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 shaft and bearing wear and performance under various loads and speeds.
| Identifier | ExFiles\Box 111\4\ scan0106 | |
| Date | 16th May 1939 | |
| -2- HPS{Horace Percy Smith - Experimental Factory Mgr}/B1.1/CB.16.5.39. the races being badly pitted and the balls severely chipped. The shaft was crack tested and found to be in good condition, except for .010" - .013" wear under the bearing. See BL.2257. The serrations were considerably worn at the shaft end as shown on BL.2257, being approximately down .002" on the diameter and .002" - .003" on the width of the splines. This wear was presumably due to the bow. GB.4020 Shaft - 40 m/m Bearing - GCK.843. (GB.3604 mod. to GB.4020). This shaft was run for similar periods to Ex.31270:- 1.0 ton. 1,000 R.P.M. 100 hours. 1.5 " 667 " 100 " 2.0 " 500 " 75 " Very smooth running was obtained throughout the test and no trouble was experienced until after 274 hours, when rough running commenced. The rig was stipped one hour later. In this scheme, the bearing is preloaded by a Bellville washer, and no gap was observed between the bearing washer and retaining collar after the test. This factor seems to justify the inclusion of the Bellville washer. The shaft was examined when stripped and the inner race showed signs of having turned round, although the wear on the shaft was only .0005"; the serrations after this test were in good condition. The reason for the rough running was found to be a chipped ball, the rest of the balls and race being in good condition - see BL.2326. The shaft also, was in very good condition. Further running is to be carried out on this shaft with a new bearing fitted with .0005" interference between the bearing and its housing, the shaft being inspected every 50 hours. From the results of running these two shafts, it is apparent that the bearing is the weakest point of the assembly. It will be interesting to see whether the 1 5/8" bearing, which is to be fitted to a new shaft and tested under similar conditions, will be an improvement. Compared with the Cadillac shaft, both of these shafts were considerably stronger, the Cadillac shaft having cracked after 53 hours at 1.5 ton, 667 R.P.M., having run 236 hours previously at 1.0 ton, 1,000 R.P.M. HPS{Horace Percy Smith - Experimental Factory Mgr}/B1. | ||