The failure analysis of a cracked bearing cage in a Bentley rear axle pinion thrust race and subsequent testing plans.
| Identifier | ExFiles\Box 114\2\ scan0021 | |
| Date | 23th February 1934 | |
| X3807 To Sg. {Arthur F. Sidgreaves - MD} From Hs {Lord Ernest Hives - Chair} /Gry. {Shadwell Grylls} c. to HSR. c. to E. {Mr Elliott - Chief Engineer} c. to By. {R.W. Bailey - Chief Engineer} c. to DA. {Bernard Day - Chassis Design} c. to Hdy. {William Hardy} c. to EV. {Ivan Evernden - coachwork} c. to IM. Hs {Lord Ernest Hives - Chair} /Gry. {Shadwell Grylls} 11/KH. 23.2.34. REAR AXLE PINION THRUST RACE - BENTLEY. On dismantling the Ransome & Marles increased capacity thrust race after running just under 10,000 miles in 4-B-IV, we found the cage in the thrust half to be cracked. The bearing otherwise was in perfect condition. We visited Ransome & Marles to discover the cause of this failure. Although they were not definite in saying so, it is probable that a contributory cause was the hard carbon deposit from the oil that had built up between the inner race and the cages, removing the .04 clearance that should exist at this point. A temporary seizure would break the cage. They are therefore re-assembling the bearing with steel cages and suggest our using Whitmore's oil instead of the Wakefield Sulphur oil used in the last test. We shall therefore run this bearing a further 10,000 miles to prove the cage; the thrust races and balls will then have completed 20,000 miles. The failure of this cage in no way detracts from the merits of the bearing in being able to deal with the load. We are arranging for a further 100 hours rig test of this type of bearing fitted with a steel cage. (We reported previously that in the rig test the bearing was perfect after 50 hours. After a further 50 the bearing was still in excellent condition; after which the test was discontinued). We are also carrying out a rig test of the Hoffmann combined roller and ball bearing. Hs {Lord Ernest Hives - Chair} /H.Grylls. | ||
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).