Cone crushers are essential crushing equipment in mining production. They are primarily classified into spring cone crushers and hydraulic cone crushers. How do they perform discharge opening adjustment, tramp iron release, and cavity clearing during operation?

Discharge Opening Adjustment

Spring Cone Crusher:
Adjustment is achieved by rotating the adjustment ring. This causes the ring to raise or lower via its threaded connection with the support ring, thereby moving the concave ring (installed inside the adjustment ring) up and down to change the discharge opening size.

Tramp Iron Release & Cavity Clearing

When tramp iron (e.g., a piece of steel) passes through the crushing chamber, the spring compression increases. This reduces the spring pressure on the lodged material in the chamber, allowing it to fall through freely.

If the crusher stalls under load, the crushing chamber must be completely cleared before restarting. Starting the crusher with a full chamber can cause severe damage to both the crusher and the motor.

How to Clear the Cavity:
After connecting the hydraulic power pack to the crusher, start it. When the hydraulic pressure reaches 56 MPa or 63 MPa, the clearing cylinders lift the support sleeve. This reduces spring pressure on the lodged material, allowing it to fall freely. Once the crushing cone is free and the chamber is empty, release the hydraulic pressure to retract the cylinders and lower the support sleeve back onto its frame seat.

Hydraulic Cone Crusher
Hydraulic cone crushers are divided into single-cylinder and multi-cylinder types.

Discharge Opening Adjustment

Single-Cylinder Hydraulic Cone Crusher:
During operation, the discharge opening is adjusted by injecting or draining oil from the main shaft cylinder via a pump, causing the main shaft to move up or down (main shaft floats). This method can make it difficult to securely lock the setting when crushing hard ores.

Multi-Cylinder Hydraulic Cone Crusher:
Adjustment is achieved via a hydraulic pusher or motor, which adjusts the cap, thereby rotating the adjusting ring within the support sleeve (the fixed cone screws up/down). This method allows for easy and secure locking of the discharge opening.

Tramp Iron Release & Cavity Clearing

Single-Cylinder Hydraulic Cone Crusher:
When tramp iron passes through, hydraulic oil flows into an accumulator, causing the main shaft to lower. After the tramp iron passes, the accumulator returns the oil, and the crusher resumes normal operation. The hydraulic pump is also used for cavity clearing.

Multi-Cylinder Hydraulic Cone Crusher:
When non-crushable material enters or the machine overloads, the hydraulic safety system activates, increasing the discharge opening to eject the material. If material gets stuck, the cavity clearing system further enlarges the opening. The system then automatically resets, and the machine returns to normal operation.

While encountering tramp iron is sometimes unavoidable during operation, frequent occurrences can damage the crusher. Therefore, focus on prevention: install metal detectors on the feed conveyor, regularly inspect the wear on chute liners, etc.