Bearing and Housing Unit: SKF bearing units typically consist of a bearing, seal, lubricant and shaft locking mechanism. The units are preassembled and adjusted at the factory. These ready to mount units are available with either ball or roller bearings. In addition to standard all steel units, SKF has more focused standard products – which target a particular industry – like the food, beverage and pharmaceutical industries where, for example, special materials, lubricants, seals and housings are needed.
Needle roller bearings with machined inner and outer rings
Needle roller bearings with an inner ring (fig. 2) are used for applications where the shaft cannot be hardened and ground. The permissible axial displacement (→ product table) of the shaft relative to the housing is limited for bearings with an inner ring. If the permissible axial displacement provided by a standard inner ring is insufficient, it is possible to use an extended inner ring (→ Needle roller bearing inner rings).
Needle roller bearings with a machined outer ring, without an inner ring
Needle roller bearings without an inner ring (fig. 1) are an excellent choice for compact bearing arrangements if the shaft can be hardened and ground. Eliminating the need for a separate inner ring enables a larger shaft diameter and a stiffer bearing arrangement. Axial displacement of the shaft relative to the housing is only limited by the width of the raceway on the shaft. By machining the shaft raceways to the appropriate dimensional and geometrical accuracy, it is possible to obtain bearing arrangements with heightened running accuracy. For additional information, refer to Raceways on shafts and in housings.