Simulation And Improvement On Braking Thermal Equilibrium In Wet Drive Axle Of Wheel Loader

As one of the fast growing and marketing construction machinery, the wheel loaderis widely used in urban construction and many projects, such as highway, railway, port,wharf, cool, mine, water conservancy and national defense. As one of the criticalcomponents, the drive axel has a direct impact on the working conditions of the wheelloader. It is one of the ways to improve the level of drive axle product technology ofengineering machinery to use wet multi-disc brakes, and it is also the inevitabledeveloping trend of domestic wheel loader.The friction piece of wet drive axle is put in cooling oil, most of the heat generatedwhen braking can be taken by the oil. But the heat capacity of oil is limited due to thewheel hub’s closely assembly of multiple components. A large number of practiceshows that the temperature of oil goes too high when the wheel loader works in highintensity and needs high frequency braking for a long time. Over the long term, thenature of the cooling oil will be changed, the service life of lining will be shorten andeven warping or ablation. The working efficiency of loader will be influence and cannotwork normally eventually.Currently the study of heat balance of wheel loader wet drive axle is most for thewet multi-disc brake, due to the narrow space and tight structure in the hub, it is difficultto make optimization to optimize the structure and size of the brake. The paper will takethe whole drive axle into consideration to study the failure reasons of the thermalequilibrium of the wet drive axle when the wheel loader has long time braking, and theimprovement scheme of heat dissipation is put forward.Taking ZL50loader as the research object, first of all, the loader driving cycles aredivided according to the cycle time and the braking energy of different driving cycles iscalculated. At the same time, the friction power loss caused by the final drive,differential, reduction final drive, bearing is analyzed, and the calculation method isgiven.Secondly, the model of the wet drive axle of ZL50loader is built by CATIA, thegrid division and boundary conditions of the model are set by GAMBIT. The flow fieldand the temperature field of drive axle braking conditions are simulated by FLUENT,using computational fluid dynamics method. The initial temperature distribution issummarized. Finally, the factors affecting the braking energy and the causes of the hightemperature of thermal equilibrium of the drive axle brake are analyzed. The circulatingcooling measures are put forward to improve the heat dissipation of the drive axle, andits feasibility is verified by experiments.