The jaw crusher uses the principle of mutual extrusion of jaw plates to process materials. It is used in a process of crushing various minerals and rocks. It can process various ores with a compressive strength of not higher than 320MPa to a medium particle size at one time. Cone crusher, impact crusher, sand making machine, etc. together form a complete set of sand and gravel production line, which is widely used in mining, metallurgy, chemical industry, building materials, electric power, water conservancy, transportation and other good areas.
Crushers are mainly used as coarse crushers and medium crushers in the mining, building materials, infrastructure and other sectors. According to the width of the feed port, it is divided into three types: large, medium and small. The width of the feed port is greater than 600MM for large machines, the width of the feed port is 300-600MM for medium-sized machines, and the width of the feed port is less than 300MM for small machine. The jaw crusher is simple in structure, easy to manufacture, reliable in work, and convenient to use and maintain.
The working part of the jaw crusher is two jaws, one is a fixed jaw (fixed jaw), which is vertically (or slightly inclined at the upper end) fixed on the front wall of the machine body, and the other is a movable jaw (moving jaw). Inclined to form a crushing cavity (working cavity) with a large upper and a lower jaw with the fixed jaw. The movable jaw plate makes periodic reciprocating motion against the fixed jaw plate, sometimes separating and sometimes approaching. When separated, the material enters the crushing cavity, and the finished product is discharged from the lower part; when it is close, the material installed between the two jaws is crushed by squeezing, bending and splitting.
Jaw crushers can be divided into simple swing jaw crushers (simple pendulum jaw crushers) according to different swing modes of movable jaws. There are three types of complex swing jaw crusher (compound swing jaw crusher) and comprehensive swing jaw crusher.
Jaw crusher (jaw crusher) has better performance:
- The crushing cavity is deep and there is no dead zone, which improves the feeding capacity and output;
- The jaw crusher has a large crushing ratio and uniform product size;
- Gasket-type discharge opening adjustment device is reliable and convenient, with a large adjustment range, which increases the flexibility of the equipment;
- The lubrication system is safe and reliable, the replacement of parts is convenient, and the maintenance workload is small;
- The jaw crusher has simple structure, reliable work and low operating cost;
- The energy saving of the jaw crusher: 15% to 30% of energy saving for single machine, and more than double the energy of system;
- The adjustment range of the discharge opening is large, which can meet the requirements of different users;
- The jaw crusher has low noise and less dust.
- Frequent attention and timely lubrication of the friction surface can ensure the normal operation of the machine and extend its service life.
- The grease used in the jaw crusher should be determined according to the place of use and temperature conditions. Generally, calcium-based, sodium-based and calcium-sodium-based grease are used.
- The grease added to the bearing housing is about 50% of the space volume and replaced every 3 to 6 months. Clean gasoline or kerosene should be used to clean the raceways of the roller bearings when changing the oil.
- Before starting the jaw crusher, an appropriate amount of grease should be injected between the thrust plate and the thrust plate support.
- The main content of minor repairs includes checking and repairing the adjustment device, adjusting the gap of the discharge opening, and turning or replacing the worn lining. Check the transmission part and lubrication system and change the lubricating oil in time. The period of minor repairs is about 1 to 3 months.
- In addition to minor repairs at the intermediate repair department, it also includes replacing thrust plates, liners, checking and repairing bearings, etc. The period of intermediate repair is generally about 1 to 2 years.
- In addition to the mid-repair work at the overhaul, it also includes replacing the turning eccentric shaft and the jaw spindle, casting the Babbitt alloy on the upper part of the connecting rod head, and replacing or repairing a worn part. The period of overhaul is generally about 5 years.
The main components
The frame is a four-walled rigid frame with upper and lower openings. It is used to support the eccentric shaft and bear the reaction force of the crushed materials. It requires sufficient strength and rigidity. It is generally cast with cast steel as a whole. Small machines can also be cast iron instead of cast steel. The frame of the mainframe needs to be cast in sections, and then firmly connected into a whole with bolts, and the casting process is complicated. The frame of the self-made small jaw crusher can also be welded by thick steel plates, but the rigidity is poor.
2. Jaw and side guards
Both the fixed jaw and the movable jaw are composed of a jaw bed and a jaw plate. The jaw plate is the working part and is fixed on the jaw bed with bolts and wedge irons. The fixed jaw jaw bed is the front wall of the frame. The movable jaw jaw bed hangs on the circumference. It must have sufficient strength and rigidity to withstand the crushing reaction force, so it is mostly cast steel or cast iron.
3. Transmission parts
The eccentric shaft is the main shaft of the crusher, which is subjected to huge bending and torsion forces and is made of high carbon steel. The eccentric part must be finished, heat treated, and the bearing lining shall be cast with Babbitt alloy. One end of the eccentric shaft is equipped with a pulley, and the other end is equipped with a flywheel.
4. Adjusting device
Adjusting devices include wedge type, backing plate type and hydraulic type, etc. Generally, a wedge type is adopted, which is composed of two wedges at the front and the rear. The front wedges can move back and forth to withstand the rear push plate; the rear wedges are adjusting wedges, which can be moved up and down. Move, the inclined surfaces of the two wedges are reversed to fit, and the screw moves the rear wedges up and down to adjust the size of the discharge port. The discharge port adjustment of the small jaw crusher is realized by increasing or decreasing the number of gaskets between the thrust plate support and the frame.
The flywheel of the jaw crusher is used to store the energy during the idle stroke of the moving jaw, which is then used for industrial formation to make the work of the machine more uniform. The pulley also functions as a flywheel. The flywheel is often made of cast iron or cast steel, and the flywheel of a small machine is often made as an integral type. The flywheel is manufactured, and the static balance should be paid attention to when installing.
6. Lubrication device
Eccentric shaft bearings are usually lubricated with concentrated circulation. The support surfaces of the spindle and thrust plate are generally lubricated with grease through a manual grease gun. The swing angle of the movable jaw is very small, which makes it difficult to lubricate between the spindle and the bearing bush. A number of axial oil grooves are often opened at the bottom of the bearing bush, and a ring is opened in the middle to connect the oil groove, and then an oil pump is used to forcibly inject dry butter for lubrication.
1. Jaw crusher lubrication
2. Jaw crusher repair
For the normal operation of the jaw crusher, in addition to the correct operation, planned maintenance must be carried out, including daily maintenance and inspection, minor repairs, medium repairs and overhauls.