How to Maintain Slewing Bearings for Maximum Lifespan

Time:2025-10-13 05:45:50 Source:LYMC Slewing Bearing

Slewing bearings are key components in heavy machinery, including excavators, cranes, wind turbines, and industrial robots. They endure massive loads in challenging environments, making proper maintenance essential for safety, reliability, and long-term performance.、

Neglecting maintenance often leads to premature failures, costly downtime, and expensive repairs. This guide provides practical steps to keep your slewing bearings running smoothly and extend their service life.

Slewing bearings

How to Maintain a Slewing Bearing for Long Life

1. Core Maintenance Principle: Prevention and Regular Inspection

Slewing bearing failures rarely occur suddenly—they usually result from cumulative damage due to improper operation or lack of maintenance. Key principles include:

Preventive maintenance first: Avoid damage at the source.

Frequent inspection: Detect early signs of wear or abnormality.

Proper operation habits: Smooth operation, avoid overloading, and monitor performance.

2. Daily Operation Tips to Reduce Wear

Smooth operation: Avoid abrupt starts/stops to minimize impact loads.

Avoid overloading: Always operate within rated load capacity to prevent raceway damage and bolt failure.

Keep the platform level: For mobile equipment, operate on stable ground to avoid excessive tilting forces.

Watch for abnormal signs: Stop the machine if you detect unusual noises, sticking, or jumping.

3. Regular Lubrication: The Key to Longevity

Proper lubrication reduces friction, prevents rust, and removes debris.

Lubricant Selection:

Raceways: Use EP (extreme-pressure) lithium grease (e.g., No.2 EP Lithium) or manufacturer-recommended greases.

Ring gears:

Open gears → Open gear grease (adhesive, rain-resistant).

Enclosed gears → Gear oil matching gearbox grade.

Lubrication Schedule:

Initial: After first 100 hours for new/replaced bearings.

General: Every 500 hours or every 2 months.

Harsh conditions: Every 100–250 hours or weekly.

Lubrication Method:

Slowly rotate bearing to top position.

Use high-pressure grease gun until old grease is expelled.

Apply evenly on ring gear teeth.

Slewing bearings

4. Regular Bolt Checks

Check mounting bolts at least every 100 hours or monthly.

Always use a calibrated torque wrench and follow manufacturer’s torque specs.

Replace deformed, cracked, or corroded bolts immediately.

Maintain inspection logs for tracking.

5. Gear Mesh and Backlash Maintenance

Inspect gear teeth for wear, cracks, or pitting.

Adjust backlash per manufacturer instructions to ensure smooth, quiet operation.

Lubricate gear teeth appropriately.

6. Seal Inspection

Check seals regularly for cracks or damage.

Replace any damaged seals immediately to prevent contamination and lubricant leakage.

7. Avoid Overloading and Shock Loads

Always operate within the designed load limits.

Avoid sudden starts, stops, and uneven loading to reduce stress on the bearing.

8. Cleaning and Environmental Care

Regularly remove dust and debris around bearings.

Avoid direct high-pressure water jets on seals to prevent damage.

9. Condition Monitoring

Vibration analysis: Detect early rolling element or raceway damage.

Oil analysis: Monitor wear particles, moisture, and lubricant health.

Temperature monitoring: Identify abnormal heat buildup.

Maintain inspection logs including all observations and corrective actions.

Slewing bearings

Create an inspection log to regularly monitor the condition of the slewing bearing.

Inspection items	Inspection method	Normal phenomenon	Abnormal phenomena and possible causes	Treatment measures
sealing strip	Visual inspection	In good condition, with a small amount of grease seepage	Damaged, falling off, severe grease leakage	Replace the sealing strip immediately and check whether the lubrication is in place
Raceway clearance	Measuring with a dial indicator	The gap value is within the manufacturer's allowable range	Too large a gap	The raceway or rolling element is severely worn and needs to be closely monitored or replaced.
Rotation	Manual slow rotation	Smooth, smooth, no stagnation	There are stuck points, abnormal noises, and jumping sensations	The inner raceways or rolling elements may be dented, chipped, or cracked
Raceway appearance	(During overhaul) Open and inspect	Smooth, rust-free	There are pits (Brinell indentation), peeling, and rust	Poor lubrication or impact, need to evaluate whether to replace
Installation Base	Check the base	Flat, no deformation	There is a gap or deformation on the mounting surface	This will cause uneven stress on the bolts and the foundation must be repaired
ring gear	Visual inspection	The tooth shape is intact and there is oil film	Wear, broken teeth, rust	Check the meshing clearance and lubrication condition, if serious, repair or replace

10. Summary: Maintenance Schedule

For ease of implementation, you can create a simple maintenance schedule:

Daily: Visually inspect seals and bolts before starting the machine, and monitor for unusual noise and vibration during operation.

Weekly/Every 100 hours: Lubricate the raceways and ring gears (under severe operating conditions).

Monthly/Every 500 hours: Perform a comprehensive lubrication and bolt torque check.

Semi-annually/Annually/Every 2000 hours: Perform a comprehensive inspection, including clearance measurement and detailed inspection of the tooth flanks and raceway condition (if applicable).

Finally, always refer to the Operation and Maintenance Manual provided by your equipment manufacturer, as different models and equipment may have specific requirements for slewing bearings.

Conclusion: Invest in Longevity

Regular maintenance not only extends the service life of slewing bearings but also reduces downtime, maintenance costs, and operational risks. Following these guidelines ensures reliable performance and a higher return on investment for heavy equipment.