Contact Free Measurement of Tooth Form Deviation (of Involute Gear Using Laser Interferometry)

1.针对干涉仪中光学元件的安装不可能没有角度、位置等误差的情况，介绍了一种测量被测表面相对于参考表面的相对形位偏差的方法，并对干涉仪中各光学元件的安装误差进行了实验分析。应用该方法，通过CCD图像传感器分别获取基准齿面和被测表面的干涉条纹图亮度数据，结果表明，小螺旋角直齿轮和斜齿轮存在一定误差时，其齿形偏差的测量精度与接触式测针相同.通过干涉测量获得的相位被限制在从-π到π的区域中。提出了一种通过部分人工数据处理将不连续相转换为连续相面的方法。根据这种方法和两片平行薄膜间距很小的原理，将相位数据转换为齿形偏差. CCD图像传感器获得的条纹密度干涉条纹图很粗。这一事实使得不连续相向连续相的转化变得困难。为了避免这一问题，提出了在参考光路中插入透镜来降低干涉条纹密度的方法，该光学系统的使用带来了干涉条纹密度的降低和噪声的增加。

1. A method of measuring relative form deviation of the surface to be measured to a reference surface is introduced, because it is impossible to set up optical parts without error of angle and position etc, and to analyze the setting error by experiment of each optical part in the interferometer. By applying this method, brightness data of interference fringe patterns for a reference tooth flank and the surfaces to be measured are respectively obtained by CCD imege sensor, as the result, the form deviation of teeth with some errors for spur gear and helical gear with small helix angle is shown to be measurable with the same accuracy as by using contacting stylus.2. Phase obtained by the interferometry is restricted in the region from -pi to pi. A method that the discontinuous phase is converted to a continuous phase surface by partially manual data processing is developed. From this method and principle of two pararel thin films with a small distance, the phase data are converted into the tooth form deviation.3. Fringe density interference fringe pattern obtained by CCD image sensor is very thick. The fact makes transformation of discontinuous phase to continuous one difficult. To avoid this problem, a method to decrease the density is shown by inserting some lenses in the reference optical path, and the use of the optical system brings a thin density of fringe patterns as well as noise.