Using 3D scanner to measure non-circular gear is to scan non-circular gear to obtain point cloud data model of non-circular gear by using non-contact grating photographic scanning technology. The point cloud data is processed, and the theoretical model and actual model after alignment are analyzed and calculated to obtain the error of tooth surface, tooth profile and tooth pitch of non-circular gear.

Firstly, according to the basic law of non-circular gear tooth profile meshing and the formation and properties of involute line of tooth profile, the tooth profile model of non-circular gear is established. On this basis, the tooth surface equation of non-circular gear is established. The tooth profile of non-circular gear is modeled by analytical method and converted tooth profile method respectively. After comparative analysis, the converted tooth profile method is selected for modeling.

Secondly, the non-circular gear is measured. The three-dimensional scanner used in this paper is Einstein SP scanner, which has the characteristics of high scanning accuracy (scanning accuracy ≤ 0.01 mm) and high measurement stability. The probe used is a non-contact probe with structured light scanning, and 180 × 1 (the number of rotations of the scanner is 180) The measurement process is to clamp the non-circular gear on the worktable, project the structured light onto the non-circular gear, use two cameras to take synchronous images of the object, and then obtain the complete and accurate point cloud data model through the point cloud data splicing The software compares the point cloud data model of non-circular gear with the three-dimensional theoretical model, and obtains the two-dimensional and three-dimensional deviation of the non-circular gear, so as to realize the error measurement of the non-circular gear. The point cloud data model is obtained by scanning the first-order elliptic gear with the 3D scanner.

Finally, the meshing method is used to analyze the tooth surface error and calculate the three-dimensional tooth surface error of non-circular gear.