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).
Investigation into the elastic deflection of a shock absorber under working loads.
| Identifier | ExFiles\Box 152\1\ scan0107 | |
| Date | 17th February 1933 | |
| Messrs. Rolls-Royce TO: Messrs. Watson, Pitt, Douglas, & File. FROM: W.A. Green INVESTIGATION 33.IA. 8. 17th February, 1933 WAG/EGR SHOCK ABSORBERS, ELASTIC DEFLECTION. This investigation was undertaken in response to Messrs. Rolls-Royce's request for information regarding the elastic deflection of our shock absorbers under working loads. An R.M.P. shock absorber was selected and the rubber packing ring removed so that the screw plug could be screwed down hard on to the rotor. The plug was then drilled in such a position that the hole broke through into the rotor, and a pin was driven tight through the plug into the rotor to prevent any movement. A second pin was drilled half in the plug and half in the working chamber to prevent unscrewing of the plug, and a third pin was fitted radially through the bottom of the working chamber into the rotor. An 8" lever arm was fitted to the rotor spindle, care being taken that the splines were a really good fit. The shock absorber was then bolted to the vertical face of an angle plate fixed on a planing machine table. It was arranged with the lever arm projecting horizontally to the right. A clock micrometer was adjusted in contact with the upper side of the boss at the outer end of the lever, and the lever was loaded with dead weights. The load was applied in stages, and a reading of the deflection as shown by the clock micrometer was taken at each stage. The maximum load applied was 200 lbs. After reaching this figure the load was removed in stages, and clock readings again taken. It was found that when the load had been completely removed the clock did not return exactly to zero, but showed a permanent deflection of .007". Apart from this small discrepancy the load deflection curve is approximately straight, and it is thought that this permanent deflection is due to the taking up of the clearance in the spindle bearings, and not to any plastic deformation. To make sure of this point, the load was again increased by stages to 200 lbs, and again reduced to zero. On this test the rising and falling points are practically coincident. The final clock reading was .008" showing a variation of only .001", which is within the limits of experimental error. The shock absorber was now removed and bolted up again to | ||