球面运动的RSRR揉面机构设计

Spherical Motion Design of the RSRR Kneading Mechanism

提出了一种新型的RSRR揉面机构,用球副代替传统的转动副。采用约束螺旋理论对机构完成自由度分析,结果表明RSRR机构是5阶机构,有1个公共约束和1个自由度。采用齐次坐标变换法建立了机构的多刚体运动模型,求得搅拌头的运动情况。并在运动学分析的基础上实现了机构的尺寸综合,得出容器的高度与半径应成两倍关系的结论。通过数值仿真和虚拟样机运动仿真及干涉检查技术,发现若发生干涉,可适当调整容器或搅拌头的尺寸和位置,更加有效地实现了RSRR揉面机构设计。

A new sort of RSRR kneading mechanism is proposed, and spherical joint replaced revolute in it. The constraint screw theory is adopted to analyze the degrees of freedom; the results suggest that the RSRR mechanism is a fifih--order mechanism, having a common constraint and one degree of freedom. The method of homogeneous coordinate transform is used to establish the multi-body kinematics model, and stir-welding head＇s movement is obtained. The dimensional synthesis of the mechanism is achieved based on the kinematic analysis, and arrive at the following conclusions that container＇s height is twice radius. The techniques of numerical simulation, virtual prototyping and interference detection are utilized to implement the design of the RSRR kneading mechanism effectively. If the interference happen, the size and gesture of container and stir-welding head will be adjusted.