Why are your bearings heating up?

Update time : 2025-10-11 16:40:00

Why are your bearings heating up? Learn how to cool your bearings!

Many customers have complained about bearings they purchased at high prices, but after a while, they became extremely hot and were afraid to continue operating.

First, we need to understand the principles of bearing heating. Simply put, the root cause of bearing heating is friction. When the frictional heat generated by a bearing during operation exceeds the heat it can dissipate, the temperature continues to rise.
The specific causes of bearing heating can be categorized as normal heating and fault heating.

-Normal heating:

Any bearing will heat up during operation. This is normal. Within a reasonable temperature rise range (usually 30-40 degrees Celsius above ambient temperature), this is acceptable.

-Abnormal heating:

An abnormally high bearing temperature indicates a malfunction or problem. Specific causes include:
1)Lubricant problems, insufficient or excessive lubricant, mismatched lubricants, or even lubricant deterioration or contamination.

2)Improper installation and fit, overtightening or undertightening, or overtightening or undertightening can all lead to...

3)Excessive load or high speed can also cause abnormal bearing heating.

4)Another issue is improper bearing clearance selection. Too little bearing clearance can lead to "negative clearance" due to thermal expansion and contraction, causing friction and increased heat generation.

Bearing heating creates a dangerous vicious cycle that accelerates, ultimately leading to bearing seizure, burnout, and even mechanical equipment failure. We must pay close attention to this, and regular inspection and maintenance are essential.

Develop good habits: regularly check lubrication; listen for sounds and vibrations; review the installation process; inspect operating conditions; and check seals and cooling systems.

In short, bearing heating is a significant fault signal, requiring prompt investigation and resolution to prevent minor issues from developing into major failures.

So, how often should we inspect our bearings?

The inspection interval for bearings depends on many factors; there's no one-size-fits-all standard.

Application	Inspection Interval (Approx.)	Inspection Items	Description
General Machinery	Every 3–6 months	Visual inspection, noise & vibration monitoring, temperature check, lubrication condition, clearance check.	Common equipment like motors, pumps, and fans. The interval can be extended depending on the actual operating conditions.
High-Speed Equipment	Every 1–3 months	Visual inspection, noise & vibration monitoring, temperature check, lubrication condition, clearance check.	Equipment with high speeds like spindle motors or electric tools, requiring more frequent checks due to higher heat and wear.
Heavy Load or Impact Equipment	Every month or more frequently	Visual inspection, noise & vibration monitoring, temperature check, lubrication condition, clearance check.	Equipment under heavy loads or impact, such as mining machines or presses, needs more frequent monitoring.
Continuous Operation Equipment	Every 1–2 months	Visual inspection, noise & vibration monitoring, temperature check, lubrication condition, clearance check.	Equipment running continuously like production line motors, needs regular checks, possibly during downtime.
Harsh Environment Equipment	Every month or weekly	Visual inspection, noise & vibration monitoring, temperature check, lubrication condition, clearance check.	Equipment operating in harsh environments (dust, humidity, corrosion) requires much more frequent inspection to avoid damage.

Prev : Bearings:The silent force that moves the world

Next : Abnormal temperature rise and vibration noise: Interpreting early warning signals of bearing housing failure!