Jaw crusher can be divided into single pendulum jaw crusher, compound pendulum jaw crusher and comprehensive pendulum jaw crusher according to the different pendulum mode of swing jaw plate. In which, the single pendulum jaw crusher, because of its simple motion trail and impact structure, is widely used in mining, smelting, construction, railway, highway, water conservancy and chemical industry, etc for the primary and secondary crushing of various ore and rocks with big granularity, the compressive strength not exceed 320Mpa.
Single pendulum jaw crusher is mainly composed of the frame, supporting device, crushing working mechanism, transmission unit, safety device, discharge opening adjustment device and other parts.
A. Frame & Supporting Device
Frame is the heaviest part of ore crusher. It should have sufficient strength, because it would bear strong squeezing force from the crushed materials. The frame can be made from cast steel as a whole, but with the large size of the crushing machine, the frame becomes more and heavier, so it is difficult to be transferred and made. As a consequence, the frame of large size jaw crusher (large than 1200mm x 1500mm) is made into combination parts including top and bottom parts (or several parts), the swing jaw suspension shaft and eccentric shaft bearing are installed in the top of frame.
B. Working Mechanism
Crusher working mechanism is the crushing cavity that equipped with fixed jaw and moving jaw. It is the place to crush ore, so is easy to wear and tear. Crushing cavity is equipped with removable liner plate, and the abrasion of liner plate in different part is different, usually lower part wears fast. In order to prolong the service life, often make liner plate as interchangeable blocks or be turn around.
In order to make the liner plate and jaw plate being tightly and firmly joint together to ensure each point on the liner plate receiving the even force, should insert the plasticity material, such as lead, zinc, or some alloy liner between the liner plate and jaw plate.
On the two side of crushing cavity install side liner plate in manganese steel. Because it doesn't crusher ore, its surface is smooth, the abrasion is small. It is fixed on the side mantle through bolts, which is helpful for replacement.
C. Transmission Units
The movement of movable jaw plate of the jaw crusher is realized the aid of eccentric rod and thrust plate. The unit comprises of flywheel, eccentric shaft, connecting rod, front thrust plate and back thrust plate (which are termed as toggle plate) Two flywheels are installed on the two ends of the eccentric shaft. Eccentric shaft is installed in the bearing, which is on the side of the frame. The connecting rod installed on the upper part of the eccentric shaft. And one side of the front and back thrust plate are installed on the lower part of the connecting rod and groove of the thrust plate seat respectively. One end of the front thrust installed on the seat of the toggle plate seat, the other end of the back thrust in installed on the thrust plate seat on the back of the frame body. The eccentric shaft was driven through the belt by the motor, which makes the connecting rod making up and down movements to drive the front thrust plate to make movement. The angle generated by the constant movement of moveable jaw plate, makes the movable jaw plate do pendulum movement along the hanging shaft and crushing the mineral ores.
Eccentric shaft is a key component of the crusher, which driving the connecting rod makes up and down movements. Since it has to withstand strong crushing impact force, usually, it is made of high quality alloy steel.
The connecting rod has to endure strong tension force, as a result, it is made of casting steel. For large type jaw crusher, combined connecting rods is adopted to reduce the weight and material costs, but such large jaw crusher does not equipped with safety device.
Thrust plate is also called toggle plate. It is a rod that transmitting movement to the jaw crusher, meanwhile, it is also functioned as the safety device, changing the length of the toggle plate and adjusting the size of the discharge opening.
D. Safety Device
Safety device is a kind of device that protects the crusher's main part free from damage when the non- crushed materials (e.g. iron) enter into crushing cavity. Thrust plate is the most common safety device to be used in the crushing machine.
E. Discharge Opening Adjustment Device
The discharge opening is increasing with the abrasion of liner plate, the products grain size become coarse. In order to get the qualified products, the discharge opening adjustment device is equipped in the machine, the adjustment method including wedge adjustment and spacer adjustment.