Application of Environmental Impact Assessments to Tribo-Components (Part 2): Effects of Oil Additives on Environmental Impact

摘要

Life Cycle Assessment (LCA) is conducted for two types of aluminum alloy bush bearings used for automotive transmissions. Equivalent CO{sub}2 emission (ECE) is used as the index of the environmental impact for global warming, and is compared through their manufacturing processes. Two types of bush bearings, which are in the market, show little difference in ECE, irrespective of different lining structure if comparison is made by taking a single piece of bearing as the functional unit. However, when the functional unit is defined so that relative life of the bearings based on their anti-wear potential is taken into account, reduction of environmental impact by higher wear resistance of the bearing material and by improved formation of lubricating oil can be estimated quantitatively. This LCA procedure is expected to be a useful tool for an environmentally friendly design of tribo-components.