论文部分内容阅读
Most parallel mechanisms (PMs) encountered today have a common disadvantage,i.e.,their low rotational capability.In order to develop PMs with high rotational capability,a family of novel manipulators with one or two dimensional rotations is proposed.The planar one-rotational one-translational (1 R1T) and one-rotational two-translational (1R2T) PMs evolved from the crank-and-rocker mechanism (CRM) are presented by means of Lie group theory.A spatial 2R1T PM and a 2R parallel moving platform with bifurcated large-angle rotations are proposed by orthogonal combination of the RRRR limbs.According to the product principle of the displacement group theory,a hybrid 2R3T mechanism in possession of bifurcated motion is obtained by connecting the 2R parallel moving platform with a parallel part,which is constructed by four 3T1 R kinematic chains.The presented manipulators possess high rotational capability.The proposed research enriches the family of spatial mechanisms and the construction method provides an instruction to design more complex mechanisms.