Research On The Modification Method Of Spiral Bevel Gears

The tooth surface of the spiral bevel gear is not expandable,and the processing is difficult.In the actual manufacturing process,the processing method using the linear blade approaching,and various errors and deformation factors in the production process,inevitably deviate the design tooth surface.If the improvement of the spiral bevel gear contact area and its transmission performance are only considered from the viewpoint of improving the manufacturing and mounting precision,the manufacturing cost of the spiral bevel gear will be greatly increased.In addition,the teeth are deformed by the action of the load during the meshing process.Eventually,the location of the contact area is unreasonable,causing vibration and noise as well as service life problems.To make up for these shortcomings,since the concept of gear shaping has been proposed in the 1950 s,many domestic and foreign experts and scholars have carried out a lot of research on gear modification methods,but there is no recognized and accurate method of shaping the spiral bevel gear.In order to improve the contact area of spiral bevel gear,in view of the understanding of gear modification principle and research status,aiming at the problem of deviation between the actual and theoretical contact position of spiral bevel gear,on the basis of studying the calculation of meshing stiffness of spiral bevel gear,this thesis analyzes the influence of installation errors on the contact area position of spiral bevel gear.Finally,the method of modification of the spiral bevel gear is studied by combining the deformation and error factors,which improves the tolerance of the contact area of the tooth surface.The main contents are as follows:Firstly,according to the gear meshing principle,the gear contact analysis method is deduced and calculated.Aiming at the contact simulation analysis and deformation calculation of spiral bevel gear,the contact analysis calculation model based on the slicing method is established.Secondly,based on the contact analysis and calculation model of the slice method,the simulation model of the spiral bevel gear pair was established by using the 225-force of SIMPACK software.The variation law of load and stiffness was studied,and the time-varying stiffness of the spiral bevel gear based on the actual coincidence degree of SIMPACK is proposed.The numerical values are compared with the ISO standard calculation method,and the correctness and rationality of the calculation results are verified.Then,in view of the deviation between the theory and the actual contact position of the spiral bevel gear,based on the roll detection method,taking the performance parameters of the contact area in Chapter 2 as the index,using KISSsoft software to analyze the influence of the installation error changes on the contact area position of the spiral bevel gear.By comparing and analyzing the index data of contact area,it is found that all kinds of errors lead to the phenomenon of tooth top contact and tooth end contact on the tooth surface of spiral bevel gear,and all performance indexes increase with the increase of error.Among them,the maximum fluctuation of transmission error curve is caused by shaft spacing error,and the shaft intersection angle error has the greatest impact on the stress concentration.Finally,aiming at the problem of end meshing and tooth top contact in the process of error analysis in Chapter 4,based on the calculation of meshing stiffness in Chapter 3,the modification method of spiral bevel gear is studied by considering the error and deformation factors.By comparing and analyzing the contact area of three methods of profile modification,tooth direction modification and comprehensive modification of spiral bevel gear,it is found that comprehensive modification of spiral bevel gear can effectively avoid the concentration of load on the tooth surface edge of spiral bevel gear and improve the tolerance of tooth surface.