Jaw crusher commonly known as jaw break, also known as tiger mouth. The crusher is composed of two jaw plates, the moving jaw and the static jaw, which simulates the two jaw movements of animals and completes the material crushing operation. Widely used in mining smelting, building materials, road, railway, water conservancy and chemical industry of all kinds of ore and bulk material crushing. The maximum compressive strength of the crushed material is 320Mpa.
Modern crushing machinery was created successively after the gradual improvement and promotion of power machinery such as steam engines and electric motors.

In 1806 came the roll crusher driven by steam engine;
In 1858, Black of the United States invented the jaw crusher for breaking rock;
In 1878, the United States developed a rotary crusher with continuous crushing action, whose production efficiency was higher than that of the jaw crusher with intermittent crushing action;
In 1895, William of the United States invented the impact crusher with lower energy consumption.
In the 1980s, the feed size of the large jaw crusher that broke 800 tons of materials per hour had reached about 1800 mm.

The commonly used jaw crusher has two types of double toggle plate and single toggle plate. The former only makes a simple arc swing when working, so it is also called a simple swing jaw crusher; The latter also moves up and down while making an arc swing.
The technical level of domestic jaw crusher manufacturers is very different, there are a few manufacturers of products are basically close to the world’s advanced level, and most manufacturers of products compared with the world’s advanced level gap. The jaw crusher frame accounts for a large proportion of the mass of the whole machine (casting frame accounts for 50%, welding frame accounts for 30%). Foreign jaw crusher is welded frame, even the moving jaw also uses welded structure. Jaw crusher using welding frame is the development direction. There are many examples of unreasonable design of jaw crusher frame structure in China, the reason is that the reinforcement reinforcement is not arranged according to the actual stress situation of the crusher
In recent years, with the increase of the proportion of open-pit mining, and the use of large electric shovels (excavators) and large mining vehicles, the ore block size of open-pit ore transported to the crushing workshop has reached 1.5~2.0 meters. At the same time, due to the decreasing grade of raw ore, in order to maintain the original production capacity of the concentrator, it is necessary to greatly increase the amount of raw ore mining and crushing, so the jaw crusher is developing in the direction of large-scale. At present, the largest specifications of jaw crusher manufactured abroad are: 3000×2100 mm (simple pendulum), the ore size is 1800 mm, and the production capacity is 1100 tons/table · hour; 2100×1670 mm (compound pendulum), when the discharge port is 355 mm, its production capacity is 3000 tons/table · hour.
With the emergence of large impact bearing, there is a trend at home and abroad to use compound pendulum jaw crusher instead of simple pendulum crusher, because under comparable conditions, the former is 30% more productive than the latter; When the production capacity of the two is the same, the former is 20% to 30% lighter than the latter. However, there are still some problems in the structure of the compound pendulum jaw crusher, which need to be studied and improved.
It should be noted that in recent years, due to the improvement of China’s large rolling bearing materials, as well as the needs of underground coarse crushing equipment, compound pendulum jaw crusher also has a trend of development in the large direction, and 900×1200 compound pendulum crusher is currently being trialed. With the large-scale of equipment specifications, the adjustment device and safety device of the general jaw crusher must adopt a new mechanism. Therefore, another trend in the development of the current jaw crusher is that the size of the discharge port uses a hydraulic adjustment mechanism, which is not only simple and rapid, but also can be adjusted at any time according to needs in the work; At the same time, the overload safety device of the machine is also a hydraulic mechanism to achieve safety and reliability, and does not damage the thrust plate, and the machine immediately resumes work after the fault is removed. At home and abroad are vigorously developing this hydraulic jaw crusher. China has produced 900×1200 hydraulic simple pendulum jaw crusher, and put into use in Laiwu Iron mine and Luozi Iron mine. Production practice has proved that the insurance mechanism and adjustment mechanism of the hydraulic jaw crusher have achieved the purpose of safety insurance and convenient adjustment, and are in good condition and are welcomed by workers on the job.
In terms of improving the crushing efficiency of the jaw crusher, in addition to making local improvements in the structure of the original equipment, such as increasing the height of the crushing chamber and improving the production capacity; Reduce the discharge port and increase the crushing ratio; In addition to increasing the swing speed of the moving jaw to improve the production capacity of the equipment and improve the quality of the product, at present, countries are researching and testing new structure of the crusher, such as impact jaw crusher, double-action jaw crusher and hydraulic jaw crusher.

The technical level of domestic jaw crusher manufacturers is very different, there are a few manufacturers of products are basically close to the world’s advanced level, and most manufacturers of products compared with the world’s advanced level gap. The jaw crusher frame accounts for a large proportion of the mass of the whole machine (casting frame accounts for 50%, welding frame accounts for 30%). Foreign jaw crusher is welded frame, even the moving jaw also uses welded structure. Jaw crusher using welding frame is the development direction. There are many examples of unreasonable design of jaw crusher frame structure in China, the reason is that the reinforcement reinforcement is not arranged according to the actual stress situation of the crusher
In recent years, with the increase of the proportion of open-pit mining, and the use of large electric shovels (excavators) and large mining vehicles, the ore block size of open-pit ore transported to the crushing workshop has reached 1.5~2.0 meters. At the same time, due to the decreasing grade of raw ore, in order to maintain the original production capacity of the concentrator, it is necessary to greatly increase the amount of raw ore mining and crushing, so the jaw crusher is developing in the direction of large-scale. At present, the largest specifications of jaw crusher manufactured abroad are: 3000×2100 mm (simple pendulum), the ore size is 1800 mm, and the production capacity is 1100 tons/table · hour; 2100×1670 mm (compound pendulum), when the discharge port is 355 mm, its production capacity is 3000 tons/table · hour.
With the emergence of large impact bearing, there is a trend at home and abroad to use compound pendulum jaw crusher instead of simple pendulum crusher, because under comparable conditions, the former is 30% more productive than the latter; When the production capacity of the two is the same, the former is 20% to 30% lighter than the latter. However, there are still some problems in the structure of the compound pendulum jaw crusher, which need to be studied and improved.
It should be noted that in recent years, due to the improvement of China’s large rolling bearing materials, as well as the needs of underground coarse crushing equipment, compound pendulum jaw crusher also has a trend of development in the large direction, and 900×1200 compound pendulum crusher is currently being trialed. With the large-scale of equipment specifications, the adjustment device and safety device of the general jaw crusher must adopt a new mechanism. Therefore, another trend in the development of the current jaw crusher is that the size of the discharge port uses a hydraulic adjustment mechanism, which is not only simple and rapid, but also can be adjusted at any time according to needs in the work; At the same time, the overload safety device of the machine is also a hydraulic mechanism to achieve safety and reliability, and does not damage the thrust plate, and the machine immediately resumes work after the fault is removed. At home and abroad are vigorously developing this hydraulic jaw crusher. China has produced 900×1200 hydraulic simple pendulum jaw crusher, and put into use in Laiwu Iron mine and Luozi Iron mine. Production practice has proved that the insurance mechanism and adjustment mechanism of the hydraulic jaw crusher have achieved the purpose of safety insurance and convenient adjustment, and are in good condition and are welcomed by workers on the job.
In terms of improving the crushing efficiency of the jaw crusher, in addition to making local improvements in the structure of the original equipment, such as increasing the height of the crushing chamber and improving the production capacity; Reduce the discharge port and increase the crushing ratio; In addition to increasing the swing speed of the moving jaw to improve the production capacity of the equipment and improve the quality of the product, at present, countries are researching and testing new structure of the crusher, such as impact jaw crusher, double-action jaw crusher and hydraulic jaw crusher.
As far as the jaw crusher is concerned, although the type of structure is different, their working principle is basically similar, but the trajectory of the moving jaw is different. In a word, when the movable jaw plate moves periodically around the suspension shaft to the fixed jaw plate, sometimes approaching and sometimes leaving, when the movable jaw plate is near the fixed jaw plate, the ore between the two jaw plates is broken by the combined action of crushing, splitting and bending and breaking; When the movable jaw plate leaves the fixed jaw plate, the crushed ore is discharged through the discharge port of the crusher under the action of gravity.

Single pendulum jaw principle
The movable jaw is suspended on the axis of the heart and can be swung from side to side. When the eccentric shaft rotates, the connecting rod does the up and down reciprocating movement, and the two thrust plates also do the reciprocating movement, so as to push the moving jaw to do the left and right reciprocating movement to achieve crushing and unloading. This kind of crusher adopts a crank double connecting rod mechanism, although the movable jaw is subject to a great crushing reaction, and its eccentric shaft and connecting rod are not stressed, so the industry is made of large machines and medium-sized machines, used to break hard materials. In addition, when the crusher works, the motion track of each point on the moving jaw is the arc of the center of the mandrel, the arc radius is equal to the distance from the point to the axis, the upper end of the arc is small, the lower end of the arc is large, the crushing efficiency is low, and the crushing ratio is generally 3-6. Because of the simple movement trajectory, it is called simple swing jaw crusher.
The simple pendulum jaw crusher is compact and simple in structure, and the transmission parts such as eccentric shaft have less force; Because the vertical displacement of the moving jaw is small, the material is less broken during processing, and the wear of the moving jaw plate is small.
Compound pendulum jaw principle
The upper end of the moving jaw is directly suspended on the eccentric shaft as a connecting rod of the crank linkage mechanism, driven directly by the eccentricity of the eccentric shaft, and the lower end of the moving jaw is hinged with the thrust plate to support the rear wall of the frame. When the eccentric axis rotates, the motion trajectory of each point on the moving jaw is from the circular line of the suspension point (the radius is equal to the eccentricity), gradually downward into an oval, the lower the lower, the more skewed the oval, until the lower and the thrust plate connection point trajectory is an arc line. Because the motion trajectory of each point on the mechanical moving jaw is more complex, it is called complex swinging jaw crusher.
Compared with the simple pendulum jaw crusher, the advantages are: lighter weight, fewer components, more compact structure, the crushing chamber is full of better, the loaded material block is evenly broken, and the lower end of the jaw is forced to launch the finished product discharge, so the productivity is higher than the productivity of the same specification of the simple pendulum jaw crusher is 20-30% higher; The material block has a large up and down rolling movement in the lower part of the moving jaw, which is easy to be discharged in the shape of a cube
Structure chart
Jaw crusher is mainly composed of: fixed jaw plate, movable jaw plate, frame, upper and lower protection plate, adjusting seat, movable jaw rod and so on. A good understanding of the internal structure of the jaw crusher can play a very good role in the use of the jaw crusher and when there are problems.
Reduction ratio
Crushing ratio is an important evaluation index to measure the jaw crusher, the crushing ratio of the jaw crusher is the ratio of the raw material particle size and the precision of the crushed product. It indicates the degree of reduction of the raw material after crushing. After the ore is broken, the particle size becomes smaller, and the ratio of the particle size before the ore is broken to the particle size after the ore is broken is called the crushing ratio. It represents the ratio of particle size reduction after the ore is broken. The calculation method of crushing ratio is as follows:
1, the maximum particle size of the ore before crushing and the maximum particle size after crushing to calculate the maximum particle size method in China’s concentrator design often uses this calculation method, because the design should be based on the maximum particle size to determine the width of the jaw crusher feed port
2, the ratio of the effective width of the feed port and the width of the discharge port with the jaw crusher
Some jaw crusher, its discharge particle size is not determined by the size of the discharge port.
3, calculate the average particle size of the ore before and after crushing, also known as the average crushing ratio

peculiarity
1, low noise, less dust.
2, its crushing ratio is large, the product particle size is uniform.
3, simple structure, reliable work, low operating costs.
4, the lubrication system is safe and reliable, the parts are easy to replace, and the equipment is simple to maintain.
5, the crushing chamber is deep and no dead zone, improve the feeding capacity and output.
6, equipment energy saving: single-machine energy saving 15% ~ 30%, system energy saving more than double.
7, discharge port adjustment range is large, can meet the requirements of different users.