2. GYRATORY CRUSHERS
The gyratory crusher is a pressure crushing device as is the jaw crusher. The crushing action itself is simple. There is a fixed crushing surface known as the concaves which is w I' FIG. 24. Sectional view of hydraulic support .~sembly (COURB~ of AllirChi men). Legend: (I) main, (2) thrustbearing wbly. (3) hydraulic piston. basically the frustum of an inverted cone. A .