The market requirements for various mechanical devices and instruments that use rolling bearings are becoming increasingly stringent, and the conditions and performance required for NSK bearings are becoming more and more diverse. In order to select the appropriate bearing from a large number of structures and sizes, it is necessary to study from various perspectives. When selecting bearings, the bearing structure is generally determined by considering the arrangement of the bearings as a shaft system, the ease of mounting and dismounting, the space allowed for the bearings, the dimensions and the marketability of the bearings, etc. The bearing structure is then compared with the bearings used in other parts of the world. Next, the bearing size is decided by comparing the design life of various machines using bearings and the various durability limits of bearings. When selecting bearings, it is often preferred to consider only the fatigue life of the bearing, and it is also necessary to fully study the grease life, wear, noise, etc., that occurs due to grease aging. In addition, according to different applications, it is necessary to select the precision, clearance, cage structure, grease and other requirements, make a special design of the bearing. However, the selection of bearings and no certain order, rules, priority should be given to consider the conditions required for the bearing, performance, related to even matters, especially practical.

Import bearing configuration bearing configuration bearing rigidity of the impact is also very large, generally speaking, for centripetal thrust type ball bearings and roller bearings, in pairs of use is recommended to take the outer ring large end face relative (i.e., its pressure line constitutes the pressure of the cone tip to the outside) configuration, so that the configuration of the bearing anti-upheaval torque of the ability of large, in the temperature change of the adjusted amount of preload is also less likely to change.

For only stamping outer ring needle roller bearings, due to the outer ring wall is very thin, good not to use a hammer to knock installation, should use the press to press in. Because when hammering, the pressure is not uniform, it is easy to make the outer ring of needle roller bearings produce local deformation.

"Cross-fixing" refers to a bearing configuration in which each NSK bearing is positioned unidirectionally on the shaft in the opposite direction. This combination is mainly used for short shafts. All radial bearings capable of withstanding axial loads in at least one direction are suitable, including deep groove and angular contact ball bearings, tapered roller bearings and cylindrical roller bearings of type NJ. When angular contact ball bearings or tapered roller bearings are used, on some occasions, a preload must be applied.

The shaft is supported in radial and axial directions by two bearings, the bearing on one side is called fixed-end bearing, which bears radial and axial loads, and plays the role of fixing the relative axial displacement between the shaft and the bearing box. The other side is called the free end, only bear radial load, axial can be relative movement.