Research On The Measuring Technology Of Spiral Bevel Gears Based On Gear Measuring Center

The tooth surface of spiral bevel gears is complex spatial curved surface, it can complete transmission on the intersecting axes or staggered shaft. Compared with straight bevel gear, spiral bevel gear has a large degree of overlap, smooth transmission, small transmission noise, high load capacity. Therefore, spiral bevel gears have been widely used in a variety of high-speed heavy transmission. Especially used in the aviation, marine, automotive, tractor, oil, mining machinery, railway locomotives, precision machine tools and other industries. Currently, processing technology and equipment for spiral bevel gears were monopolized by the Gleason company and Klingelnberg company, these two companies have realized the digital closed-loop manufacturing of spiral bevel gears, thereby improved the machining precision and efficiency significantly.In order to realize the digital closed-loop manufacturing of spiral bevel gears, it needs to use the gear measuring center or coordinate measuring machine (CMM) to measure the tooth profile errors of actual tooth surface. A few Chinese companies are able to manufacture gear measuring center. Compared with foreign products, there are a lot of shortcoming in the measuring efficiency, accuracy and application scope. First, the spiral bevel gears measuring software of domestic gear measuring center is developed based on spread blade/fixed setting method. It can’t measure the spiral bevel gears manufactured by completing method or UMC method, it limits the application of gear measuring center; Secondly, the method for planning the measuring path and processing the measuring data is not perfect, the accuracy and efficiency needs to be improved. According to the domestic status of spiral bevel gears measuring technology, the paper studied the measuring technology of spiral bevel gears based on gear measuring center. The main research results are as follows:1) Based on the machining principle of spiral bevel gears and gear meshing theory, and using the knowledge of vector operations and differential geometry, the universal mathematical model for spiral bevel gear manufactured by formate method, generated method and completing method was established.2) The tooth surface of spiral bevel gears was discretized.The spatial coordinates and normals of spiral bevel gears manufactured with completing method is calculated by Newton’s two dimensional iterative method. In Visual Studio2008programming environment, and based on C++/CLI, the software for calculating the spatial coordinates and normals vector of theoretical tooth surface was developed.3) The center of standard ball was fitted by least-squared method and the measuring coordinate system was established. The transformation between the measuring coordinate system and the gear coordinate system is established.4) The measuring path of pinion and gear was planned. Based on the functions library of gear measuring center, the software for measuring profile errors was developed with Visual Studio2008programming environment.5) Based on the coordinates of probe ball center and using the NURBS surface fitting technique, the surface formed by the center of ball was fitted. Compensating probe radius along the normal direction of the fitted surface, a mathematical model of the actual tooth surface was built. The tooth profile errors between actual tooth surface and the theoretical tooth surface was obtained by iteration algorithm. A software that processing the data of tooth profile errors was developed in the Visual Studio2008programming environment. The correctness of the tooth profile errors measuring software and data processing software is verified by experiments.