The fit clearance between the bearing and the shaft must be appropriate to prolong the service life of the bearing. The following methods can be selected for the detection of the radial clearance of the bearing:
1、 Match rule method
Bearing with larger diameter usually has larger clearance, so it can be directly detected with a narrow feeler gauge. For bearings with small diameter, the thickness of the feeler gauge must be paid attention to the side clearance because of its small clearance.
2、 Lead intrusion detection method
The lead pressing method is relatively more accurate in detecting bearing clearance. During the test, the lead wire with soft and moderate diameter, which is not suitable for too large or too small, should be selected, and its diameter is usually 1.5~2 times of the gap.
Detection process:
Open the bearing cover, cut the lead wire with appropriate diameter into 15~40mm long, place it on the journal and the interface between the upper and lower bearings, cover the bearing cover again, tighten the fixing bolts with the specified torque, and then loosen them, finally take out the lead wire and use a micrometer to detect the flattening thickness, which can also calculate the average value of the bearing top clearance.
During the measurement, if the top clearance is too small, pad the joint surface of the upper and lower pads. If it is too large, it shall be cushioned, scraped or re-cast.
Change of bearing bush tightening force: the bearing bush is pressed with the bearing cap, which can avoid the rotation and axial movement of the bearing bush during operation. The bearing bush tightening force can also be calculated by measuring the top clearance.