Analysis Of Thermal Equilibrium And Steady-State Thermal Field About Walk Part Reducer Of The Roadheader

Cantilever roadheader is a kind of combined unit which can cut,load and transport,walk by itself and spray dust in the underground coal mine.With the continuous development of science and technology,the requirement for the power and efficiency of roadheader is also increasing,especially in the case of tunnelling coal mine,the requirement for tunnelling speed of underground roadway is also higher and higher.In order to improve the speed of mining roadway,cantilever roadheader is developed and gradually developing vigorously,the whole machine is becoming larger and larger and the power of the walk part reducer of cantilever roadheader also increases accordingly,as well as the working condition is increasingly bad,then it brings some corresponding issues,the more prominent is that thermal value of the cantilever roadheader walk part reducer is too large,the thermal equilibrium temperature is too high.This issue will seriously damage the sustainability of the function of all parts,reduce the working efficiency of the whole machine,or even failure,moreover seriously affect the service life.Therefore,it is necessary to effectively solve this issue to ensure the function of roadheader walk part reducer,reduce the occurrence of faults,furthermore ensure the stability and reliability of its work.In this paper,EBJ-120 type cantilever roadheader is taken as the research object to study the issue of too high thermal value when the walk part reducer functions.Firstly,the thermal equilibrium state of the walk part reducer of EBJ-120 cantilever roadheader(hereafter referred to as walking reducer)is studied through theoretical calculation.The thermal analysis of the whole walk part reducer includes the study between heat generation and heat dissipation of the box body,gears,bearings,shafts,planetary gear trains and heat dissipating medium.When the whole walk part reducer functions,the meshing friction of gears,contact friction between each small structure of bearing and the surface,movement resistance of agitating oil by gear rotating in the oil,contact friction energy loss between oil seal and shaft are the main approaches of heat generation of the walk part reducer.Heat transfer by convection of lubricating oil,air and heat conduction of each component are the main approaches of heat dissipation.According to the actual working condition data of the walk part reducer,heat generation and dissipation of the walk part reducer are calculated,and the thermal equilibrium temperature of the walk part reducer is calculated according to the law of energy conservation.Then,UG is used to establish a 3D model of the walk part reducer and simplify the small structure which does not affect thermal analysis.Then according to the actual working condition calculating the convective heat transfer coefficient between each component and heat dissipating medium,using ANSYS Workbench to load the corresponding thermal coupling boundary conditions that mainly include: the environment temperature and material coefficient of thermal conductivity,thermal value of the heat source,the convective heat transfer coefficient of each heat dissipating approach,the simulation solves the walk part reducer steady-state temperature field results.Finally,the heat transfer theory is used to analyze the causes of heat generation and characteristics of temperature field of each part,in addition the optimal design proposal is put forward to solve the issue of excessive heat generation of the walk part reducer,it can provide a reliable basis for the cooling system design of roadheader walk part reducer and other mechanisms in the future.