How to choose between ball bearing and rolling bearing
Because of the different structural characteristics of various types of bearings, can be adapted to different conditions of use, designers can choose according to their own needs. Usually when choosing the bearing type should be integrated consider the following key factors:
Load is the most important basis for the selection of bearings, usually should be based on the size of the load, direction and nature of the choice of bearings.
1) under normal circumstances, the roller bearing is suitable to bear a large load due to its large bearing capacity due to linear contact; Ball bearing is small in bearing capacity due to point contact, suitable for light and medium loads. The load capacity of various bearings is generally expressed by the rated load ratio.
2) pure radial force in the direction of load, deep groove ball bearing, cylindrical roller bearing or needle roller bearing should be selected, and centering bearing can also be considered. The pure axial load action, chooses the thrust ball bearing or the thrust roller bearing. When combined with radial load and axial load, angular contact ball bearings or tapered roller bearings are generally selected. These two kinds of bearings follow the contact Angle. Increased ability to withstand axial load. If the radial load is large and the axial load is small, you can also choose the deep groove ball bearing and the cylindrical roller bearing with the inner and outer rings. If the axial load is large and the radial load is small, the thrust angular contact ball bearing and the thrust taper roller bearing can be selected.
3) roller bearing should be selected when there is impact load.
High speed performance
Generally, the bearing with small friction torque and small calorific value has good high-speed performance. Ball bearing has a higher limit speed than roller bearing, so it should be given priority to choose ball bearing at high speed. When radial load is small, choose deep groove ball bearing: when radial load is large, choose cylindrical roller bearing. For joint load, load hour, choose angular contact ball bearing; When the load is large, the combination of tapered roller bearing or cylindrical roller bearing and angular contact ball bearing is selected. In the same inner diameter, the smaller the outer diameter, the lighter and smaller the rolling body, and the smaller the centrifugal force of the rolling body on the outer ring during operation, so it is more suitable for working at a higher speed. Under certain conditions, bearings with diameter series of 8,9,0,1 should be selected when the working speed is high. The material and structure of the cage have great influence on the speed of the bearing. The solid cage allows a higher speed than the ram cage. High speed and heavy load bearings need to check their limit speed.
Axial swimming performance
General mechanical work, due to mechanical friction or the relationship between the working medium and the shaft heating, so there are thermal expansion and cold contraction. When selecting the type of bearing structure, the bearing should have the possibility of uranium swimming in its axis. Therefore, usually at one end of the shaft to choose an inner ring or an outer ring without retaining edge cylindrical roller bearings or needle roller bearings, in order to adapt to the thermal expansion and contraction caused by the shaft elongation or shorten.