Analysis Of Temperature Field And Load-bearing Contact Performance Of Gear Transmission System Of Shearer Cutting Section

The proportion of coal in my country’s energy structure is related to the lifeline of the national economy and people’s livelihood.As the core equipment of the fully mechanized coal mining face,the reliability of the shearer directly determines the production capacity of the fully mechanized mining face.The failures of the shearer are mainly attributed to the pitting corrosion and gluing of the gear transmission system of the cutting part,and the tooth surface failure caused by the friction heat generated by the gear meshing is unpredictable.This paper takes the gear transmission system of the shearer cutting section as the research object,numerically analyzes the change law of the temperature field of the gear body,studies the thermal elastic coupling characteristics of the transmission system,and explores the effect of tooth surface modification on reducing the instantaneous contact temperature,contact stress and vibration of the tooth surface.performance impact.A gear transmission test bench was set up to measure the instantaneous temperature of the gear at the designated position under rated conditions,and the thermal network node method was used to analyze the maximum instantaneous temperature of the tooth surface,and compared with the finite element numerical analysis results.This method is important for studying the bearing contact performance of gear meshing theoretical value and academic significance.Considering that the load received by the shearer drum cutting coal and rock is not constant and steady state,it is characterized by a strong random change,and the coal rock is anisotropic,and the speed of the drum cutting coal and rock is the traction speed and the drum rotation speed.In the numerical calculation,the equivalent random load of the alternating load is used for the force analysis of the pick and the drum.The thermal steady state equilibrium equation was constructed,the dimensionless coordinates on the gear meshing line were set,the load sharing coefficient between the teeth was analyzed,the influence of the tooth surface load and relative motion speed on the frictional heat flow load was explored,and the friction coefficient and Hertz contact stress were calculated.The convective heat transfer coefficients applicable to the gear tooth contact surface,tooth top surface and tooth end surface are derived based on gear meshing parameters such as the radius of curvature and the gear tooth.Using the boundary loading conditions of friction heat and convective heat transfer,the variation law of the temperature field of the gear body and the influence of the gear accuracy o n the temperature field of the body are analyzed,which provides a temperature numerical basis for the analysis of the thermo-elastic coupling characteristics of the gear transmission system.Based on the variational structure matrix theory,the thermal de formation offset of the involute profile of the gear teeth in the uniform temperature field and the non-uniform temperature field is calculated,the node temperature is set by the maximum temperature of the gear body,and the gear node is applied in the form of body load.Analyze the relationship between the thermal expansion deformation of the contact meshing tooth surface of the gear pair,the elastic deformation caused by the contact pressure and the heat flow load caused by the frictional heat,that is,the mutual coupling relationship between the temperature field,stress field and displacement field of the thermoelastic characteristics,revealing the gear meshing heat Variation of stress and strain in elastic coupling characteristics.The surface fitting method is constructed based on the superposition of the tooth surface,the potential vector and normal vector of the modified surface are analyzed,the modified surface is fitted with a spline curve,and the three-dimensional topological modification and diagonal modification of the spur and helical gears are constructed.The optimal design of gear tooth modification is carried out with the goal of minimum,transmission deviation and instantaneous temperature change of tooth surface,and the selection me thod and principle of optimal modification tooth profile and gear modification parameters are determined.The vibration model of the support shell structure of the shearer cutting section is constructed,and the restraint damping and noise control structure is designed and modal analysis is carried out to obtain the temperature field before and after modification of the gear,the thermo-elastic coupling characteristics and the change law of the vibration characteristics of the support shell It is determined that the gear tooth modification can significantly reduce the instantaneous temperature of the contact tooth surface of the gear transmission system,reduce the contact stress,and suppress the vibration and noise of the support shell,thereby improving the load-bearing contact performance of the gear transmission system of the shearer cutting section..A power flow closed gear transmission test bench was set up,and shallow buried thermocouples were used to collect the instantaneous contact temperature of the meshing tooth surface in real time,and the change law of the instantaneous temperature of the gear meshing surface under different working conditions such as speed,load and lubrication form was studied,and the gear transmission system was deduced.The heat balance equation,the heat conduction network,the heat conduction relationship and the thermal node layout are constructed,the thermal network node method model of the gear transmission system is established,and the variation law of the instantaneous temperature of the gear meshing surface is simulated and analyzed.Correctness of load-bearing contact performance for thermal elastic coupling characteristics of cutting gear transmission system.