1. Inspect Installation Position
After bearing installation, first check whether the moving parts collide with the stationary parts, whether the lubricating oil flows smoothly into the bearing, and whether the sealing device and axial fastening device are installed correctly.
2. Inspect Radial Clearance
Except for bearings with pre-fit, radial clearance should be inspected. Deep groove ball bearings can be inspected by hand rotation; smooth, flexible rotation without vibration or lateral wobble is ideal. Cylindrical roller and self-aligning roller bearings can be inspected with a feeler gauge. Insert the feeler gauge between the roller and the bearing ring; the insertion depth should be greater than 1/2 of the roller length.
When the radial clearance of the bearing cannot be measured with a feeler gauge, the axial movement of the bearing can be measured to represent the reduction in radial clearance. Generally, if the bearing inner ring has a tapered bore, the axial movement on the tapered surface is approximately 15 times the reduction in radial clearance.
The radial clearance of some bearings can be adjusted after installation if it is not up to standard, such as angular contact ball bearings and tapered roller bearings; however, some bearings are pre-adjusted according to standards during manufacturing and cannot be adjusted after installation if they are not up to standard, such as deep groove ball bearings, self-aligning ball bearings, cylindrical roller bearings, and self-aligning roller bearings.
If these types of bearings fail inspection after installation, and the radial clearance is too small, it indicates that the bearing fit was not properly selected or the assembly part was not machined correctly. In this case, the bearing must be removed, the cause identified, and the problem rectified before reinstallation. Of course, excessive bearing clearance is also unacceptable.
3. Inspecting the tightness between the bearing and the shaft shoulder. Generally, bearings with tight fit interference fits must be close to the shaft shoulder. Inspection method:
(1) Light method. Point a light at the bearing and shaft shoulder and observe the light leakage to determine the tightness. If no light leaks out, the installation is correct; if light leaks out evenly around the shoulder, the bearing is not properly seated against the shoulder, and pressure should be applied to tighten it; if light leaks out partially, the bearing is installed tilted, and a hammer, copper rod, or sleeve can be used to tap the inner ring of the bearing to slowly straighten it.
(2) Feeler gauge inspection method. The feeler gauge should start with a thickness of 0.03mm. During inspection, insert the feeler gauge at several points along the entire circumference of the bearing inner ring end face and the shoulder. If a gap is found and it is very uniform, the bearing is not properly installed, and pressure should be applied to the inner ring to tighten it against the shoulder; if it cannot tighten even with increased pressure, the fillet radius of the journal is too large, jamming the bearing, and the journal fillet radius should be adjusted to make it smaller; if the feeler gauge can pass through individual parts of the bearing inner ring end face and the bearing shoulder, it must be disassembled, repaired, and reinstalled. If the bearing is installed in the bearing housing bore with an interference fit, and the outer ring of the bearing is fixed by the shoulder of the housing bore, the thickness gauge can be used to check whether the end face of the outer ring is close to the end face of the shoulder of the housing bore and whether the installation is correct.