Sliding bearings are essential components in many machines. They allow shafts to rotate smoothly while handling heavy loads. Repairing sliding bearings correctly is crucial for keeping machines safe, efficient, and long-lasting.

Sliding bearings work under sliding friction, providing smooth, reliable, and quiet operation. They are mainly used in low-speed, heavy-load applications or in parts where maintenance and lubrication are difficult.

In this article, I will cover types of sliding bearings, their repair methods, practical tips, and how to choose the right repair technique. All instructions are fact-based and easy to follow.

What Are Sliding Bearings?

A sliding bearing is a bearing where the shaft slides against the bearing surface rather than rolling. They are used in:

• Low-speed and heavy-load machinery

• Industrial equipment with minimal maintenance

• Machines where lubrication is hard to maintain

Sliding bearings are preferred for their low noise, smooth operation, and reliability.

Types of Sliding Bearings

Sliding bearings are mainly divided into two categories:

Integral Bearings

• One solid piece of bearing material

• Usually used in heavy-duty shafts

• Repair options include bushing replacement, machining, or plastic deformation

Split Bearings

• Made in two halves (upper and lower)

• Easier to repair and maintain

• Common in large machinery where disassembly is required

Common Sliding Bearing Repair Methods

Repairing a sliding bearing depends on its type, wear, and damage level. Below is a detailed breakdown including all your original technical steps.

1. Integral Bearing Repair

Bearing Hole Worn

• Repair by replacing the bearing and machining the hole via boring, reaming, or scraping

• Can also use plastic deformation by shortening bearing length and reducing inner diameter

Inner Hole Without Bearing Bush Worn

• Repair by bushing method: enlarge the bearing hole, press in processed bushing, and trim to match the journal

2. Split Bearing Repair

Split bearings are more common in heavy machinery. Repair methods include:

Bushing Replacement

Replacement is needed when:

• Severe burnout or wear

• Bearing alloy thinned to limit size

• Bearing bush cracked or broken

• Radial clearance too large

Scraping and Grinding Damage

• Scratches or glued/burnt tiles during operation must be corrected

• Adjusting radial clearance reduces oil leakage, vibration, and wear

Repair Welding / Surfacing Welding

Used when bearings are worn, scratched, or broken:

1. Clean the part using a flat chisel, scraper, or similar tools

2. Use an electrode matching bearing material

3. Apply gas welding in layers (2–3mm per layer)

4. For large areas, immerse the bearing in water for cooling or allow intermittent cooling

5. Reprocess welded areas: manual trimming or machining

Recasting Bearing Bush

For severe wear:

• Prepare tools, materials, and fixtures

• Remove old alloy using a blowtorch or melting

• Clean and preheat the bearing surface

• Pour molten bearing alloy carefully (tin-based: 400–450°C, lead-based: 460–510°C)

• Cool slowly and inspect quality for defects

Plastic Deformation

Used for bronze bushings or minor wear:

• Upsetting: Compress upper mold to reduce inner diameter

• Compression: Reduce inner and outer diameters using a mold, then restore with metal spraying

• Correction: Press half-bearing bushes into oval, cut joint surfaces, and adjust dimensions

Key Performance Factors in Bearing Repair

1. Retaining proper radial clearance to avoid vibration and oil leakage

2. Maintaining contact angle and oil wedge for smooth lubrication

3. Cleaning and degreasing bearing surfaces before welding or recasting

4. Controlling pouring and welding temperature to avoid defects

5. Using correct materials to match bearing alloy grade

Choosing the Right Repair Method

Factors to consider:

• Bearing type (integral or split)

• Extent of wear or damage

• Operating conditions

• Cost and time for repair

Tip: Regular inspection prevents severe wear and extends bearing life.

Maintenance Tips to Prevent Bearing Wear

• Regular lubrication using the correct oil or grease

• Monitor radial clearance to prevent vibration

• Avoid overheating which accelerates wear

• Keep bearing and surrounding area clean from dust and debris

Conclusion

Sliding bearing repair requires technical skill, careful inspection, and correct method selection. By following proper techniques like bushing replacement, repair welding, recasting, or plastic deformation, you can ensure bearings operate smoothly and reliably.

With regular maintenance and attention to wear, sliding bearings can last longer, reduce machine downtime, and maintain performance.

For high-quality bearing alloys, repair tools, and professional support, contact a trusted supplier for reliable industrial bearing solutions.

FAQ: Sliding Bearing Repairs

Q1: How do I know if a sliding bearing can be repaired?
A: Minor wear can be repaired; severe burnout, cracks, or large wear may need recasting.

Q2: What tools are needed?
A: Scrapers, chisels, press tools, welding equipment, measuring tools, and preheating tools for recasting.

Q3: How long does a repaired bearing last?
A: Depends on repair quality, lubrication, and operation. Proper maintenance extends life.

Q4: Can plastic deformation replace welding or recasting?
A: Only for minor wear; severe damage requires welding or recasting.