介绍了一类避免瞬时运动两转动一移动(2T1R)并联机构综合的详细过程。根据约束螺旋与运动螺旋之间的几何关系,找到了并联机构瞬时运动产生的拓扑规律,可以简便地判断并联机构的瞬时运动,并用于避免瞬时运动的并联机构综合。在3-RPS并联机构基础上,综合得到两种结构新颖、避免瞬时运动的两转动一移动并联机构。 A detailed process of avoiding the instantaneous movement of two rotating and one moving (2T1R) parallel mechanisms is introduced. According to the geometrical relationship between the constrained spiral and the moving spiral, the topological law of the instantaneous motion of the parallel mechanism is found, which can be used to judge the instantaneous motion of the parallel mechanism easily and to avoid the parallel combination of instantaneous motion. On the basis of the 3-RPS parallel mechanism, two kinds of two-movement-parallel moving mechanism with novel structure and avoiding instantaneous movement are obtained synthetically.