Mechanism And Experimental Study On Spur Gear Manufactured By The Warming Forced Throughfeed Rolling Process

Gears are important mechanical transmission parts and occupy an important position in modern industrial production.The conventional gear processing method is mainly based on cutting,and there are problems of low production efficiency,material utilization rate,and low fatigue strength.The axial rolling of the gear is made by the development of the rolling wheel and the workpiece,so that the flow of the workpiece material is finally formed into the target gear.The axial rolling process does not need to damage the streamline structure of the workpiece material,can improve the strength of the gear,and can improve production efficiency and material utilization.However,when the large modulus gear is cold-rolled at normal temperature,the material flowability of the tooth blank is poor,and the formed gear tooth shape is incomplete.At the same time,the stress on the rolling wheel is high,which will reduce the service life of the rolling wheel and the machine tool.In order to solve the above problems,this paper studies the axial warm rolling process of the workpiece under heating.The research content of this paper mainly includes:(1)Study the basic principle of axial rolling of gears.Firstly,the basic process of gear axial rolling forming is analyzed,and two kinds of indexing methods(forced indexing and free indexing)are described.The design problem of the rolling wheel is discussed.The main structural design of the rolling wheel includes the height of the tooth top of the rolling wheel,the full tooth height,the plunging angle,etc.,and the number of teeth and the material determination of the rolling wheel.In order to achieve correct tooth separation,the initial installation phase of the rolling wheel is discussed.The material of the workpiece was determined,and the diameter of the workpiece blank was calculated by the equal volume method.(2)Design an electromagnetic induction heating system.The electromagnetic induction heating system is designed according to the principles of electromagnetic induction law,Joule's law,and skin effect.The parameters of the power supply,current frequency and other parameters of the induction heating system are calculated,and an electromagnetic induction coil is designed.Using the induction heating module of DEFORM-3D software,the effects of different induction and heating of the tooth blank under different current frequency,current density(power supply)and heating time parameters are analyzed and compared.Provides theoretical guidance for optimizing induction heating parameters.(3)The forming mechanism of gear axial rolling is studied.The axial forming process based on induction heating gears was simulated using the plastic forming module of DEFORM-3D software.The stress field,temperature field distribution and metal flow characteristics of the workpiece during the rolling process were analyzed.According to the "rabbit ear" defects in the rolling process,the causes and influence parameters were analyzed.The orthogonal experiment was designed to analyze the influence of different parameters on the "rabbit ear" defects by orthogonal test,and provide parameter optimization guidance and theoretical support for subsequent test verification.(4)The structure and parameters of the axial rolling test platform of the gear are introduced.The electromagnetic induction heating test of the workpiece and the test of the axial rolling of the gear were carried out.Successfully rolled out gears with a number of teeth of 44 and a modulus of 2.5 mm.Through the test results,the correctness of the theoretical analysis of induction heating and gear rolling is verified.Through the research in this paper,we have a clear understanding of the axial rolling of gears based on high frequency induction heating.The principle of electromagnetic induction heating and the process of gear axial rolling are analyzed in detail,which provides a strong support for the subsequent research of gear rolling.