9 Common Faults in Large Cone Crushers and Their Solutions

In large-scale mining crushing processes, three-stage closed-circuit crushing is the standard. The closed-circuit crusher is key for achieving "more crushing, less grinding" across coarse, medium, and fine stages. Cone crushers, as high-power, efficient crushing equipment, are the mainstream choice for medium and fine crushing of hard and medium-hard ores and rocks.

This article details common faults in large cone crushers and their solutions.

1. Abnormal Oil Pressure and Temperature

• Clogged Oil Circuit: Causes simultaneous rise in oil pressure and temperature. If the return pipe is blocked, oil may leak from the water seal. Solution: Stop and clean the pipes.

• Faulty Eccentric Sleeve: Oil temperature >55°C without rising pressure. Solution: Stop and check/replace the straight and cone sleeves.

• Clogged Filter: A pressure difference >0.04 MPa across the filter indicates a blockage. Solution: Bypass the filter temporarily (<2-3 hours) and then clean it.

• No Oil Flow: Caused by low oil temperature, closed oil switch, or faulty oil pump, resulting in pressure <0.05 MPa. Solution: Heat the oil, open the switch, service or replace the pump.

• Cone Lifting: Occurs in winter due to low oil temperature, faulty safety valve, or excessive pump pressure. Solution: Heat the oil, adjust the safety valve, or replace the pump.

• High Oil Temperature (>60°C): Caused by bearing/sleeve/gear failure, high ambient temperature, or cooling issues (no water, low pressure, clogged cooler). Solution: Stop the crusher, fix mechanical issues, and restore cooling.

2. High Operating Current

• Cause: Overfeeding, uneven feeding, or too many fines/wet ore.

• Solution: Ensure even, continuous feeding; remove excess fines before crushing; service and lubricate moving parts; check and replace damaged bearings; resurface or replace contact surfaces; add shims if gears rub; replace broken main shaft.

3. Cone Liner Wear and Failure
High speed and immense crushing forces in large cone crushers lead to significant liner wear through cutting, plastic deformation, and fatigue, resulting in deformation and spalling. Liners are the primary wear part.

4. Crusher "Runaway"
This is an abnormal increase in the mantle's rotation speed.

• Consequences: Blockage, overload, severe vibration, current spike, rising oil temperature, and potential for major damage like burnt motor, broken gears/shaft, or cracked frame.

• Causes: Poorly fitted/worn bushings; insufficient running-in & poor lubrication; worn spherical seat or socket liner; tramp iron disrupting balance; worn thrust bearing at the eccentric bottom; insufficient cooling; high oil pressure disrupting balance; poor or contaminated lubricant.

5. Excessive Bevel Gear Wear and Tooth Breakage

• Causes: Inadequate protection devices; tramp metal exceeding max. allowed size; attempting to start a blocked crusher under load; mismatched drive motor.

• Solutions: Use improved materials/hardfacing; install a second magnetic separator on the feed belt; adjust protection relay settings to prevent overload starting; monitor hydraulic oil for metal content; implement strict operating procedures and tramp iron oversight.

6. Frequent Adjustment Ring Jumping

• Cause (During Commissioning): Uneven feed around the crushing chamber, leading to fluctuating current.

• Solutions: Modify feed hopper and distributor for even, "choke-fed" loading; control feed size; prevent non-crushables; lock the adjustment cap; check ring thread clearance and wear before startup; ensure feed chute directs material to the crusher center; replace broken lock bolts and adjust ring gap.

7. Tramp Iron and Instantaneous Stall
Tramp iron (especially manganese steel) causes sudden load spikes, ruptures the oil film (risking bushing burn), and can lead to shaft breakage.

• Solution: The crusher's hydraulic release system should lift and discharge the iron. For added safety, install a reliable metal detector to monitor and prevent stoppages, maximizing uptime.

8. Lubrication Oil Failure

• Causes: Worn dust seals allowing dust into oil; insufficient air seal pressure drawing in dust; failed T.U. labyrinth seal; oil used beyond its 2000-hour service life.

• Consequences: Rapid oil degradation, poor lubrication, gear wear/breakage, runaway, or seized shafts.

• Solutions: Regularly check seals and air pressure; clean the labyrinth seal; change oil strictly per the maintenance schedule.

9. Excessive Crusher Vibration

• Causes: Over/uneven feeding; too small discharge setting; too many fines/sticky material; insufficient spring pressure; incorrect sleeve clearance; lack of lubrication; worn socket liner causing cone settling.

• Solutions: Feed correctly; adjust discharge setting; reduce fines; tighten or replace springs; check/replace sleeves/shaft; ensure proper lubrication; resurface or replace contact surfaces.