非正交坐标系中转子振动的测量

Measurement of Rotor Vibration in Nonorthogonal Frame

为了解决实测转子振动时所产生的失真问题 ,分析了非正交坐标系中转子振动的变化 ,建立了非正交坐标系与正交坐标系的变换关系 ,并进行了实验验证。结果表明 ,无须强求两个传感器相互垂直安装 ,只要利用本文所建立的变换关系仍可得到转子在正交坐标系中的振动 ,但两个传感器间的夹角最好控制在 2 5°～ 15 5°之间。由此不会产生明显的误差 ,为传感器的安装带来极大的方便。

In practice,the two transducers measuring rotor vibrations sometimes can not be mounted in mutually perpendicular directions because of the restriction of machine structure.In this case,the interpretation and description of the measured vibrations will not represent the true rotor vibrations,compared to those in orthogonal frame.In this paper,the description of motion of a rotor in a non-orthogonal frame is discussed,which reveals a significant deformation of the interpretation of the rotor motion.The transform relationship between non-orthogonal frame and orthogonal frame is established,with which the vibrations measured in non-orthogonal frame can be easily transformed into orthogonal frame,as in general,the vibrations of a machine are evaluated in orthogonal frame.In this way,two transducers in the same transverse plane are allowed to be mounted in any arbitrary radial directions.It is suggested however that the angle between two transducers be kept within 25°～155°.This result provides an obvious convenience for installation of transducers in practice.An experimental verification shows that the transform is feasible and reliable