How to maintain a small jaw crusher?

The core of maintenance for a small jaw crusher lies in regular inspection of wearing parts, timely lubrication of key components, prompt cleaning of the equipment, and proper daily protection.Standardized maintenance can extend the service life of the equipment and reduce downtime due to failures.Specific requirements can be classified into: daily maintenance, periodic maintenance, seasonal maintenance, and special maintenance for wearing parts.

I. Daily Maintenance (Performed after each shift / daily operation)

1. Daily maintenance is the foundation for ensuring normal operation of the equipment each day, focusing on lubrication, cleaning, and abnormal noise inspection.

Lubrication Maintenance

• Key lubrication points: Bearing housings at both ends of the eccentric shaft (critical lubrication points for small jaw crushers).
• Operation requirements: Before each shift, use a grease gun to inject lithium-based grease into the grease nipples of the bearing housings. Stop injection when a small amount of grease overflows near the nipples (to avoid waste and contamination caused by over-greasing). Increase injection frequency if the bearing housing seals are defective.
• Note: It is strictly prohibited to use expired or highly contaminated grease, to prevent accelerated bearing wear.

Cleaning Maintenance

1）Promptly clean residual materials in the crushing chamber after operation (a wooden stick can be used for assistance; never reach into the crushing chamber with hands) to prevent material agglomeration and hardening, which affects next startup.

2）Remove dust and oil from the equipment surface, especially rotating parts such as the pulley and flywheel, to prevent dust from entering bearings or reducing belt transmission efficiency.

3）Clean up scattered materials around the base to keep the surrounding area tidy and prevent increased equipment vibration caused by material accumulation.

2. Operation Status Inspection

Pre-start Inspection:Check the belt tension (press the belt by hand; a deflection of 10–15 mm is suitable), whether the safety guard is firmly installed, and if the discharge opening shims are loose.

Monitoring During Operation:Listen for abnormal noises during operation (such as metal knocking or bearing noise). If abnormal noise occurs, stop the machine immediately for inspection, and restart only after troubleshooting.

Post-operation Inspection:Check for loose liner plates, whether the toggle plate connections are secure, and whether the bearing housing temperature is normal (temperature shall not exceed 60 °C after operation).

     II. Periodic Maintenance (By operating hours: weekly / monthly / quarterly)

Periodic maintenance requires in-depth inspection of the equipment to identify potential faults in a timely manner.The specific intervals and requirements are as follows:

Weekly Maintenance

1.Check liner plate fixing bolts

2.Check belt wear

3.Clean bearing housing vents

4.Use a wrench to tighten the fixing bolts and wedges of the stationary jaw and swing jaw liners to prevent loosening.

5.Inspect Vbelts for cracks or aging; replace promptly if severely worn.

6.Clean the vents on the bearing housing to ensure good heat dissipation.

Monthly Maintenance

1.Check bearing clearance

2.Check contact conditions of toggle plate with swing jaw and frame

3.Calibrate discharge opening width

4.Measure bearing clearance with a feeler gauge; replace the bearing if clearance exceeds 0.5 mm.

5.Check that the contact surfaces at both ends of the toggle plate are flat and free of cracks; replace immediately if cracked.

6.Measure the discharge opening width with a caliper and adjust by adding or removing shims according to the required product size.

Quarterly Maintenance

1.Replace bearing grease

2.Inspect frame for cracks

3.Check motor insulation performance

4.Remove the bearing housing end cover, clean out old grease, and fill with new lithiumbased grease (fill to 2/3 of the bearing cavity).

5.Use a magnifying glass to inspect the frame welds or steel castings for cracks; repair by welding and grind smooth if cracks are found.

6.Measure the motor insulation resistance with a megohmmeter. The resistance value shall not be lower than 0.5 MΩ; otherwise, drying treatment is required.

III. Seasonal Maintenance (Summer / Winter)

Seasonal changes affect equipment operation, so targeted maintenance adjustments are required:

Summer Maintenance

Focus: Heat dissipation and high temperature prevention

Measures:Increase lubrication frequency of bearing housings (grease once per shift);Check that the motor cooling fan operates normally and clean dust from the fan cover;Avoid long continuous operation during high-temperature periods (12:00–15:00) to prevent motor overload.

Winter Maintenance

Focus: Anti-freezing and anti-condensation

Measures:Replace with low-temperature lithium-based grease (suitable for temperatures from -20℃ to 60℃);After shutdown, drain any accumulated water from the bearing housings to prevent freezing damage to bearings;Preheat the motor before startup to avoid excessive current during low-temperature starting.

 

     IV. Special Maintenance for Wearing Parts (Liners, Toggle Plates, Belts, etc.)

The wearing parts of a small jaw crusher directly affect crushing efficiency and service life. Their wear conditions must be monitored and replaced in a timely manner.

Jaw Plates (Stationary Jaw / Swing Jaw Liners)

Wear Judgment:Severe wear of the liner tooth profile (tooth height worn by more than 50%), large-area pits or cracks on the surface.

Maintenance Requirements:If the liner wears unevenly between top and bottom, it may be flipped upside down for continued use (supported on some models) to extend service life.When replacing liners, clean dust and debris between the liner and the jaw body to ensure tight fitting.Thread locking adhesive must be applied to fixing bolts to prevent loosening.

Toggle Plates (Thrust Plates)

Wear Judgment:Contact surfaces at both ends worn by more than 2 mm, cracks or fractures present.

Maintenance Requirements:The toggle plate is a safety wearing part. If cracks are found, replace it immediately; continued use is strictly prohibited.When replacing the toggle plate, check the contact area with the swing jaw and frame. If the contact area is less than 70%, grind the contact surfaces.

     V.Belts

Wear Judgment:Cracks, aging, stretching, or slipping during transmission.

Maintenance Requirements:Use Vbelts of the same model as the original when replacing. Multiple belts must be replaced simultaneously to avoid uneven tension caused by length differences.Adjust belt tension to ensure transmission efficiency, while avoiding excessive tightness that increases bearing load.

It is recommended to establish an equipment maintenance log to record the date, items, replaced part models, operators, and other information for each maintenance. This facilitates traceability of equipment status and timely detection of potential problems.