Research On Calculation And Machining Technology Of Straight Bevel Gear Based On Inner Concave Cutter

Bevel gear transmission has the characteristics of high transmission efficiency,good transmission stability,large torque and long service life.The straight bevel gear is more simple than spiral bevel gear and hypoid bevel gear in design and manufacture,so it is widely used in power transmission between intersecting shafts.Today’s bevel gear manufacturing technology has become mature after a long period of development,and has an irreplaceable important position in aerospace,national defense and military affairs.The machining methods of straight bevel gears include gear shaping,gear milling and gear pulling.Double cutter gear milling is an extremely important method in the production process of straight bevel gears.However,this method can only be processed on a special mechanical machine tool,which is not only difficult to adjust,but also has low machining accuracy.Although Gleason Company has realized the method of machining straight bevel gear with concave cutter on the CNC spiral bevel gear machine tool,its core technology is strictly confidential.In order to machine straight bevel gears on domestic CNC spiral bevel gear machine tools,the principle and processing method of machining straight bevel gears with internal concave cutter are studied in this paper as follows:1.The design and calculation method of geometric parameters for machining straight bevel gears based on concave cutter is established,which ensures the correctness of geometric parameters of straight bevel gears to be machined.Based on the principle of tooth cutting for machining straight bevel gears with internal concave cutter,the design and calculation methods of machine tool adjustment parameters and basic parameters of internal concave cutter for machining straight bevel gears are established.2.Based on the cutting principle of machining straight bevel gear with internal concave cutter and the kinematic relationship and relative position among cutter,generating gear and the gear to be machined,the tooth surface mathematical model of straight bevel gear is deduced.The tooth surface is discretized,and the three-dimensional coordinates of the discrete points on the tooth surface and the unit normal vector of each point are obtained.3.According to the mathematical model of tooth surface of straight bevel gear machined with concave cutter and the principle of tooth surface contact analysis,the theoretical contact point,contact area and transmission error curve of tooth surface during meshing are solved.4.Based on the software development platform of Matlab,the calculation software of geometric parameters,the calculation software of basic parameters of concave cutter,the calculation software of adjustment parameters of gear cutting machine tool,the calculation software of discrete point coordinates and unit normal vectors of tooth surface and the contact analysis software of tooth surface are developed.5.On the basis of the above research results,the domestic H350C CNC spiral bevel gear milling machine was used to carry out tooth cutting processing experiments.The tooth profile error of the processed straight bevel gear pair was measured on the gear measuring center,and the contact area of the gear pair was inspected on the rolling inspection machine.The results of tooth profile error detection meet the actual engineering requirements,and the contact area of the tooth surface after rolling inspection is basically consistent with the contact analysis results of the tooth surface.The correctness of the basic geometric parameter design,the parameter design of the concave cutter,the adjustment parameter design of the gear cutting machine,the mathematical model of the tooth surface,the discrete points of the tooth surface and the contact analysis of the tooth surface for machining straight bevel gears with the concave cutter are verified.