Compared with traditional mechanisms, a new class of mechanism considering both the rigid and the flexible elements is proposed to satisfy the demands of modern engineering in this paper. This class of mechanism is named as generalized mechanism, and they consists of generalized links and kinematic pairs. First, based on screw algebra, we derive the motion spaces of generalized links and the
... [Show full abstract] constraint spaces of generalized kinematic pairs. Then, we analyze the minimal and maximal mobilities of generalized links, as well as the minimal and maximal constraints of generalized kinematic pairs. Finally, three formulas for calculating the degree of freedom (DOF) of generalized mechanisms are established. The analytical results show that the DOF of each generalized mechanism is not unique, but an interval value. The real DOF of generalized mechanisms depends on both the links’ materials, the magnitude and direction of external loads.