A jaw crusher refers to a type of crusher. A crusher is a machine that breaks material, usually rocks, into smaller pieces. Jaw crushers are most often seen in mining or disposal, where they are used to break objects into smaller pieces. Used in processing facilities and on construction sites, jaw crushers can be found as stationary machines installed in a building, portable machines that can be relocated where they are needed, or as bucket extensions to excavator digging machines.
In mining, a jaw crusher is used to reduce large rocks into smaller pieces of rock, like gravel. A jaw crusher is usually the first part of a system of several crushing machines that break down the material into the desired shape and size. Large rocks are inserted into the mouth of the crushing chamber, where hydraulic pressure is applied to the material to crush it into a roughly uniform smaller size. There are essentially two types of jaw crushers: overhead eccentric and double-toggle. Each type of jaw crusher uses a different method to power the crushing chamber of the jaw crushing unit.
Jaw crushers can also reduce the size of crushable trash, making it easier to load and transport. Crushed material is significantly easier and safer to load, transport, and dump. This option is frequently used in the construction or demolition business, when large amounts of breakable material, like concrete, require processing in order to efficiently remove the debris.
One notable difference between the two types of jaw crushers is the location of the pivot point on each crusher. The pivot point is the moving joint at which the metal walls of the crushing chamber are connected. On an overhead eccentric jaw crusher, the pivot point is at the bottom and a rotating wheel is used to guide the moving parts of the crushing chamber. With a double-toggle jaw crusher, the jaw pivots on the top. Double-toggle jaw crushers are often preferred because they tend to be easier to use and consume less energy than overhead eccentric jaw crushers.
Important things to remember when considering types of jaw crushers includes the size of the crushing chamber opening and the length of the crushing chamber. The crushing chamber opening should be large enough to fully and easily fit the original material to be crushed. With jaw crushers, the longer the crushing chamber is, the more crushing power the jaw crusher exerts. Long crushing chambers are ideal for extremely hard material that requires more strength to crush.