Tooth Contact Analysis Of Spiral Bevel Gear Based On The Ease-Off Topological Surface

Spiral bevel gears are important mechanical transmission components. They can not only transfer power and movement, but also can change the direction of transmission and they have the advantages of stable transmission, bearing capacity and so on. Therefore, they are applied widely as key components in the transmission of motion and air power. The meshing quality reliability and service life is an important factor affecting the safety performance of the product. Due to the high level of spiral bevel gear tooth surface sophistications and there are many difficulties in the aspects of design, manufacturing and testing. So quality control of tooth surface design and manufacturing process are always hot issues of concern to this industry. Usually the index to measure the performance of gear pair is the driving error and contact area.At present, the engineering is generally used induced curvature to estimate the tooth contact zone. This method is only considering the second order differential neighborhood, it is not accurate, sometimes in order to improve the estimation precision, a deep discussion to the three order differential neighborhood is needed. Not only the theory analysis is very complex, but also a significant increase in the amount of calculation. In view of these problems of traditional TCA, This paper presents a new method of tooth contact analysis that is based on the ease-off topological surface of spiral bevel gear, and has carried on the thorough theory discussion and research. The main research contents of this paper are listed as follows:1 Based on the meshing principle method, the procedure of ease-off topological surface has been written that based on the method of SGM. The mathematical model of pinion and gear have been established and the equation of gear surface was obtained through the coordinate transformation. The mesh coordinate system has been established and the conjugate tooth surface equation of pinion was obtained by the completely conjugate principle. Relations between the two tooth surface space corresponding points was established by the conjugate tooth surface and theoretical tooth surface coordinates in rotating projection plane overlapping relationship. Through the ease-off surface topology was establish by the deviation vector of two tooth surface corresponding points.2 Using ease-off topological surface as a tool, according to the distance relationship of the mapping curves of the instantaneous contact line on the ease-off topological surface to the rotation of the projection plane, solving the contacting point of the tooth surface, and then determining the contact trace. Transforming the distance of the contact point to the rotating projection of the point of the mapping curves to the contacting point, and then determining the contact ellipse through iterative method. According to the principle of spiral bevel gear TCA based on the ease-off topological surface, writing the corresponding TCA program through the FORTRAN software.3 The machining experiment was carried out for spiral bevel gear of gear and pinion in the CNC gear grinding machine. The real tooth surface of grinding was tested using Mahr machine of measuring instrument. The real tooth surface of gear that was grinded processing was been tested. Finally, the spiral bevel gears were installed in rolling inspection machine for rolling inspection test. Rolling test experiment and topological surface of spiral bevel gear based on ease-off TCA simulation contact region were comparison and analysis.