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).
Comparison of different lubricants, their properties, and performance in gearboxes and axles.
| Identifier | ExFiles\Box 27\3\ Scan244 | |
| Date | 7th October 1939 | |
| -3- 7th. October, 1939. The main types that we have found to be successful together with their disabilities are:- (1) All the full "hypoid lubricants" such as - Wakefield Hypoy Vacuum H.G.L. Shell Hypoid lubricant are very similar and are lead soap free sulphur oils which attack copper very quickly. We have used them up to 160°C. Prolonged high temperature cause decomposition and sludge formation. We do not use any of them in production because we get equally good results on Hi-Press and this is less abrasive. (2) Milder E.P. oils - Wakefield's Hi-Press. Sulphur Chloride. Wakefield's TEX Thio-ether. Copper attack much less, TEX hardly at all. Hi-Press excellent lubricant as good as those above for load carrying and less abrasive. TEX - little known about this. Decomposes at about 135°C. Hi-Press runs up to 130°C in our gearbox and axle without giving trouble. (3) Whitmore's "No.0" is as good for load carrying as (1) but is abrasive and settles out when standing. All gearboxes are run in on mild E.P., and generally speaking, will afterwards perform without tooth plucking on a straight mineral oil, owing to the fact that full torque on the lower gears is very seldom used continuously. The box temperature runs up to 130°C and as no untoward results eventuates these oils can be considered relatively stable. Axles, particularly those having hypoid gears, will not function as at present designed without an E.P. oil. The improvement in tooth loads which is permitted by the use of such lubricants may be gauged by the fact that since their introduction it has been possible to halve the weight of an axle gear assembly to carry a given torque. | ||