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).
Analysis of spring and piston resistance in a hydraulic system during return and rebound.
| Identifier | WestWitteringFiles\O\2April1926-June1926\ Scan145 | |
| Date | 20th May 1926 | |
| Contd. -4- Hs{Lord Ernest Hives - Chair}/ACL/T20.5.26. (2) RESISTANCE TO RETURN OF SPRING TOWARDS ITS MEAN POSITION. The piston still operates over the same part of the bore a-s previously but now the flap valve shunts and the only path for the displaced oil is round the sides of the piston and through the release valve. None, however, is likely to pass the release valve because a very high velocity would have to be reached in this part of the bore before the pressure became sufficient for its operation. During our tests up to a velocity of 47 feet per min. all the oil passed the sides of the piston. The resistance curve No.2 is similar to the previous one but the resistance increases more rapidly. (3) RESISTANCE TO REBOUND PAST MEAN POSITION. When the spring reaches the mean position, moving in the "rebound" direction, the piston enters the small bore of the cylinder where the radial clearance is only .0025". The flap valve is shut, consequently there is only very small path for leakage and when the pressure becomes sufficiently high the displaced oil passes through the spring loaded valve in the piston head. Reference to Curve 3 shews us that the resistance increases very rapidly up to 160 lbs. after which the release valve starts to open and the increase of resistance is not so rapid. The effect of the opening of the valve is clearly defined on the curve and takes place at a pressure between 150 and 170 lbs/sq.". This has further Contd. | ||