How to Lubricate Jaw Crusher Bearings: Expert Guide to Prevent Failure

Why Bearing Lubrication Matters

Jaw crusher bearings operate under extreme loads (up to 200 tons force) and temperatures exceeding 80°C. Inadequate lubrication causes:

• Premature wear (reducing lifespan by 75%)
• Overheating failures (15% of unplanned downtime)
• Increased energy consumption (18-25% higher)

Step-by-Step Lubrication Process

1. Select the Right Lubricant

Condition	Grease Type	Viscosity
Normal	Lithium Complex	NLGI #2
High Temp	Polyurea	NLGI #1.5
Wet Environment	Calcium Sulfonate	NLGI #3

2. Clean Bearing Surfaces

Use solvent flushing to remove old grease (part of routine maintenance):

1. Disengage crusher power
2. Remove grease fittings
3. Flush with kerosene until runoff clears

3. Calculate Grease Quantity

G = 0.114 × D × B
Where:
G = Grams of grease
D = Bearing bore (mm)
B = Bearing width (mm)

Example: 150mm bore × 75mm width = 1,282g

4. Apply Grease Correctly

Proper Injection Method:

1. Use high-pressure grease gun (5,000-7,500 psi)
2. Pump grease slowly until purge port showsfresh grease
3. Rotate eccentric shaft during application for even distribution

Critical Tip: Avoid overgreasing – excess grease increases internal pressure by 30-40%, damaging seals.

5. Verify Lubrication Effectiveness

Test	Acceptable Range	Tool
Temperature	65-75°C	Infrared thermometer
Vibration	＜4 mm/s RMS	Vibration analyzer
Grease Color	No dark streaks	Clean cloth test

6. Document Maintenance Records

Track key parameters using digital maintenance logs:

Date: 2024-03-15 | Bearing: Eccentric
Grease Type: Mobilith SHC 220
Quantity: 1200g
Post-lube Temp: 68°C | Vibration: 3.2 mm/s

7. Implement Condition Monitoring

• Weekly: Check grease consistency withstiffness test
• Monthly: Send grease samples for lab analysis
• Annually: Perform full bearing inspection during shutdowns

Common Lubrication Mistakes

• Overgreasing: Causes seal damage (30% of failures)
• Mixing Greases: Creates incompatible chemical reactions
• Ignoring Temperature: Standard grease fails above 90°C

Advanced Monitoring Techniques

Infrared Thermography

Detect under-lubrication through temperature anomalies duringcrusher operation:

• Normal range: 65-75°C
• Warning threshold: >85°C

Case Study: Solving Premature Bearing Failure

A granite quarry extended bearing life from 6 ile 18 months by:

1. Installing automatic grease metering systems
2. Implementing our 7-step protocol
3. Training staff on proper crusher startup procedures

Essential Tools for Proper Lubrication

• Grease compatibility chart (prevent chemical reactions)
• Digital torque wrench for fitting installation (35-50 N·m)
• Ultrasonic grease thickness gauge

Lubrication as Performance Strategy

Masteringhow to lubricate jaw crusher bearings reduces maintenance costs by 40% and extends component life. Remember: Effective lubrication combines proper crusher operation, quality greases, and data-driven monitoring. Implement these protocols with yourpreventive maintenance program for maximum equipment availability.