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).
The rejection of Wraith gearboxes due to 'Clonking' caused by end float in ball bearings and recommending an improved bearing type.
| Identifier | ExFiles\Box 8\11\ 11-page157 | |
| Date | 18th February 1939 | |
| 628 To BY.{R.W. Bailey - Chief Engineer} & Rm.{William Robotham - Chief Engineer} From RHC.{R. H. Coverley - Production Engineer} c. Hs.{Lord Ernest Hives - Chair} c. LA.{L. A. Archer} RHC.{R. H. Coverley - Production Engineer}3/FH.18.2.39. BALL BEARINGS - WRAITH GEARBOX. The Test Department are rejecting a considerable number of Wraith Gearboxes which are undergoing 1st. Motion Shaft conversion, on the grounds of "Clonking". It has been found that in the main all internal components are satisfactory as regards dimensional standards and the trouble is now proved to be due to end float in the 1st. & 3rd. Motion Shaft Ball Bearings. The Bearing Drawings GW. 788/9 specify .00075 radial clearance, which due to the track formation provides an end clearance of anything up to .009. Gearboxes rejected on Test have been fitted with an improved type of Bearing have negligible end clearance, with entirely satisfactory results and it is therefore recommended these Bearings be adopted. Enquiries of Messrs. Hoffman's reveal that only a small percentage of Wraith 'C' Series Bearings have been finished and that the balance could be machined to give reduced end float providing an immediate decision is made. As regards A.{Mr Adams} and B. Series, there are still a number of Chassis to undergo the 1st. Motion Shaft conversion and it may therefore be considered advisable to obtain a certain number of improved type Bearings for use on these Chassis. RHC{R. H. Coverley - Production Engineer} | ||