空间凸轮驱动的单自由度PRS型并联机构及其设计

On Design of 1-DOF PRS Type Parallel Mechanism Actuated by Three Cylindrical Cams

提出一种用直动从动件空间凸轮驱动的PRS型并联机构,应用一套齿轮传动系统使各分支联动,构成单自由度并联机构。通过设计各分支的运动周期,可使机构在一个很长的公共周期内实现特定的运动。另外,可通过改变分支的相位,实现动平台的随机任意空间运动,模拟一种多自由度并联机构的模糊控制效果。给出了系统的结构简图及相关参数设计的公式,讨论了设计参数对动平台运动输出的影响,并给出了应用实例。

A new kind of 1-DOR（Degrees of Freedom） PRS type parallel mechanism actuated by three cylindrical cams was presented. The cylindrical cams were driven by gear system so the PRS type mechanism became 1-DOF. The long kinematic cycle of mechanism were obtained through designing cam cycle of each branch and the gear ration. The moving plate of the PRS parallel mechanism can simulate three dimensional random motion by modulating the phases of cams both in manually control and in automatic random modulation through changing center of gravity and dynamic force of the mechanism by putting the clutches in the cam shafts. The schematic diagram of system and formulas of the design parameters were given, and the influences of design parameters on output motions were discussed. The mechanism is suitable for the case where the three dimensional ouput motions of moving plate of parallel mechanism have not accurate requirements such as in entertainment and healthy devices. An example is given to show applications of the mechanism.