Jaw Crushers are used to reduce the sizeof many different types of materials in many applications. The Jaw Crusher was first introduced by Eli Whitney Blake in 1858 as a double-toggle Jaw Crusher. Introduced in 1906, McLanahans Universal Jaw Crusher was one of the first modern era overhead eccentric Jaw Crushers. On the overhead eccentric style Jaw Crusher, the moving swing jaw is suspended on the eccentric shaft with heavy-duty double roll spherical roller bearings.
The swing jaw undergoes two types of motion: one is a swing motion toward the opposite chamber side (called a stationary jaw die due to theaction of a toggle plate), and the second is a vertical movement due to the rotation of the eccentric. These combined motions compress and push the material through the crushing chamber at a predetermined size.
More than 110 years of engineering and customer service experience keep customers running to McLanahan tomeet their production goals. McLanahan Jaw Crushers are proudly made in the USA and have imperial designs. With our grass roots design coupled with listening to customer needs for product enhancement over the years, McLanahan offers traditional hydraulic-shim adjustment Jaw Crushers as well asH-Series Jaw Crushers that featurehydraulic discharge setting adjustment, adjust-on-the-fly chamber clearing in the event the site loses power (once power is restored) and hydraulic relief for overload events with auto-reset.
Whether the traditional hydraulic-shim adjustment or the H-Series Jaw Crushers, both machines have an aggressive nip angle that providesconsistent crushing throughout the entire crushing chamber, which leads to increased production and less downtime on maintenance.
A Jaw Crusher uses compressive force for breaking material. This mechanical pressure is achieved by the crusher'stwo jaws dies, one of which is stationary and the other is movable. These two vertical manganese jaw dies create a V-shaped cavity called the crushing chamber, where the top of the crushing chamber is larger than the bottom. Jaw Crushers are sized by the top opening of the crushing chamber. For example, a 32 x 54 Jaw Crusher measures 32" from jaw die to jaw dieat the top opening or gape opening and54 across the width of the two jaw dies.
The narrower bottom opening of the crushing chamber is used to size the discharge material. A toggle plate and tension rods hold the pitman tight near the bottom of the moving swing jaw. The toggle plate is designed to perform like a fuse and protect the crusher in the event that an uncrushable materialenters the crushing chamber. As a rule, Jaw Crushers have a 6:1 or 8:1 ratio for crushing material. Still using the 32 x 54 Jaw Crusher example, the top size of thefeed entering the crushing chamber has to follow the F80 rule that 80% of the top size feed material is smaller than the gape opening. Using the F80 rule with the 32 x 54 Jaw Crusher, the32 gape opening equals a26 top sized feed, and with the 6:1 ratio of reduction, the discharge setting would be around 4.
Since the crushing of the material is not performed in one stroke of the eccentric shaft, massive weighted flywheels are attached to the eccentric shaft andpowered by a motor. The flywheels transfer the inertia required to crush thematerial until it passes the discharge opening.
While Jaw Crushers are mostly used as the first stage of material reduction in systems that may use several crushers to complete the circuit, the Jaw Crusher has also been used as a second-stage crushing unit. Depending on the application requirements, Jaw Crushers can be used in stationary, wheeled portable and track-mounted locations. The Jaw Crusher is well suited for a variety of applications, including rock quarries, sand and gravel, mining, construction and demolitionrecycling, construction aggregates, road and railway construction, metallurgy, water conservancy and chemical industry.
F100 is the maximum gape opening on a Jaw Crusher. F80 is the feed size to the Jaw Crusher, calculated by taking 80 times the gape opening divided by 100. P80 is the percent passing the closed side setting in tph.
A best practice, if possible, is to blend the material arriving from the source. This will ensure a constant and well-graded feed to the crushing chamber. In turn, this will produce a steady rate of tph andpromote inter-particle crushing that helps break any flat or elongated material. It also aids in equal work hardening the manganese jaw dies and prolonging the life of the jaw dies.
Usually a Jaw Crusher is in an open circuit, but it can be used in a close circuit if the return load is not greater than 20% of the total feed and the raw feed is free of fines smaller than the closed side setting.
Efficiency can be defined by the ratio of the work done by a machine to the energy supplied to it. To apply what this means to your crusher, in your reduction process you are producing exactly the sizes your market is demanding. In the past, quarries produced a range of single-size aggregate products up to 40 mm in size. However, the trend for highly specified aggregate has meant that products have become increasingly finer. Currently, many quarries do not produce significant quantities of aggregate coarser than 20 mm; it is not unusual for material coarser than 10 mm to be stockpiled for further crushing.