嵌入控制油腔的静压主轴轴心运动主动控制分析与试验

Analysis and experiment of active motion control of hydrostatic spindle embedded with control recess

为了进一步提高机床主轴的回转精度,在不增加主轴机械结构复杂度的情况下,通过控制主动单面薄膜节流阀,主动调整嵌入控制油腔的静压轴承的油膜力,对主轴的径向运动进行控制。基于雷诺方程以及流量守恒方程得到轴承油膜力,建立了主轴轴心运动的理论模型。基于PID控制器进行了主轴径向回转误差主动控制的理论和实验研究,对比分析了不同类型载荷条件下的主轴轴心运动控制情况。结果表明,在定载荷条件下,该主动控制静压主轴系统能够将轴心保持在目标位置;在动载荷条件下,轴心运动幅度能够得到有效降低且运动中心相比于无控制的情况更靠近目标位置。

In order to improve the rotation accuracy of the machine tool spindle without increasing the mechanical structure complexity,by controlling the active single-sided film throttle valve,the oil film force of the hydrostatic bearing embedded with control recess is actively adjusted to control the radial motion of the spindle.The oil film force of the bearing was obtained according to the Reynolds equation and the flow continuity equation,then,the theoretical model of the spindle motion was established.Theoretical and experimental researches on active control of the spindle radial rotation error were carried out based on PID controller,and the spindle motions under different types of loads were compared and analyzed.The results show that the spindle center can be kept at the target position under fixed load with the control of active hydrostatic system.The amplitude of the spindle motion under dynamic load can be reduced effectively and the orbit center is closer to target position than that without control.