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).
Mechanical testing report on Vandervell and other specified bearings for the Merlin engine.
| Identifier | ExFiles\Box 115\2\ scan0587 | |
| Date | 24th July 1940 | |
| To E o Hs{Lord Ernest Hives - Chair} Lov.{Mr Lovesey} Rbn Rm{William Robotham - Chief Engineer} HPS{Horace Percy Smith - Experimental Factory Mgr} Lr{Mr Ellor}/Brns/REM E/TGD c Psn (Glasgow) Lr{Mr Ellor}/LBH{Mr Hall - Aero Design Engineer} Lr{Mr Ellor}/AT.4/GR.{George Ratcliffe}24-7-40 Report No. MR 58 Mechanical Testing. Vandervell Bearings for Merlin. CONCLUSION Fatigue tests on the Vandervell tri-metal bearing are so far not too promising and it is recommended that conversion of the Merlin be held up pending satisfactory results from the Single Panel Rig. On similar tests the L.25S alloy has given very good results but has not yet been checked for antiseizing properties. Further to memo Lr{Mr Ellor}/AT.1/FC.13-7-40 we have now carried out additional endurance running on Vandervell and L.25S bearings on the Single Panel Rig. Results to date are as follows:- (1) 1/2% silver bearing - 50 hours running produced cracking up in a manner very similar to the cracking up exhibited by Vulture main bearings after the same running time. (2) L.25S - No signs of any cracks after 50 hours running. Bearing in very good condition and refitted for further endurance running. [Handwritten note next to (2): 25% lead 75% copper] (3) Vandervell bearing No.1. - fitted in steel shell similar to those it is proposed to fit to a Merlin Crankcase. After 10 hours the white metal had wiped away near the joint face leaving the journal running on the lead-bronze, and cracking of the white metal was also apparent for approximately 1/2 inch either side of the joint face. Examination of the bearing suggested that the nip of the tri-metal strip in the steel housing was too great and arrangements were made to test a second bearing with reduced 'nip' Note. - Vandervell's measure nip under loaded conditions, under these conditions the diametral nip would be approximately .0025" [Handwritten note between (2) and (3): began to crack up after 85 hours] (4) Vandervell bearing No.2.- as No.1. but diametral nip reduced to .00125" and clearance increased from .004" - .0055". | ||