Analysis Of Temperature Field In Gearbox Of Straddle Monorail Train

During the running of the train,all kinds of power loss caused by friction in the gearbox will eventually act on the gearbox in the form of heat energy,causing the temperature of the gearbox to rise continuously.If the steady-state temperature of the gearbox is too high,the physical parameters of the lubricating oil will be changed,which will affect the lubrication and cooling effect of the lubricating oil on various parts,and in serious cases will cause pitting corrosion and burn of the bearing,even the situation such as bearing holding dead,seriously affect the transmission effect of the train and driving safety.Therefore,it is of great significance to study the steady temperature field of the straddle monorail gearbox for the reliable operation of the gearbox and the improvement of the structure of the lubricating oil flow channel in the gearbox.In this paper,the gear box of a straddle type monorail train is taken as the research object,based on the theory of heat transfer and fluid mechanics,the steady temperature field simulation model of the Gear BOX is established by Fluent software,the temperature field of the gearbox is simulated,and the temperature distribution of the main parts of the gearbox is analyzed.In this paper,the influence of external wind direction,oil level and positive and negative rotation of large spiral bevel gears on the steady temperature field is analyzed.The main contents of this thesis include:1.Based on the theory of heat transfer and fluid mechanics,the heating mechanism of the heat source of the gear box is analyzed,and the reasonable power loss calculation model is selected to calculate the friction power loss of the gear box under different working conditions The heat transfer path and heat transfer mode of the gearbox in steady state are analyzed,and the convective heat transfer coefficient of the surface of each part of the gearbox is calculated.2.The Gear Box is modeled by Solid Works software,and the model is further simplified by Space Claim software to remove unnecessary structural features such as rounded corners and chamfered corners,so as to ensure that the high quality grid can be drawn next;The inner basin of the gearbox was extracted,and the wind field was set outside the gearbox to restore the real operation of the gearbox,and the simplified geometric model was meshed by Fluent meshing,then the simulation model of temperature field is established in Fluent software.3.The temperature field of the gear box under various working conditions is simulated,the highest temperature and temperature cloud chart of the main parts of the gear box are extracted,and the temperature distribution of the gear box is analyzed The influence of external wind direction,oil level and positive and negative rotation of large spiral bevel gears on the steady temperature field of the gear box is analyzed.When other factors are invariable,the external wind direction of the gearbox has relatively little influence on the temperature field;the increase of the oil level will make the stable equilibrium temperature of the gearbox rise,and the highest temperature of the gearbox will rise with the increase of the oil level,however,the maximum temperature of all parts except the gear box decreases at first and then increases with the increase of the oil level.That is,when the oil level of the gear box is in the middle of the oil level,the lubricating oil has the best cooling and lubricating effect on the parts.When the big spiral bevel gear is rotating,it will bring more lubricating oil to the first gear mesh area and the input shaft bearing,which will have better lubrication and cooling effect on the gear box.