Analysis of component performance and modifications related to pressure, load, and flow characteristics.
| Identifier | ExFiles\Box 56\1\ Scan228 | |
| Date | 18th October 1932 guessed | |
| -4- axle velocities on the 4" stroke (i.e. 45 and 180 flywheel r.p.m. respectively) and these have been so far adhered to. The initial static loads were reduced to 40/40 lbs, and it was found that owing to an unaccountable leakage which disappeared if the loads were increased to approximately 75 lbs. This setting was therefore difficult to ascertain. After setting the L.P. load as closely as possible to 40 lbs, the whole valve chamber was removed, and it was then discovered that the valve was not being retained on its seat by the spring, and the static loading was therefore being determined by the restriction of the valve taper. This was repeated and the same results obtained. It is interesting to note that with .156" diameter pipes the pressure-time lag between the pump and the Governor gauge (pipe length approx. 1 1/4 ft) was 15 secs, and between the pump and the damper gauge (pipe length 12 ft) 65 secs. It was eventually found that by increasing the diameter of all the pipes to .250" much better diagrams were obtained, also the pressure time lag along the 12 ft. pipe was reduced to approx. 15 secs. Two peculiar effects were observed from the diagrams obtained with .250" pipes :- (a) On the short stroke the maximum pressures obtained at the slower speed were slightly in excess of those obtained at the higher speed. (b) On the long stroke, the rate of pressure rise at the beginning of the stroke was rapid, then having attained a certain maximum pressure, instead of maintaining that level, it gradually declined to almost zero at the end of the stroke. The possibilities of using pipes between the two sizes already quoted were considered as a means of reducing peculiarity (b), but since these were not readily obtainable, the small inlet hole in the external pressure cylinder was reduced to half of its original area. After performing this operation, the cylinder was replaced, and a diagram immediately taken at 45 flywheel r.p.m. with amazingly good results, but | ||
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).