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).
Test report on J.III type shock dampers and bellows control in conjunction with a governor.
| Identifier | ExFiles\Box 151\2\ scan0030 | |
| Date | 14th March 1933 | |
| Files. J.III TYPE SHOCK DAMPERS - N.SCH.3465/3497. R.R.SCH.284 BELLOWS CONTROL IN CONJUNCTION WITH N.SCH. 3466/3592/3593. GOVERNOR. From the tests previously reported it was concluded that the oil tended to recede along the pipe line, but not to such an extent as to produce the effects obtained on the road when negotiating "hump-backed" bridges. It was thought that the proximity of the exhaust system to the O.S. dampers was having some effect on this flattening of the damper loads, since it was reported that these particular dampers were apparently weaker than those on the N.S. Tests taken at a damper temperature of 60°C showed that the efficiency of the damper was not impaired. Further tests were taken at 90 r.p.m. with 0, 5, 10 lbs/sq.in. governor pressure with both the damper and pipe line temperatures increased to 40, 50 and 60°C, from which it was found that up to 40°C there was no marked change in the diagram. At 50°C the pressure tended to fall off towards the end of the stroke as the bellows pressure increased, but the maximum pressure was not decreased, whilst at 60°C there was apparently loss of oil at the commencement of the stroke with 5, and 10 lbs/sq.in. pressure, and as at 50°C, the pressure tailed off, but the max. pressure was the same as at 40°C. More of these tests, however, produced the effect obtained on the road due to sudden change from large to small strokes, and in order to reproduce this effect as closely as possible, the bellows complete with end cover and pipe line, was detached from the valve chamber. Using cold oil + 20°C approx., and a governor pressure of 5 lbs/sq.in. the bellows was pressed back - by hand - as rapidly as possible to its limit, and the maximum pressure attained on the damper gauge (i.e. at the bellows, or damper end of the 12 ft. pipe line) and also on the governor gauge (i.e. at the governor end of the pipe line) recorded. Then with the bellows compressed to the limit, and retained, there until the pressures settled again to 5 lbs/sq.in. | ||