A Novel Family of Parallel Mechanisms With Synchronous Telescopic Parallelograms

A novel synchronous telescopic parallelogram mechanism with movement realized by a belt drive is proposed, from which a compound kinematic limb is derived. According to the configuration derivation, a class of two-translation (2T), three-translation (3T) and three-translation-one-rotation (3T1R) parallel mechanisms is obtained by assembling the above kinematic limbs. Since the motion of these limbs in the parallelogram mechanism are dependent, screw theory is applied to illustrate the mobility of the obtained lower mobility parallel mechanisms. Moreover, through the simplified kinematic equations for these mechanisms, their position, velocity and singularity are analyzed and their workspaces are calculated. Finally, the prototype of the 2T parallel mechanism is manufactured and experimented to validate mobility and motion feasibility.