Improved lubrication and the consequent reduction of friction on gear sets can result in energy savings of up to 15%, suggests international research. Benefits can accumulate from fuel savings as well as a reduction in carbon emissions, South African Institute of Tribology (SAIT) president Patrick Swan tells Engineering News.
Recent nanotechnology research, which exam- ines molecular structure and the effects between two surfaces, has been useful for industries that use gears and bearings. Swan explains that if the surface texture of a gear or bearing is changed, friction can be reduced. The current research in this field attempts to understand the relationship between surfaces on the molecular level and create new bearings, for instance, with characteristics for the least amount of friction possible.
Research suggests that changing from mono- grade to multigrade hydraulic fluids in construction and mining equipment can result in significant energy savings. Energy and fuel- efficiency technologies available today are applied to mining, construction, and hydraulic machines.
Changing from a monograde hydraulic fluid to a multigrade, or high-viscosity index fluid, has the potential to improve overall efficiency or reduce energy consumption by up to 25%, says Swan.
Multigrade engine crankcase lubricants can reduce fuel consumption by between 3% and 4% owing to lower internal friction.
Swan says that although technology resulting from the research undertaken is emerging in selected industries, it is not readily applied in most South African sectors. He attributes this to the industry’s resistance to change and to general perceptions of hydraulic fuel as a commodity. In addition, the costs of using a new fuel would be slightly higher than the costs of regular fuels used. Swan states that consumers are more likely to use the cheapest fluid available in their vehicles.
Swan points out that choosing the right energy-efficient and friction-reducing oil and lubricant for a particular machine or vehicle can be difficult. He adds that it is difficult to determine the quality of the lubricant by simply looking at it, as its internal characteristics and specifications cannot be quantified without testing.
As technology is continually upgraded, devel- oped and improved, the lubricant industry is simultaneously developing better products in order to satisfy the demands of new technology requirements.
Modern systems are much smaller in size and dwell time. Dwell time, or the time it takes a fluid to circulate around a pump, has been reduced to between 30 seconds and one minute, depending on the size of the pump used. Because less energy is consumed to move the machine, greater stress is placed on the fluid in the pump, meaning that improved lubricants are required.
The Sait’s research activities are centred on the study of tribology, which is the science of friction and wear.
This covers material science and lubrication engineering, and deals with prolonging the life of components.
Good tribology practice determines what the appropriate lubricant or oil is for use in a particular piece of equipment.