半转机构的简约化设计研究

Research on simplest design for half rotating mechanism

半转机构是一种用于动物运动仿生的新机构,对其进行简约化设计是提高仿生机械性能的需要。文中在半转机构不动点运动特征基础上,提出从结构简单的曲柄摇块机构到半转机构的演绎设计方法。指出当曲柄摇块机构的摇块处于与动轴重合的特殊位置时,导杆的回程摆动消失而演变为半转杆。对于在此特殊位置可能出现的运动干涉,给出了带槽动轴及摇块对置两种破解方案。对于破解干涉后出现的机构奇异性问题,提出了带槽动轴与转动滑块组合及止转片与止转槽组合两种局部约束方案,保证了新型半转机构的运动稳定性。试验结果表明,文中提出的干涉破解、奇异性消除及局部约束设计等方法具有可行性和正确性,不但实现了结构极简单的半转机构的简约化设计,而且局部约束消除奇异性方法对于机构创新设计具有借鉴意义和参考价值。

Half-rotating mechanism （HRM） is a new mechanism for animal motion bionic. It is necessary to improve the bionic mechanical properties by HRM simplest designing. Based on the characteristics of fixed point during running for HRM, a deductive design method from crank swing-slider mechanism（CSM） to HRM was proposed. When the swing-block of CSM was in special position which superposed with shaft, the return stroke of guide rod would disappear, by which the guide rod should e- volve to half-rotating rod. Two solutions, such as grooved shaft and swing-block installed in reverse manner, were used to prevent the moving interference occurred in special position mentioned above. To avoid the mechanism singularity after breaking interference, two local restriction solutions, including combination of grooved shaft and turning block and combination of stop turning blade and stop turning slideway, were provided, by which could ensure the stability of mechanism motion of the new HRM. The prototype test illustrated that these design methods, including breaking interference, removing mechanism singularity and local restriction, were feasible and reliable. Removing singularity by local restriction is especially useful to creative design of mechanism.