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).
Investigation report on shock absorber performance at temperatures below 20°C.
| Identifier | ExFiles\Box 152\1\ scan0110 | |
| Date | 23th February 1933 | |
| TO: Messrs. Watson, Pitt, Douglas, & File. Messrs. Rolls-Royce. FROM: W.A. Green. INVESTIGATION 33.IA. 1.(CONTD). 23rd February, 1933 WAG/EGR ROLLS-ROYCE SHOCK ABSORBER, CONTINUATION. Mr. Robotham, of Messrs. Rolls-Royce, expressed a wish to see some indicator cards taken from the Shock Absorber submitted to them at temperatures below 20° C, this being the minimum temperature dealt with in the first part of the above investigation. As this particular shock absorber is now in Messrs. Rolls-Royce hands, the second similar shock absorber referred to in Inv. 33.IA.2 was used for these tests. The shock absorber with the indicator attached was removed from the test stand and left over-night in the refrigerator. In the morning it was removed and mounted as quickly as possible on the test stand and coupled up for test. The temperature in the refrigerator was minus 2° C, and it was estimated that by the time the shock absorber was coupled up, the temperature in the working chamber could not be above 0° C, although the temperature in the recuperating chamber had by that time risen to about 3° C. The test rig was started up and a card taken immediately. As soon as this card had been taken, the test rig was stopped and allowed to stand until the thermometer in the recuperating chamber read 5° C. At this point another card was taken, and so on at 5° intervals up to 20° C. A series of cards was taken in this way on the 10th February and a second series on the 16th. Particulars of the cards obtained are given in the attached indicator card record No.51, and photostats of the cards Nos.451-460 are also attached. It will be seen that the increase in the maximum pressure recorded at the lower temperatures is comparatively small, and is actually below some of the figures obtained at higher temperatures on other occasions. This discrepancy may be due partly to some small variation in the behaviour of the valves and springs, but it is thought that the greater part of it is due to the impossibility with this apparatus of determining the effective temperature of the shock absorber. There is no doubt that, even after a very few strokes, the temperature of the oil actually passing the valves is appreciably higher than that recorded in the recuperating chamber. The general conclusion to be drawn from this test is, that the valves provided in this shock absorber are sufficiently large to deal with the flow of oil at temperatures down to 0° C, and that | ||