Why Does A Crusher Make Abnormal Noise During Operation?

Crushers are heavy-duty machines designed to reduce large rocks,ore,and other materials into smaller,more manageable sizes.During normal operation,they produce a consistent,rhythmic sound characteristic of their mechanical action.However,the emergence of abnormal noises-such as grinding,squealing,banging,scraping,or excessive vibration-is a critical warning sign.These sounds often indicate developing problems that,if unaddressed,can lead to severe equipment damage,unplanned downtime,and costly repairs.Understanding the root causes of these noises is essential for effective maintenance and safe operation.
Common Causes of Abnormal Noise in Crushers:
1.Mechanical Wear and Failure:
◦Worn or Damaged Bearings:Bearings are among the most common culprits.Lack of lubrication,contamination,or normal fatigue can cause bearings to wear out.This results in a high-pitched squealing,grinding,or rumbling noise,often accompanied by overheating.Failed bearings can seize,causing catastrophic damage to the crusher shaft and housing.
◦Loose or Broken Components:Over time,vibration and impact forces can loosen fasteners,bolts,and wear parts.A loose liner,mantle,concave,or jaw plate can create a loud banging or rattling sound with each cycle.Similarly,a cracked frame or a broken rotor hammer will produce violent,irregular impacts and excessive vibration.
◦Improper Gear Mesh or Damaged Gears:In crushers with gear drives,abnormal grinding or whining noises can signal misaligned gears,insufficient lubrication,or worn/broken teeth.This issue can quickly escalate to complete gear failure.
2.Operational and Feed-Related Issues:
◦Tramp Metal or Unbreakable Material:The most dramatic abnormal noise often occurs when uncrushable material like drill bits,bucket teeth,or excavator parts enters the crushing chamber.This causes sudden,loud bangs or grinding noises and can bend shafts,break liners,or cause other instant damage.
◦Overfeeding or Uneven Feeding:Feeding the crusher too quickly or on one side only can cause it to choke.The machine may make a deep,struggling rumbling sound as the chamber becomes packed.This places extreme stress on the drive motor and can lead to overheating and stalling.
◦Incorrect Material Properties:Feeding material that is significantly harder or more abrasive than the crusher is designed for can accelerate wear and produce a different,harsher grinding noise,even under normal feed conditions.
3.Misalignment and Balance Problems:
◦Misaligned Drive Belts or Couplings:A V-belt drive that is misaligned or has worn belts will often produce a high-pitched squeal,especially on startup or under load.Similarly,a misaligned coupling between the motor and crusher can cause vibration and rhythmic knocking sounds.
◦Unbalanced Rotor:In impact crushers or hammer mills,an unbalanced rotor-due to uneven wear of hammers or a buildup of material-causes severe vibration and a rhythmic wobbling or thumping noise.This imbalance stresses bearings and the entire machine structure.
4.Lubrication Issues:
◦Insufficient Lubrication:A lack of grease or oil in bearings or gears creates metal-on-metal contact,leading to intense grinding,squealing,and rapid heat generation.This is a fast track to component failure.
◦Contaminated Lubricant:If lubricant becomes contaminated with dust,water,or metal particles,it loses its protective properties and acts as an abrasive paste,accelerating wear and creating noise.
5.Wear Parts at End of Life:
◦Worn-Out Liners/Mantles/Jaws:As the manganese liners wear thin,the metal backing material(the mantle or jaw itself)can begin to contact the opposing surface(the concave or fixed jaw).This produces a loud,continuous metal-on-metal scraping or grinding noise,indicating immediate replacement is needed to avoid damaging the core crusher body.
Abnormal noise in a crusher is never"just noise."It is a primary symptom of an underlying issue.Common causes range from routine wear(like worn liners)to severe mechanical failures(like broken bearings)and operational errors(like tramp metal).Implementing a proactive maintenance schedule-including regular visual inspections,lubrication,vibration analysis,and timely wear part replacement-is crucial.Most importantly,operators should be trained to recognize these acoustic warnings.When an abnormal sound is detected,the crusher should be stopped,locked out,and inspected immediately.Ignoring these warnings turns a minor,repairable fault into a major breakdown,resulting in significant production losses and repair costs.Prioritizing early investigation and intervention based on these audible clues is key to maximizing crusher reliability,safety,and operational lifespan.