cylindrical roller bearing / double-row / four-row / high-speed
high-speed, with lubricant, for heavy loads
spindle, for machine tools
Double-row cylindrical roller bearings come in two types: with a cylindrical or a tapered bore. As for those with a tapered bore, the specified amount of clearance can be obtained by adjusting the press-in distance. Some bearings are fitted with lubrication holes and lubrication grooves on the outer ring. They are identified by supplementary code "W". These bearings can accommodate high radial loads, and are often used in machine tool spindles.A machined bronze retainer maintains proper distance between the rolling elements and is very effective for high-speed applications. It reduces vibration, has a quiet operation and can accommodate heavy radial and impact loading.
Another option is to have separable inner or outer rings. This simplifies the mounting and dismounting of the R type bearing. It also increases load rating capacity.