Research On The Method Of Spiral Bevel And Hypoid Gear Measurement

Spiral bevel and hypoid gears are important components applied to transfer drive in modern gearing. With the marked improvement of gear manufacture technology, the process of manufacturing spiral bevel and hypoid gears have been a synthesis process integrated mechanism, material, control technique, computer science and measuring technique, as well as the tooth surface measurement have evolved from the traditional contact precision control to the tooth surface geometrical precision control, to meet the measuring conditions of gear manufacturing process in modern. Presently, the spiral bevel and hypoid gears are usually measured by imported gear measuring center. Along the measuring grid path spread over the tooth surface, the grid coordinates of real tooth surface can be measured, and then the tooth surface errors are evaluated by software. Though the gear measuring center imported could gain the geometric information of real tooth face of spiral bevel and hypoid gears, its price is high, especially the measurement technique is no open with secrecy, which hampered the digitized development of our own gears manufacture. Therefore, it is very important for improving our country gear product quality and competitive power in international marketplace that study the method of spiral bevel and hypoid gears measurement. Whereas that, the method of tooth surface measurement based on the tooth theory and the identification and compensation of the machine tool regulation error are mainly discussed in this thesis, which would be helpful for developing our own tooth surface precision control system of spiral bevel and hypoid gears. The main work of this thesis is summarized as follows:1. Tooth surface mathematic modeling. The basic tooth principle of spiral bevel and hypoid gears is introduced briefly; the machining theory of spiral bevel and hypoid gears, the manufacturing method and machine tool regulation parameters are studied; according to the machining theory of spiral bevel and hypoid gears, gear mesh theory and kinematics theory, the mathematic model of tooth surface is established, which is the theory proof of both the real tooth surface measurement and calculating the theoretical tooth surface data. 2. Programming the measuring grid path. Based on rotating projecting method, the measuring grid could be programmed and the theoretical coordinate values of measuring grid crunodes in tooth surface are obtained. The result of these data subtract from the corresponding real data measured by gear measuring center are the tooth surface normal errors.3. Studied the measuring method of spiral bevel and hypoid gears in gear measuring center. The problems including the distilling method of measured data, the conversion between gear reference frame and measuring reference frame, the tooth error arithmetic and tooth surface orientation in measuring reference frame are analyzed and solved in detail. At last, the measuring grid coordinates of real tooth surface are measured, and the tooth surface accuracy were analyzed and evaluated by calculating the normal errors of the coordinate points, and the tooth map of errors are drawn. And the data would be the reliable basis of adjusting machine tools regulation and compensating the contact pattern of the tooth surface.4. Discussed the machine tool regulation error recognizing and compensating. By the study of the spiral bevel and hypoid gear machine tool regulation error, the error compensation mathematical model is established, and the of Adaptive Genetic Algorithm (AGA) is advanced to calculate the machine tool regulation parameter compensating value.