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).
Deceleration tests performed with a recession valve in the external pressure inlet.
| Identifier | ExFiles\Box 179b\4\ img027 | |
| Date | 6th March 1933 | |
| "DECELERATION" TESTS WITH RECESSION VALVE IN EXTERNAL PRESSURE INLET. Having found that a .015" diameter release vent in conjunction with a recession valve was required to check recession of the external pressure oil along the pipe line, deceleration tests were taken to find whether or not the small orifice affected to any appreciable extent the normal rate of the return flow. As for the previous deceleration tests (6.3.33) a diagram was taken at 90 R.P.M., 1" stroke with governor pressures equivalent to 30 and 80 m.p.h. road speeds and the time required for the maximum damper pressures to decelerate from 80 to 30 m.p.h. in comparison with the time taken to reduce the governor speed recorded. This procedure was repeated at 180 and 360 r.p.m. without a recession valve and with a ball recession valve fitted. It should be noted that the previous tests were taken with a union in the bellows end cover, whereas a banjo fitting was used in this case, with no marked difference to the results. In addition, tests were taken with the governor speed reduced from 80 m.p.h. to nil, instead of 30 m.p.h., but the time taken to reduce the maximum pressures from 80 to 30 m.p.h. recorded. This method was found to be more consistent than the former, since it was easier to determine just when the indicator needle reached the 30 m.p.h. line, whereas with the previous method, any variation of the governor speed after the initial reduction, varied the time. This gives a possible explanation of the 19 secs. recorded in the previous results. The average results obtained by both methods are herewith recorded, and show that the normal rate of return flow is practically unaffected by the release vent. Hs{Lord Ernest Hives - Chair}/W.Bell. | ||