Purpose

The torsional vibration of RV reducer is the key factor affecting the positioning accuracy and trajectory accuracy of industrial robots. It is of great significance to study the torsional stiffness periodic fluctuation and parametric torsional vibration to improve the torsional vibration performance and transmission accuracy of RV reducer.

Methods

Based on the torsional stiffness test device of RV reducer, the torsional stiffness is measured and the torsional stiffness curve with periodic fluctuation is obtained. The trigonometric function fitting and mathematical description of torsional stiffness curve are carried out, and the torsional vibration equation of RV reducer parameters is established. The parametric torsional vibration response of RV reducer is simulated by Runge–Kutta method, and the combined frequency characteristics and system stability are analyzed. The torsional vibration test device of RV reducer is developed to study the torsional stiffness fluctuation and torsional vibration fault.

Results

The torsional stiffness fluctuation of RV reducer can be divided into a short period and long period, corresponding to different manufacturing errors, and the mechanism of torsional stiffness fluctuation is found out. The frequency spectrum of torsional vibration under working condition is highly consistent with the simulated response spectrum, and the harmonic resonance interval obtained by frequency sweeping is close to the peak of the torsional vibration–speed curve, so the correctness of the established torsional vibration model is verified. Using the mechanism of RV reducer stiffness fluctuation to realize rapid diagnosis of defective parts of RV reducer has a strong engineering application value.

Conclusion

The time-varying torsional stiffness of RV reducer will cause the phenomenon of parametric torsional vibration. The vibration response characteristic frequency is a linear combination of internal reference variation frequency and external excitation frequency. The parametric torsional vibration will cause the harmonic resonance of RV reducer and aggravate the torsional vibration. Therefore, it is of great engineering value to study the time-varying torsional stiffness and torsional vibration of RV reducer.

中文翻译：

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基于时变刚度的RV减速机扭转振动研究

目的

RV减速机的扭转振动是影响工业机器人定位精度和轨迹精度的关键因素。研究扭转刚度的周期性波动和参数化扭转振动对提高RV减速机的扭转振动性能和传递精度具有重要意义。

方法

基于RV减速机的扭转刚度测试装置，对扭转刚度进行了测量，得出了具有周期性波动的扭转刚度曲线。进行了三角函数拟合和抗扭刚度曲线的数学描述，建立了RV减速器参数的扭转振动方程。通过Runge–Kutta方法模拟了RV减速器的参数扭振响应，并分析了组合的频率特性和系统稳定性。开发了RV减速机的扭转振动试验装置，以研究扭转刚度波动和扭转振动故障。

结果

RV减速机的扭转刚度波动可分为短期和长期两种，分别对应于不同的制造误差，找出扭转刚度波动的机理。工作条件下的扭转振动频谱与仿真响应谱高度吻合，扫频得到的谐波共振间隔接近扭转振动速度曲线的峰值，因此建立的扭转振动模型的正确性是已验证。利用RV减速器刚度波动的机理，实现RV减速器缺陷部位的快速诊断，具有很强的工程应用价值。

结论

RV减速器的时变扭转刚度会引起参数扭转振动现象。振动响应特征频率是内部基准变化频率和外部激励频率的线性组合。参数扭转振动会导致RV减速器产生谐波共振，并加剧扭转振动。因此，研究RV减速器的时变扭转刚度和扭转振动具有重要的工程价值。