FOUR-BAR MECHANISM FOR A PORTAL CRANE: A BRIEF OVERVIEW

The present article aims to increase knowledge of a four-bar mechanism. A four-bar system is a planar mechanism. There are many types of simple mechanisms, such as: Chebyshev, Chebyshev lamda, Hoecken, Roberts, Watt’s, Grasshopper, horse-head, pantograph and Peaucelier. More complex mechanisms are: Stewart platform or Jansen’s linkage. The determination of the degrees of freedom (DOF) for a system is done using the Chebychev-Gruebler-Kutzbach relationship. Due to this fact, the DOF for the four-bar system has the value one. Moreover, we analyze the following angles: θ, α, β and φ3in the mechanism. Finally, using Matlab software the drawing and the dynamic simulation of a four-bar mechanism is carried out. Besides, the dynamic simulation is represented after 3s, 6s and 12s.