SKF has developed new generations of deep-groove ball bearings and tapered roller bearings, designed to cut energy consumption by at least 30%. The ball bearings (shown below) are being targeted initially at motor applications and SKF estimates that if all the motors in the EU and the US were fitted with the new bearings, the savings would amount to 2,460 million kWh a year.
The new roller bearings are aimed at heavy-duty applications, such as wind turbines, conveyors, extruders, hydraulic pumps and locomotives. SKF reckons that replacing a bearing in a typical 2MW wind turbine with the new, more efficient design, would allow it to generate an extra 2.6 million kWh a year. If all of the world’s wind turbines used the new bearings in their gearboxes, they would generate an extra 770 million kWh a year.
The energy-efficient bearings are part of a company-wide drive by SKF to promote green measures, both in terms of its products and services, and its internal operations.
SKF announced the two families of energy-efficient bearings as part its centenary celebrations last month. They represent the biggest selling types of bearing. The company now plans to expand energy-saving capabilities gradually to encompass its entire range.
"Starting with the most-used bearings in the world, we are ensuring that our solution can be used in most machines in most industries around the world," SKF chief executive, Tom Johnstone (above), explained at the launch. "That way we provide the possibility of reducing the world’s energy consumption and also reducing customers’ energy costs."
The "green" ISO ball and roller bearings are the result of several years of research and development. The improved energy performance has been achieved through a combination of enhancements involving theb bearings` surface topologies, raceway profiles, and internal geometries. The bearings also incorporate special polymer cages and use low-friction greases. The reduced friction will lower operating temperatures, improve lubrication conditions, and allow the bearings to deliver the same service lives as existing ISO bearings.
Although a motor’s bearings represent just 0.6% of its total energy consumption, SKF argues that over the life of the motor, the energy savings will be substantial. The new bearings are currently undergoing pilot trials with motor manufacturers before going on sale in the last quarter of this year. SKF has not yet decided on the pricing for the bearings, which could also be used in other applications such as gearboxes, compressors and fans. According to Johnstone, the pricing will depend on "the value the products bring".
The tapered roller bearings (shown above) will be produced initially in outer diameters from 200–600mm, targeting applications above 1MW.
Another element of SKF’s green strategy is a Web-based application designed to help manufacturers to cut their energy bills. The "Client Energy and Environment Analysis Application" establishes an "opportunity map" of potential energy savings and identifies those likely to give the greatest savings.
Two years ago SKF launched an initiative called BeyondZero, aimed at ensuring that the energy savings from its products and services exceed its own energy consumption. It also set a target of reducing its carbon dioxide emissions by 5% a year. In 2005, it achieved a 7% reduction, followed by a further 5% in 2006.
These savings are being achieved partly by applying environmental measures to SKF’s own operations. For example, at its factory in Gothenburg, Sweden, the company has cut its CO2 emissions by 60% by switching to energy-efficient pumps and motors, reducing its use of compressed air, and adopting intelligent machine controls. By applying similar measures at 13 of its global network of factories, SKF reckons it is already saving 20GWh a year.
