Research On Digital Analysis And Manufacture Technology Of Spiral Bevel Gears

Since spiral bevel gears have many advantages,it is widely used in many occasions where transmitting power and motion between intersecting axes is needed.Universal NC machining centers are more and more popular among manufacturing enterprises,because of its powerful machining ability and high level of automation.In order to realize the digitization of the spiral bevel gears manufacture process using universal NC machining tools,in this paper,the research works about the tooth contact analysis and NC machining of spiral bevel gears were done.Firstly,the geometrical parameters and machine setting parameters of spiral bevel gears used for tilting generating method were calculated.Secondly,based on the parameters calculated,the tooth contact analysis(TCA)were completed.According to the result of TCA,the machine setting parameters were modified for many times until the meshing performance was better.The final machine setting parameters were achieved.Third,through kinematic transformation of the machining process,the kinematic formulas of the axes of dual turntable five-axis machine tool were calculated,when the machine tool was used to machine the spiral bevel gears.Corresponding NC program was generated.Finally,machining simulation with VERICUT and actual cutting experiment on the NC program were completed.The main points of the research work of this paper are lay out as follow.(1)In the aspect of tooth contact analysis,the tooth surface models of both pinion and gear which could mesh with each other were established.The two models were assembled according to their designed assembly relationship.The equations which should be satisfied by meshing points were established.The tooth contact pattern and transmission error curve were achieved by solving the equations iteratively.Two methods for tooth contact analysis were applied,so that the advantages of these two methods could be combined.One method used vector rotation and vector operation as its tool.And anther method used kinematics coordinate transformation as its tool.The first one made the calculation of the first meshing point become simply.The second one made the meanings of tooth surface meshing become more clear.A calculation method to calculate the meshing points was proposed,which made the calculation of the first meshing point more effective,and by which the possibility of error was avoided while the meshing points were calculated.(2)The kinematic models of both Gleason No.116 type machine tool and dual turntable five-axis machine center were both established.The cutter position vector and cuter axis vector with respect to the coordinate system of the gear blank were achieved,when the gears were machined by Gleason No.116 type machine tool.These cutter position vector and cutter axis vector were functions of the rotation angle of the cradle.To achieve the same cutter position vector and cutter axis vector,the motions of five axes of the dual turntable five-axis machine center were solved using post processing method.(3)The correctness of the kinematic transformation of the machining process was validated by machining simulation with VERICUT.The technological process,while the spiral bevel gears were machined by dual turntable five-axis machine center,was studied.The tool setting method,when the pinion was machined by this machine tool,was proposed.The machining experiments were completed,which validated the feasibility of the technological process.