1. Bearing installation space
Analyze the size of installation space to ensure that the bearing can be accommodated; In the design process, the rigidity and strength of the shaft should also be paid attention to. Therefore, the size of the shaft diameter, namely the inner diameter of the bearing, needs to be determined first when designing the bearing.
2. Load
The working load size, direction and other properties of the bearing can be selected according to the bearing size table of the bearing; For example, the size of the load force, the type of shaft and radial load, whether the force is one-way or two-way, the degree of vibration or impact, and other factors can be determined. According to these actual needs, the appropriate bearing type can be selected.
3. Speed
The bearing type needs to be able to adapt to the speed of the machine, and its limit value reference is usually expressed by the limit speed; The limiting speed of the bearing usually depends on the following factors: bearing type, size, cage, accuracy, lubrication method, etc. Among the common bearing types: deep groove ball bearing, angular contact ball bearing, cylindrical roller bearing are mostly used for high-speed rotation:
4. Rotation accuracy
Dimensional accuracy and rotation accuracy required by bearing type; For example, in the application of machine tool spindle, gas turbine and control machine, the bearing is required to have the performance of high rotation accuracy, high speed and low friction, which requires the selection of deep groove ball bearing, contact ball bearing, cylindrical roller bearing and other bearing types with at least 5 levels of accuracy.
5. Rigidity
The bearing type shall meet the rigidity required by the mechanical shafting; "High rigidity" usually means that the deformation of the bearing is small due to elastic deformation. For example, in the application of machine tool spindle and automobile final reduction device, the rigidity of the shaft and bearing must be guaranteed. Pre-tightening of bearings such as diagonal contact ball bearings and tapered roller bearings can also improve rigidity.
6. Relative inclination of inner ring and outer ring
Analyze the relative inclination of inner ring and outer ring caused by factors such as shaft deflection caused by load, poor accuracy of shaft and housing or installation error, and select the appropriate bearing type through the analysis of these factors. In addition, the relative inclination between the inner ring and the outer ring should also be considered.
7. Installation and removal
When the bearing needs to be assembled and disassembled frequently during the regular inspection, the cylindrical roller bearing, needle roller bearing and tapered roller bearing with separable inner and outer rings can be given priority. The self-aligning ball bearing and self-aligning roller bearing with round taper hole can also be easily disassembled and inspected through fasteners or withdrawal sleeves.