A jaw crusher is a type of crushing machine that reduces large materials

A jaw crusher is a type of crushing machine that reduces large materials into smaller sized rocks, gravel, or rock dust. It is commonly used in mining and construction applications.

It has a simple structure that allows easy operation and maintenance. It also uses less energy than other types of crushers.

Jaws

Jaw crushers provide initial size reduction of rock samples prior to pulverisation. They have large capacities and operate under harsh working conditions. Size reduction takes place in the wedge-shaped crushing chamber between a fixed and a moving breaking jaw that follows an elliptical path of motion. The squeezing action causes the sample to break into smaller pieces that fall down through the gap and are crushed further. Adjustable gap width regulates final particle size.

The reciprocating movement exhibited by the moveable jaw generates compression force that breaks rock or ore into smaller particles. Operating characteristics such as sloped angle between the moving and stationary jaw, nip angle, gap width and the frequency of operation all influence capacity. The lower the sloped angle, the more a rock or ore is broken into smaller particles. The higher the speed of a jaw crusher, the more it reduces particle size by compressive forces. However, it is important to ensure that the speed does not become too high and that the breakage mechanism does not overload.

Cones

The cone crusher consists of two surfaces-a mantle and a conical head. The mantle gyrates as it crushes the material inside. The distance between the widest point of the cone and its narrowest point, which is called the CSS, determines the size of the resulting crushed material.

While cone crushers can be used on their own, they typically work in conjunction with a first-stage jaw or impact crusher to reduce the size of the raw materials they receive. This helps to prevent foreign objects from jamming the crusher, which could cause significant damage and downtime. For this reason, it's best to consult with a sales team member when considering a cone crusher for your business.

Concave

Concave shapes curve inward, like the inside of a bowl or a partially spherical surface such as a mound. The opposite of a concave shape is a convex one, which resembles a dome or the outside of a contact lens.

Convex shapes have at least one interior angle that measures greater than 180180. A good mnemonic device for remembering the difference between these two terms is to recall that concave has the word “cave” in it, while convex has the word “flat.”

The movement of particles down the crusher chamber can be visualized as a series of wedges that reduce the size of particles progressively until they exit the chamber at the bottom. This process is determined by the frequency of the opening and closing of the jaws (nip angle). To prevent choking near the discharge, concave plates are sometimes used on the lower half of the swing jaw. This allows a more gradual reduction in size and minimizes the chance of packing.

Liner

A liner is one of the most important parts of a jaw crusher. It is a metal plate that sits against the inner mantle to provide support for it during crushing. It also prevents bridging across the crushing chamber.

When a liner is pushed too far, it will crack or bend and cause mechanical problems with the crusher. Understanding your gradation will help you determine the best liner configuration to achieve your production goals.

If you compare a standard Blake crusher with one fitted with non-choking jaw plates, it can be seen that the action of the liners above the point of nip follows quite closely the pattern found in straight concaves in gyratory machines. This is a very favorable feature for these types of crushers and demonstrates the benefit of employing non-choking jaw plates.

Manganese steel is the most common material used in crusher liners. It is work-hardening and will hold up well under stress and impact. It is also very affordable.