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Views: 0 Author: Site Editor Publish Time: 2026-06-10 Origin: Site
Jaw crushers are vital in mining and construction. But what happens when they break down? Jaw Crusher Problems can halt operations and increase costs. Understanding these issues is crucial for smooth performance. In this post, you’ll learn about common jaw crusher problems and how to fix them effectively.
Jaw crushers face several common issues that can affect their performance and lifespan. Understanding these causes helps prevent breakdowns and keep operations smooth.
Jaw crushers crush ores and rocks of medium hardness or less. When harder materials enter the crusher, they accelerate wear on components, especially jaw plates. Harder materials cause faster abrasion, leading to increased maintenance frequency and higher replacement costs. For example, manganese steel jaw plates wear out faster if crushing very hard rock. Selecting jaw plates with proper hardness and alloy content helps resist wear.
Feeding the crusher incorrectly causes many problems. Overfeeding or feeding oversized materials can block the feed opening, stopping the crushing process. Uneven feeding leads to inconsistent crushing and uneven wear on jaw plates. For instance, dumping large boulders directly into the crusher can jam the feed opening. Using vibrating feeders or pre-screening oversized materials prevents blockages and ensures smooth feed flow.
Jaw crushers have many moving parts that experience mechanical fatigue over time. Bearings, toggle plates, and shafts wear from constant stress and vibration. Loose bolts or worn springs cause abnormal noise and vibration, signaling component fatigue. For example, a fractured toggle plate often results from continuous overload or impact with uncrushable objects. Regular inspection and timely replacement of worn parts reduce mechanical failures.
Operating jaw crushers beyond their design limits causes damage. Feeding materials too large or too hard, running the crusher at excessive power, or ignoring manufacturer guidelines leads to fractures in plates, shafts, or frames. For example, exceeding the rated power capacity can break the elbow plate. Operators must follow recommended feed sizes, power settings, and maintenance schedules to avoid costly breakdowns.
Tip: Always match jaw crusher feed size and material hardness to manufacturer specifications to minimize wear and prevent blockages.
One common problem in jaw crushers is an increase in the final product size. This usually happens because the jaw plates wear down over time. The lower jaw plate tends to wear about three times faster than the upper one. As these plates wear, the discharge opening—the gap where crushed material exits—becomes larger. This means bigger pieces pass through, increasing the product size beyond desired specifications.
Detecting wear early is key to maintaining product size quality. You can check the jaw plates visually for signs of thinning or uneven surfaces. The lower jaw plate often shows more wear, especially at the bottom, where the crushing force is greatest. Another way is to measure the thickness of the jaw plates and compare it to the original specifications. If wear exceeds about 30% of the original thickness, it’s time to take action.
To fix increased product size caused by jaw plate wear, there are several options:
Rotating Jaw Plates: If the plates are symmetrical, you can rotate them 180 degrees. This uses the less worn side and extends the life of the plates.
Adjusting the Discharge Opening: Sometimes, adjusting the discharge opening size helps reduce product size. This can be done by moving wedge stones or adjusting bolts to narrow the gap.
Replacing Jaw Plates: When wear is severe (over 30%), replacing the jaw plates is necessary. Install new plates that meet the manufacturer's specifications for material and size. This restores the crusher’s ability to produce the intended product size.
Regular monitoring and timely maintenance of jaw plates prevent oversized final products, keeping crushing operations efficient.
Tip: Routinely measure jaw plate thickness and rotate or replace plates before wear causes significant product size increase.
Feed opening blockage is a common issue in jaw crushers that can halt operations and reduce efficiency. Understanding the causes and how to prevent blockages is key to maintaining smooth crushing processes.
Blockage often happens when too much material is fed into the crusher at once. Overfeeding leads to material piling up and jamming the feed opening. Another cause is oversized materials that are larger than the crusher’s designed feed size. These materials cannot pass through the opening and cause a blockage. For example, dumping large boulders or uncrushed rocks directly into the crusher can easily jam the feed.Uneven or inconsistent feeding also contributes to blockages. When material supply fluctuates, the crusher may receive sudden surges of material, increasing the risk of blockage. Feeding techniques that do not match the crusher’s capacity or design specifications often cause this problem.
Uneven feeding causes the crusher to work irregularly. This results in fluctuating load on the jaw plates and other components, leading to increased wear and tear. It also reduces crushing efficiency and throughput, as the crusher may stop frequently to clear blockages.Moreover, uneven supply can create unbalanced crushing forces, which may cause mechanical damage over time. For example, the eccentric shaft and bearings may experience excessive stress, shortening their service life.
To avoid feed opening blockage, controlling the feed rate is essential. Feeding a consistent, moderate amount of material prevents overloading the crusher. Operators should monitor feed rates closely and avoid dumping large quantities at once.Installing vibrating feeders before the jaw crusher helps maintain uniform material flow. Vibrating feeders evenly distribute material into the crusher, preventing sudden surges and ensuring steady feeding. This reduces the risk of blockage and improves overall crusher performance.
Pre-crushing large or hard materials before feeding them into the jaw crusher is an effective way to prevent blockages. Using secondary crushers or hammer mills can reduce oversized rocks to manageable sizes.Screening materials before feeding also helps remove oversized pieces. Vibrating screens or grizzlies separate large rocks, allowing only properly sized material into the crusher. This protects the jaw crusher from damage and keeps the feed opening clear.
Tip: Use vibrating feeders and pre-screen oversized materials to maintain a steady, controlled feed rate and prevent feed opening blockages in jaw crushers.
Vibration or unusual noise in a jaw crusher often signals mechanical or structural problems. Common causes include loose bolts, worn liners, or damaged gears. Loose crushing chamber liners or fixing bolts create rattling sounds. If you hear clattering or banging, stop the machine immediately to inspect.Fixes involve:
Tightening all loose bolts and nuts.
Replacing fractured or worn bolts with high-strength ones.
Checking liners for proper fit and wear; replace if necessary.
Inspecting gears and shafts for damage.
Ignoring these signs can lead to bigger failures, so early action is crucial.
Jaw plates are critical wear parts. Loose or damaged plates reduce crushing efficiency and can cause further damage. Signs include:
Visible gaps between plates and crusher frame.
Movement or rattling of plates during operation.
Cracks or severe wear on plate surfaces.
Maintenance tips:
Regularly check and tighten jaw plate fixing bolts.
Inspect plates for wear and cracks.
Replace plates once wear exceeds 30% of original thickness.
Use plates matching manufacturer specifications for size and material.
Proper maintenance keeps plates secure and extends crusher life.
The elbow plate absorbs impact forces but can fracture from:
Overloading or exceeding rated power.
Crushing materials harder than design limits.
Manufacturing defects or poor welding.
Long-term wear reducing strength.
To prevent fractures:
Operate within crusher power limits.
Choose crusher models suitable for material hardness.
Pre-treat very hard materials to reduce impact.
Conduct regular inspections and timely replacements.
Avoiding overload and using quality parts reduces elbow plate damage.
The toggle plate acts as a safety fuse, protecting the crusher from severe damage. Fractures occur when:
Uncrushable objects enter the crushing chamber.
Excessive force or improper settings stress the plate.
When the toggle plate breaks, it prevents damage to expensive components like the eccentric shaft.Maintenance points:
Inspect toggle plates regularly.
Replace fractured plates immediately.
Avoid welding broken toggle plates; always use new parts.
Ensure proper tension of tension rods and springs to hold the toggle in place.
This safety feature helps avoid costly repairs.
Flywheels store energy for crushing strokes. Wobble or axial movement indicates problems such as:
Loose or worn flywheel key.
Loose locking assemblies.
Damage or scoring on shaft or flywheel bore.
To fix:
Shut down the crusher before inspection.
Check flywheel key and replace if worn.
Tighten locking bolts to manufacturer torque specs.
Inspect shaft and flywheel bore; repair or replace damaged parts.
Correcting flywheel issues prevents shaft breakage and ensures smooth operation.
Tip: Regularly inspect and tighten all bolts and components, replace worn parts promptly, and operate crushers within design limits to prevent mechanical and structural failures.
Bearings in jaw crushers support heavy loads and high-speed rotation. Overheating often signals lubrication problems or mechanical faults. Typical causes include:
Insufficient lubrication causing metal-to-metal contact.
Contaminated or degraded lubricant losing its protective properties.
Excessive tightness in bearing assembly restricting movement.
Over-tight or loose drive belts affecting load distribution.
Misalignment or wear inside the bearing itself.
Bearings usually operate safely below 70°C (158°F). Temperatures exceeding this indicate trouble. If the bearing temperature rises above 80°C (176°F), immediate action is necessary to prevent failure.
Proper lubrication extends bearing life and prevents overheating. Follow these best practices:
Use the lubricant grade recommended by the manufacturer, typically Grade 45 anti-wear hydraulic oil or approved grease.
Maintain lubricant levels between two-thirds and full in oil-lubricated bearings.
Replace lubricant regularly to avoid contamination buildup. Darkened or dirty oil must be changed.
Clean grease nipples before applying new grease to avoid dirt entry.
Avoid mixing different lubricant types, which can reduce effectiveness.
Monitor lubrication schedules closely and adjust based on operating conditions.
Correct assembly and tension prevent undue stress on bearings:
Ensure bearing clearance is within manufacturer specifications. Over-tightening causes friction; too loose leads to misalignment.
Adjust drive belt tension to avoid slipping or excessive load. Loose belts slip, causing uneven power transmission; tight belts increase bearing load and heat.
Regularly inspect belts for wear and replace as needed.
Use proper tools and torque settings during assembly to maintain correct bearing positioning.
Bearing failure leads to costly downtime and damage:
Overheated bearings can seize, halting crusher operation.
Damaged bearings may cause shaft misalignment, increasing wear on other components.
Failure can result in costly repairs or replacement of the entire crusher shaft or housing.
Preventive maintenance includes:
Regular temperature monitoring during operation.
Scheduled lubrication and oil changes.
Routine bearing inspections for noise, vibration, or play.
Immediate repair or replacement if abnormalities appear.
Proactive care reduces unexpected failures and extends jaw crusher service life.
Tip: Always monitor bearing temperature and maintain proper lubrication to prevent overheating and costly bearing failures in jaw crushers.
Sudden shutdowns of jaw crushers disrupt production and cause costly delays. Knowing common causes and how to fix them helps restore operation quickly.
Several issues can cause the main crusher unit to stop abruptly:
Feed inlet blockage: Material jams in the crushing chamber, causing overload and automatic shutdown.
Loose or slipping V-belt: If the drive belt slips or breaks, power transmission stops, halting the crusher.
Low voltage or electrical faults: Insufficient power supply or electrical failures can cause the motor to stop.
Bearing damage: Overheated or seized bearings force the crusher to stop to prevent further damage.
Motor burnout or power cable breakage: Motor failure or broken cables cut power, stopping the crusher.
To identify the shutdown cause:
Check the feed opening and discharge port: Look for material buildup or blockages.
Inspect the V-belt: Examine belt tension, wear, or breakage.
Measure motor voltage: Confirm voltage meets equipment requirements.
Listen for bearing noise: Overheated bearings often make unusual sounds.
Test motor and cables: Look for signs of damage or burns.
When blockage causes shutdown:
Turn off power: Ensure safety before inspection.
Remove material jams: Use tools to clear the feed inlet and discharge area.
Check jaw plates and discharge opening: Adjust or replace worn plates to prevent recurring blockages.
Restart crusher slowly: Monitor operation for smooth feeding.
If the blockage is severe, inspect the crushing chamber for damage before resuming work.
Motor or cable issues require:
Visual inspection: Look for burnt smells, melted insulation, or physical damage.
Electrical testing: Use a multimeter to check continuity and resistance.
Replace damaged cables: Use cables meeting manufacturer specs.
Repair or replace motor: Consult a professional if motor burnout occurs.
Check power supply: Ensure stable voltage and proper grounding.
Regular electrical maintenance prevents unexpected shutdowns.
Tip: Always shut down power before clearing blockages and perform routine inspections of V-belts, bearings, and electrical components to minimize sudden jaw crusher shutdowns.
Proper maintenance is crucial for keeping jaw crushers running smoothly and preventing costly breakdowns. Following a solid maintenance routine helps extend equipment life and ensures consistent performance.
Set up a routine inspection schedule to catch issues early. Key points to check include:
Jaw plates and liners for wear or damage
Bolts and fasteners for tightness
Bearings for noise or overheating
Drive belts for tension and wear
Lubrication points for sufficient grease or oil
Structural parts like frames and toggle plates for cracks or deformation
Daily visual checks combined with weekly or monthly detailed inspections help identify problems before they escalate.
Wear parts like jaw plates, toggle plates, and bearings degrade over time. Replace these parts as soon as wear reaches critical levels to avoid damage to other components. For example:
Replace jaw plates when wear exceeds 30% of original thickness
Change bearings if overheating or excessive play is detected
Swap out toggle plates immediately after fractures
Using OEM or manufacturer-approved parts ensures proper fit and durability.
Correct installation is vital for reliable operation:
Follow manufacturer guidelines for mounting and torque settings
Ensure jaw plates are installed in the right orientation and securely fastened
Adjust discharge opening to maintain desired product size
Set drive belt tension to prevent slippage or overloading bearings
Incorrect installation or adjustment can cause uneven wear, vibration, and premature failure.
Always operate and maintain the crusher according to manufacturer specs. This includes:
Feeding materials within recommended size and hardness limits
Using specified lubricants and maintaining lubrication intervals
Observing power and load limits to avoid overload
Keeping to scheduled maintenance and inspection intervals
Ignoring these guidelines risks damaging the crusher and voiding warranties.
Well-trained operators reduce the risk of problems caused by human error. Train staff on:
Feeding materials evenly and avoiding overloading
Recognizing signs of wear or malfunction
Proper startup and shutdown procedures
Reporting issues promptly for maintenance
Educated operators help maintain consistent crusher performance and reduce downtime.
Tip: Establish a detailed maintenance plan including regular inspections, timely part replacements, correct adjustments, and operator training to maximize jaw crusher reliability and lifespan.
Jaw crushers often face issues like wear, blockages, and mechanical failures that impact performance. Addressing these problems with timely maintenance and proper operation improves efficiency and extends equipment life. Proactive troubleshooting and following best practices help prevent costly breakdowns and ensure consistent output. Adopting these strategies maximizes jaw crusher durability and productivity. AXSON Industry offers reliable jaw crushers designed for durability and efficiency, supporting your operations with quality products and expert service.
A: Jaw crusher problems often include jaw plate wear, feed opening blockage, mechanical fatigue, and bearing overheating, caused by improper feeding, material hardness, mechanical stress, and poor maintenance.
A: Prevent feed opening blockage by controlling feed rate, using vibrating feeders, and pre-screening oversized materials to ensure smooth and consistent feeding.
A: Jaw plates wear due to crushing hard materials, causing increased discharge opening size and larger final product size; rotating or replacing plates restores product quality.
A: Regular inspections, timely replacement of wear parts, proper lubrication, correct installation, and operator training prevent jaw crusher problems and extend equipment life.
A: Check for feed blockages, inspect V-belts, verify electrical supply, and examine bearings; clear jams and repair or replace faulty components to restore operation.
