Matching conditions of bearing
It is to project or convert the thickness of the gasket or spacer bearing that cannot be measured directly to a place that is easy to measure. This effect can be achieved by using a special gauge sleeve and spacer. When the inner ring and outer ring of the bearing are tight fit conditions, the removal and adjustment of the bearing will be very difficult and time-consuming. At this time, its advantages are reflected.
This method requires separate gauges for different series of bearings, and the relative cost is high. But when installing in large quantities, the average cost per installation is very cost-effective. Especially in the field of automation, it has proved to be a very effective method.
Use probability method and control the dimensional tolerance of relevant parts to ensure that 99.73% of the bearing clearance in all assembly assemblies falls within the acceptable range. This is a mathematical prediction after the combination of a group of random variables. The variables are the bearing tolerance and the tolerance of installation components such as shaft and bearing seat.
This method does not need installation and adjustment, and can be simply assembled and clamped with components. Therefore, mass installation is very convenient. However, in the end, a clearance range (about 0.25mm) will be obtained. Whether set right can be used in some applications needs to be determined in the design stage. For many years, methods have been successfully used in both industrial and automotive fields.
For separate bearings such as cylindrical roller bearings and tapered roller bearings, the inner ring and outer ring can be installed on the shaft and shell respectively. When combining the installed inner ring and outer ring, the key is to stably close them so that the centers of them do not deviate, and pressing them reluctantly will cause jamming on the raceway surface.
Hot charging method
Large bearings require a lot of force when pressing in, so it is difficult to press in. Therefore, the method of heating the bearing in oil to expand it and then installing it on the shaft is widely used. Using this method, the operation can be completed in a short time without adding improper force to the bearing.
The heating temperature of the bearing is based on the bearing size and the required interference. Precautions for hot loading operation are as follows:
(a) Do not heat the bearing above 120 ℃;
(b) In order to prevent the bearing from directly contacting the bottom of the oil groove, it is best to consider placing the bearing on the metal mesh platform or lifting the bearing;
(c) Heat the bearing to 20 ℃ - 30 ℃ higher than the required temperature so that the inner ring will not become cold during operation and it is difficult to install;
(d) After installation, the bearing cools down and shrinks in the width bearing direction, so it should be fastened with shaft nut or other appropriate methods to prevent gap between inner ring and bearing shoulder.
