Research On Mechanical Properties Of PA6GF33 And POM Plastic Gears Based On Material Characteristics

Plastic gears are widely used in national key development fields such as small service robots,intelligent furniture,micro transmission equipment and so on because of their advantages of low density,simple design,recyclable waste materials,vibration and noise reduction.However,in practical engineering application,there are many kinds and models of plastic gear materials.There is a lack of accurate and reliable performance parameters for this kind of engineering plastics in China,and there are great differences in basic properties between different plastic gear materials,which will greatly change the mechanical properties of plastic gears.Taking the small sweeping robot produced by the enterprise as an example,this paper studies the mechanical properties of PA6GF33 and POM engineering plastic materials and gears commonly used by the robot.Using the method of material experiment,theoretical research,numerical analysis and experimental verification,based on three different material mechanical models,this paper studies the deformation characteristics and mechanical properties of plastic gears under different loads.The main work and research contents are as follows:(1)Combined with the application requirements of PA6GF33 and POM engineering plastic materials in small sweeping robot,according to the experimental standard of material tensile properties,the basic mechanical property parameters of plastic materials are calculated,the mechanical property curve of plastic materials is drawn,the mechanical property characteristics of materials are revealed,and the mathematical idea of turning curve into straight is adopted to obtain the appropriate mechanical model of materials.The results show that the change process of PA6GF33 and POM plastic material curves can be approximately simulated by transforming the experimental curves of material mechanical properties into linear elastic model,bilinear strengthening model and multilinear strengthening model.(2)Based on the linear elastic model of material under small load,different elastic parameters of gear material are defined.The deformation characteristics and mechanical properties of plastic gear are analyzed by finite element method.The results show that the contact stress of plastic gear becomes proportional.Due to different elastic parameters of materials,the contact stress of PA6GF33 plastic gear will increase faster than that of POM plastic gear.(3)Based on the material bilinear strengthening model under large load,the material model parameters of PA6GF33 plastic gear are defined.The deformation characteristics and mechanical properties of PA6GF33 plastic gear are analyzed by finite element method.The results show that with the increase of torque,the growth rate of mechanical property curve of PA6GF33 plastic gear slows down,and the tooth surface bearing capacity of PA6GF33 plastic gear is significantly enhanced.When the torque reaches 5Nm,PA6GF33 plastic gear will fail.(4)Based on the material multilinear strengthening model under large load,the material model parameters of POM plastic gear are defined.The deformation characteristics and mechanical properties of POM plastic gear are analyzed by finite element method.The results show that with the increase of torque,the strain and deformation of POM plastic gear extend outward along the width of contact line,and POM plastic gear shows strong deformation ability.When the torque reaches 3Nm,POM plastic gear will fail.(5)By designing an experimental scheme for the mechanical properties of plastic gears,the accuracy of the mechanical properties curves of PA6GF33 and POM plastic gears is verified.The results show that the deviation between the finite element calculation results of PA6GF33 and POM plastic gears and the experimental values is less than 6%.The simulation values of mechanical properties of plastic gears have the same variation characteristics with the experimental curves,and the two are in good agreement.