Design And Machining Experiment Of Arc Equal-height Tooth Hypoid Gears With High Reduction Ratio

The application of hypoid gears with high reduction ratio is expanding.The hypoid gear can be manufactured by hard tooth surface grinding process,so it can keep the meshing precision for a long time.As for the Gleason gear,the longitudinal curvature evolution is complex,and it is not suitable for HRH gear precision cutting.As for the arc equal-tooth gear HRH gear,the pressure angle error of the pitch cone is not produced,and the shape gear is consistent with the root cone of the machined gear.Based on this,this paper has put forward the design and processing method of arc equal-height tooth hypoid gears with high reduction ratio.The main contents of this paper as follows:1 In this paper,the evolution process of HRH gear with curved teeth is discussed,and the pitch angle of the hypoid gear pair is determined by the method of optimization.The influence of the cutter radius on the sum of the root angle has been discussed.According to the sum of the root cone angles corresponding to the shrinkage method,the parameters of the gear and pinion,such as cone angle,the root cone angle and the cone angle,are determined.The geometric parameters of four shrinkage modes of Gleason hypoid gears are calculated and analyzed by Matlab.2 The method of numerical differentiation is presented to calculate the principal direction and principal curvature of the conjugate tooth surface.The method is compared with the LITVIN method and the induced normal curvature method.The advantages and disadvantages of the three methods are compared: the LITVIN method is accurate,but the calculation process is complicated,the induced curvature method involves a lot of angles and vectors,but also gives a lot of meshing information,the numerical differentiation method is clear and simple.3 The coordinate system of the gear and pinion and the gear pair meshing coordinate system has been established.According to the machining parameters of the gear,the gear tooth surface equation and the discrete points of the gear tooth surface are solved.The conjugate pinion tooth surface equation is solved in the meshing coordinate system.The tooth surface of the conjugate pinion is constructed by using the close surface of the calculation point,and the curvature parameter of the pinion profile is solved.The objective equation is constructed by using the curvature parameters of the modified tooth surface and the machined tooth surface,and the optimization method is used to solve the machining parameters.4 The ease-off surface between the conjugate surface and machining teeth surface is established and the contact area of tooth surface is obtained by simulation.The gear pair model is built and simulated.The gear pair is processed and tested and the instantaneous contact zone has been got.The tooth is normal and the contact area meets the design requirements,which has demonstrated the correctness of the design.