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).
Bearing test to investigate the effect of lateral slack on a bevel pinion application.
| Identifier | ExFiles\Box 84\4\ scan0285 | |
| Date | 8th September 1937 | |
| +202 REPORT ON TEST NO. 784.B. OBJECT OF TEST: To note the effect on this bearing when mounted with the outer rings .010" slack laterally and to compare with a bearing mounted with the outers correctly gripped up. In service on a bevel pinion application a distance piece which holds the outers together, is found to flatten and reduce in thickness by .010" thus allowing the outers to become slack laterally. This test was conducted at the request of Messrs. Rolls Royce. BEARINGS: 5/MDJT.30 - Steel cages - Cage clearance over inner shoulders .006". SPEED: 3000 R.P.M. LOAD: 1050-lbs. Journal : 1420-lbs. Thrust. LUBRICATION: Wakefield Hi Press Oil - pump feed. See drawing No.TR.{Capt. F. W. Turner - Finance}79 for arrangement of rig and oiling system. DURATION: Test with outers .010" slack - 92 hours. Test mounted correctly - 100 hours. GENERAL REMARKS RE TEST: A 5/MDJT.30 bearing was mounted on a horizontal rig as shown on drawing TR.{Capt. F. W. Turner - Finance}79, with the outer races .010" slack laterally, and was tested at 3000 R.P.M. under combined loads of 1050 lbs. journal and 1420 lbs. thrust. On examination after 92 hours, the cage on the thrust side of the bearing was found to have worn in the bore, due to twist in the bearing. The slackness of the outers had allowed the shaft to deflect, causing misalignment in the bearing and heavy rubbing of the cage on the shoulders of the inner. Maximum Temperature rise 84°F.{Mr Friese} Normal Temperature Rise 76°F.{Mr Friese} Atmospheric Temperature 75°F.{Mr Friese} A repeat test was conducted with a new bearing mounted correctly, and after 100 hours the bearing was found in excellent condition, no signs of cage wear were present. Maximum temperature rise 97°F.{Mr Friese} Normal Temperature Rise 82°F.{Mr Friese} Atmospheric temperature 78°F.{Mr Friese} CONCLUSIONS DRAWN FROM TEST: The results of this test conclusively proves that the trouble experienced by customer is entirely due to the reduction in thickness of the distance piece, and if this is corrected the bearing should give satisfactory service. Copies to: G.M.W. Technical Office. Test Shop. | ||