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 sticking and tightening of worm and nut components, detailing the effects of temperature and various lubricants.
| Identifier | ExFiles\Box 154\3\ scan0031 | |
| Date | 1st August 1927 guessed | |
| contd :- -2- In addition, if the bedding or finish of the worm and nut is not very good, we can get sticking and tightening up under conditions (b). The main point is that we have satisfied ourselves that the .720 worm and nut can be made so that it will not stick when used with a reasonable lubricant under any condition that may conceivably be encountered in rational service. Effect of temperature and lubricant on sticking. We have been carrying out tests on a rig in parallel with road tests to ascertain the effect of various conditions on the liability of an imperfectly made worm and nut to tighten up. We find that with any of our normal lubricants a rise of temp. to 50°C in the box produces a definite increase in the tendency to tighten up. At 85°C this tendency is very marked and the American oil Iso-Vis certainly alleviates the trouble in a marked degree. However with a good steering under our normal steering box temperatures of 45°C or lower, Iso-Vis in our opinion gives slightly inferior results to our present Motorine 'C' or 'B'. As our steering conditions approximate, when shunting, to those of boundary lubrication we are investigating numerous types of 'oily' oils with a view to find something that will assist an inherently sticky worm, so far without much success. contd :- | ||