| Harmonic gears have a variety of tooth shapes.Among them,the double-circular-arc tooth shape has the double-conjugate characteristics in the meshing transmission,which makes the bearing performance and dynamic performance of the harmonic gear transmission significantly better than the involute tooth shape.Therefore,the double-circular-arc tooth shape is widely used in harmonic gear reducers.Although China has studied the double-circular-arc-toothed harmonic gear transmission earlier,due to the high confidentiality of foreign harmonic gear transmission technology,the research progress is relatively slow,and there are still problems that the meshing theory of harmonic gear is not perfect,gear transmission accuracy and service life are not high,the structure is not compact.Therefore,it is of great significance to break the technical advantages of foreign countries and develop high-performance harmonic gear transmission technology with independent intellectual property rights in China.In this paper,the tooth profile parameters of double circular arc harmonic gear are optimized,and then the design and simulation system of double-circular-arc harmonic gear transmission is developed.The purpose is to shorten the harmonic gear transmission optimization design cycle.Achieve the goal of improving the stability and mechanical properties of gear transmission.The main research contents and innovations of this paper are as follows:The accurate calculation method of the double-circular-arc tooth shape of the flexible wheel and the accurate calculation method of the rotation Angle of the flexible wheel in the process of meshing transmission are presented.According to the geometry of the common tangent and double-circular-arc profile,the exact formula for calculating the tooth shape of flexible wheel is derived.Considering the characteristics of the extension of the midline after the flexible wheel is deformed,the angle position of the flexible wheel during the meshing transmission process is accurately calculated.Based on the theory of harmonic gear transmission,a mathematical model for deriving the tooth shape of the rigid wheel from the soft tooth shape is established.According to the actual meshing characteristics of the conjugate tooth profile of the harmonic gear transmission,the calculation method of the actual tooth profile of the rigid wheel is further studied.According to the existing formula for calculating the tooth side clearance,a method for calculating the tooth side clearance accurately along the normal line based on the potential meshing position of the flexible gear profile is proposed by optimizing the calculation flow.Then,with the minimum tooth side clearance and the maximum effective meshing height as the optimization goal,a multi-objective optimization model is established and an optimization example is given.According to the mathematical model of the tooth contact analysis that has been constructed in the previous section,the meshing simulation of the harmonic gear transmission is carried out,and the simulation results before and after optimization are obtained respectively.By comparing and analyzing the results,it can be seen that after optimization,the continuity of the conjugate region is improved,and the tooth side clearance between the rigid and flexible wheels is obviously reduced,achieving the goal of improving the stability and mechanical properties of gear transmission.According to the meshing theory,the physical and mathematical models of the flexible wheel hob and the rigid wheel pin cutter are established.The flexible wheel hob tooth shape and the rigid wheel insert tooth shape are derived from the flexible wheel tooth shape and the rigid wheel tooth shape respectively.With the MATLAB software development platform as a tool,the design and simulation system of double arc harmonic gear transmission was developed.According to the tooth shape parameters designed by the design simulation system,the structural parameters of the rigid wheel and the flexible wheel are calculated,and the three-dimensional simulation model of the harmonic gear is constructed by the three-dimensional modeling software.The interference between the teeth is tested.According to the designed tool tooth shape,the flexible wheel hob and the rigid wheel pin cutter were developed,and the processing technology of the flexible wheel and the rigid wheel was established,and the processing of the flexible wheel and the rigid wheel and the processing of other parts were completed.According to the assembly process simulated by 3d software,the prototype of harmonic gear reducer is completed to prepare for the subsequent performance test of harmonic gear reducer. |
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