基于振动中心固定的静偶分离摆架研究

传统双面立式平衡机由于摆架结构关系，振动中心不固定，往往导致实际测量误差较大，静偶分离效果不佳。通过对传统双面立式平衡机振动模型的理论推导，建立了传统双面立式平衡机振动中心的位置公式，计算出簧板绕振动中心的扭转刚度。依据振动中心和扭转刚度的相关参数变化趋势图，分析出传统平衡机测量误差来源。以误差来源提出一种能够保持振动中心固定的静偶分离摆架结构，同样基于振动模型推导了振动中心位置公式，验证了振动中心的不变性；依据静偶分离摆架系统的扭转刚度公式，得到常量刚度值，实现了传感器的测量稳定。另一方面通过对不同结构参数下静偶分离摆架的模态分析，发现了摆架结构的独特分离性。即柔性铰链只传递摆动信号而平动簧板只传递平动信号，两者在功能上相互独立从根本上决定了摆架的静偶分离。同时模态分析结果与不同形状柔性铰链的静力分析结果为摆架结构的优化设计提供了参考依据。最后动平衡测量实验表明，静偶分离摆架有效的提高了对低速旋转载荷的静偶分离能力。

Research of Static-couple Separation Swing Frame on the Fixed Vibration Center

Owing to the structure of the swing frame, the vibration center of the traditional two-plane vertical balancing machine is fluctuated, which often leads to the large error on measurement and the poor effect for static-couple separation. Based on the theoretical derivation of the vibration model of the traditional two-plane vertical balancing machine, the position formula of the vibration center was established, the torsional stiffness of the springboard around the vibration center was calculated, and the source of error was obtained by the change trend chart of the vibration center and torsional stiffness in the end. In accordance with the source of error, a static-couple separation swing frame that can keep the vibration center unchanged was presented, the position formula of the vibration center was also derived based on the vibration model and the invariance of the vibration center was verified. The constant stiffness value was proved by the torsion stiffness formula of the static-couple separation system, and the measurement stability of the sensor was realized. By the modal analysis of the static-couple separation swing frame, it was found that the flexure hinge only passed the swing signal while the translational spring plate only transferred translational signal. The two functions were independent of each other, which fundamentally determined the static-couple separation of the swing frame. The influence of structural parameters on the swing frame was analyzed for optimizing the design of structure too. Ultimately, the dynamic balance measurement experiments showed that the static-couple separation swing frame effectively improved the capability of static-couple separation for low speed rotating loads and provided an important basis for the structure design of balancing machine swing frame.