The kinematics and mechanical advantage of the double-toggle jaw crusher

The purpose of this article is to obtain a comprehensive mathematical description of the kinematics of a double-toggle jaw crusher. The driving mechanism of the crusher is modeled as a planar six bar linkage. Two closed position vector loops that characterize the configuration of the mechanism are used to derive expressions for the angular position, velocity and acceleration of the moveable jaw. Dimensional data of a typical double-toggle jaw crusher are used in the derived mathematical expressions to demonstrate their application. Moreover, starting with the equation for the angular velocity ratio of the moveable jaw, with respect to the input crank, an expression for the ideal mechanical advantage of the crusher is derived. The expressions derived in this paper provide the foundation for further investigations into the mechanics and the design of the double-toggle jaw crusher.