Abstract
The scoring-load capacities of the vegetable oils with anti-wear additive of Dibutyl Phosphonate (DBPo) were studied by using a power-circulating gear test rig. The tests were carried out under a slash-pan lubrication. From the tests, the following results were obtained. (1) The scoring-load capacities of the vegetable oils increased in following order : Turbine oil<Corn Oil<Soybean oil<Rapeseed oil. The normal load per unit face width, Pn, at the incipient stage of scoring when lubricated with the rapeseed oil was approximately 1.7 times as large as that when lubricated with a turbine oil. (2) With respect to the vegetable oils with DBPo additive, surface failure by scoring didn't occur at the final load range in tests. The increases in the scoring-load capacities of rapeseed oil, corn oil and soybean oil with DBPo additive were over 78 N/mm, over 378 N/mm and over 449 N/mm, respectively. (3) The critical temperature at a risk for scoring with the rapeseed oil was about 400°C, and was the highest of all test oils. On contrast, the critical temperature with the vegetable oils with DBPo additive exceeded about 400°C.
