Common failure causes of jaw crusher and solutions

Common failure causes of jaw crusher and solutions

1. Abnormal vibration of the machine

Causes

  1. Loose foundation anchor bolts;
  2. Uneven wear or fracture of jaw plates;
  3. Eccentric shaft bearing damage or insufficient lubrication;
  4. Unbalanced flywheel, toggle plate falling off;
  5. Hard non-crushing materials (iron blocks) enter the crushing cavity.

Solutions

  1. Stop the machine and tighten all anchor bolts; check the foundation for settlement;
  2. Replace worn or broken jaw plates, ensure the two jaw plates are installed symmetrically;
  3. Inspect bearings, replace damaged parts, clean and refill qualified lubricating grease;
  4. Reinstall toggle plate and check flywheel weight balance;
  5. Remove foreign metal materials before feeding, install iron remover.

2. The main shaft (eccentric shaft) heats up, bearing temperature over-limit

Causes

  1. Lack of lubricating oil, oil blockage, grease deterioration;
  2. Too much grease added;
  3. Bearing clearance too small, bearing bush burned;
  4. Dust and ore powder enter the bearing chamber and pollute lubrication system.

Solutions

  1. Clean lubrication pipeline, drain old grease, inject new lubricant as required;
  2. Control grease filling volume (1/2 ~ 2/3 of bearing housing space);
  3. Adjust bearing clearance, replace burnt bearing bush or bearing;
  4. Check and replace oil seal, seal cover to prevent dust ingress.

3. Crushing cavity blockage, machine stuck

Causes

  1. Feeding speed is too fast, raw material moisture is high and sticky;
  2. Discharge opening is too small;
  3. Power failure during operation, materials stay in cavity;
  4. Blocky materials get wedged between jaw plates.

Solutions

  1. Stop feeding first, cut off power; clean blocked materials safely (do not clean while running);
  2. Adjust feeding rate, pre-screen wet sticky materials;
  3. Properly increase discharge gap according to finished product requirements;
  4. Install overload protection device; restart only after cavity is fully cleared.

4. Finished product size becomes coarse and unstable

Causes

  1. Jaw plates severely worn;
  2. Toggle plate wear or toggle plate seat loose;
  3. Discharge opening adjustment mechanism slips;
  4. Raw material hardness and particle size exceed design range.

Solutions

  1. Flip or replace jaw plates;
  2. Check toggle plate and bracket, fasten loose parts;
  3. Re-lock the discharge opening adjusting gasket;
  4. Control feed size, forbid oversized rock entering the crusher.

5. Flywheel rotates but jaw stops swinging

Causes

  1. Toggle plate broken;
  2. Toggle plate pin falls off;
  3. Severe material jamming locks the movable jaw.

Solutions

  1. Shut down power, replace new toggle plate; check toggle plate seat groove;
  2. Reinstall and fix toggle pin;
  3. Clear the stuck materials in crushing cavity.

6. Oil leakage from lubrication parts

Causes

  1. Oil seal aging, damaged;
  2. Fastening screws of bearing cover loose;
  3. Excessive grease filling leads to internal pressure too high.

Solutions

  1. Replace oil seal;
  2. Tighten end cover bolts evenly;
  3. Discharge redundant grease.

7. Unusual impact sound inside crushing chamber

Causes

  1. Jaw plate fixing bolt loose, jaw plate beating;
  2. Metal foreign matter mixed in ore;
  3. Toggle plate collides with bracket.

Solutions

  1. Tighten jaw plate fixing bolts, add anti-loosening measures;
  2. Stop feeding and take out metal impurities;
  3. Check toggle plate installation dimension, adjust gap.

8. Low production capacity

Causes

  1. Feed material not evenly distributed;
  2. Discharge opening blocked by fine powder;
  3. Jaw plate tooth profile worn flat;
  4. Motor power insufficient or belt slipping.

Solutions

  1. Equip uniform feeding device;
  2. Regularly clean the discharge port;
  3. Turn over or change jaw plates;
  4. Adjust belt tension, check motor and voltage.