How Long Is the Service Life of Slewing Bearings? Key Factors That Determine Durability

Slewing bearings play a crucial role in heavy machinery, construction equipment, wind turbines, material-handling systems, and various industrial applications. As the core rotational support component, their durability directly impacts equipment stability, operating efficiency, and long-term maintenance costs.

Therefore, a primary concern for many companies before purchasing slewing bearings is their service life.

This article will provide a comprehensive analysis of the typical service life of slewing bearings from a professional perspective, highlighting the key factors influencing their lifespan and offering practical maintenance recommendations to help companies effectively extend equipment lifespan.

Typical Service Life of Slewing Bearings

Under standard working conditions and with proper maintenance, a high-quality slewing bearing typically offers a service life ranging from 50,000 to 100,000 hours.

However, actual service life is often shortened by load variations, improper lubrication, installation problems, or harsh operating conditions.

Understanding a bearing's true lifespan helps businesses:

Develop reasonable maintenance and replacement plans

Prevent equipment downtime due to bearing failure

Match more suitable models and structural designs during procurement

Main Factors That Affect Slewing Bearing Life

1. Load Conditions

Load is the primary factor affecting the lifespan of a slewing bearing.

When a bearing is subjected to its rated load, its lifespan is usually maintained within its design range. However, if:

Prolonged overload

Frequent impact loads

Unbalanced load distribution

All of these will accelerate the wear of the raceways and rolling elements, causing fatigue spalling and ultimately leading to premature failure.

Recommendation: Accurately calculate the overturning moment, axial load, and radial load during the selection phase to ensure a sufficient safety factor.

2. Lubrication Quality

Lubrication quality and frequency directly affect the rolling performance of the bearing.

Good lubrication can:

Reduce the coefficient of friction

Reduce metal-to-metal contact and wear

Prevent surface fatigue cracks

Reduce operating temperature

Insufficient lubrication, improper grease, or excessively long lubrication intervals will significantly shorten the lifespan.

Recommendation: Use high-quality lithium-based grease or manufacturer-recommended specialized grease, and top-up regularly.

3. Material Quality and Bearing Design

Long-life slewing bearings typically possess:

High-quality alloy steel material

Precise heat treatment process

Optimized raceway contact angle

High-efficiency sealing structure

Material and structural design determine the bearing's load-bearing capacity, fatigue strength, and corrosion resistance, and are crucial factors affecting its lifespan.

4. Installation Accuracy

Even high-grade bearings can have significantly reduced lifespan if improperly installed and adjusted.

Common installation problems include:

Eccentric installation

Insufficient flange flatness

Incorrect preload setting

Uneven stress on connecting bolts

Installation quality often determines the upper limit of lifespan.

5. Working Environment

Harsh environments accelerate the aging and damage of slewing bearings:

High humidity or salt spray causes corrosion.

Dust entering the raceway causes abrasive wear.

Extreme temperatures cause grease failure.

Chemical media cause seal aging.

For harsh environments, specialized bearings with reinforced seals or surface coatings can be selected.

How to Extend the Service Life of Your Slewing Bearings

To improve equipment reliability and reduce downtime losses, companies can take the following measures:

✔ Scientific Model Selection

Select the appropriate model based on equipment load, rotation speed, installation method, and environmental conditions.

✔ Standardized Installation and Commissioning

Ensure that flange flatness, bolt preload, and bearing clearance all meet standards.

✔ Regular Lubrication and Maintenance

Replenish grease regularly based on actual operating time, and replace with higher quality lubricant when necessary.

✔ Equipment Condition Monitoring

Temperature, vibration, and torque monitoring can detect signs of wear or fatigue in advance.

✔ Enhance Environmental Protection

Add dust covers, anti-corrosion coatings, or sealing structures to bearings to reduce the risk of external influences.

Conclusion

The service life of a slewing bearing is not fixed—it is the result of multiple interacting factors, including load, lubrication, material quality, installation, and environment. Through scientific selection, standardized installation procedures, and regular maintenance, companies can not only significantly extend bearing life but also reduce downtime risks, improve production efficiency, and ultimately achieve a higher long-term return on investment.