Search

In the wind turbine industry, mechanical components sometimes have to operate under starved lubrication. This occurs mainly after maintenance and/or repairing procedures, when the wind turbine is starting up again after a prolonged inactive period. In field observations have shown that oil starvation is more prominent in warmer climates and of course for longer durations where the mechanical components remained 'inactive'. To get a better insight on this issue, a validation test procedure was developed based on reciprocating sliding tests. This protocol was used to investigate the starvation behaviour of two commercially available oils on metallic components, which were exposed at different temperatures (ranging from −20° to 40°C) and durations (ranging from 5 to 21 days). Based on these tests the resistance to starvation (failure time) and the effect of critical waiting time and temperature to initiate starvation were assessed. [ABSTRACT FROM AUTHOR]

ASTM Method D3233A uses a Pin&Vee Block tester to evaluate cutting fluids. However, the standard defines a steel-steel contact, uses a small volume of lubricant, and the test report is limited to the 'ultimate failure load'. With our approach, we bring testing closer to reality, using different metallurgies and testing the oils in aqueous emulsion-form. We monitor the frictional torque throughout increasing load, so that differences between products are revealed that are not visible in failure load alone. By modifying lubrication to recirculated or misted conditions, we simulate cutting of forming operations. Consequently, this provides an additional tool for cost efficient ranking of cutting fluids, based on an industry-accepted instrument. We demonstrate same ranking of cutting fluids as well established Tapping Torque Tests, with the advantage of using a simplified and lower cost configuration. Developing a standardized test protocol involves more work on reproducibility and correlation to real machining processes. [ABSTRACT FROM AUTHOR]