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).
Proposing improvements to the heating and quenching process for manufacturing lead bronze bearings.
| Identifier | ExFiles\Box 173\2\ img135 | |
| Date | 14th February 1934 | |
| SG{Arthur F. Sidgreaves - MD} NOR / HS{Lord Ernest Hives - Chair}/RHC{R. H. Coverley - Production Engineer}12/N334 Cleveland, Ohio. February 14, 1934. To HS{Lord Ernest Hives - Chair} from RHC{R. H. Coverley - Production Engineer} LEAD BRONZE BEARINGS In order that heating and quenching tackle for bearings can be proceeded with, I enclose rough layout. The original furnace used for bearing production could no doubt be modified by fixing false floor over heating element and arranging doors at each end. Allison's quenching tackle is rather crude. As bearings leave furnace, they are picked up on a tray by pulley blocks and lowered through jet ring into quenching tank until submerged. This is not only awkward to operate, but requires too many workmen. It is therefore suggested that a ram should be arranged inside quenching tank at correct height to receive bearings as they leave furnace. Casting operation will then be carried out and ram which will be hydraulic or air controlled, lowered through jet ring which quenches bearing before passing into tank below. Face of ram should be made large enough for all types of main bearings and location provided to position bearing when ready for quenching. Tank will have sufficient capacity to keep water cool and may be equipped with small capacity pump to provide about 5 lbs. pressure for cooling and would therefore be self-contained. The water jet is directed at right angles to wall of bearing. This is considered important. The rapid cooling which takes place gives a radial crystalline structure of lead bronze lining, which, being thick in section when cast, insures good lead distribution. Allison's have certain amount of trouble when lead bronze is carried round flange, as in the case of thrust bearings, owing to difficulty of directing cooling element at correct angle. Lead therefore is liable to be in lakes. It may be possible to modify centrifugal process to give similar quenching conditions. This, however, can be dealt with later. | ||