Common Causes and Solutions for Overheating (Burning) in TIMKEN Deep Groove Ball Bearings

In summary, there are three primary causes for the overheating (burning) of TIMKEN deep groove ball bearings: inadequate lubrication, excessive load, and poor precision of the shaft or housing. The following sections provide a detailed explanation of these causes.

Primary Causes of Bearing Overheating:

1. Inadequate Lubrication: This includes the use of incorrect or non-specified lubricants, as well as an incorrect lubricant quantity—whether too much or too little.

2. Excessive Operational Stress: Factors include excessive load on the bearing, excessively high rotational speed, insufficient internal clearance, or the ingress of water and other contaminants.

3. Poor Fitting Conditions: This refers to poor precision of the shaft or bearing housing, or excessive shaft deflection.

These three primary causes can lead to a condition where the bearing's raceways, rolling elements, and cage rapidly overheat during operation, resulting in discoloration, softening, metal smearing (melding), and ultimately failure.

It is recommended that during bearing usage, careful attention is paid to installation, lubrication, and internal clearance to ensure all procedures are performed accurately and thoroughly. This helps prevent overheating and extends the bearing's service life.

Additional Note on Causes of Bearing Noise

The causes of bearing noise are complex. One common cause is wear on the mating surfaces of the bearing's inner or outer rings. Such wear disrupts the proper fit between the bearing and the housing or the bearing and the shaft, causing misalignment and resulting in abnormal noise during high-speed operation. Noise can also occur when surface metal spalls off due to bearing fatigue, increasing radial clearance. Additionally, insufficient lubrication (leading to dry friction) or a fractured bearing will create abnormal sounds. A loose or damaged cage caused by bearing wear can also generate noise.

Solutions for Abnormal Noise and Performance Issues:

1. Bearing Damage: If the bearing is already damaged, it should be replaced immediately.

2. Lubricant Issues: Causes include too little or too much grease, or grease contaminated with impurities (e.g., iron chips). The grease volume should not exceed 70% of the bearing's free space. Contaminated grease must be replaced.

3. Shaft Fit Incorrect: The fit between the shaft and the bearing may be too tight or too loose. If too tight, the shaft should be re-ground. If too loose, the shaft should be sleeved.

4. Housing Fit Incorrect: The fit between the bearing and the end cover/housing may be too tight or too loose. If too tight, the housing bore should be machined. If too loose, a steel sleeve should be installed in the end cover.

5. Improper Assembly: The motor end covers or bearing caps may be improperly assembled. Ensure they are correctly seated and aligned, and tighten the screws securely.

6. External Component Issues: Excessive belt tension or improper coupling alignment. Adjust the belt tension or realign the coupling.

7. Lubricating Oil Issues (For Oil-Lubricated Bearings): Insufficient oil, contaminated oil, or a stuck oil ring. The solution is to add oil, replace with new oil, or repair/replace the oil ring.