3-TPT型并联机床刚度分析

Stiffness analysis of 3-TPT parallel mechanism

以3-TPT型并联机床为研究对象,对机床运动平台的刚度进行分析。首先从运动平台所受作用力和发生位移的关系角度出发,建立刚度模型,并得到机床静刚度的度量指标;然后计算分析上下平台外接圆半径差对机床静刚度的影响;最后在MATLAB环境下,对机床运动平台在工作空间的静刚度情况和各坐标方向上的位置偏差进行分析,研究结果表明:运动平台在中心处具有较大刚度,远离中心时刚度下降,且Z方向刚度下降较快,X和Y方向刚度降低较为缓慢,这一分析为3-TPT型并联机构的优化设计应用提供了理论依据。

The 3-TPT parallel machine to01 was taken as the study object to study the stiffness of the motion platform. Firstly, the stiffness model was established according to the relationship between the force exerted on the motion platform and the relative displacement. The static stiffness of machine tool was obtained. The influence of eircumradius difference between up and down platform on the static stiffness was analyzed. Finally, the static stiffness of motion platform workspace and potion differences in each coordinate direction were analyzed in MATLAB environment. The results showed that the motion platform was with the greater stiffness in the center. If the motion platform left away from the center, the stiffness decreased. And the stiffness in the direction Z decreased much faster than that in the direction X and Y. This provided theoretical foundation for the optimal design and application of 3-TPT parallel machine tool.