Study On Tooth Flank Mismatch Design And Modification Theory Based On Fully Conjugated Cycloid Bevel Gears

Face hobbing method of cycloid bevel gears is currently the most advanced manufacturetechnology, and the manufactured gears have advantages of high load carrying capacity, lownoise and stable transmission, so they are widely applied in automotive rear axle. Comparedwith face milling method of Gleason spiral bevel gears, the continuous indexing of cycloidbevel gears makes flank forming theory become more complex, and the gear design andprocess calculation become more difficult; Moreover, the double flank cut makes contact areacontrol become more difficult. The technical difficulties limit face hobbing technology ofcycloid bevel gears development in the domestic.The theory of tooth flank design and modification for cycloid bevel gears is studied in thispaper, and the method of tooth flank mismatch design is not only established, but also a newtheory of tooth flank modification based on pre-control mismatch tooth flank is put forward,and it will provide theory guidance for cycloid bevel gears design and contact area correction.In this paper the important achievements are listed as follows:Based on fully conjugated tooth flank, the theory of mismatch tooth flank design andmodification method which can cause tooth flank double crowned modification by modifyingcutter parameters is proposed. The tooth flank mismatch topology is constructed, and themapping relationship between cutter parameters correction and tooth flank mismatch topologyis established. By use of tooth contact analysis for mismatch flank, the influence law of cutterparameters correction on tooth contact area and transmission error is studied.The analysis method for the influence law of basic process parameters variation on toothsurface errors is established. The tooth flank is discreted by means of grid dividing, then theflank grid data is solved by use of numerical algorithm, and the tooth flank is simulated; thecalculated method for tooth surface errors is studied, and the mapping relationship betweeneach basic process parameter error and tooth surface errors is established; the analysis methodfor tooth surface errors by use of second order surface is proposed, and the qualitativeanalysis and quantitative analysis for tooth surface errors is studied to acquire the law of basicprocess parameters variation on tooth surface errors.A method of process parameters correction by pre-controlling tooth flank mismatch topology is proposed. The pinion target tooth flank can be created by pre-controlling tooth flankmismatch topology; the pinion real tooth flank can be derived from mathematical model. Byminimizing the deviations between pinion initial flank and pinion target flank, the pinionoriginal process parameters can be corrected, therefore the process parameters of pinionwhich meet the predetermined requirement can be acquired and can be evaluated by means ofTCA technology. Aiming to single flank cut and double flank cut, the construction method ofsensitivity matrix and tooth flank topology modification process are introduced separately.Based on tooth flank mismatch design theory and modification method, the software of toothflank design and tooth flank modification for cycloid bevel gears is developed, and thesoftware of tooth surface errors measurement based on domestic gear inspecting center isdeveloped, and the manufactured and corrected experiment of cycloid bevel gears is achieved.By analyzing the experiment results, the method of tooth flank mismatch design and the toothflank modification theory are verified.