JAW CRUSHERS

Jaw crushers are widely used for crushing of large lumps of blaseted rock and river gravel. Crushing action takes place between tow jaws, the moving jaw is suspended on the eccentric shaft and is supported by a toggle plate against the crusher frame , performing a to-and-fro motion against the fixed jaw.

In the upper section of feeding opening, the moving jaw performs a nearly circular elliptical motion, while the motion at the discharge end is a narrow elliptical one leading to an up-and-down motion. This causes the grip-crush effect at the upper part of the crushing chamber and accelerated material flow at the discharge end.

Often in practice its not possible to obtain the desired degree of reduction with one crusher. Jaw crushers with large feed openings are used as primary crushers for crushing of large lumps. Secondary jaw crushers have feed openings smaller than primary crushers and can be operated at finer crusher settings to obtain fine products. The size of the crusher should be selected on the basis of the lumps size to be fed required product size and desired capacity . the charts on back page contain data on crusher capacities and product disttibutions at various crusher settings. Jaw crushers should be selected such that the feed opening should be considerably larger than the maximum lump size to be crushed .This reduces the danger of irregular shaped lumps blocking the feed inlet and as a result material can be fed continously, the capacity of the whole plant is increased .

To achieve the average desired capacity, losses in working conditions should be taken in to consideration and crushers should be selected above theoretical values .