Maintaining a jaw crusher is essential for preventing costly downtime and ensuring a long service life. Because these machines handle high-stress materials, wear and mechanical fatigue are inevitable.
Here is a comprehensive guide to the seven most common jaw crusher issues and the practical steps to resolve them.
The Kingshun jaw crusher is known to be very durable in day-to-day operations, but maintenance is crucial in ensuring the machine operates efficiently. But in case you have not yet been acquainted with the main specifications of this series of products, we suggest that you first of all read our Jaw Crusher Guide.1. Crushing Capacity or Throughput reducedWhen the machine is operational, and the volume of output has greatly reduced, it is normally a pointer to a configuration or wear problem.
- The Cause: Sometimes, due to a loose drive belt slipping under load, or the discharge opening (CSS) being too small to achieve the intended flow. The efficiency of the bite may also be decreased by worn jaw plates.
- The Fix: Tighten or change the V-belts to achieve the best power transfer.
- Set the Close Side Setting (CSS) to a range suggested by the manufacturer.
Check jaw plates; if the contour of the teeth is flat, then it is time to turn them over or change them.
2. Overheating Bearings
The core of the jaw crusher is the bearings. When they overheat (usually above 70°C to 80°C), then urgent steps must be taken to avoid a catastrophic seizure.
- The Cause: Too much or too little lubrication, grease contamination, or excessively tightened eccentric shaft.
- The Remedy: Review your lubrication schedule. Only the recommended grade of grease as suggested by the manual should be used.
Before pumping, clean grease nipples to prevent forcing dirt into the housing.
When a grease change is made, and the bearing is still hot, check to see that there is no internal wear or misalignment.
3. Sudden Machine Stoppage (Stalling)
A grind-out-when-loaded crusher is a huge safety issue and a manufacturing murderer.
- The Cause: The most common culprit is a power failure or the V-belt slipping. It may also be the result of an uncrushable item (tramp metal) getting into the chamber or a clogged discharge conveyor, however.
- The Fix: Turn off the crushing chamber, then start it (never start a jaw crusher black).
Check the tension of the V-belts.
Check that the voltage and amperage of the motor are constant.
4. Over-vibrating or Abnormal Noise.
Although jaw crushers are inherently loud, alteration in the rhythm or abrupt shaking is a sign of a loose point in the structure or the machinery.
- The Cause: Slack foundation bolts, a broken toggle plate, or deteriorated tension spring rubbers.
- The Solution: Check with a walk-around and tighten all mounting and foundation bolts.
Check the plate and seats; they should be good and shiny, otherwise they will chatter or clatter.
Make sure that the flywheel is balanced, and the keyway is not playy.
5. Early Wearing of the Jaw Plate
Jaw plates are consumables; however, when you are changing them more frequently than normal, your operating expenses will outweigh.
- The Cause: The wrong tooth profile to the material hardness or wrong installation that leads to bellying. Localized wear at the top is also caused by feeding material that is too large to pass through the intake.
- Fix: Have the plates supported with zinc or special backing compound to avoid movement.
Use a constant feed rate; do not choke feed when the material is too abrasive.
Switching to a higher manganese content (e.g., Mn18Cr2 or Mn22Cr2) to hard rock should be considered.
6. Fractured Toggle Plate
The toggle plate is made in the form of a safety fuse. When it fails, it has probably served its purpose rescuing more costly parts such as the eccentric shaft.
- The Cause: An indestructible object (such as a loader tooth or rebar) made it into the chamber, or CSS was set to an excessive amount.
- The Fix: Fetch out the tramp metal of the chamber.
Install a new toggle plate (do not weld a broken toggle plate).
Ensure the tension rod and spring are set in the proper position to hold the toggle in place.
7. Flywheel "Wobble" or Movement
The kinetic energy required in the crushing stroke is stored in the flywheels. Any instability in this case can break the main shaft.
- The Reason: The flywheel key is loose, or the heavy-duty locking assembly has lost its torque.
- The Fix: Turn the machine off.
Check the shaft and flywheel bore for scoring or damage.
Install the key and locking bolts to the particular Newton-meter (Nm) torque required in your maintenance manual.
How to Choose a Jaw Crusher: Please Click to View the Selection Guide
