A Gyratory Cone Crusher is one of the main types of primary crushers in a mine or ore processing plant. Gyratory cone crushers are designated in size either by the gape and mantle diameter or by the size of the receiving opening. Gyratory cone crushers can be used for primary or secondary crushing. The crushing action is caused by the closing of the gap between the mantle line (movable) mounted on the central vertical spindle and the concave liners (fixed) mounted on the main frame of the crusher. The gap is opened and closed by an eccentric on the bottom of the spindle that causes the central vertical spindle to gyrate. The vertical spindle is free to rotate around its own axis. The crusher illustrated is a short-shaft suspended spindle type, meaning that the main shaft is suspended at the top and that the eccentric is mounted above the gear.