Oil-free pure refrigerant lubricated bearings for chillers

Pure refrigerant lubricated bearings from SKF combine ceramic (silicon nitride) rolling elements, rings made of high-nitrogen, specially heat-treated stainless steel, and glass fibre-reinforced PEEK cages. The result is a bearing that can operate reliably using low-viscosity refrigerant as a lubricant, an innovation that enables energy savings of at least 10 per cent versus conventional centrifugal compressor drive designs.

Traditionally, centrifugal compressors using low-viscosity refrigerants have been gear-driven designs that use hydrodynamic bearings lubricated with an oil-refrigerant mixture.

Richard Law, SKF Global Segment Manager, Fluid Machinery, explains: "It's an approach that requires both a lubrication system and an oil separator to provide an oil-rich mixture to the gears and bearings and a refrigerant-rich mixture to the evaporator and condenser. Pure refrigerant lubricated bearings from SKF provide simplified system design and oil-free operation by allowing low-viscosity refrigerants to be used as the lubricant in direct drive centrifugal compressors, enabling a much more energy efficient, low-maintenance solution."

Tested and proven reliable through more than a decade of field operation, pure refrigerant lubricated bearings from SKF are already at work in chillers, helping to lower energy use and costs, reduce maintenance, and eliminate oil-related environmental concerns. Go to www.skf.co.uk for further information.