Bearing Installation Best Practices

Proper installation directly affects bearing service life. Follow these steps for a reliable mounting.

1. Clean the work area

Dirt is the leading cause of premature bearing failure. Clean the shaft, housing, and workbench before unpacking the new bearing. Leave the bearing in its original packaging until installation.

2. Check shaft and housing dimensions

Measure the shaft diameter and housing bore with a micrometer. Verify the shaft is within tolerance (usually h6 or j6 for standard motor shafts). Check for wear, scoring, or corrosion.

3. Choose the mounting method

• Cold mounting (small bearings, up to 100mm bore): Use a mounting sleeve and press or hammer. Apply force ONLY to the ring being fitted (inner ring for shaft fit, outer ring for housing fit). Never press through the rolling elements.
• Hot mounting (medium to large bearings): Heat the bearing to 80-100degC using an induction heater or oil bath. Slide onto the shaft while hot; it will shrink to a tight fit as it cools.
• Hydraulic mounting (large bearings with tapered bore): Use a hydraulic nut and oil injection for controlled mounting.

4. Apply lubrication

Fill the bearing 30-50% full with the specified grease. Over-greasing causes overheating. The housing cavity should be 30-40% full for normal speeds.

5. Verify alignment

After mounting, rotate the shaft by hand. It should turn smoothly without catching, roughness, or noise. Check with a dial indicator if alignment is critical.

6. Run-in

Run the bearing at reduced speed for the first 30 minutes. Monitor temperature. A gradual temperature rise is normal; a rapid spike indicates a problem.