I. Misalignment to the same side under both no-load and heavy-load conditions → Tension or installation problem
Characteristics: The belt always deviates to one side regardless of whether it is loaded or not.
Main causes:
Uneven tension: Improper adjustment of the tensioning devices on both sides of the conveyor belt leads to an imbalance of force. Follow the principle of "tightening the belt before loosening it."
Improper roller installation: The drive or redirecting roller axis is not perpendicular to the conveyor centerline, causing continuous unidirectional deviation.
Idler roller axis misalignment: When the installation error exceeds 3mm/m, uneven friction distribution causes misalignment.
✅ Key points for diagnosis: Check whether the tensioning mechanism is synchronized. Use a laser alignment instrument to check the parallelism of the rollers.
II. Misalignment only under heavy load, normal under no-load conditions → Material distribution or structural load-bearing problem
Characteristics: Misalignment begins after loading material and returns to normal after unloading.
Main Causes:
Feeding Eccentricity: The material drop point is not at the center of the belt, causing the material's weight to cause "running to the larger side" phenomenon.
Guide Chute Misalignment: Uneven gaps between the baffle plates generate periodic lateral impact forces.
Insufficient Frame Rigidity: Elastic deformation occurs under load, disrupting the original alignment.
✅ Key Judgment Points: Observe whether the material drop point is centered and check the alignment of the guide chute installation position with the belt.
III. Unpredictable Deviation Direction, Sometimes Left, Sometimes Right → Belt Slack or Component Abnormality
Characteristics: No fixed deviation direction; swaying left and right during operation.
Main Causes:
Conveyor Belt Slack: Insufficient tension or aging and elongation leads to serpentine movement.
Improper Joint or S-Shaped Deformation: The straightness deviation of the vulcanized joint center exceeds the belt width by 5%, causing traction direction drift.
Idler Roller Jam or Sluggish Rotation: Increased resistance on one side disrupts the operating balance.
✅ Key points for diagnosis: Check belt tension, observe whether the joint is straight, and test the flexibility of the idler roller rotation.
IV. Concentrated belt misalignment at the roller → Abnormal roller condition
Characteristics: The belt deviates significantly near the drive/redirecting roller.
Main causes:
Material adhering to the roller surface: Coal powder and slag adhere, forming localized protrusions, increasing the diameter and attracting the belt, following the principle of "running higher, not lower";
Uneven wear of the roller's rubber coating: Differences in friction coefficients cause uneven stress;
Bearing movement or excessive axial clearance: Causes roller wobbling, disrupting the running trajectory.
✅ Key points for diagnosis: Stop the machine, clean the roller surface, and check the integrity of the rubber coating and the condition of the bearings.
V. Fixed belt misalignment in a specific section → Local structural or component problem
Characteristics: Misalignment only occurs in a certain section, other areas are normal.
Main causes:
Idler bracket deformation or installation misalignment: This section of the idler assembly is not aligned;
Local damage to the conveyor belt: Edge tears, indentations, or aging leading to uneven stress;
Scrubber failure: Material accumulation on the return belt surface affects the operation of the lower idler.
✅ Key points for judgment: Check the alignment of the idlers section by section and observe whether there are local defects in the belt.
