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).
Technical document detailing spring load requirements and washer specifications to eliminate high-speed wobbles.
| Identifier | ExFiles\Box 12\1\ 01-page104 | |
| Date | 17th November 1928 guessed | |
| contd :- -2- To eliminate high speed wobbles, the minimum load required will not be less than 50 lbs. on the low pressure and high pressure side. If we assume that we always require a .025 washer under the valve cap to make a joint, the length of the spring with the valve closed will have to be .920 ins. when this washer is in position to give the maximum load required. By supplying washers .050, .075, .100, .125 thick to go under the valve caps we shall then be able to obtain the following loads which will cover the range we require. Washer. .025 .050 .075 .100 .125 L.P. load. 100 90 80 70 60 H.P. load. 90 80 70 60 50 In the H.P. valve cap it may be desirable to increase the width of recess 'L' to ensure that the air vent is in action with the .125 washer under the cap, otherwise we can see no difficulty in the scheme. All the washers can be clearly marked with their respective thickness, and a table issued with spares to Depots of ball end loads obtainable. As it is desirable to be able to work to 5 lbs. a supply of .010 washers to compensate for the variations in manufacture would be an asset. We do not consider that the spring F.54807 would be over-stressed when giving a ball end load of 100 lbs. because we have proved that this type of valve does not open more than .025". There does not seem to be any obvious explanation why the same spring should give 10 lbs. less load over the contd :- | ||