A Novel Synthesis Method for the Hydraulic Excavator Working Arm Based on Type Synthesis

The innovative design of working arm (WA) structures that deliver optimal performance remains a challenge in the development of hydraulic excavators. This study introduces a method for automatic synthesis of hydraulic excavator WA configuration, which conforms to the comprehensive rules of excavator’s working mechanism. First, a Caterpillar excavator WA is presented, and its topographic map can be deconstructed into a contracted picture and several open-loop kinematic chains. Next, the combination rules and the isomorphism identification method are detailed. Following that, an automated method for synthesizing WA configurations with the required bucket degrees of freedom (DOF) and active pair constraints is discussed. Ultimately, all viable 12-bar configurations with 3 DOF are obtained.