also the audible knock of the high pressure valve coming to its seat. Our rig test consists of a heavy flywheel imparting a reciprocating movement to the shock absorber arm through a 5 ft. tube. We found that we could eliminate the knock from the high pressure valve by plugging up the oil relief hole drilled at the bottom of the guide. Endurance tests shewed us that this modification contd :- | ||