A Guide to Emergency Measures to Handle Overheating Bearings

Overheating and the resulting damage are the most common issues during the daily operation of the equipment. When bearing is found to be overheating, many people’s first is to pour the water or blast it with cold air. This often cause a "crack" sound—this is the bearing steel fractures due to thermal stress.

Today, we will analyze the "five main reasons" about the bearing overheating , and provide a guide for rapid on

I. How to Quickly Knows Bearing Overheating On-Site?

During an inspection, just need a simple three-step method—"Look, Listen, Touch"—is sufficient for a preliminary diagnosis:

1. Temperature Check with Hand

Lightly touch the bearing housing with your hand. If it feels too hot to maintain contact for more than 3 seconds, the temperature has exceeded the 70°C warning threshold

2. Grease Inspection:

Check the grease at the inspection port or grease discharge outlet. If the grease has turned black, become runny (liquid-like), or emits a burnt odor, it proves that the high heat generated by internal friction has caused the grease to oxidize and fail completely.

3. Sound Check :

Place a listening rod or a screwdriver against the bearing housing. If you hear a continuous, high-pitched metallic screeching or a dry friction sound, it is a classic sign that the protective oil film between the rolling elements and the raceway has been lost, and adhesive burnout is imminent.

II. The "Five Main Culprits" Behind Bearing Overheating and Burnout

Insufficient lubrication or grease deterioration

Loss of internal clearance due to excessive interference

Excessive preload

Frictional heat from seals

Concentrated loads (uneven loading)

III. Correct methods for addressing bearing overheating

Once confirmed the bearing overheating is confirmed, strictly follow these steps:

1.Stop the machine immediately and allow it to cool naturally! Rapid cooling is strictly prohibited!

2.Cut off the power immediately: This prevents the overheating from worsening, which could lead to bearing seizure, motor burnout, or spindle damage.

3. Do not use water or cold air for rapid cooling:Bearing steel is in an expanded state at high temperatures; rapid cooling generates severe thermal stress, which can directly cause the bearing rings to crack or shatter.

4. Disassemble and inspect after cooling: Systematically check components in the order of "lubrication—clearance—fit—load," replace damaged parts, and readjust tolerances and clearances