2.1 Basic Concepts of Mechanisms(I1) Coupler 连杆 2 B Crank 曲柄 Rocker Frame or ground r Fully rotating revolute; 摇杆 机架 r Partially rotating revoluteCrank 曲柄 Rocker 摇杆 Coupler 连杆 Frame or Ground 机架 2.1Basic Concepts of Mechanisms(11) Fully rotating revolute; Partially rotating revolute;