Heat-fluid Coupled Analysis On Convection Heat Transfer And Temperature Field Of Gears

Because of the relative sliding of tooth meshing surface, a large amount of heat will be produced in the process of gear meshing. If the produced heat cannot be dissipated timely, the excess heat would lead to gear temperature rising, which will decrease bearing capacity of gears and reduce their working performance, and even cause gear failures directly. Cooling effect of lubrication of gearbox is the main factor of gear temperature determination, which can be influenced greatly by the flow characteristics of lubricant in gearbox. Therefore, a numerical simulation analysis of gear convective heat transfer and temperature field based on heat-fluid coupled method has important theoretical significance and great engineering value for improving heat transfer characteristics of gear pair.The topic of this thesis is supported by scientific and technological project of Chongqing. Based on principles of gear engagement, hydrodynamics and the theory of heat transfer, the flow field in the gearbox with oil-bath lubrication, the convective heat transfer and temperature field of gears are studied by numerical simulation method. The main content of this paper can be summarized as follows:â‘ Parametric model of involute gears are constructed with UG, which can be imported into Gambit to establish the fluid calculation model of gearbox. Using the moving mesh technology and user-defined function (UDF), the transient flow field of gas?liquid two?phase oil-bath lubrication of gearbox was analyzed by the software of Fluent. As a result, the transient fluid distribution, oil pressure and velocity in the gearbox are obtained.â‘¡After hydrodynamic simulation of flow field with different gear velocities and oil depths in the gearbox, transient fluid distribution and time history curves of pressure and velocity in the gearbox are discussed. Thus the influence law of the flow field characteristics can be concluded after comparison.â‘¢The 3D transient heat transfer finite element model of gearbox including fluid and solid is constructed, and then the average heat flux on the meshing gear surface is calculated, based on which the heat?fluid coupled simulation analysis of the thermal model of gearbox is carried on by Fluent, and the contour of convective heat transfer coefficient of gears is obtained.â‘£The temperature contour of gears and temperature time history curves of nodes in the meshing zone of gear tooth in difference time are obtained after the transient hydrodynamic simulation of gearbox in rotation has been carried out, and the influence of different gear velocities on gear temperature distribution is analyzed.