Simulation Optimization And Experimental Research Of Gear Box Churning Losses Based On CFD

As the main component of the electric vehicle reducer,the transmission efficiency is an important technical indicators to measure the power losses of the gear transmission.With the improvement of the transmission efficiency of modern mechanical devices,the gear churning losses is becoming an important part of the transmission losses.During the gear rotation,the contact between the lubricating oil and the tooth surface produces friction resistance,which leads to the accumulation of heat,quickening the gear wear and shortening the service life of the gear.Therefore,it is very necessary to provide a perfect lubrication system for gear mechanism.But limited by experimental methods,the fluid motion law in the reducer is not clear,and the test cost is relatively large.Through CFD numerical simulation,we can get more intuitive and clear watershed information,and then analyze the influence of different factors on gear transmission.The specific research contents are as follows:(1)According to situation of the immersion lubrication oil state of gear transmission,the inner basin of gear box finite element model is established.It is used to analyze the change of the spatter of the oil in the outer circle and meshing area of the gear and the meshing area,and the pressure change law at the meshing point,and the resistance moment of the gear.Then,the gear churning power losses are calculated.(2)Combined with the π theorem of fluid mechanics and the lubrication condition of the gear box.The general formula of churning losses of external gear pair is obtained by using the fluid mechanics π theorem,taking the gear speed,radius and the viscosity coefficient of the lubricant as the 3 basic physical dimension,and 6 derivative dimensions,such as tooth height and oil volume,etc.According to the simulation data,the undetermined coefficient of the general formula of churning losses is solved.Finally,the formula of oil churning losses and the reliability of the numerical simulation results are verified by the experimental study.(3)The experimental platform of the reducer is established by the simulation model.The gear churning losses with different rotational speed,steering,oil immersion depth and lubricating oil viscosity is measured by experiments,and the reliability of the simulation analysis is verified by comparison with the calculation model of the gear churning oil losses.The proportion of the gear speed,the depth of the oil and the viscosity of the lubricating oil in the gear churning oil losses is analyzed by the orthogonal experimental method,so as to realize the optimization and energy saving of the gear transmission.In summary,the main contents of this paper include simulation analysis,formula deduction,experimental verification and parameter optimization.By analyzing the influence of gear speed,steering,depth of oil and viscosity of lubricating oil on the losses of gear oil,the optimal design of reducer can be realized...