An Offset Laser Measurement Method for the Deviation Analysis of Cylindrical Gears

Abstract

Generally, in the laser measurement of gears, the laser beam passes through the center of the gear, and the laser displacement sensor reads the spatial distance from the gear involute tooth surface to the laser displacement sensor. However, in this method, the angle between the laser beam and the normal vector of the measured tooth surface is too large, which affects the accuracy of the measurement and the stability of the data. This paper proposes an offset laser measurement method. The laser beam is offset from the center of the gear by a certain distance to form a larger incident angle with the tooth surface, which can effectively address the problem and increase the measurement accuracy. Through a selection of the optimal offset distance, the range of optimal offset measurement positions was obtained and clarified by experiments. We solved the data conversion problem caused by the change in measuring position, and we measured the pitch deviation and helix angle of the gear to confirm the feasibility of this method. According to the theoretical calculation and experimental verification, it was found that this method has the advantages of better measurement accuracy and less fluctuation in measurement data. It is, thus, suitable for precision gear measurement.