Jaw crusher operation and maintenance

Jaw crushers are generally installed on top of the concrete foundations. Take into consideration of the weight of jaw crusher, the tough working conditions and the high inertia forces generated by the machine during operation, which may cause the slight vibration of foundation and machine system; therefore, the foundation of the jaw crusher should be separated from the foundation of the workshop. Meanwhile, rubber or wood padding should be placed between the crusher foundation and the jaw crusher base frame to reduce the vibration.

In order to ensure the continuous operation of the jaw crusher to reach full production capacity, it is important to pay attention to the correct operation, regular maintenance and periodic overhaul of the jaw crusher.

I Operation of jaw crusher

Proper operation is one of the important factors to ensure the continuous and normal operation of the crusher. Improper operation or negligence in the process of operation is often an important cause of equipment and personal accidents. The correct operation is to strictly follow the provisions of the operating procedures.

Preparation before starting

Before starting the jaw crusher, a comprehensive and careful inspection of the equipment must be carried out, typically checking list as follows

  • Check the wear condition of jaw plates, adjust the discharge opening accordingly;
  • Check whether there is any rocks in the crushing chamber; if any, they must be taken out of the crushing chamber.
  • Check if there is any loose for the coupling bolts;
  • Check if the protective cover(safety guards) of the pulley and flywheel is intact; Check if the v
  • belts and tie rod with spring are intact;
  • Check the lubrication system, make sure there is enough grease for lubrication
  • Check the correct connection of electrical cables, etc.

Precautions in operation

  • Before starting the crusher, must add enough grease for lubrication
  • After starting, if any abnormal knocking sound, the crusher should be stopped immediately. After checking and eliminating the problem, restart the crusher.
  • The crusher must be started with empty load, after starting for a period of time and crusher runs normally, feeding can be started. The feeding of rocks to the crusher should be gradually increased until it reaches full load operation.
  • During operation, the rocks should be evenly fed to the crusher, it is allowed to be overload in the crushing chamber; the maximum feeding size of rocks should not be larger than 0.85 times of the feed opening width.
  • Meanwhile, during feeding the ore, it should strictly prevent non
  • crushing objects such as shovel teeth, drill bit of drilling rig from entering the crusher. In case these non
  • crushing objects are found to enter the crushing chamber and pass through the discharge opening of the crusher, the crusher operator should immediately notify the belt conveyor operator to take it out in time, so that it will not enter the next crushing section to cause serious equipment accidents.
  • During the crusher operation, the operator should also pay attention to the large rocks, which may block the feed opening of the crusher, if it has been stuck, the operator must use special tool to remove the rocks. It is forbidden to use hands to avoid accidents.
  • During the crusher operation, if the ore feeding is too much or the crushing chamber is blocked, the feeding should be stopped temporarily, until the crushing chamber is emptied can start the feeder again, at this time the crusher is not allowed to stop running.
  • During the crusher operation, the operator should check the crusher parts and bearing temperature from time to time. Normally the bearing temperature should be no more than 60 ℃. If the bearing temperature is very high, crusher is not allowed to stop production immediately. Some proper measures should be taken to reduce the bearing temperature, like forced ventilation or adoption of water cooling, etc. Stop the crusher only after the bearing temperature has dropped, then check and solve the problems.
  • In order to ensure the normal operation of the crusher, personnel who are not familiar with the operating procedures are not allowed to operate the crusher alone.
  • When stopping the crusher, it must be stopped according to the production flow sequence. First of all, the ore feed must be stopped, and after the ore in the crushing chamber is all discharged, then stop the crusher and belt conveyor.
  • It should be noted that if the crusher stops suddenly for any reason, the accumulated ore in crushing chamber must be cleared before the crusher is ready to start again.

Ⅱ Maintenance and repair of jaw crusher

In the operation of the jaw crusher, attention must be paid to frequent maintenance and regular overhaul. In the crushing workshop, the working conditions of the jaw crusher are very harsh and the problem of wear and tear of the equipment is inevitable. However, it should be seen that too rapid wear of machine parts, or even fracture, is often caused by incorrect operation and inconsiderate maintenance. For example, poor lubrication will accelerate the sharp wear of bearings. Therefore, the correct operation and careful maintenance (regular maintenance) is an important way to extend the service life and improve the operation of the equipment. In the daily maintenance work, for the correct judgment of equipment failure, accurate analysis of the causes, so as to quickly take the elimination method, which is skilled operators should understand and master.

Common failures, causes and elimination methods

NO. Failure phenomenon Causes Elimination methods
1 The sound of metal impact is heard during jaw crusher operation, jaw plates shaking. The crushing chamber jaw plates are loose, the fixing bolts are loose or broken. Stop the jaw crusher, check the fixation of jaw plates, and use hammer to tighten the wedge on plates, then fasten the bolts or replace the bolts if they are broken.
2 Toggle plate and seat generates impact sound. Insufficient spring tension or damaged spring, toggle plate seat wear or loosen, toggle plate end is severely worn. Stop the jaw crusher, adjust the tension of spring or change new spring. Change the toggle plate seat, change toggle plate
3 Main shaft or eccentric shaft generates impact sound Eccentric shaft bush ring is worn Change the bush ring
4 Discharged gravel sizes are increased The lower part of the jaw plates is significantly worn. Turn the jaw plates 180 degrees and install them well; or adjust the discharge size to reduce the width.
5 After a violent cracking sound, the moving jaw stops swinging, the flywheel continues to rotate, the connecting rod swings back and forth, and the tie rod spring loose. Toggle plate was damaged due to the falling of non-breaking objects. Toggle plate seat was broken Stop the jaw crusher, change the toggle plate, change the toggle plate seat.
6 Bolts are loosened Vibrating Stop the jaw crusher, check and tighten all the connection bolts. Find the cause of vibrating and eliminate it.
7 The flywheel rotates and the crusher stops working operation, the toggle plate is released from the support seat The spring of the tie rod is damaged; the tie rod is damaged; the tie rod nut is disengaged. Stop the crusher, remove the ore from the crushing chamber, check the cause of damage, replace the damaged parts and install the toggle plate.
8 The flywheel oscillates significantly and the eccentric shaft returns is slowing down. Flywheels fixation keys are loosen or damaged Stop the jaw crusher, change the fixation keys, regulate the keys.
9 The lower part of the jaw crusher has a crashing sound Loss of elasticity or damage to the tie rod cushion spring Change spring

The jaw crusher can often maintain intact condition, in addition to the correct use of the operation, it also depends on maintenance and overhaul (repair), and the maintenance is basis of equipment repair. As long as the operator has diligent maintenance, diligent inspection, and master the wear cycle of equipment parts, the equipment parts defects can be early found, so that timely repair and replacement can be carried out, this way it won’t reach a serious point of scrapped. Therefore, the timely repair of equipment is an important part of ensuring the normal production.

The wear and tear of equipment parts working under certain conditions is usually regular, and after working for a certain period of time, they need to be repaired or replaced, and this time interval is called the wear cycle of the parts, or the service life of the parts. The approximate service life and minimum reserves of the main wear parts of the jaw crusher can be found in the table

Wearing parts service life and reservation

Wearing parts name Material Life time(Months) Recommend backup quantity
Moving jaw plate ZGMn13-2 4 2 pieces
Station jaw plate ZGMn13-2 4 2 pieces
Toggle plate Gray cast-iron HT200 4 pieces
Toggle plate seat Carbon steel 10 2 pieces
Bearings Alloy 36 1 units of 4 pieces
Spring 60SiMn 2 pieces

According to the length of the easy wear cycle, the equipment should also be planned for overhaul. Planned maintenance is also divided into minor repair, medium repair and major repair.

Minor repair, It is the main form of repair for the jaw crusher, i.e. the daily maintenance and repair work of the equipment. In the minor repair, mainly check and replace the severely worn parts, such as, jaw plates, toggle plate seat, etc. Repair journals, scraping bearings; adjust and tighten bolts; check lubrication system, replenish the amount of lubricant, etc. The cycle of minor repair is about 1 to 3 months.

Medium repair, It is based on the minor repair. According to the problems inspected and found in the minor repair, the repair plan should be made to confirm the items of replaced parts. In the medium repair, it is often necessary to carry out complete dis-assembly of the equipment, check the usage condition of important parts in detail, and solve the problems of repairing and replacing parts that are impossible to solve in the minor repair. The cycle of medium repair is usually about 1 to 2 years.

Major repair, It is a more thorough repair of the crusher. Overhaul includes all the work of small and medium repair, mainly dismantling all parts of the machine, conducting a careful and comprehensive inspection, repairing or replacing all wear parts, and conducting a comprehensive work performance measurement of the overhauled machine to achieve the same performance as the original equipment. Overhaul is generally about 3 to 5 years.