Jaw crusher, 16 types of common problems causes and solutions

1. Jaw crusher suddenly stop

A. Causes
1. blockage of the discharge port, resulting in silo blockage.
2. The triangular belts are too loose, cause slippery of belts and the flywheels.
3. Loose eccentric shaft tightening bushing, causing no clearance on both sides of the frame bearing seat, making the eccentric shaft stuck and unable to rotate.
4. The voltage of the working site is too low, and the jaw crusher is powerless to crush when encountering large materials.
5. The bearing is damaged.

B. Solutions
1. Clear the blockage at the discharge port to ensure smooth discharge.
2. Tighten or replace the triangle belts.
3. Reinstall or replace the tightening bushing.
4. Adjust the voltage of the work site, so that it meets the requirements of the jaw crusher working voltage.
5. Replace the bearing.

2. The main machine groove wheel and moving jaw run normally, but the crushing work stops

A. Causes
1. Breakage of tensioning spring.
2. Broken tie rod.
3. The toggle plate falls off or breaks.

B. Solutions
1. Replace the tensioning spring.
2. Replace the tie rod.
3. Reinstall or replace the toggle plate.

3. The process capacity does not reach the standard

A. Causes
1. The hardness or toughness of the crushed material exceeds the range specified in the instruction manual.
2. The wiring of the motor power supply is reversed, so that the main machine is driven in reverse (the moving jaw rotates clockwise), or the motor power triangle connection is mistakenly connected to the star connection.
3. The size of the discharge opening is less than the specified limit.
4. Jaw plate displacement, the moving jaw and fixed jaw tooth top relative to the tooth top.
5. The voltage at the work site is too low.
6. The gap between the movable jaw and the bearing mating place is too large after wear, which makes the outer ring of the bearing rotate.

B. Solutions
1. Replace the jaw crusher.
2. Switching the wiring of the motor.
3. Adjust the discharge opening to the size specified in the manual, or add a crusher for fine crushing.
4. Check the tooth pitch size of the tooth plate, if it does not meet the standard, the jaw plate must be replaced; adjust the relative position of the fixed jaw plate and the movable jaw plate, and fix the pressure after the top of the tooth is facing the tooth root to prevent displacement.
5. Increase the voltage at the work site to adapt to the heavy load requirements of the jaw crusher.
6. Replace the bearings and the movable jaw.

4. Moving and fixed jaws work with jumping or crashing sound

A. Causes
1. The fastening bolts of the jaw plates are loose or fallen off.
2. The discharge opening is too small, and the two jaws hit each other at the bottom.

B. Solutions
1. Fasten or replace the bolts.
2. Adjust the discharge opening to ensure the correct gap between the two jaws.

5. Bending or breaking of eccentric shaft

A. Causes
1. The jaw crusher slips to one side during lifting, so that the eccentric shaft is bent by the force on one side.
2. The hardness of the crushed material exceeds that specified in the product instruction manual.
3. Long-term overload operation of the jaw crusher.
4. The toggle plate does not meet the standard, it should play the role of self-breaking protection when the non-crushing material enters the crushing chamber.
5. Improper thermal treatment of the eccentric shaft leads to stress concentration, resulting in short-term fracture.

B. Solutions
1. Replace the eccentric shaft with a new one and lift the main machine correctly.
2. Select the appropriate crusher according to the compressive strength of the crushing material.
3. Adjust the operating load or switch to a suitable crusher.
4. Using toggle plates and toggle plate pads that meet design standards.
5. Replace the eccentric shaft with a properly heat-treated one.
jaw crusher

6. Moving jaw fracture

A. Causes
1. Serious defects such as dense type air holes left in the movable jaw during casting.
2. Use of unqualified toggle plate and toggle plate pad, the toggle plate does not break to protect during strong impact of unbreakable materials.
3. Displacement of the movable jaw within the frame, with the bottom of one end colliding with the guard plate on the side of the frame.
4. Tie rod spring fails to be replaced in time after failure.
5. The size of the discharge opening is less than the specified limit.
6. The feeding material is not in the right position, biased to one end or the angle of the lower hopper is too steep, so that the material directly hits the head of the moving jaw.

B. Solutions
1. Replace the moving jaw.
2. Replace the original toggle plate and toggle plate pad produced by the manufacturer.
3. Correctly assemble the eccentric shaft, bearings, tightening bushings and moving jaw, and replace the damaged parts.
4. Replace the tie rod spring.
5. Adjust the size of the discharge opening as required.
6. Increase the feeding hopper to ensure that the material is discharged evenly, smoothly and divided from the middle to both sides.

7. Jaw crusher frame bearing or moving jaw inside bearing’s temperature rise is too high

A. Causes
Lack of grease, or too much grease in the bearings.
Lubricant hole blockage, grease can not be added.
3. Flying groove wheel counterweight block position runaway, frame jumping.
4. Tightening bushing axial runout.
5. Bearing wear or frame damage, etc..
6. The moving jaw sealing sleeve and the end cover have friction heating, or frame bearing embedded cover and main shaft rotates together create friction heating.

B. Solutions
1. Add grease on time and in quantity according to Deya Machinery’s operation manuals.
2. Clean the blockage on the lubricant hole and oil groove.
3. Adjust the position of the counterweight block of the flying groove wheel.
4. Tighten the fastening bushings.
5. Replacement of bearings.
6. Replace the end cover and sealing sleeve, or loosen the upper bearing cover of the fevered end of the frame bearing seat, and then press into the frame bearing seat with the fuse as a gasket and embedded cover, and then fix the upper bearing cover to eliminate the rotation of the embedded cover.

8. The flying groove wheel swings axially from side to side

A. Causes
1. Wear of the flying groove wheel hole, wear of eccentric shaft or flat key, causing loosening of the assembly.
2. Stone rolled into the inner side of the fly groove wheel, causing the fly groove wheel shell cracking.
3. Flying groove wheel has casting defects.
4. Loose expansion sleeve of flying groove wheel.

B. Solutions
1. Replace the flat key if it is worn out, or replace the eccentric shaft and flying groove wheel.
2. Add the safety guard of flying groove wheel, replace the eccentric shaft or flying groove wheel if it is broken.
3. Replace the flying groove wheel.
4. Re-tighten the expansion sleeve.

9. The jaw crusher frame back has knocking sound

A. Causes
1. The tie rod is not tightened, so the toggle plate hit the toggle plate pad of the moving jaw and adjusting seat.
2. Friction between the tie rod and the lower hook of the moving jaw.
3. The spring and the spring seat hit each other.
4. The jaw plate fasteners are slack and the moving jaw plate hits the stationary one.
5. The jaw plates or other parts are broken.

B. Solutions
1. Tighten the tie rods.
2. Check whether the spring fails, if it fails, replace the spring and tighten the tie rod, or retighten the spring.
3. Install the spring seat in place and tighten the tie rod nut to the appropriate position.
4. Check the fastening of the jaw plates and the clearance between the moving jaw plate and the stationary jaw plate.
5. Replace the broken parts.

10. Jaw crusher main frame has serious jumping

A. Causes
1. Loose or broken foundation bolts.
2. Offset position of counterweight block of flying groove wheel.
3. The jaw crusher main frame foundation is not stable, no vibration damping measures.

B. Solutions
1. Tighten the foundation bolts, or replace the broken bolts.
2. Remove the cover plate of the shaft end of the flying groove wheel, loosen the expanding bolt of the flying groove wheel, adjust the position of the counterweight of the flying groove wheel, and then tighten the expanding bolt.
3. Strengthen the foundation, add pillow or rubber between the jaw crusher and foundation, etc.
jaw crusher

11. Crushing jaw plate shaking, metal impact sound

A. Causes
1. Jaw plate fixing bolts are loosen.
2. The jaw plate liner falls off.
3. Fixed wedge iron is not tight.

B. Solutions
1. Stop the operation, check the fixing screws and tighten them.
2. Overhaul the liner, if it comes off, it should be re-lined.
3. Squeeze the wedge iron tightly.

12. Toggle plate support produces impact sound

A. Causes
1. Insufficient spring tension or broken spring and worn support pad.
2. Fastening bolt cap is not locked.

B. Solutions
1. Adjust the spring tension, replace the spring and support pad.
2. Tighten the nut, adjust the right degree of tightness.

13. Discharged size increases

A. Cause
The lower part of the tooth plate is significantly worn.

B. Solution
Turn the tooth plate 180° or adjust the size of the discharge opening.

14. Flywheel rotates, crusher stops working, toggle plate falls off

A. Cause
Spring is damaged, tie rod is damaged or tie rod nut is off.

B. Solution
Check the damaged parts and replace them, install the toggle plate.

15. Flywheel obviously swing, eccentric shaft rotation gradually slow

A. Cause
The key of pulley and flywheel is slack or damaged.

B. Solution
Stop the operation, repair the keyway and replace the key.
jaw crusher

16. Crushing chamber blockage, the main motor current is higher than the normal operating current

A. Causes
1. Large stones enter the crushing chamber but cannot be crushed, thus causing blockage.
2. The belt conveyor machine below the crusher malfunctioned and the discharge opening was blocked.
3. Entry of sticky materials and other debris blocking the discharge opening.
4. The feeding volume is too large.

B. Solutions
1. Stop the machine, clean and discharge large pieces of material from the crusher.
2. Stop feeding and troubleshoot the belt conveyor machine.
3. Stop feeding and unclog the discharge opening.
4. Slow down the feeding speed and reduce the feeding volume.

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