Spiral bevel gear is an indispensable part of the power transmission system. Spiral bevel gear is a kind of complex structure among various gears. It has the advantages of large coincidence, high bearing capacity and high transmission efficiency. Therefore, it is widely used in aviation, aerospace, transportation, machinery, instrument manufacturing and other industries. The spiral bevel gear of helicopter transfers all the load of the engine in the main reducer, which is the core part of the main reducer. The traditional spiral bevel gear crown is manually rounded by the fitter driving the grinding wheel with wind rotation. The rounding quality is irregular and the consistency is poor. Sharp edges and burrs are easy to appear, which will interfere in the meshing process of spiral bevel gears and crush the root position of matching gears. Under long-term working conditions, it is easy to form stress concentration at the root of the matched gear, produce fatigue cracks and form hidden dangers of tooth breakage, which seriously affects the flight safety of the helicopter.
After studying the current situation of spiral bevel gear machining in detail, an automatic rounding machining method based on reverse engineering modeling is proposed. Using the reverse engineering modeling function of spiral bevel gear calculation software, the mathematical model of spiral bevel gear tooth profile is established, the model is imported into three-dimensional drawing software to establish the mathematical model of tooth top, and then the five axis NC program of corresponding rounding part is compiled and processed. This technology can fundamentally solve the technical problem of high-efficiency and high-precision rounding of spiral bevel gear tooth top. Compared with the traditional manual rounding process, it has good product quality consistency, high processing efficiency, wide popularization and application prospects, and has remarkable economic and social benefits.
The technology uses the technologies of spiral bevel gear digital machining, P100 measurement, spiral bevel gear reverse engineering modeling, UG software programming, VERICUT software machining simulation and five axis machining center rounding machining, which belongs to the integration of many technologies. The nano blue coated integral cemented carbide ball end milling cutter is used to overcome the difficult problem of carburizing and hardening alloy steel material processing through five axis high speed and high feed. The processed spiral bevel gear has good tooth top rounding consistency and high machining efficiency. It improves the rounding quality of spiral bevel gear tip, so as to improve the service life of parts, which has remarkable economic value and social benefits.