There are two ways to adjust the discharge opening of jaw crusher:
1) Washer adjustment
Put a group of washer with same thickness between back thrust plate base and frame back wall. By increasing or decreasing washer quantity to enlarge or reduce discharge opening. This kind of method can be applied in multi-level adjustment. The compact structure can reduce machine weight, so when adjusting the machine, should stop it firstly. Large-scale jaw crushers normally adopt this method.
2) Wedge adjustment
By use of the two wedges between back thrust plate base and frame back wall to complete the adjustment of discharge opening. Turn the nut to move the wedge up and down along the frame back wall, or move the wedges forward and backward to push thrust plate and swing jaw to adjust the discharge opening. In this way, you can adjust discharge opening without limit that can save time and easy for adjustment. But this method increases the machine weight and dimension. Medium and small size of jaw crusher adopts this method.
Jaw crusher adopts hydraulic protection device which is stable and easy to eliminate fault. There is a hydraulic cylinder and piston on the connecting rod. Cylinder connects with the top of rod, and piston connects with the thrust plate base. When the machine running well, the oil cylinder is full of pressure, the piston and oil cylinder can be deemed as a whole connecting rod. When the materials enter into crushing chamber, the oil pressure increases quickly which pushes the fluid valve, drain the oil, and the piston separates from the cylinder. Meanwhile, although the connecting rod moves up and down with the rotation of eccentric shaft, the piston does not move. So the thrust plate and swing jaw do not move to play the role of safety device.