The accuracy grade of Koyo cylindrical roller bearing is improved successively from grade 0. Grade 0 is sufficient for general purposes, but grade 5 or higher accuracy is required for the conditions or occasions shown in Table 1. Although the above Accuracy grades are based on ISO standards, their names are different in national standards. The Accuracy grades applicable to various types of Koyo cylindrical roller bearings and the comparison between national standards are listed.
1. Allowable deviation of inner diameter, outer diameter, width and assembly width
2. Allowable deviation of inner and outer diameter of roller set
3. Allowable limit value of chamfer size
4. Allowable variation of width
1. Allowable radial runout and axial runout of inner ring and outer ring
2. Allowable lateral runout of inner ring
3. Allowable variation of inclination of outer diameter surface
4. Allowable variation of thrust bearing raceway thickness
The standard Koyo cylindrical roller bearing has many sizes and forms, and the standard bearing is used in the design of mechanical devices This is a long time to say whether the bearing is easy to purchase. Some models of KOYO cylindrical roller bearings are available, but some non-standard bearings are not available in Chinese mainland. Sometimes, futures will be very long. Therefore, when bearing selection, we should consider the cost of time and the cost of later replacement. The load of Koyo cylindrical roller bearing and the load applied on the bearing are variable in nature, size and direction. Generally, the rated basic load is shown in the size table. However, axial load and radial load are also important factors for selecting suitable Koyo cylindrical roller bearing.
When the sizes of ball and needle roller bearings are the same, needle roller Koyo cylindrical roller bearings usually have high performance Load capacity and bearing large vibration and impact load. The allowable speed is determined according to the type, size, accuracy, cage type, load, lubrication mode, cooling mode and other factors of Koyo cylindrical roller bearings. The table of Koyo cylindrical roller bearings lists the allowable speed 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 Occasion. The dimensional accuracy and rotation accuracy of Koyo cylindrical roller bearings are based on ISO and JIS standards. For machines requiring high accuracy and high-speed operation, it is recommended to use Koyo cylindrical roller bearings with accuracy of grade 5 or above.
Deep groove ball bearings, centripetal thrust ball bearings or cylindrical roller bearings are suitable for machines with high operation accuracy. Rigidity, when the contact surfaces of rolling elements and raceways of Koyo cylindrical roller bearings are affected Pressure will produce elastic deformation. Some machines need to reduce the elastic deformation to a small extent. Roller bearings produce less elastic deformation than ball bearings. In addition, in some cases, preloading shall be applied to Koyo cylindrical roller bearings to increase rigidity. This procedure is usually used for deep groove ball bearings, centripetal thrust ball bearings and tapered roller bearings.
Offset of inner and outer rings, shaft bending, change of shaft or bearing housing tolerance and wrong fit will lead to eccentricity of inner and outer rings. In order to prevent excessive eccentricity angle, self-aligning ball bearings, self-aligning roller bearings, Or self-aligning bearing seat is a better choice. The voice frequency and torque of 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 special requirements for low voice and low torque.