New large sealed bearings from SKF

Tests show new bearings reduce grease consumption by up to 99% when used in HPGRs

SKF have extended their range of large bearings for roller presses with a sealed version that reduces grease consumption in the bearing up to 99%, prolongs service life, and cuts costs.

Explorer spherical roller bearings (SRBs) in the 241 series are now available up to 1,250mm bore. This series and sizes are commonly used in high-pressure grinding rolls (HPGRs) in the cement industry.

‘Using sealed bearings is the best way to increase mean time between failures,’ said Daniel Ortega, product line manager for sealed SRBs at SKF. ‘It is a long-term investment that increases machine availability and reliability.’

The new version – which is sealed on both sides – offers up to double the lifetime of an open bearing and has showed in tests that it reduces grease consumption up to 99%.

For example, in a HPGR, four large spherical roller bearings are usually used. During a maintenance interval of three months, normally 540kg of grease is used for certain sizes.

However, with SKF sealed Explorer spherical roller bearings, only 7kg of grease is needed during the same interval, which reduces both cost and environmental impact.

SKF say this raises productivity and machine availability while lowering total cost of ownership. In addition, the sealed SRB can be remanufactured twice, which further extends service life.

The new bearing has been redesigned to have a higher load-carrying capacity. Bearings with a bore-diameter below 1,000mm have an HNBR seal that is retained by a snap ring. Larger bearings use a G-ECOPUR seal that is bolted to the bearing’s outer ring.

The new bearings, even in the largest sizes, are available with short delivery times.