NSK Bearing NNU4921K

Product description of NSK Bearing NNU4921K

NSK Bearing NNU4921K Category: NSK Bearing > Rolling Bearings > Cylindrical Roller Bearings > Double-Row.In bearings of this type, the cylindrical rollers are in linear contact with the raceways. They have a high radial load capacity and are suitable for high speeds.There are different types designated as NU, NJ, NUP, N, NF (for single-row bearings), NNU, and NN (for double-row bearings depending on the design or absence of side ribs).The outer and inner rings of all types are separable.Some cylindrical roller bearings have no ribs on either the inner or outer ring, so the rings can move axially relative to each other. These can be used as free-end bearings. Cylindrical roller bearings, in which either the inner or outer rings has two ribs and the other ring has one, are capable of taking some axial load in one direction Double-row cylindrical roller bearings have high radial rigidity and are used primarily for precision machine tools.Pressed steel or machined brass cages are generally used, but sometimes molded poly-amide cages are also used.Depending on the existence of ribs on their rings, Cylindrical Roller Bearings are classified into the following types:NU, N, NNU, and NN are suitable as free-end bearings. Types NJ and NF can sustain limited axial loads in one direction. Types NH and NUP can be used as fixed-end bearings.NH-type cylindrical roller bearings consist of the NJ-type cylindrical roller bearings and HJ-type L-shaped thrust collars.The inner ring loose rib of an NUP-type cylindrical roller bearing should be mounted so that the marked side is on the outside.

NSK Bearing NNU4921K if a cage is nonstandard for a given bearing number the number of rollers may vary, in such a case, the load rating will differ from that listed in the bearing tables.

NSK Bearing NNU4921K Double row full complement cylindrical roller bearings are suitable where:

• Bearing arrangements are subjected to particularly high radial loads
• Not only particularly high radial forces but also axial loads from one or both directions must be supported by the bearing position (semi-locating or locating bearing function)
• Bearing arrangements must have very high rigidity
• Axial displacements of the shaft relative to the housing must be compensated without constraint in the bearing (in the case of bearings with a non-locating or semi-locating bearing function)
• Very high radial loads occur at lower speeds, i. e., the bearings do not need to achieve speeds as high as those of cylindrical roller bearings with cage
• Space-saving designs are required despite very high load
• The bearings should be separable for easier mounting (bearings with non-locating bearing function)