problems of jaw crusher

the most practical jaw crusher repair and maintenance manual | fote machinery

Just like other stone crusher machines, jaw crusher also needs a regular repair and maintenance after a certain time of working, or it will get decreased service life because of severe wear of important parts.

So many customers have common misconception that jaw plates only need repair when appearing flat, holes, cracks. Actually if jaw plates wears badly, it is not only hard to repair but seriously affects the normal working of other parts, which then will take a great sum of money to change a jaw plate and maintain other parts.

The pitman drives the moveable jaw dies to push stone material towards stationary jaws, which would create strong pressing forces to both jaw dies. Therefore, if the pitman cannot get lubrication in time, it will be broken under the high pressure of material and interrupt the whole work.

Proper plan and preparation make the whole repair and maintenance ordered and effective, which helps operators save time, cost, and enhance their safety. You can make a checklist just like the following chart in which you can list need-checked jaw crusher parts with a different period then making a mark if you are done with them. This not only prevents missed inspections, but also makes the arrangement clear, and saves a lot of time.

The lubrication of the interface between the parts of the jaw crusher is very important. It can minimize the friction generated during the operation, make the whole jaw crusher run smoothly, and extend its service life.

Unlike gyratory crushers, the main lubrication used in jaw crushers is grease instead of oil. When using grease, there may be several different ways to inject it into the necessary lubrication points. It can be operated manually with a grease gun, an oiler or metering pump.

Eccentric shaft (pitman bearing): It is behind the moveable jaw plate, and together with flywheel with toggle plate to create a motion. So, the most important thing you must do is keeping a regular lubrication to eccentric shaft, or you will spend more than four hours in changing a new one when it is broken.

Main shaft To keep the main shaft in good lubricating situation, you need to guarantee enough geese between thrust plate.The grease added to the bearing box needs to occupy about 50% of its space and be replaced every 3-6 months. When changing the engine oil, please use clean gasoline or kerosene to clean the roller bearing raceways.

There are different jaw plates material in the market, and some of them suits for hard stone while other is not. Therefore, you have to choose the right jaw plate for your crusher. For example, generally the jaw plate of single toggle jaw crusher is not good at crushing strongly abrasive and hard stone material with large production.

The function of toggle plate is to adjust the outlet of the jaw crusher to the desired size. There are two specific methods: one is to replace the support pad between the toggle plate and the body frame, and the other is to adjust the two wedges between the toggle and the body frame.

Fote Company has more than 40-year manufacturing experience, mainly engineering different types of jaw crushers including PE jaw crusher, Dodge jaw crusher, Blake type jaw crusher(double toggle jaw crushers), single toggle jaw cruhser, etc., and all of them can be customized.

As a leading mining machinery manufacturer and exporter in China, we are always here to provide you with high quality products and better services. Welcome to contact us through one of the following ways or visit our company and factories.

Based on the high quality and complete after-sales service, our products have been exported to more than 120 countries and regions. Fote Machinery has been the choice of more than 200,000 customers.

how to quickly solve jam problem in jaw crusher?

Jaw crusher is the first stage crushing machine in the crushing process, then broken material goes to impact crusher or cone crusher for secondary crushing work. Because the jaw crusher in the first crushing, the material is relatively large, irregular shape, it is easy to block. When dealing with the blocking problem, most will choose to turn off the power supply of the jaw crusher, check the reason, then solve it. But this will waste sereval hours to finish,whats more the service life of equipment will be reduced due to frequent shutdown and startup. So what are the methods to deal with the jaw crusher plugging problem?

1. If theres plugging problemIn the process of using jaw crusher, workers could knock it around for a few times and make some small vibration to see if the material can be down. At the same time it should stop feeding and wait until the equipment eliminates blocking.

2. It is a better way to use the sound and light indicator to indicate the feeding directly. Install an electric alarm at the feeding mouth of the jaw crusher. When the feeder reaches a set current value, the alarm will start to remind. If the downstream equipment mediation, feeder conveying current is zero, alarm will be prompted.The mine car driver receives the alarm prompt to be able to stop to pour the material, thus prevents blocking the material.

3. If there is too large stone material that cannot enter the cavity and, result in obstruction during crushing working, the worker can use a iron bar, probing into the gap of the stone, using the machine movement force to change the stone position, after adjusting the position for many times, the blocking problem can be sovled quickly.

Baichy Machinery is a mining machinery manufacturer since 2003. We are mainly engaged in manufacturing stone crushing machines, grinding equipment, mobile crushing plant and mineral processing machines, integrates research and development,design, manufacturing, sales and after-sales service. Welcome to visit our factory.

maintenance and repair of jaw crusher | jxsc mine

Jaw crusher is a universal stone crusher in the mining industry. Application: jaw crusher machine widely used in the mineral processing plant, building material industry, aggregate processing plant, roads, railways, water conservancy, chemical and so on industries. Mainly in the medium size crushing operation, the maximum compressive strength of the crushed material is 320 MPA. Working principle of jaw crusher: the crushing chamber consists of a moving plate, and fixed plate, the pressing force from of the two plates movement will crush the rock material. It simulates the progress of the animalsjaws do the crushing operation.

JXSC, jaw crusher manufacturer, supply types of jaw crusher, contact us to get the latest price of the mineral processing machines, besides, jaw crusher design and crushing plant layout design services are offerable. JXSC provide spare wear-resistant parts and installation guidance.

Jiangxi Shicheng stone crusher manufacturer is a new and high-tech factory specialized in R&D and manufacturing crushing lines, beneficial equipment,sand-making machinery and grinding plants. Read More

jaw crusher maintenance : pit & quarry

With proper planning and preparation, maintenance programs can be made easier and more effective. Importantly, operations can meet time management, cost savings and safety goals by employing good maintenance strategies.

So workers may take shortcuts that ultimately cost the operation more in the long run, Macini says. Crews need to be trained in the proper methods, and management needs to provide the support and resources to do the job correctly.

Cleanliness is key: Keep oil systems free of contamination. With a production, production, production mentality comes the attitude of, lets hurry up and change the oil. But crews dont bother to clean out any sludge buildup in tanks; and the new oil becomes contaminated.

Keep the breathers clean as well, and keep the right gaskets and oil filters on hand. Dont run oil filters into the red. Always have the right replacement parts and cleaning components set aside and ready to go. Be proactive, and remain prepared as oil-change intervals come up.

Keep the toggle area clean, particularly before any crusher adjustments. Its best to wash out the toggle seats and plates daily, as wet material buildup results in a gritty compound that grinds down components, causing premature wear.

Also, remove dirt and debris from crusher frame surfaces and from areas around the machine. Monitor discharge chutes for any obstructions and check for any material buildup under the jaw to avoid excessive wear on the pitman.

Conduct regular inspections: As specified by owners manuals, crews should follow the discipline of daily, weekly and monthly recommended inspections. While there are many inspection items listed on a manufacturers maintenance schedule, several are worth highlighting.

Check jaw dies daily, making sure bolts are kept tight. Check cheek plates for any excessive wear that may affect the mainframe of the jaw. Monitor flywheels for cleanliness, tightened bolts and potential cracks; and make sure drive belts arent worn or cracked.

Additionally, log your coast-down time daily. How long does it take the machine to come to a dead stop? If the time starts to shorten, this could indicate a bearing problem. Check all indicators and switches daily for proper operation as they are integral to proper shutdown in the event of issues such as high temperatures or low hydraulic pressures.

Dont over-extend wear parts: Avoid running jaw dies so long that they become too thin. You may find that you can no longer flip them over and now, youve lost half the wear. To get the full life of the manganese, change them out sooner than later.

Know the right fit for you: Consider that if youre an operation resigned to a less-than-the-best maintenance regime, youll be better off with a greased-versus-oil bearing machine. Requiring less-intensive maintenance than that of oil-lubricated systems, grease machines need a proper cleaning of the fittings and the application of the right grease. Applying the wrong grease (because thats whats on the shelf) is not an option, as this shortcut can ultimately cause equipment failure.

Update your equipment: As an example, Macini points to modern crusher designs that incorporate hydraulic tensioning cylinders that replace conventional toggle tension rods and springs. As a result, the tension cylinders automatically maintain the proper tension on the toggle, eliminating the need for spring adjustment. With proper tensioning being automatic, producers save time as well as reduce wear and tear on parts.

Furthermore, two oversized hydraulic cylinders behind a moving toggle beam enable all closed side setting (CSS) adjustments. A flip of a switch extends or retracts the cylinders and the adjustment is complete and made safely without shims being needed at any time. For safe toggle maintenance, the hydraulic adjustment cylinders push the pitman forward where it is locked into position with lockout pins, which insert from the side.

Then hydraulic tension cylinders, mounted on the side of the toggle, pull the toggle beam back, allowing it to be safely lowered away. Operations stress that this safety aspect is very important to them as they no longer need to have workers with wrenches climbing in, around or under this equipment, he says.

To prevent crusher damage, downtime and difficult maintenance procedures, the hydraulic overload relief system opens the crusher when internal forces become too high, protecting the unit against costly component failure. After relief, the system automatically returns the crusher to the previous setting for continued crushing.

He goes on to explain that typical older-style crushers may make use of a shear toggle that acts somewhat like a fuse. In other words, the toggle is a weak link that bends or breaks away when pressure becomes too great, and prevents further damage. But once the toggle is sheared or broken, the maintenance crew may have to spend up to four hours to remove and replace it, and that assumes the part is available.

Develop a maintenance discipline: So ditch the shortcuts. As with anything, you get out of it what you put into it. Learn to do maintenance jobs right the first time, and continue the discipline throughout the life of the equipment. The payoff is measurable in time and cost savings, and a far safer working environment.

jaw plate failure and life - crushing, screening & conveying - metallurgist & mineral processing engineer

What is the root cause of jaw plate that has a very short life span, failure rate is bad. I hope we can improve the liners life, I will inform you all if their is a progress on our Jaw liner. thank you so much.

The abrasion index of the material, the feed presentation and size of feed and profile of the jaw all have an impact on wear. If you send me a photo or sketch of the wear pattern I am sure I can offer you some additional advice

We cannot rule out the manganese Jaws themselves as being poorly manufactured i.e. incorrect methods/risers, poor chemistry control and or Heat Treatment issues. We at crushing Equipment would be happy to assist as advisedby Helena.

How have you bench-marked the performance of the liners you are using. Do you have any historic Tonnes per liner data? Has the feed source changed? Have you changed jaw liner suppliers? Has your liner supplier changed the Manganese content of the liners supplied?

There have many causes to make jaw plate short life. It mainly depends on your rock hardness and your crusher working conditions (wet, dry, etc.). You should make sure the jaw plate you bought is good quality. Usually our customer use Mn18% with Cr2%. In order to help customer to improve the jaw plate's lifetime, we have our special material with 20 years experience, such as adding some %Molybdenumwithspecialheat treatment, the jaw plate can increase about20%lifetime. Hope this can help you.

The comments you received so far is spot on. Jaw plate wear is dependent on the type of material you are crushing and other variables like material size. You will want to reduce the amount of fines that enter into the crusher like with the use of a grizzly feeder. Too many fines can accelerate jaw plate wear. What happens is the fines will fill the jaw plate corrugations or valleys. These valleys are necessary for the crusher to crush efficiently. Filling the valleys with fines creates an event called compaction. Normally a jaw crusher will squeeze the material between the stationary and moving jaw plates. The peaks and valleys of the jaw plates are offset from one another and use the mechanical advantage of leverage to break the rock. Without this the crusher has to rely on energy and friction to crush the rock. Compaction will also impose increased loads to the crusher as much as five times the normal crushing force. To the opposite,feed material that is too large also affects wear life. A jaw crusher in most applications is a 6 to 1 ratio of feed reduction. Exceeding the reduction ratio can create crushing forces that can exceed the crushers design limits and will affect your overall production and machine performance. With theover-sizedfeed material you will have a tendency toscrub the material until the jaw plate can get a bite on it. This will also accelerate wear.

If you are using dust suppression it to can also be a factor. Water is actually very abrasive and will accelerate plate wear. If you are using dust suppression you should keep in mind that the dust is better controlled by using a fine spray as appose to using a stream of water. Match the water to the dust and you will control more dust and use less water. Also more dust is present at the discharge than the inlet so water nozzle placement is very crucial to controlling dust without causing accelerated wear.

Like several have mentioned already buying quality is very important. Your supplier should be able to tell you what metal composition your jaw plate is made off. Getting the "right tool for the job" in regards to a good quality jaw plate will give the best performance and longevity.

He is also right about the feed reduction ratio of 6-1. This has been proven worldwide in most applications. In the case of a cone crusher the ration is closer to 8-1. Exceeding the crusher design limits is a common problem, and does not just affect wear on the plates, but the entire hydraulic system too, thus causing other severe issues to your machine.

I agree as well that the dust suppression should be with light spray nozzles and not a stream of water. Water also slows down the further process of screening.The only case where I have seen the benefit of adding water to material is before entering a VSI tertiary crusher, as this adds weight to the stone. Only if the stone is light and porous in weight, though it may still be abrasive... such as volcanic rock.

There are different types of jaw plates available that can have different depths and pitches to the corrugation. A jaw plate without corrugation will create a compaction event. You need corrugation but you can get a straight to a full belly style plate to help with your specific application. If this is what you meant by the profile then yes it could have an effect on jaw performance. There are also what they call "filled in end jaw dies" but should only be used for specific applications and only after consulting the crusher manufacture. And then it is only used on the stationary side as a rule. What I would recommend is talking to your crusher manufacture for specifics related to the types of plates available for your crusher. As with my company and others we have a teams of application specialist that would be happy to help and could offer a recommendation that could best fit your applications needs and help your crusher performance.

If usually your customer use Mn 18% with Cr 2%.The Materials work index that we crushed is 28, can you comment if we use a Jaw Plate with Mn 18 % with Cr 2% can reach a 500 hrs ?, last replacement of our Jaw Plate its only 150 hrs. this is our battle neck . As also mention in a comment about the different types of Jaw Plates, I think we have to find the correct design with this kind of materials we crush. We are in a river quarry, materials are mix .

The issues are very wellsummarized:including about the deleterious effects of fines and water on jaw life. Low-strength abrasive materials can cause standard manganese to wear surprisingly fast, as the wearing surface does not work-harden. With very abrasive materials, special 21-23% Mn alloys can help.

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