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 development and production of oxygen-free copper bearings using a lithium-calcium deoxidizing agent.
| Identifier | ExFiles\Box 114\2\ scan0118 | |
| Date | 23th February 1935 guessed | |
| (2) and running with 20 pounds oil pressure would positively not score the shaft nor score the bearings. It might seize, and in fact several of these bearings did seize, and when allowed to cool off would continue to run with perfect results. Well, of course, this was something to think about. So later on we learned the Maywood Chemical Company have developed a method of deoxidizing copper by using a 50% mixture of lithium and calcium. Inasmuch as this method of deoxidizing produces a perfectly oxygen free copper, and this tied up with Mr. Boegehold's tests of bearings made with oxygen free copper, we decided that probably it would be a good thing for us to try out. In trying out anything new like this, of course, you usually have a lot of grief and we ran into it in probably its most violent nature, and found that our set up was not exactly right and that the lithium and calcium packed our crucible and our bottom pour valve. This integrated very badly and further the tremendous quantities of oxides thrown off by the lithium and calcium mixture would gum up the valve so badly that it was almost impossible to pour the bronze. This happened when we introduced the lithium calcium in the crucible after the metal was poured into it from the rocking furnace. We finally got over this trouble by introducing the lithium calcium into the rocking furnace and making the transfer through the funnel into the crucible through a cover of neutral gas. By the way, the entire furnace all the way to the water seal on the back end is filled with a neutral gas. This includes the crucible and the rocking furnace. The only openings are at the three points marked with a yellow pencil where the gas burns continuously in sufficient volume to prevent any air from getting into the furnace and coming into contact with metal or pans when being used. Briefly, that's our story as far as the furnace is concerned. The drawing attached, which I am sending you in duplicate, is marked for layout purposes but in a manner that I believe will give you a fairly good index to the various parts and their functions. If at any time you should want further information and in more detail concerning this furnace we will be glad to send it to you. Now, the interesting part of all this is that our bearings when cast with lithium calcium neutral gas method are entirely oxygen free. To say that these bearings are better than bearings cast by the ordinary method is expressing it very mildly. Since we have been using this method our tests show 100% good bearings. Lithium-calcium mixture can be obtained in metal form from the Maywood Chemical Company, Maywood, New Jersey, costing about $20.00 a pound in small quantities. The charge we use for 60 pounds of bronze is about seven grams. The cost per bearing is about .15 of 1%. This is for a bearing 2 5/16 inside diameter and 1 inch wide. continued. | ||