Crushers may be used to reduce the size, or change the form, of waste materials so they can be more easily disposed of or recycled, or to reduce the size of a solid mix of raw materials (as in rock ore), so that pieces of different composition can be differentiated. Crushing is the process of transferring a force amplified by mechanical advantage through a material made of molecules that bond together more strongly, and resist deformation more, than those in the material being crushed do.
A jaw crusher is generally used as a primary crusher in a crushing circuit. Product is fed into the top of the jaw crusher by an vibrating grizzly feeder. The eccentric rotating drive shaft causes the movable jaw to oscillate crushing the aggregate against a fixed jaw. Jaw crushers are run on belt drives driven by an electric motor or diesel engine. Jaw crushers are used extensively throughout the aggregate and mineral processing industry.
Jaw crushers are often used as primary crushers and are perhaps the most popular crusher worldwide. These compressive crushers are suitable for most any type of material.
In this type of crusher, reduction takes place between a stationary jaw plate and a moving jaw plate. The moving jaw plate is mounted on the pitman, which is given a reciprocating motion. Crushing takes place when the pitman moves toward the stationary jaw, compressing the material.
The Perfromance Characteristics of Jaw Crusher:
1. Crushing cavity is deep and there is no dead area, which improves feeding capacity and output;
2. High reduction ratio and uniform final product size;
3. Spacing piece type discharge-hole adjustment device is reliable and convenient;
4. Reliable and safe lubrication system, convenient replacement of parts and small work load of maintenance;
5. Simple structure, operational reliability and low operation cost.
Jaw crusher is widely used for medium crushing various ores and bulk materials in mining, smelting, building materials, highway, railway, water, chemical industry and other industries. The crushed materials are of a compressive strength less than 320MPa. Jaw crusher has the characteristics of big crushing ratio, uniform finished product size, simple structure, reliable work, convenient repair and low operating costs.
This jaw crusher is mainly used in various industries, such as mining, road, railway construction and chemical industry etc.
Single toggle jaw crushers
In the single toggle jaw crushers, the swing jaw is suspended on the eccentric shaft which leads to a much more compact design than that of the double toggle jaw crusher. The swing jaw, suspended on the eccentric, undergoes two types of motion- swing motion towards the fixed jaw due to the action of toggle plate and vertical movement due the rotation of the eccentric. These two motions, when combined, lead to an elliptical jaw motion. This motion is useful as it assists in pushing the particles through the crushing chamber. This phenomena leads to higher capacity of the single toggle jaw crushers but it also results in higher wear of the crushing jaws. These type of jaw crushers are preferred for the crushing of softer particles.
Double toggle jaw crushers
In the double toggle jaw crushers, the oscillating motion of the swing jaw is caused by the vertical motion of the pitman. The pitman moves up and down. The swing jaw closes, i.e., it moves towards the fixed jaw when the pitman moves upward and opens during the downward motion of the pitman. This type is commonly used in mines due to its ability to crush tough and abrasive materials.
