The first is the size limit. Usually the space in which the bearing can be installed is limited. In most cases, the shaft diameter (or bearing inner diameter) is based on mechanical design or other design constraints. Therefore, the choice of bearing type and size is determined by the inner diameter of the bearing. Therefore, the main dimension tables of standard bearings are compiled according to the international standard inner diameter dimensions.

There are many sizes of standard bearings. It is best to use standard bearings in the design of mechanical devices. (This is to say whether the bearings are easy to purchase. Here is a digression. Some imported bearing catalogs do have models, but some non-standard bearings There is no spot in mainland China, and sometimes the futures will be very long, so the time cost and the cost of later replacement should be considered when selecting the bearing.) The load of the bearing, the load imposed on the bearing, its nature, size, and direction changing. Generally, the rated basic load is shown on the dimension table. However, axial load and radial load are also important factors in choosing a suitable bearing. When the size of the ball and needle roller bearings are the same, the needle roller bearings usually have a higher load capacity and can withstand greater vibration and shock loads.

Rotation speed, the permitted speed is determined according to factors such as bearing type, size, accuracy, cage type, load, lubrication method, and cooling method. The bearing table lists the permitted speeds of standard precision bearings under oil lubrication and grease lubrication. Generally, deep groove ball bearings, self-aligning ball bearings and cylindrical roller bearings are suitable for high-speed operation.

Bearing tolerance, bearing dimensional accuracy and rotation accuracy are based on ISO and JIS standards. For machinery requiring high precision and high-speed operation, it is recommended to use bearings with accuracy of 5 or above. Deep groove ball bearings, radial thrust ball bearings or cylindrical roller bearings are suitable for machinery with high operating accuracy. Rigidity, when the contact surface of the rolling element and raceway of the bearing is compressed, it will produce elastic deformation. Some machines need to minimize elastic deformation. Roller bearings produce smaller elastic deformations than ball bearings. In addition, in some cases the bearing needs to be preloaded to increase rigidity. This program is usually used for deep groove ball bearings, radial thrust ball bearings and tapered roller bearings to offset the inner and outer rings, shaft bending, shaft or bearing housing tolerance changes, and matching errors will all lead to eccentricity of the inner and outer rings. In order to prevent the eccentric angle from being too large, self-aligning ball bearings, self-aligning roller bearings, or self-aligning bearing seats are better choices. The voice frequency and torque, and rolling bearings are manufactured according to high-precision standards, so the voice and torque are small. Deep groove ball bearings and cylindrical roller bearings are suitable for occasions with extraordinary requirements for low noise and low torque.