Jaw Crusher, Mobile Crusher Plant, Primary Crushers

Jaw crushers are widely used for crushing of large lumps of blasted rock and river gravel. Crushing action takes place between two 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 the feed opening, the moving jaw performs a nearly circular elliptical motion, while the motion at the discharge end is a very 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 an accelerated material flow at the discharge end. Often in practice it is 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. The size of the crusher should be selected on the basis of the lump size to be fed, required product size and the desired capacity. 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 continuously, the capacity of the whole plant is increased. To achieve the average desired capacity, losses in working conditions should be taken into consideration and crushers should be selected above theoretical values. DESCRIPTION THE FEED OPENING is the horizontal dimension between the fixed and moving jaw plates, measured from a tooth top on one jaw plate, to a root between two teeth on the other. THE CRUSHER SETTING is the discharge opening between the jaw plates farthest down in the crushing chamber. This is measured in the same way as, when the discharge opening is in the fully closed position. THE NIP ANGLE is the angle between the fixed and moving jaw plates. This angle must not be greater than the optimum value otherwise the jaw plates can not grip the material properly and the capacity will fall considerably