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).
Experiments on a damper system, focusing on pressure diagrams, hole sizes, and various air venting schemes.
| Identifier | ExFiles\Box 105\3\ scan0281 | |
| Date | 18th October 1932 guessed | |
| -2- was .105" diameter. Since the main object of the holes was to prevent building up of the static load, and the diagrams previously obtained with the original 'hat' proved the pressures to be contrary, it was decided to take diagrams at 25° and 60°C, this time at 2" stroke (presumed to be maximum movement on a normal road) since it was possible to obtain a good length diagram and a greater range of axle velocities than was obtainable on the 1" stroke. These were taken with:- (a) An atmospheric inlet hole on the valve side of the 'hat' - .105" diameter. (b) Atmospheric inlet holes on both sides of the 'hat', the second inlet being obtained by means of a drilled stud. The method employed was to statically load the damper to 90/90 lbs. with little or no oil in the 'hat' chamber, take a series of L.P. diagrams, run the damper until a temperature of 60°C was obtained, then retake the diagrams, cool off the damper, and repeat the diagrams. It was thus found that the pressures did not materially vary, nevertheless the static load after re-cooling was found to have increased, and required approx. 140 lbs. to initially move the lever, and 110 lbs. to maintain steady movement. Attention was then turned to the venting of the main pressure cylinders. Previously the original scheme of air venting the damper via the bearings had been adhered to, but it was decided before proceeding with the Governor Control scheme, to try the effect of providing the necessary air vents at the top of the piston, since there was a danger of the bearing vent getting below the oil level and drawing air back into the damper, and at the same time retain to a more limited extent the bearing lubrication system. It was already known that the bearing vent, which was on the H.P. side, sufficed for both high and low pressure cylinders, and that the provision of an extra vent in the L.P. cylinder provided no material advantage, but it was decided to vent both halves of the piston to make it reversible, and avoid production complications. | ||