Fault analysis of motor NSK bearing

There are many reasons for motor failure. Here NSK bearing dealers share with you the fault analysis related to the bearing when the motor is out of order.

When the motor is running, the sound is not normal and there is abnormal noise.
One of the causes
1 The rotor is rubbed with the stator insulating paper or the wedge;
2 bearing wear or foreign matter such as sand in the oil;
3 fixed rotor core loose;
4 bearings are short of oil;
5 air duct packing or fan air hood,
6 fixed rotor core rubbing;
7 The power supply voltage is too high or unbalanced;
8 stator windings are staggered or shorted.


Motor NSK bearing overheating
  1. cause of issue
1 too much or too little grease;
2 oil quality is not good with impurities;
3 bearing improperly matched with the journal or end cap (too loose or too tight);
4 bearing inner hole eccentric, rubbing with the shaft;
5 motor end cover or bearing cover is not flat;
6 The motor and load coupling is not corrected, or the belt is too tight;
7 bearing clearance is too large or too small;
8 The motor shaft is bent.
  2. Troubleshooting
1 add grease according to the regulations (1/3-2/3 of the volume);
2 replace the clean lubricating grease;
3 over-loose can be repaired with adhesive, over-tightening the car, grinding the journal or the inner hole of the end cap to make it suitable;
4 repair the bearing cap to eliminate the rubbing point;
5 re-assembly;
6 recalibrate and adjust the belt tension;
7 replace the new bearing;
8 Correct the motor shaft or replace the rotor.

For more information and purchase please visit: https://www.supplyforever.com

Minimum load of angular contact ball bearings

    In order to ensure satisfactory performance, needle roller/angular contact ball bearings, like all ball bearings and roller bearings, must always withstand a certain minimum load acting on the radial and axial directions, especially if they are to be operated at high speed or Subject to rapid acceleration or rapid changes in load direction. Under these conditions, the inertial forces of the rolling elements and the cage and the friction of the lubricant may have a detrimental effect on the rolling condition of the bearing arrangement and may cause destructive sliding between the rolling bodies and the raceways.

The minimum necessary radial load applied to a radial needle bearing can be estimated using the following formula:

Frm = 0.02 C

The minimum necessary axial load for angular contact ball bearings can be calculated using the following formula:

In the middle
Frm = lowest radial load, kilonewton
Fam = lowest axial load, kilonewton
C = basic dynamic load rating (see product table), kilonewton
C0 = basic static load rating (see product table), kilonewton
Dm = average diameter of the bearing
= 0,5 (d + D), mm
n = speed, rev / min

Higher loads are required even at low temperatures or when the viscosity of the lubricant is very high. The weight of the components supported by the bearing plus the external force generally exceeds the necessary minimum load. If this is not the case, additional radial and/or axial loads must be applied to the needle/angular contact ball bearings.

For more information and purchase please visit: https://www.supplyforever.com