How to install and maintain a slewing bearing？

In large-scale engineering equipment, automated systems, and heavy machinery, slewing bearings are crucial core components for achieving rotational motion and load-bearing. Whether it's cranes, excavators, wind power equipment, or mining machinery, all rely on stable and reliable slewing rings. However, in practical applications, many equipment failures are not due to bearing quality issues, but rather to improper slewing bearing installation or inadequate slewing bearing maintenance.

Therefore, correct installation methods, standardized maintenance procedures, and timely slewing bearing repair are of great significance for extending equipment lifespan, reducing maintenance costs, and improving equipment operational stability. As a professional slewing bearing manufacturer, LTZC has accumulated extensive experience in slewing bearing installation and maintenance through long-term engineering practice and provides technical guidance and solutions to customers worldwide.

What is a Slewing Bearing?

A slewing bearing is a large bearing structure capable of 360-degree rotation and simultaneously bearing axial loads, radial loads, and overturning moments. It is compact, has a high load-bearing capacity, and is easy to install. Slewing bearings are widely used in various heavy equipment. Its basic structure includes an inner ring, outer ring, rolling elements, cage, seals, and lubrication system.

Applications of Slewing Bearings

Due to their excellent load-bearing capacity and rotational performance, slewing bearings are widely used in the following fields:

Excavators, cranes, and aerial work platforms in construction machinery

Mining equipment such as mining equipment and stacker-reclaimers

Yaw and pitch systems in wind power equipment

Robot arms and precision rotary tables in automation equipment

The Importance of Slewing Bearing Installation and Maintenance

In actual engineering cases, approximately 70% of slewing bearing failures are not due to manufacturing quality issues, but rather caused by the following reasons:

Incorrect slewing bearing installation

Non-standard slewing bearing maintenance

Insufficient lubrication

Insufficient mounting surface precision

Uneven bolt preload

Therefore, proper installation and maintenance can not only extend bearing life but also significantly reduce equipment maintenance costs.

Key advantages include:

Extended bearing life

Proper installation reduces raceway stress concentration, thereby extending bearing life.

Improved equipment operational stability

Reasonable maintenance keeps bearings running smoothly, reducing vibration and noise.

Reduced equipment downtime risk

Regular maintenance and timely slewing bearing repair can prevent sudden equipment failures.

Down load  LTZC slewing bearing installation and maintenance

How to Install a Slewing Bearing?

1. Pre-installation Inspection of the Slewing Bearing

Before installing the slewing bearing, a comprehensive inspection is necessary to ensure the mounting surface is flat, free of burrs and imperfections. An uneven mounting surface will cause uneven stress on the bearing raceway, thus reducing its service life. Also check the bearing's seals for damage and any minor issues such as dents or chips on the gear ring.

2. Positioning the Slewing Bearing

Slewing bearings typically have a soft zone, i.e., a transitional area in raceway hardness. During installation, the soft zone should be placed in non-primary load areas to avoid affecting load-bearing capacity.

3. Bolt Installation

Slewing bearings are usually secured with high-strength bolts. The installation steps include:

Install the bolts diagonally

Pre-tighten gradually in three stages

Use a torque wrench to control the pre-tightening force

This method ensures even bolt stress.

4. Gear Meshing Adjustment

If the slewing bearing has a gear ring, check the gear meshing clearance and tooth surface contact. Insufficient meshing clearance may cause gear wear.

5. Slewing Bearing Lubrication

After installation, the supplier-recommended grease should be injected immediately to reduce friction and appropriately extend bearing life.

How to Maintain and Repair Slewing Bearings？

Regular Lubrication

Lubrication is one of the most important measures for maintaining slewing bearings. Replenish grease every 100-200 hours according to the supplier's recommended grease type, and shorten the lubrication cycle in high-dust environments.The grease should be injected evenly into the raceway.

Regular Bolt Inspection

Slewing bearing bolts may loosen after long-term operation. The equipment should be stopped periodically to check the bolt preload. If the bolts are loose, retighten them to avoid damage to the slewing bearing and safety issues.

Check Bearing Clearance

Increased bearing clearance usually indicates raceway wear. If the clearance exceeds the allowable range, slewing bearing repair or replacement should be considered.

Check Gear Ring Wear

The gear ring is an important transmission component of the slewing bearing. Long-term operation of the slewing bearing can lead to problems such as tooth surface wear, tooth root cracks, and poor gear meshing. If the wear is severe, the slewing bearing should be repaired or replaced promptly.

Bearing Fault Repair

When a slewing bearing malfunctions, it can be repaired through the following methods: raceway repair, replacement of rolling elements, and replacement of seals.

LTZC Installation and Maintenance Technical Guidance for Slewing Bearings

1. The LTZC team provides enhanced technical guidance on slewing bearing installation, ensuring that installation meets equipment requirements.

2. LTZC offers professional bearing maintenance training, including lubrication management and equipment operation checks, helping customers establish a complete maintenance system.

3. Customized solutions: LTZC can customize large direct-slewing bearings and high-precision slewing bearings according to customer's operating conditions.

Contact LTZC for technical guidance