How does a single toggle jaw crusher work?

The jaw crusher consists of a fixed jaw plate which is mounted within the crusher mainframe and a movable jaw plate which is mounted to a jawstock. There are cheek plates mounted on the insides of the crusher to act as additional wear parts to protect the crusher mainframe. The two jaw plates are positioned in a V-shape so that the space narrows from top to bottom. The angle within the V is known as the nip angle. An elliptical motion is created by an eccentric shaft passing through the top of the jawstock which pivots around a toggle plate at the lower half of the jawstock. This geometry turns the rotary motion of the eccentric shaft into a fore aft motion at the bottom of the jaw plate creating the crushing action. The material is then compressed between the two jaw plates, reducing in size as it gets lower in the crushing chamber until it extits at the bottom. The output size of the material can be varied by adjusting the gap between the fixed jaw plate and moving jaw plate. This is known as the CSS (closed side setting) and is generally measured between the peak of one jaw plate and the trough of another.